# Elmer's #32 - Tall Vertical Open Column



## arnoldb (May 3, 2012)

Having fitted the DRO to my mill, I looked through my list for a project to try it out and get to grips with it. Even though I have an itch to build a complex and detailed engine, I thought something fairly simple would be better to try out the DRO to get the gist of working with it.

One of Elmer's would do. The collection of engines on my side-board are growing, but there's a lack of height there, so I settled on Elmer's #32 as a relatively simple engine (compared to the Kimble and Coombers) that has a fair amount of work that can be done on the mill, as well as adding some height to the collection.

I'm not going to go overboard on this build; for the most part I'm going to build it exactly to plans. One exception will be that I'm going to add a slip-eccentric to make it reversible, as this is very easy to add to this engine as a custom touch.

Don't expect too many photos, but if there are any members that would like more detail on certain bits or processes of the build, please ask (publicly, or pop me a personal message), and I'll be happy to accommodate. Any suggestions or criticism is also welcome 

I started off with sawing a 78x78x12mm bit of aluminium from a sheet of 12mm plate I have. That was roughly squared up, and then I brought out a bit of kit I have that I've used rarely before - the venerable edge finder. Mine is of slightly dubious quality, and I've never really bothered to set up test equipment on the mill to check it's accuracy and repeatability. Another disadvantage that I had with the edge finder is that it is 5mm in diameter, and my mill's feed screws are 3mm per turn, meaning that in the past I had to be careful about finding an edge and setting the zero-able hand wheel dials correctly to obtain my datum point. So first things first, I tested the edge finder - and much to my surprise it ended up repeatable within 0.005mm (1/5 of a thou) in four out of five tests  - that's much better than I expected, and plenty good enough for my shop; 0.01mm repeatability would be fine with me. With the DRO, backlash becomes a lot less important, and it's easy to set absolute zero.

Next I put the DRO to test; I located the right-hand back edge of the workpiece; I tend to work from the right-hand side of the vise as that way I end up with the least amount of chips thrown toward myself while milling, and the fixed end of the vise jaw remains in position on the Y axis. The block of aluminium plate was then properly squared up to size, with the aid of the vise stop. 

For the next step, I didn't lay out anything; I simply coordinate drilled four 3mm clearance holes and the small square's 2.5mm tapping holes for M3 using the DRO and incremental readings:






After a bit of decorative milling with a 6mm ball nose mill, tapping the M3 holes where the cylinder will mount, and a bit of elbow grease with riffler files and emery paper to get rid of toolmarks, the base was done with a brushed finish:




We have a long weekend coming up here in Namibia, so I'm going to try and give the engine a good go, but I might divert a bit to attend to a special request I received from a South African member.

Kind regards, Arnold


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## b.lindsey (May 3, 2012)

That base looks fantastic arnold!! I suspect you will become addicted to that DRO rather quickly and then wonder what you ever did without it 

Regards,
Bill


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## rhitee93 (May 3, 2012)

This will be fun to watch. I'll be along for the ride.

Congrats on the DRO. I would hate to be without one now.


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## bearcar1 (May 3, 2012)

OOOO! OOOO! Another one coming out of the barn from Arnold. I can't wait. This should be another good one to watch. Have a safe holiday Arnold.

BC1
Jim


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## ProdEng (May 4, 2012)

My next planned build is Elmer's #32 so will be watching with interest.


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## arnoldb (May 4, 2012)

Bill, thanks  - I'm already in love with the DRO ;D; it makes life a lot easier.

Thanks Brian  I hope the ride will be worthwhile.

Thank you Jim  Safety's always a main concern; I'm going to stay put and work in the shop ;D. Safe as barns, as long as I don't stick my fingers where they shouldn't go or have a mid-life moment. I'm much too young for a senior moment :big:

Jan, thanks for checking in . If you want more detail on any specific bits of the build, just give a shout.

On to the table. I scrounged up a bit of 6mm aluminium plate for that. It had a couple of dings in it, so I gave it a quick rub-down with Scotch Brite on both sides, and chose the best-looking side for the top. There's only one deepish ding on this side, so I juggled things so that it would get hidden by one of the bearing columns, and just used a permanent marker to mark things out as a reference:




The ding is the black spot above the rectangular ink lines for the cut-out.

I milled the plate to size, and from the underside drilled all the mounting holes. The ones for the bearing mountings were countersunk as well:





Next I milled out the hole for the eccentric rod. Now this is where the DRO really is nice to use, as I could get the readings straight off the display. Compensating for backlash was always a problem in the past. Here it was easy to just center the DRO on incremental setting and mill out the pocket 0.2mm under-size on all sides, and follow that with a full-depth clean-up pass on all sides to remove the last bit. That left a very nice finish and a pocket very nicely to size:





Clearance for the connecting rod was easily dealt with:





The plans don't call for it on the table, but I decided to add matching decorative work for the base to it. As the bearing blocks will be on the edges, I had to compensate for that, but that was easily done:





After a bit more manual elbow grease, the table was done:



 : Really not much to show for 3 hours' work...

For the columns, I went with some hex brass. I bought it as 6mm hex, but it measures out at 6.2mm across flats. So it's not really 6mm, and neither is it 1/4" (6.35mm) : - at least I got a bit more than originally bargained for :big::





My small lathe is still not properly mounted, but it's 3-jaw chuck has a lot less run-out than the Myford's one. As the work required on the columns is light, I fired up the small lathe, and started facing the columns and drilled for M3 threading:





I've never pulled my finger from you-know-where to make backstops for either lathe, so I fell back to clearly marking out the lengths for the sections on the columns and turning down to "split the line" by eye. No photos of that. 

The holes for the pivot pins in the columns was easily dealt with, though I did fall back to using good old marking out, the vise back stop, and eyeball mk1 for repeatability on the X axis. There's four different operations for each of the columns; one had to be drilled 1.6mm (not through) and tapped (M2 in my case after bastardizing Elmer's plans to metric) - and a matching 2mm through hole in a second column. Then on the next pair of columns, the same happens; a 2mm thread, and a 2mm through-hole - but at a different distance from the bottom of the columns.
In a scenario like this where I need to drill smaller blind holes and then larger through-holes, I always do the small blind holes first. If I make a booboo and drill the small hole through in a moment of inattention, I can always enlarge it, and try the blind hole on the second workpiece. Here I'd just drilled the 1.6mm blind hole for tapping to M2 in the first column:





All the holes drilled and tapped in the columns, and a bit of clean-up later, the columns were done:



 : From the enlarged photo, I see I missed a couple of spots with the clean-up, and got some angles skewed on the rub. I'll sort those out at final assembly.

With one of the swarf magnets repeatedly digging his paws into my leg and running out the shop to his stainless steel food bowl and loudly bashing that around, it was time to shut shop and feed the dogs. I took a quick assembly shot showing overall progress:



Please excuse all the clutter :hDe:. I think I need to take about 1.5mm off each of the threaded sections of the columns, as these are standing a bit too tall. I need to make up acorn nuts to fit on top, and I don't want those out of proportion.

Regards, Arnold


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## Blogwitch (May 4, 2012)

A very good start to a new project Arnold. woohoo1

Count me in as an avid follower.


John


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## rebush (May 4, 2012)

Looking good Arnold. Will be following your progress. Thanks for taking the time to post your work. Roger


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## ProdEng (May 4, 2012)

I like the idea of the hex columns, adds a bit of visual interest as does the extra machining on the table. Look forward to the next instalment.

Jan


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## arnoldb (May 5, 2012)

John, Roger & Jan, thanks very much Gents 

Some of the "simple" parts in engine builds can take the most time to make...

I started today's session with two blocks of 8mm aluminium plate for the bearing blocks:





Those were glued together with one reference side in common, and finished to size together. Then I drilled a 10mm hole through them to insert bushes later for the crank shaft, and finally I drilled the mounting holes to tap M3:




The "uneven" look between the two pieces you see there is because this was the reference side I used initially for gluing them together. When I drilled the hole for mounting the bushes, I'd also brought the vise backstop op to the workpiece; this allowed me to just position them vertically and maintain the X setting on the DRO for the center. 

On to what I've personally come to call "Elmer's Folly" ;D - the "fake" bearing shells. I had actually considered making real split bearings, but decided against that for this build - that can wait for a future highly detailed build. On some of my Elmer's engines I actually completely skipped the faux bearing cap structure, but on this one I decided to add it, so I set about milling them out:





A bit of filing got rid of the facets left after milling the tops:





Then I split the pieces, and spent some time to get their finish to match that of the table and base- keeping the "brush grain" in the same direction:





On to the bushes - a bit of phosphor bronze drilled 5.9mm and then for a press fit on the OD for the holes in the bearing blocks. Getting ready to part off the first bush:





The two bushes done:





And pressed into the bearing blocks:




The little bit the bushes stands out from bearing blocks is intentional. On many of Elmer's engines he has other bits - often time the eccentric - running directly against the bearing blocks. I'm not too keen on that, as it can add quite a bit of friction especially on painted engines. This is my way to get things away from the bearing blocks. On this engine, the eccentric would run against the bearing block if built to plans. Of course, one can just turn up a very thin spacer to prevent that as well, but it's much harder to turn up thin washers than it is to just make the bushes a bit longer. One downside of doing as I did, is that your finish on the bearing blocks must be done; it's darn hard finishing up things around a sticky-outy-bit.

Finally, I marked each bearing block for it's location and orientation on the bottom, and screwed them to the table. Then I used a 6mm hand reamer to line-ream them:




Reaming was done from both sides as the reamer is just long enough to do the job. I've found that reaming from both sides for this type of scenario helps a lot, as the holes end up just slightly over size, which is nice to get a running fit. I don't have any over or under size reamers.

On to the crank web. I have a suitable size of aluminium bronze floating around that I got a couple of years ago - mistaking it for brass. I had other ideas for it back then, but I didn't know that it is hard to solder or silver solder - that I only learnt here on HMEM, but for this job it's fine. SO I set about turning it down a bit - it actually machines quite nicely:





Normally I'd get the chuck to the mill and onto the rotary table at this point for the next operations, but today I decided to use a different route. Parting off the ~34mm disc was a breeze as well:





I just plonked the tooling plate on the mill, and with a bit of 6mm rod with an accurate conical point pressed the disc to the plate - with some sacrificial plate and pieces of paper to add friction wedged in between. Then I just clamped it down, and zeroed up:





Then I just drilled for the crank pin thread, and milled out the webs with a 14mm end mill. The plans do not specify the size of the arc in the webs, so I guesstimated it at 12mm, but I don't have a 12mm cutter, so I went for 14mm:





After a bit of cosmetic work with files and emery, and tapping, the web was done:





I then attempted to turn the end of a bit of 6mm silver steel for a press fit in the web's central hole for the main shaft, missed the press fit by a tiny bit, and fell back to high-strength retainer to fit the web to the shaft.

At that, I called it a day, and did a quick assembly for the progress shot:




Regards, Arnold


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## bearcar1 (May 5, 2012)

Nice! Thm:


BC1
Jim


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## Smithers (May 5, 2012)

Nice work there Arnold, like the R6 decorative additions.

Andrew


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## ProdEng (May 5, 2012)

That's coming along very well. Your build description is so detailed that I won't have to think too much when I do mine  Thanks for the good info.

Jan


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## arnoldb (May 6, 2012)

Jim, Andrew & Jan , thanks for checking in  
It's a pleasure Jan 

Today it was on to the cylinder. Some 1" aluminium square stock - left over from the Grasshopper engine back when I built it - and showing how much I overtightened my poor chuck on it :-[:





I faced that down to length in the lathe - I just eyeballed it close to center in the four-jaw. It was much quicker than setting up the mill to do it:





Normally I would have drilled and reamed in the lathe for the cylinder bore as well, but as one of the objectives of building this engine is to get to know my DRO, I moved over to the mill, used the function provided to locate the center of the workpiece, offset it the needed 0.8mm, and then drilled and reamed the bore:




You'll also notice I brought the vise backstop up; that would be needed later - just to make life easier.

Then I used the PCD function to set up to drill the holes for mounting the cylinder head. When the read-out got to the point where I needed to enter the number of holes to drill, it defaulted to 65535 - one would have expected 0:




I actually found this extremely amusing - that value happens to be the maximum number that can be represented using 16 binary bits... It seriously shows up my geeky background :big:. I suspect that that is the maximum number that can be used for "bolt holes" on this unit - though I don't fancy actually drilling that many :

Not being entirely confident in this PCD method and that I got the angles correct, I dotted black marks on the workpiece roughly where I expected the holes should go, as a visual reference, and then followed the cycle with a center drill - spotting each location:




 ;D What do you know... It worked - and is more accurate than myself.

The PCD function fortunately does not exit on its own, so I was able to go back and actually drill each hole (1.6mm to tap M2) in each location:




This is where the vise back-stop came into play; to drill the mounting holes on the other end of the cylinder, I just flipped it 180o around relative to the mill's X axis, and still using the same PCD function, drilled the other mounting holes. A nice time-saver.

On to the ports. The side hole for the exhaust connection was easy; I drilled it 2.5mm to thread M3. The plans call for three #57 holes from the steam chest side into that. In my metric parlance, that translates roughly, but close enough to, 1.1mm. Last year I treated myself to some 1mm slot mills, so I drilled the holes 1mm, and then used one of the slot mills to actually mill out the port, enlarging the slot to 1.1mm. That officially became the smallest slot I've milled to date  :





The two other ports (1.6mm wide, 3.2mm deep) were easily done with a 1.5mm end mill:





I remembered just in time that I needed to poke some more 1.6mm holes in there to mount the steam chest:





As the cylinder bore is only 12mm compared to the 12.7mm (1/2") on the plans, I had to compensate a bit on the angle of the steam passages. I could just have calculated it out (I do enjoy some maths), but I wasn't in the mood for that, so I just transferred the needed offsets to the sides of the workpiecs, and with a rule drew up the angled lines along which the passages had to be drilled:





Then I just set the workpiece in the vise with the scribed line aligned with the side of the vise jaw:



Had a bummer of a time getting that photo... It's on the "dark" side of the mill; if you click the image, you can see a more detailed view.

Then started the hole with a center-cutting slot mill - slightly bad practice with it in the drill chuck, but OK for the tiny job here:




After that I just drilled the passage 1.6mm - with the workpiece on the end of the vise like that, it's easy to visually see when the drill breaks through into the milled pocket on the side.

Off to the lathe, and with a suitably cobbled-together mandrel, it was easy to turn the round ends of the cylinder - once again just splitting the scribed line on the length:





Back to the mill, and bringing the "sides" down to size:





Next, the round-robin to get rid of more stock:





After quite a bit of fettling with a selection of files and a bit of emery, the cylinder is nearly done. It needs some final cosmetic work and all the holes tapped, but after 7 hours in the shop, I was a bit spent, so I called it a day:




Regards, Arnold


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## Blogwitch (May 6, 2012)

I said, and a few other people as well, that once you became accustomed to your DRO, it DOES make life a lot easier.

With almost all of Elmers engines, the cylinder ends are invariably the same style with holes in the same locations, so for those people who are going to be making a few of his engines, and don't have a DRO, it pays to make up a steel drop on drilling jig for all the end holes. It can also be used for drilling the cover plates as well.


















It saves having to break out the RT every time, and it only takes minutes to drill all the holes.

Lookin' real good Arnold.


John


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## ShedBoy (May 6, 2012)

Nice work Arnold looks really nice. Looking forward to seeing it run.
Brock


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## rhitee93 (May 6, 2012)

Thanks for doing such a detailed summary of the cylinder construction. I plan to do a couple of Elmer's engines soon, and was a bit put off by having to make the 1-piece cylinder. Your method makes it seem very straight forward!

Looking good Thm:


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## Troutsqueezer (May 6, 2012)

I've made two of those cylinders in the past. Always fun to see how others tackle the setups. Nice job documenting the build, I know how much extra work that is but it sure does help a lot of people.

Trout


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## clivel (May 6, 2012)

Looking really good Arnold.
It is a pleasure watching how you go about your tasks.
Detailed descriptions of builds such as this and the many other excellent builds on this forum are such a valuable resource for us newer machinists. I can't begin to tell you how much I have learnt from following along.

Clive


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## arnoldb (May 8, 2012)

Thanks John.  - That's a different view of Elmer's Mine engine lying on its side . A great tip on the drilling jig Thm: A slightly thicker one with tap clearance sized holes (or just one hole for that matter) will make a great tapping guide as well; it can be a bit of a chore tapping the holes on the cylinders.

Brock, Thanks 

Thanks Brian, & it's a pleasure. Don't be put off with the cylinder (or any other "complex" looking parts); it may look daunting on paper, but if you visualize the machining steps in your mind with the tools you have available, it becomes a lot easier. John (Bogstandard) has many times advised that it's a good idea to do this and write down the steps to follow when machining, and I can vouch for this. You might want to have a look at the differences (and similarities) in my #37 Grasshopper build of exactly the same cylinder. I had much less equipment at my disposal when I built that, and the results are pretty much the same.

Trout, thank you 

Thanks Clive  The detailed builds was part of what attracted to me to HMEM about three years ago - I'm also a "newer" machinist and continuously learning from what other members post - in fact, that will never end; there is always something to be learnt from how other hobby machinists are going about things. You're doing just fine with your wobbler build, and by showing how you're going about it and the problems you run into, you are already sharing knowledge for others to learn from. Its a pleasure for myself - and I'm sure most other members - to follow along on your build Thm:

I doubt I'll be able to show more build progress before the weekend; some social and official commitments are taking up my evenings - fortunately in a pleasant way 

Kind regards, Arnold


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## bearcar1 (May 8, 2012)

....... "some social and official commitments are taking up my evenings - fortunately in a pleasant way"




Well how _*dare*_ they(sniff)?  :big:


We will all be here anxiously awaiting your return. TALLYHO!!

BC1
Jim


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## arnoldb (May 12, 2012)

> Well how *dare* they(sniff)?  :big:


 Rof} Jim, side-effects of my career move last month  I'm really enjoying my new job though, so I don't begrudge the infringement ;D

This afternoon I started off with a bit of 6mm aluminium plate, and two bits of sorry-looking 1.2mm brass plate for the steam chest, valve plate and steam chest cover:




The bit of aluminium was milled to size, and then I located what would be the center of the steam chest, and from there coordinate drilled the mounting holes, as well as four 3mm holes in what would be the corners of the cut-out:




Then I started milling out the cavity with a 4mm end mill, but 0.2mm under-size on all sides:




A final clean-up pass to take off the 0.2mm excess left nice and smooth edges:




For the next step, I reverted to some manual lay-out for a change:




Off to the lathe and clocked up in the 4-Jaw; When I started out in the hobby, this was one of the most time-consuming things to do, but has gotten much easier; today it took me literally less than a minute to adjust to less than 0.02mm run-out; it nearly takes longer to set up the dial indicator...:




The boss turned - with the block marked out as it was, it's easy to turn to the marked-out line as it remains visible while the workpiece is revolving:




Then I center drilled and drilled the boss through with a 2mm drill, as I will use a 2mm valve rod. The other end of the stem chest needs a 1.6mm (1/16") hole according to the plans, but as I'm using metric threads, I had to compensate a bit. From the plans, the valve rod has a 1/16" end and #2-56 threads for the valve nut. For my metric threading equipment, the thread will be M2, but I know my M2 die cuts to a core depth of less than 1.6mm, but more than 1.5mm, so the hole must be 1.5mm and the end of the valve rod as well.
If one would try and start the opposite hole with a 1.5mm drill, it is more than likely to wander, so I also spotted the far side of the steam chest with the 2mm drill, as it is a bit stiffer and less likely to wander. The spotting mark is just to the depth of the drill point:




Drilling the back hole to depth can be a bit tricky. As I'm lazy by nature, I just inserted the 1.5mm drill to touch the spotted hole earlier, and marked it with a permanent marker for the depth it must go to. The left side of the black dot (well... top in the photo, but left when you're standing in front of the lathe) is at the required depth, and as you can see, there's not a whole lot of drill shank left to chuck up on:




After I drilled the 1.5mm hole, I flipped the workpiece in the chuck to turn the boss on the other side. The boss is purely cosmetic, and does not need to be turned to a high degree of accuracy, so I cheated a bit. By just loosening two adjacent jaws on the 4-jaw chuck (#1 and #2), flipping the workpiece, and tightening it up again using the same two jaws that were loosened, it gets back close enough to center so that no-one will notice. Well, everyone who read this will know, but that's OK with me  Then I turned the boss; and just free-hand turned the approximate curve on the end:



The curve was completed with a small file - very very carefully, as I was working fairly close to the chuck jaws with file and fingers. If you're not comfortable doing this, you could just grind up a suitable form tool to turn the curve.

After a quick rub-down on emery to smooth the surfaces, the steam chest was done:



 : Not quite done... I forgot to drill and tap it for the steam connector.

On to the bits of brass plate, and I just milled them down to size and drilled the mounting holes as a pair. The vise backstop in combination with the DRO is really a pleasure to use, as I just used the stop to maintain workpiece X position to remove the plate that will become the cover, and then I spot-drilled with a 1mm center drill for the steam ports on the valve plate:




The holes on the plan is for a #57 drill. In Metric parlance, that is 1.092mm. On the #37 Grasshopper I drilled the holes 1mm, and it runs like a champ, but I decided to go for 1.1mm holes on this one; closer to the actual #57 size. With the hole locations spotted, it was easy to just run through the coordinates and poke the holes through with the mill running at it's maximum 1200RPM spindle speed:




On to some flat-lapping of the valve plate with a bit of 320 emery paper on the glass sheet that serves as my surface plate:



Once it was flat and free of blemishes on both sides, I followed the flat-lapping up with some 600 grit paper to smooth it out a bit more.

The steam chest cover was also tidied up a bit, and the two pieces were done for now:




Well, what do you know... Even though all the bits were made separately for the most part, all the mounting holes line up  :




At that point, I decided that the Eccentric Nut needed a bit of attention... So I closed up shop and indulged in the first bottle of Namibia Breweries' Urbock beer that I found for the season. There's an upside and a downside to this exclusive seasonal beer... The upside is that I particularly like it, and the downside is that it's availability really rings in the Winter season here in Namibia. Winter's a small price to pay for a good beer by an eccentric nut ;D

Regards, Arnold


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## ProdEng (May 12, 2012)

It's all going well Arnold. Along the way you have answered a few questions I had about machining processes for this engine and I will be using your build as a reference for mine :bow: 

Winter beers where a feature of life in England and I miss them but would rather have an Australian winter than an English one


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## arnoldb (May 13, 2012)

Thanks Jan  I'm glad that you're finding this useful. If you do have any questions please fire away; it helps other people too. I'm just blundering along in my own style, so it's not necessarily right or the best way. Everybody's welcome to chip in with ideas and suggestions.
 :big: I might complain about Namibian winters, but they are much more like the Aussie ones. And no thick layers of white stuff on the ground either; I've only ever touched snow once in my life, and seen it in real life from a distance about 5 times. The only downside is the humidity here; today it was nice and humid, and right now as I'm posting, it's a whopping big 33%. Later in the week that will most likely drop to about 20% - and then people wonder why Namibians drink a lot ;D

Not much done today, but some progress none-the-less.

A bit of 25mm round aluminium bar turned for the face of the inboard cylinder head, and drilled through at 3.2mm:



The 3.2mm is for the 1/8" brazing rod that I'm going to use as the piston rod. That's quite a bit thicker than the 3/32" the plans call for. I have 2mm and 3.2mm rod available, and while I could knock up a box tool to turn the 1/8" rod down to 2.4mm (~3/32"), the engine might actually look better with the thicker rod, even though it would impair performance slightly on the down-stroke by the loss of upper cylinder volume.

Even though this thread is as much about getting to grips with the DRO as it is about building an engine, for the next step I reverted back to what I know well and do fairly quickly. So, chuck unmounted from the lathe - workpiece-and-all - and re-mounted on the rotary table on the mill. I just used the 3.2mm drill chucked up in reverse in the mill chuck to center the RT to the spindle, and zeroed the DRO on that:




Then I just dialed in the 9.525mm PCD offset on the Y axis (3/4" ~19.05mm - halve of that = 9.525mm) and used the RT to index the holes for drilling:




Back to the lathe, and then drilled 4.2mm part-way and tapped M5 for the packing nut, and then I started parting away. The cylinder head needs a small boss on the back side, and I just used a pair of calipers to check for size:




Inboard head done:




Next up, the outboard head. I don't know if I'm starting to turn into a grumpy old man and getting pedantic, or just plain having fun in my own perverse personal way, but thinking through the looks of the engine and what I'd like as an end result, I thought it would be nice to make the outboard head in brass to contrast a bit with the aluminium cylinder and base. So I squared up a bit of 1/8" (3.2mm) brass plate:






Then I clamped it up on the mill and poked a lot of holes in it. I coordinate drilled the 3mm mounting holes on the outside corners, and used the DRO's PCD function to drill the cylinder mounting holes. I got a nice surprise there; when I switched the DRO to PCD mode, it actually remembered the last settings I entered, which was when I drilled the cylinder block's holes. Instant time-saver and really nifty ;D:



The 6mm hole in the middle is NOT on the plans - actually there's supposed to be a 1/2" boss (or for my metric build a 12mm one) there... I was just being my lazy self...

A quick job on the lathe to turn up a bit of brass with a 6mm diameter protrusion to fit the hole in the last part, and 12mm to fit the cylinder bore:





That was parted off leaving a 0.6mm "flange" and then I just soft-soldered it to the brass mounting plate - seen from the bottom:




All done:




On to tapping the cylinder. I don't dislike tapping, but it can be a bit of a chore and requires attention and a good feel to avoid heartache. As always for aluminium, I use methylated spirits as tapping fluid, and as there was 16 holes to tap three times over on each, 48 operations in total, I just decanted some meths into a bottle cap to swash the tap in after each hole to clean off swarf and lubricate it:




It's a real pleasure to plonk six screws into a bolt circle, and just tighten them down. I've made parts in the past and successfully done this without having to fiddle about enlarging a hole here & there, but with using the DRO this was even easier... Plonk in screws & tighten up. QED.:




Even the valve chest screws fit like a glove:



 : And NO - I won't be using those cheese-head screws on the finished engine! - To paraphrase a certain Mr. Yoda: Horrible look, they do...

So much for today's bit then. More when I get a round tuit 

Regards, Arnold


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## ausdier (May 16, 2012)

Hi Arnold.
Just a quick model of the engine with a few little personal touches.
Hope you don't mind the post here on your thread. 
Keep up the good work it's looking good.


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## arnoldb (May 16, 2012)

Thanks Darren  - I don't mind.

Very nice model Thm:; I like the "chuffer" you added to the exhaust. Actually that reminded me - I must still tap the exhaust hole on mine as I want to add pipework to it for running on live steam at a later stage 

Tomorrow's a public holiday here, so I might get to make some more bits for a change ;D

Kind regards, Arnold


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## Blogwitch (May 16, 2012)

Arnold,

A working 'chuffer'

http://www.homemodelenginemachinist.com/index.php?topic=536.0

Glad you are putting your own stamp on this engine rather than following plans religiously. :bow: :bow:

John


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## vcutajar (May 16, 2012)

Arnold

You make everything look so easy. :bow:

It seems you are enjoying your new toy/DRO.

Vince


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## arnoldb (May 17, 2012)

John, thank you  - I knew I'd seen your "chuffer" somewhere - that's a definite to "play" with in future. And thank you; yes I'm adapting the plans to my own taste, available materials and equipment. All the critical measurements are the same as on the plans though. With each Elmer engine I'm building, I'm gaining even more respect for Mr.Verburg. I'm sure he could have "dollied" up all the engines like I'm doing now and you've done, but I think he on purpose left them simple to build for newcomers to the hobby. There's only three or four engines in his book that I wouldn't advise for a first or second engine build.

Thanks Vince  I'm enjoying the new toy ;D. I don't know about the easy part though; it does require a bit of effort. The basic machining is easy - that wasn't the case three years ago though, so maybe I've learnt a bit along the line. Attempting good finishes remains a lot of hard work though 

Some bits done today...

I started of with some 6mm hex brass rod for the two packing nuts. From difficulties I encountered on other builds, I learnt that it's better to first turn down and thread the needed section, put in the threading undercut after that, and only after that was done drill through and part off. I've found that if one first drill the central hole through, the action of the threading nut tends to reduce the hole diameter. If the thread run-out undercut is made before hand on these small pieces, it's very easy to break off the section being threaded, as the threading operation places quite a bit of torque on the workpiece.
So I first turned it down to 5mm and threaded with the tailstock die holder:





And then put the thread run-out groove in using the parting tool, drilled through, and parted off, using the drill to catch the piece:





The second packing nut followed - same process - and after some elbow grease to tidy them up, they were done:





On to some fiddly work next; the valve rod. As has become usual for me, I made it up of two bits - a bit of 2mm rod turned down and threaded as needed, and a separate bit for the eccentric rod end. Some 2mm brazing rod turned down to 1.5mm for 8mm - with the little ER11 collet chuck gripped in the lathe's ER25 chuck:



Turning thin bits like this can be problematic; the toolbit needs to be honed sharp enough to easily cut a tough steak, positioned dead on lathe center line, the radius on the toolbit needs to be small - so as to keep the area in contact with the workpiece to a minimum, and the cut made to depth in one pass, so that most of the cutting action is on the left hand side of the toolbit rather than on the front of it. Well, that's my theory anyway.

Next up some threading... And that ruined a bit of the carefully turned section from the last photo :-[ I moved the workpiece a bit more out of the chuck to get to the section to thread. I forgot to add a bit of taper lead-in for the M2 die though, and as a result it didn't "catch" immediately on this tough bronze rod when I started threading, and ruined a section of the previously turned section. The tail end bit is still fairly smooth and parallel, so will work fine as the guide in the steam chest:



If you click on the last two photos, you can see more of the gory detail.

While I was set up for cutting the M2 threads, I did a bit more; I've been running out of M2 threaded rod, so I made up some more. The previous threads were done manually; I turned the chuck by hand. To make threaded rod, that would be tiring to say the least, so for longer threaded sections, I just start off with a bit of rod and the tailstock die holder for support to get it started. With the lathe at it's lowest non-back gear speed (200 RPM) and plenty of cutting fluid, I do this under power. The M2 threads are fairly fine, so it takes a while to run through the section. Once the die holder leaves the tailstock support, I just guide it by hand, adding cutting fluid all the way:




When close to the chuck, I stop the lathe, and reverse it to get the section off.

A couple of minutes' work, and I have some more threaded rod:



The torque of threading does distort the rods somewhat, but they are good enough to use as fasteners on short sections.

Next up, two 2mm nuts screwed on each section (the short sections are what I had left), and a dab of thread retainer on the end of each section:





The sections screwed into the cylinder - with the head in place:





After a couple of minutes or ten, I screwed the bottom nuts down to retain the cylinder head properly, and lightly screwed down the top nuts to those. Then with my small and sharp and trusty electronics side-cutter, I clipped off the rods level to the top nuts. The cutter is upside-down in the photo:





The top nuts do two things - They add enough length to the studs as I'm going to make up slightly thicker nuts than the single nuts used used so far - purely for looks - and they also remove burrs from the threads left after clipping off the rods, ensuring that later on nuts can easily be screwed back on. After removing the top nuts, I filed the studs down a bit to get rid of the cutting marks:





After that, I built a bit of a booboo - things were just going too well :big: - I got a measurement out of kilter while making up the eccentric rod end for the valve rod:




Not good enough, so a re-do was in order.

On to the re-do, and this time the cut-outs were in place, so I just got ready to spot it for cross-drilling 1.5mm:





After parting off the eccentric rod end from the parent stock, I poked a 1.8mm deep 2mm hole into its back side with a center cutting slot mill:





With the previously made valve rod shortened appropriately, I proceeded to solder it into the eccentric rod end:




Just ordinary electronics soft solder; the valve rod should never see high loads put on it.

Completed valve rod - not a stirling piece of engineering, but good enough for me for now:





In between, the steam chest received the same threaded rod treatment as the cylinder head, and as a parting shot for today's work, things are starting to look a bit more interesting:



I have some 3mm and 4mm hex bar on order to make some nuts out of, but if it does not come in time (next 2 weeks or so), I guess I'll revert to filing down some rod to make suitable nuts from; the proportions of the nuts shown are just not right to my eye.

Regards, Arnold


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## arnoldb (May 19, 2012)

This morning I awoke to the phone ringing - with a sagging heart I thought it's one of my work sites that have a problem, but that soon turned to joy. It was my dad informing me that I'm now the owner of a well-kitted tool & cutter grinder - Thanks Dad !! I just have to figure out a way to get it the 2000km from South Africa to here in Windhoek. On Monday some phone lines will be turning warm ;D

For the shop session today, I started on the eccentric. In the first post of this thread I mentioned that I want to kit the engine out with a slip eccentric, so I sat down and did a rough sketch of how it should go together. The bit of mystery metal is what the bits will be made from:





The bit of "mystery" metal is only unknown to me in terms of precisely what kind of alloy it is. What I do know about it, however, more than makes up for the unknown and makes it really suitable for the use it's going to be put to:
 * It's from a dot matrix printer head bearing shaft - and the print head assembly used to run on bronze or oilite bushes on it - so it's a good bearing metal in combination with bronze. Pretty wear resistant as well.
 * I have a bunch of these shafts, some of them sat outside in the rain, and it appears the are pretty rust resistant.
 * Last but not least, I know this stuff machines like an absolute dream and gives great finishes.

After facing the saw-marks off the steel, I centered the rotary table under the mill spindle, transferred the chuck to it, and spotted three locations - center, eccentric offset, and the position for the eccentric engagement pin:




Before I spotted the engagement pin location, the 6mm offset I noted for it on my drawing looked a bit too much, so I used 5mm rather than 6mm for it's offset. I can't even keep to my own plans :big:

Then I drilled a 2mm hole 3mm deep into the workpiece for the pin:





Back to the lathe, and this time with the four-jaw chuck, I centered up on the eccentric offset:





And turned the eccentric to 11.2mm diameter:





Next I centered the workpiece, turned the outside diameter down to size, and center drilled, drilled 5.9mm and reamed to 6mm:




Reaming was not done under power; I turned the chuck by hand - a good bit of exercise for an office dweller 

A quick part-off - old broken end mills make great workpiece catchers :




You might notice I forgot to smooth off the burr raised by the parting tool - that came back and bit me a bit later - literally. I happened to pass my left index finger over it later on, and it released some red stuff :

After parting off the "slip" side of the eccentric, I faced the the remaining stock, leaving about a 1mm boss 0.4mm thick in the center. That's not on my sketch, but with a basic understanding of how a slip eccentric works, I added that to minimize friction:





Back to the rotary table on the mill, and I milled the needed slot with a 2mm slot drill:





After parting that lot off on the lathe, the last step was to drill 2.5mm for an M3 grub screw:





With a bit of 2mm diameter music wire fitted - secured with high-strength retainer - the eccentric bits were done:





For a final process today, I started on the eccentric strap - nowhere close to the original plans here - Just some bronze turned down and bored for the job, and parted off:




Fits on the eccentric like a glove. Some more work required on that bit though...

Hopefully more tomorrow ;D

Kind regards, Arnold


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## rhitee93 (May 20, 2012)

Looking good! Thanks for all the pics. It is neat to see how you do your setups.


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## SBWHART (May 20, 2012)

Great work and well shown Arnold

I've had a symilar engine to this in mind for some time so I have a particular interest.

Stew


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## arnoldb (May 20, 2012)

Thanks Brian - & it's a pleasure 

Stew, thank you  Hmmm... Sounds like we might be in for another Potty Engineering special; I can't wait ;D


 : Well, zero progress for me today; I felt in an extremely lazy mood today - so rather than go to the shop and build junk parts, I just lazed around.
At least we have another long-weekend coming up next weekend, and hopefully the material I've ordered will be here in time for that.

Kind regards, Arnold


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## arnoldb (May 25, 2012)

A bit of progress today. The build is now on the fiddly parts stage - making up all the linkages and so on. On plans these look easy, but they take a lot of time to make - for a good runner they need a good bit of accuracy.

The plans mostly call for 1/16" (1.6mm) brass plate for many of the linkages, but I only have 2mm and 1.2mm available - so I'll be using the 1.2mm plate and compensating for the thickness difference where needed. For a start, two ruler-wide strips sawn off the big bit of stock I have:





I felt like a bit of exercise, so filed one edge of one piece nice and straight:





Then I marked the strip for the eccentric rod, sawed to just over size and filed it down, and then filed a curve on the end to match the ring I turned up for the eccentric last Saturday. It's nice to file a fitting curve that's also shaped well enough that the ring can just sit on top of it:





Then I drilled the hole for the connection to the valve rod - I decided to make the pin size a bit bigger - 2mm instead of the 1.6mm:




The valve rod's hole will have to be enlarged as well, but that's not a problem.

On to a bit of silver soldering - things located with some flux and a sliver of silver solder plate on top:





A bit more flux added to protect the silver solder sliver:





And a quick showing-of-the-torch and cooling down. The job looks horrible here:





Into the citric acid pickle. The level in my pickle container was running a bit low, so I popped into the kitchen for some boiling water from the kettle (that also made a nice cup of coffee). The addition of hot water makes the pickling job go faster, and I just plonked it down on top of the firebrick with a piece of aluminium to distribute and use of the latent heat left in the fire brick:




The pickle has been used a bit, that's why it's starting to turn green - from the copper dissolved in it.

By the time my coffee was finished, the pickle had also done its job - and things were looking a bit better:





After a bit of clean-up, the eccentric rod looks OK:




As you can see, the bronze ring looks - and is - very copper coloured. I've noticed this in the past as well after silver soldering and pickling, and I have a hunch its because the zinc in the bronze starts to evaporate at silver soldering temperatures, while the pickle might also leach it out of the copper. I didn't want to fuss around too much and remove a lot of material from the workpiece though, as it was pretty close to final size already. This is something I'll have to keep in mind for future builds.

A quick trial fit, and a problem : :




The eccentric rod is a whole 1mm too long... I traced that back to a calculation error, but fortunately I won't have to re-make any parts to fix the problem; the valve rod has enough length and available play to it to shorten it by 1.5mm to ensure adequate clearance. As stated earlier, the smaller holes in the valve rod is not a problem; those will be opened up to 2mm to match the eccentric rod.

On to the connecting rod, and a start on the fork from a bit of 4.6x8x11.2mm sized brass - here drilled through 3mm:





Next I milled a 7.1mm deep x 4.6mm wide slot through it:




A 4mm cutter works well here; mill down to depth on the center line in 2mm steps, and then clean up the sides to width - makes the slot come out very nice.

I might get lynched or laughed at for what I'm going to say next, but I'm going to do it anyway.
Often times I notice posts where machinists are chasing extremely close tolerances on chucks and collets, and then are disgusted that the "cheap" items they buy are out by quite a bit. I know there are very close tolerance kit out there - at a premium - and if I'd bought one of the premium kits I'd be disgusted as well. My budget simply does not extend to the premium tools, so I have to make do with the less accurate and affordable stuff.
When I make my own kit, I try and do it as accurately as possible - as I have done with several collet chucks - but once I add the budget collets I can afford to it, a lot of that accuracy goes down the drain. Well, rather than fight an impossible battle, one can use a bit of run-out in one bit to minimise run-out in another bit. Nowhere perfect, but it helps. The one 16mm ER25 collet I have has an eccentric run-out of about 0.05mm close to the chuck, and the 3.5mm ER11 collet I have has an eccentric run-out of about 0.04mm. If the two are combined, and the run-outs set 180o apart, that leaves just a 0.01mm (0.0005") run-out on the workpiece close to the chuck, and I can easily and fairly accurately skim a bit of 3.2mm brazing rod down to 3mm while maintaining a fair modicum of accuracy:




Sometimes even the weak points of tools can be used to advantage 

The same bit of 3.2mm rod flipped, turned down to 3mm, and threaded M3:





Another bit of silver soldering - please excuse the out-of-focus photo :-[:





I could have soft-soldered the last joint, but there was some turning left to do on it, and I wanted the strength of a silver soldered joint. Very carefully and slowly, I used the sharply honed parting tool to skim the workpiece down:





With the rod in place and used to set up nice and square, it was easy to drill the 2mm cross-hole:





After a bit of rounding over with a file, and some elbow grease, the bit looked like this:





Next up, the big end connector. Not really hard to do, but when I started to drill 2.5mm for the M3 threaded hole, I noticed that the workpiece wanted to move downward; I'd forgotten to add some paper to prevent that, so I just used some bits from the mill clamping kit to make an impromptu screw-jack:



Dark photo - if you click on it, the detail should be better.

Rather than sawing off the workpiece from the parent stock on the band saw or with a hack saw, I just slit it off - not all the way through, but just till the workpiece started lifting:




Using the slitting saw meant I could get very close to final size with little surface finish needed, and by leaving the last bit attached, it was easy to just break it off. If I slit it all the way through, I would have had to hunt through the shop for the workpiece wherever the saw tossed it.

On the plans, this bit remains fairly rectangular, but I thought it might look better rounded over, so I did a couple of quick facets on it:





A bit more file & emery work, some tapping, and a bit of reaming, and the connecting rod was done:




 : Well,not quite - it still needs a lock-nut.

Regards, Arnold


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## bearcar1 (May 25, 2012)

Beautiful, beautiiful, Arnold. Of course, I would expect nothing less than your usual high quality of work. ;D You do make it look so effortless. Well done indeed.

regards and have a great holiday weekend.

BC1
Jim


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## ProdEng (May 25, 2012)

I was looking forward to see how you made the links and now I will have a lot less thinking to do. I guess there are many ways to approach the machining sequence but your methods are pretty direct. As for calculation errors, I have had a few of my own recently but the outcome was a remake.

Jan


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## arnoldb (May 27, 2012)

Thank you Jim  - sound's like I've set up some expectations to meet for myself then :big:

 Thanks Jan. Yes, there are always many ways to do things - I tend to go for methods that are fairly straight forward to set up and does not waste too much raw material... The calculation errors will always be there; it's part of the fun ;D

Yesterday was a dead loss as far as the build goes; I paid some attention to domestic issues like fixing leaking toilets and taps, washing and polishing the car and some pleasant social interactions.
I love polished up brass cannon casings - don't ask me why; I just do. This is my tiny collection:





A couple of months ago, my one friend's father-in-law noticed these while on a visit, and yesterday evening as part of the aforementioned social interactions, that friend invited me over for a braai (BBQ/barbecue/barbie for folks in the rest of the world depending on where you are). Well his father-in-law was also invited, and upon arriving insisted that I open the Golf's boot - and then promptly plonked this one in there:




 ;D That's going to take a wee bit of work and a bit more to polish up! I haven't measured it yet, but it's about 1m long and looks to be about 140mm caliber, and has been safely discharged.

This morning I was awake nice and early - all bright-eyed and bushy tailed and looking forward to about eight hours of shop... Alas, that wasn't to be; we had a long power outage, so only a couple of hours in the shop.

First off, the crank screw. Some 6mm stainless steel rod turned down as needed, and threaded and a tread run-out groove added:





On to the mill, and with the dividing head mounted in the vise, a hex head milled on it. I took a cue from Dr Jo's description on milling hex bits on bolts here to minimise the burr on the threaded side, and climb milled the hex. My mill's rigid enough for this kind of operation, and it worked a treat:





After parting off the screw (or perhaps more accurately bolt, since it won't be slotted) I faced the parted end off to tidy it up a bit:





All done, though the hex head needs some finishing still:





Next, some thin washers from brass - these are not on the plans, but I want to add them to minimise friction on the crank screw The first washer was too thick:





Getting rid of the burrs on the washers after parting off can be a bit of a pain-in-the-finger - I rubbed them down on some 320 emery:





The assembled crank screw and connecting rod with the washers:





On to the piston rod. Some 4.7mm brass bar drilled 3.2mm to a depth of 3mm to accept some 3.2mm brazing rod, and slit at the needed length - in this case the workpiece length lying along the mill's Z axis:





With the bit of stock set vertical in the vise, once again slit to just before final break-through:





A suitable bit of brazing rod - with the point filed down to approximate the drill bit cone, and nipped all around with a pair of electronics side-cutters to raise some burrs and make some grooves:




The rod and the little block will be silver soldered, and the mutilation at the end of the rod serves a dual purpose. One is to make it fit snugly into the hole in the little block to keep things aligned. The other is to allow space for flux to bubble out and silver solder to wick into to ensure a good joint.

Off to the silver soldering next; I dropped some flux and a small bit of silver solder into the hole in the block - you'll notice I didn't bother to clean up the permanent marker - that adds some contamination that will help prevent solder from going over those bits. I also fluxed the tip of the rod a bit. Poor photo; I don't know where the heck the focus was:





All clamped up and ready for the torch. A bit of weight at the top will show when the solder trapped between the pieces melts - and also prevent things coming apart as the flux starts to bubble before that, and gentle pressure on top of it once the solder melted will make sure both bits go together well:





Soldered up, and after a quick pickle:





Finally, drilling the cross-hole for the linkage. I do it this way around, so that even if the little brass block at the end of the rod was a little mis-aligned, things could be recovered by filing or machining the block a bit:





I did some finishing work on the connector after that - very carefully - and as a last step the rod needed to get machined to length and threaded. Easily done by inserting it in reverse in the small ER11 collet chuck:





That end was turned down to 3mm:





After threading, adding a run-out groove, and some blinging the piston rod was done:





On to the piston. When I started off building these little engines, I thought making cylinders and pistons was the hardest part. Not so; it can be a bit of work making the cylinder, but making a well-fitting piston can be a really quick and easy job if the machining is done in the correct order on it IMHO.
What I've found to work quite well for me, is to bring the piston close to final size, start the parting groove, chamfer both the edges with a small fine file at about 45o, and add the oil grooves deep enough that they would still be there after finishing the piston to size:





After a finish pass to get the piston to size (11.99mm in my case for the 12mm reamed bore in the cylinder - slightly on the tight side but it will run in quickly), I drilled it through 2.5mm, then 3.2mm for 3mm deep. Next I tapped it M3 to match the threads on the rod. As I'm deviating from Elmer's plan a bit here with the thicker piston rod, my thinking is along the lines that by drilling the 3.2mm bit to match my rod thickness before tapping through, a kind of a register is formed for the rod to keep it concentric, whereas if I tapped M3 first, the threads would deflect the 3.2mm drill when it started, thus preventing concentricity. Just my thoughts; you might have our own:





After parting off and removing the parting burr, the piston was done:




Took me a LOT longer to type this up than actually making it :big:

After making the piston, I set about correcting the issues so far. The valve rod's 1.5m holes were drilled out to 2mm to match the eccentric rod, and the valve rod was also shortened by 1.5mm to compensate for my earlier calculation error.
I also mounted things together, and noticed a bit of friction in the connecting rod assembly - not related to not having the parallel motion links made up yet. I chased that down to the combination of the protruding bearing bush in the column and the back of the crank disk forcing the connecting rod over at a slight angle. That was cured by skimming of 0.5mm from the back of the crank disk.

Assembled as it is in the next photo, there's very little friction left - most of it associated with the crank rod not getting guided with the parallel motion links, and the slip eccentric looks to be working smoothly as well. A Cobbled-together assembly shot:




Not much progress visible for quite a bit of work...

Regards, Arnold


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## rhitee93 (May 27, 2012)

Looking good Arnold 

One trick I figured out a couple of months ago to keep me from saning off my finger prints was to use a piece of leather between my finger that the part I am sanding. your mileage may vary, but it worked well for me when i made a similar set of washers.

I like the shell casings. I have a few 40mm casings that my dad fired from the deck gun of the USS Sealion. I have always intended to turn up some dummy projectiles for those and polish them up real nice. One of these days...


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## Sshire (May 27, 2012)

Looking great! 
I seem to remember a one of your previous tips for making washers without burrs. Correct me if it wasn't you.
Something like round rod. Parting tool in to just a bit bigger than the ID of the washer. Repeat for the number of washers needed. Then drill out the ID. Washers all done, no burrs. I remover thinking how brilliant it was at the time. 

Best
Stan


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## Sshire (May 27, 2012)

Astounding! My brain is still working. 
Burrless washers here
http://www.homemodelenginemachinist.com/index.php?topic=16870.msg183877#msg183877


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## ProdEng (May 28, 2012)

Not too many pieces left to make now. I am looking forward to watching the linkage with the arms working. Once more Anold, lots of construction tips for me to store away if only I can remember them. 

Jan


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## arnoldb (May 28, 2012)

Thanks Brian  - Great tip on the leather Thm:; I've used leather strips with "Brasso" on them to polish up small flywheel spokes. I have some 40mm machine gun casings as well - five of them; I want to make "shot glasses" with them, but the "shots" might be a tad too big ;D

Stan, thanks  - I only remembered my own washer trick after those were parted :hDe: - I didn't want to waste the bits, so I did it the hard way ;D Your memory's better than mine it seems, but it's great to know that some of my methods are useful!

Thanks Jan  There's actually still quite a few pieces to make - and all of them fiddly. The steam valve will be easy, and the linkages are fairly straight forward as well, but the little bolts and nuts will take a bit of effort and time...

Kind regards, Arnold


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## Ken I (May 28, 2012)

arnoldb  said:
			
		

> Took me a LOT longer to type this up than actually making it



Don't doubt it - KP for going to the trouble to keep us lookenpeepers entertained.

Wonderful documentation as usual.

Regards,
      Ken


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## arnoldb (Jun 2, 2012)

Double thanks Ken  ; "lookenpeepers" - I like that term ;D

I got a call on Thursday; the brass stock I'd ordered a couple of weeks ago had arrived. Went to fetch it on Friday - two 2m lengths of stock well wrapped in shrink wrap... When I opened it at home yesterday evening, it was two lengths of 3 and 4mm round and not the hex sections I'd ordered :wall: - that'll teach me to check at the supplier. So Monday they'll be getting a visit *knuppel2*. Fortunately I can use the round section - especially the 3mm one.

On to today's bits. First off the fork links for the parallel motion. The rest of the engine seems to be evolving as a mix of aluminium and brass in sort of layers, so I thought these would look OK if made from aluminium rather than the brass specified. As I'll be using small bolts to substitute for the link pins, this can be done; if the original plans are followed some pins need to be soldered to these forks and aluminium wouldn't work.

I squared up a bit of 8mm aluminium plate, and clamped that on the tooling plate on the mill - with suitable packing, bits of paper to prevent slipping, and the vise stop also set to keep the X position for a later machining process. Then I drilled two 1.6mm holes to tap M2 on the left side, and two 2mm holes on the right side - using the DRO to locate them:






Then I shifted the one clamp to allow me to mill out some excess:





The workpiece was flipped, and more excess milled out:





Next, the workpiece was clamped vertically, and a slot milled in the top:




The centering feature for the DRO is really nice to use for jobs like this; take the edge finder, and zero Y on one side when it kicks out, then move to the other side, and when it kicks out, press "Y" and 1/2 and the center is located ;D

Before separating the links from the parent stock, the M2 holes were tapped; its easier to tap things when there's a bit to hold onto and flat surfaces:





A quick bit of work with the slitting saw - one cut at the length of the forks:





Two cuts to separate the forks from the parent stock - I used the height gauge to set the saw height for each cut. The gauge was set to zero at the height of the workpiece, and then adjusted for the required depth, and the spindle adjusted till the top of the slitting saw just touched the gauge foot:





Fresh after slitting off - still in need of the elbow grease toolkit:





After application of the elbow grease toolkit - and finished to match the brushed finish of the rest of the aluminium bits on the engine:





For the links, I milled some brass plate down a bit to get one straight edge on it, and sawed a long enough section off to form one link. Then I heated both bits up and dabbed with some electronics solder to tin them:





Then I set up the bits with their straight edge on a rusty bit of plate with one of my much abused but well loved toolmaker's clamps also lying on the plate:




The rusty plate is to prevent excess solder from sticking to it, while helping to keep the bits parallel. The toolmaker's clamp is to force the bits together after heating enough to melt the solder. Heat was applied and the clamp screwed up, and the brass plate bits stuck together.

The soldered assembly was milled to final width:





With most of the excess stock sawn off, the workpiece was centered, and holes drilled - 3mm on the outsides and 2mm for the middle one. This is much bigger than on the plans, but the reason will become apparent later in the build:





After more use of the elbow grease toolkit:





The engine so far - assembled with various odds and ends to keep things in place temporarily:



The chromed dome nuts does not look right. I've been trying all suppliers in Windhoek looking for M4 brass dome nuts, and all of them assure me that I won't find any. To quote one supplier: "Your chances are better at getting pregnant than finding brass dome nuts locally". Well,  - I think making them is easier (and quicker) than the quoted option ;D

Regards, Arnold


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## steamer (Jun 2, 2012)

Love the build Arnold!
I really like the fixture plate!

Dave


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## lazylathe (Jun 2, 2012)

Another excellent thread Arnold!!! ;D

Looks like you are putting your DRO's to very good use!!!

Andrew


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## vcutajar (Jun 2, 2012)

Arnold

You seem to be quite confortable with the DRO. Can you imagine life without it now? ;D

Vince


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## ProdEng (Jun 2, 2012)

Great process for the links, I had no idea how to make those and would have spent forever trying to machine the tiny parts individually. :bow: Also like the idea of using threaded parts instead of pins to join the links, it should look a lot better.

Jan


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## arnoldb (Jun 3, 2012)

Thanks Dave  - making that tooling plate has proven to be some of the best time I've spent on tool building. It does need a couple of accessories though - eccentric clamps for holding down thin workpieces and so on. And fences - when I built it Marv suggested those, and for work like this it would be really handy.

Dankie Andrew  - of course; the kit has to justify the expense... a bit anyway :big:

Vince, thanks  I don't have to imagine it; been there done that :big:. The tooling plate Dave mentioned was made by reading the hand wheels - to drill, slightly countersink and to power tap each hole with the three successive M6 taps. The DRO would have made that lot MUCH easier ;D

Thanks Jan  - any method to make them will work, but I'm inherently lazy, so I try and find easy ways to do things. The often-used term about making as much as possible of small parts while they are still attached to the parent stock also helps  I hope the threaded parts will work out OK; it's a lot of additional and very time-consuming work for such small details.

Well, not much done today, but some progress is better than none...

With a brand new 6mm HSS blank in hand I spent a couple of minutes on the bench grinder grinding an approximate 3mm radius on the tip, and a couple of minutes more with the Dremel and a round stone to hone it a bit:





A quick try-out on some hex brass, and a satisfactory dome evolved:





Making similarly sized dome nuts this way wouldn't be too easy, so I started making them the other way around - drill and tap the hex brass, touch the end at a shallow angle with a file to add some clearance on the corners so that they wouldn't scratch the engine table while tightening down, and part off. The parting tool was a tiny tad below the lathe's centerline, but that was OK, as it was easy to just break off each bit after parting; it also saved me from digging through the swarf pile each time to find the bits ;D:





I made a couple of extras, just in case. It was easy and quick enough:





Then I chucked up a 4mm cap screw from behind in the small collet chuck - with just enough thread sticking out for maximum engagement in the workpieces, and then each workpiece was threaded on to seat against the collet and turned down. Very carefully... This was essentially a "forming" operation, and that adds a lot of strain while turning. While turning the first nut, I locked the carriage at the point the workpiece looked good to go, and I took a note of the cross-slide reading. This meant I could turn all the nuts the same:





After some spit 'n polish, I had four acceptable-looking nuts - the other two I left as-is for now




I have a length of 3mm OD x 2mm ID brass pipe - from this I parted off some 1.4mm long sections. The one was a bit more than 1.4mm - but I can shorten it if needed - such as in the case where one of the others goes into the fourth dimension:





The little pipe sections will be used as the bushes for the links - meaning I don't have to fiddle about making run-out grooves for the threads in the M2 bolts when I make those:





That was all I did for today... But at least there was some bits made, and I'm fairly happy with how the dome nuts look on the table:





Winter's started to hit home here in Windhoek - I know this because yesterday evening Shrek decided to climb in my jacket rather than perch on my shoulder as usual:




 : It's difficult to take a photo if you can't see the screen to get focus...

Regards, Arnold


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## steamer (Jun 3, 2012)

When I make them, I leave the blank holes and tap them as I need them

Dave


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## rhitee93 (Jun 3, 2012)

Wow, you made the acorn nuts look easy. I'll have to try to do that on my next engine...


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## arnoldb (Jun 4, 2012)

> When I make them, I leave the blank holes and tap them as I need them


Thanks Dave - scratch.gif Now, why didn't I think of that :big: Something to keep in mind for future fixture plates; it'll be nice to spread the work!

Brian, thanks , they were easy to make. The biggest concern I had was forming the dome with the bits just engaged by the threads. The simple rule is to have a very sharp toolbit and to take it easy on the in-feed.

Hopefully I can give the build a bit of a go this coming weekend; too cold in the evenings for shop now.

Kind regards, Arnold


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## ronkh (Jun 4, 2012)

Oh goody!

Arnold's back after too long a break between postings!!!!
Brilliant work again mate. 
I have watched this from the first post and as always, suburb work.
Thanks for sharing.

Kind regards,

Ron.


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## RCGUY (Jun 4, 2012)

Arnold,

I have been watching your build with great interest. I am building Elmers #29. Since I am new at this I find your pictures and text to be of great value for me. I am currently starting on the cylinder and following your procedure step for step. I hope to reach your level of expertise some day.

Ed (RCGUY)


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## arnoldb (Jun 9, 2012)

Thanks Ron  - The posts will pretty much be weekend-to weekend now; a sudden cold spell has hit, and I tend to stay out of the shop if the machines turn a cold shoulder 

Ed, thank you  - I'm glad there's something of value to you in the posts. I very nearly built the #29 as this build, as it's also a really nice-looking engine, but I wanted a "quick" build and I have some other ideas in store for the #29 which will make my build of it very slow. You're doing a great job on it :bow: - keep it up! I've been following along, just have not posted yet. As to "expertise" - you already have it; it comes from the heart.

Today I made a couple of bits, then digressed from the build for a bit of tooling.

First up, the piston-rod to connecting rod link bolt - some 4mm brass round turned down to 2mm for a length and then I just filed hex flats at the thick end, using the big collet chuck's slots as indexing grooves. Four strokes with the fine 200mm flat file in each position; after the first rotation the flats weren't quite right, so a further 3 strokes for each face:




After threading a 2mm long section at the end with the tailstock die holder, parting off and a bit of clean-up, the bolt was done:





Four short bolts followed - for the link-to-fork arm connections:




The last bit for the engine I made today was the bolt for the valve rod:




I need to make at least 13 2mm nuts and a lot of thin 2mm washers... So far I'd been eyeballing the bolt head sizes, but it takes longer and screw-ups are very easy to make with the thicknesses, so I digressed to build an accessory to help me with the rest of the small bits tomorrow:





Regards, Arnold


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## arnoldb (Jun 11, 2012)

:-X I didn't get a chance to update yesterday evening, but it's a bit boring anyway...

I just made about twenty 2mm washers x 0.2mm thick from some 4mm brass rod. Stan (sshire) mentioned earlier when I made some other thin washers about a method I'd shown in another thread, but I'll just show it here again.

The bit of stock just grooved up with the parting tool to leave "flanges" the thickness of the wanted washers, and with the grooving done to leave a core just smaller than the hole in the washers needs to be:




It's a bit of a toss-up; you can't have too much stock sticking out from the chuck, as the groove parting will go pear-shaped. But one wants the maximum number of washers possible for one go.

Then drill through the lot - using a light feed rate with as stiff / short a drill as you can get. If you drill too hard, either the workpiece or the drill will deflect resulting in tears (at best washers with off-center holes, and at worst, a ruined bit of valuable stock and/or a broken drill bit). I just used a 2mm center drill here as I wanted the holes 2mm and the 2mm center drill is about as stiff as you can get:




That leaves a bunch of washers sitting neatly on the drill.

Here's the batch from the previous photo:



They don't look good - well, to be honest, they look pretty crappy - and ended up being slightly dish-shaped. The deformation was due to my parting tool both flexing and being slightly blunt, hence pushing over the thin flange while doing the parting cuts. Not a major problem though; in some locations I can use the "dishing" to benefit, and where that's not OK, I'll just squeeze the washers flat in my old milling vise.
 : Taking a macro photo also tends to exaggerate flaws - all the tiny imperfections looks HUGE when enlarged... - that's my theory anyway :big:
I really need to look into getting a selection of shim stock and a press for this kind of job on the common sizes I'm doing; turning up a punches and dies from silver steel (drill rod) and hardening those up to punch washers from the appropriate shim stock would be a lot easier and neater...

Next I cut some lengths of 4mm brass rod to extend out both ways from the ER11 collet chuck for about 18mm - which is a carefully chosen random distance at which I'd be comfortable to do light milling and parting on:




The one section's a bit shorter, as that was the left-over bit from the section of rod I cut up.

On to the Mill, and with the dividing head mounted, I started milling the brass rod down to hexagon shape. VERY carefully, and with a sharp cutter:




There's a lot of excess sticking out, and going about things hastily would end up in tears. Closer to the collet chuck, the feed rate can be increased as the workpiece gets stiffer toward it. 

Once I'd milled hex sections on the bits of brass round, back to the lathe, drilled through 1.6mm to tap M2 and parted off 1.7mm thick sections, catching them on a bit of wire held in the tailstock chuck:





I forgot to take a photo of what the milled sections looked like - so I snapped this after I'd parted off some nut blanks:





A bit more parting off later, and I had a selection of nut blanks. On the left, the blanks are 2mm thick, on the right 1.7mm, and in the middle is a commercial M2 stainless steel nut, that measures out at 1.4mm thick:



All in their gory detail so far; the nuts still need to be cleaned up and tapped M2, but I've hatched a plan for that to save some energy that entails a bit of shopping this week when I get a chance. I just hope my plan will work :noidea: - otherwise I'm going to sit with a lot of egg on my face :fan:

 :hDe: Shucks, this build have come a long way from just starting a relatively simple engine build to test a set of DROs to messing around with nuts & bolts... I guess that's just part of the fun ;D

Regards, Arnold


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## ProdEng (Jun 11, 2012)

I enjoy making the smallest parts most of all, just tends to consume a lot of time. 

Jan


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## Rayanth (Jun 11, 2012)

Forgive the newbie question, but this is how I must learn - Could you have threaded a length of the hex rod, prior to parting off the nuts, and then just run each nut over the tap again to clean up the mess from parting (if any) ?

- Ryan


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## arnoldb (Jun 12, 2012)

Thanks Jan  - Yes, I agree there's a certain level of pleasure in making the really small bits... Sometimes it borders on masochism ;D

Hi Ryan, no problem; please ask away if you have questions 
Yes, I could have threaded before parting and run each nut over the tap afterwards - in fact, that's how I've done it in the past.
My M2 taps can only thread to a depth of 8mm though, so that means making 2 nuts at a time if the loss of material for the parting tool is taken into account. That becomes very time-consuming with all the tool changes in between, and it also gets easy to cross-thread the nuts while picking up the left-over threads in the parent stock for each 2-nut batch. So I'm trying a different method to see if I can make things a bit easier and quicker...

Kind regards, Arnold


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## Rayanth (Jun 12, 2012)

Understood, Arnold, was just thinking threading afterwards, with brass, would be more likely to damage or mar the he'd surface of the nut. I will be watching and learning!

-Ryan


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## Blogwitch (Jun 12, 2012)

This is coming along great Arnold :bow:

I am a bit like Jan, making lots and lots of tiny things like nuts and bolts, to me, is really relaxing. 

I don't think there are any shortcuts, it is just a matter of setting something up and going through each stage as required. I have some very small commercial threaded rod in stainless that I use for facing my nuts to size (that sounds painful), it can take the strain of the machining in such small sizes, whereas sometimes if normal steel is used, it is continually snapping off.
Making your own can be very advantageous, you can make smaller nuts with say a larger thread through them, to keep everything looking nice and neat when assembled.

Keep up the good work and we will soon be looking at another stunning engine from you.

John


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## ozzie46 (Jun 12, 2012)

Arnold, You're doing a fabulous job. Even making your own bolts and nuts. 

I've often thought about it but it seems so time consuming. I suppose it would get quicker the more you do it and develop a system.

 Not to detract from this thread but your tooling thread has given me so many ideas I don't know where to start.

  Thanks so much for sharing. A "K" to ya.

 Ron


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## RCGUY (Jun 13, 2012)

Hi arnolb,

I have been following your expert build and have learned a lot. I just started the cylinder on Elmer's #29 and used your procedure. It has helped me a lot. Thanks for posting all the pictures.

Ed


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## arnoldb (Jun 16, 2012)

Hi Ryan - I hope today's post will reveal the rest.

Thank you John  I'm actually also starting to enjoy making the small bits - that is when I don't drop them  And I have to agree; there's no shortcuts; it all just takes a bit of effort. "... I use for facing my nuts to size (that sounds painful),..." :big:

Double thanks Ron  I've made the nuts for nearly all my engines so far - simply because initially I couldn't buy them. As John mentioned, it can be useful to make one's own; I'm looking at my own work with an ever-more critical eye while building each engine, and I want things to look "right" - even though that is very subjective as different people's tastes differ.  Thm: I'm glad you're enjoying the tooling thread as well. You'll notice I make up the bits of tooling as I need them - or in advance if I'll need them for a new project.

Thanks Ed  I'm glad there's some useful information in my ramblings. Thanks for labeling my build as "expert" - but I am just an amateur and very much still learning as I'm going along.

More work on the nuts this afternoon...

First up was a little jig to hold them for tapping; just a 2mm slot milled into a scrap bit of aluminium - to allow clearance for the tap, and widened to 3.4mm at the top to hold the nuts; I made them 3.4mm across flats:




If you have a look at the previous set of photos I posted, you'll notice that all the nut blanks still have a little parting pip on them; that's about 1.7mm in diameter and fits nicely in the tap-groove in the jig. I had a hunch that the tap would also remove the pips when threading the nuts, and that actually worked. While tapping, the tap neatly removed the pip, and when unscrewing the nut from the tap, the bit just falls off:




My "makeshift and ugly" tapping handle in the previous photo is really nice to use when tapping cylinder blocks and so on while using a tapping guide, but I found it a bit awkward for the nuts. Then I remembered I'd made a tapping handle for my M3 taps when I needed to get into a tight spot where the tap shanks were too short to use my regular tapping handle. The shanks on my set of M2 taps is the same thickness as that of the M3 taps, so I switched to that handle - it's much easier to use, and I'd made a convenient indentation on it's top to twirl against my index finger:





That made tapping really quick and easy; before a batch of fourteen nuts, I went to get a cup of coffee, and by the time I'd finished tapping all the nuts, the coffee had cooled just enough to be drinkable without scalding my mouth ;D

The nuts all still had some burrs on them from parting off; I just used a bit of threaded rod with a section of pipe to make a handle to hold onto them for cleaning up:





A quick lick with a file on each nut, then some emery, and a trip to the buff, and each nut was cleaned up in turn:




I ended up with a nice selection of nuts; screwed on threaded rod to prevent dropping them - the shop-monster must be starving, as I only dropped one nut for it to lunch on during the entire process:




The bits needed for the engine are getting less; I had a quick scan trough the plans and made a list, and what's left is the flywheel, steam connector, and I'd somehow slipped up making the valve and it's nut so far. The cylinder base mounting screws are also outstanding; I can't make up my mind whether I want to make those as studs 'n nuts or use dome nuts to match the column nuts...

So back to the original intent of this build, and a try-out of the pocketing feature of the DRO while making the valve.
First off, I milled a bit of 8mm flat bar down to 5.16 mm on one side - that's the thickness of the valve - and then milled the slots for the valve nut and valve rod clearance; these are both 2mm wide - adapted a bit from Elmer's dimensions to match my valve rod and some 2mm plate I'll make the nut from:





Then I flipped the block, and milled the pocket using the DRO's feature. It's really easy to use; one enters the size of the milling bit, the center point of the pocket, and it's X and Y dimensions, and the DRO tells you to which positions to move while milling to hack out the pocket in a sort of square spiral fashion. What I found interesting was that it looks like the DRO software also compensates for the cutter thickness in terms of it's diameter while cutting; I used a 2mm cutter, and the coordinates were spaced to only take 1mm off each side, and amazingly, to conventional mill all the way ;D




I then used a slitting saw to slit the valve off the parent stock:





The completed valve, after a bit of clean-up work and flat-lapping the port face:



I'm not entirely happy with it; the one side looks like it's narrower - that's because of the chamfer on that side; I didn't notice that chamfer while machining the stock : The valve will work, as that chamfer is on the "side" and will not impact while in operation; if it was on one of the edges joined to that side, it would make setting the valve position very difficult... Maybe I'll just re-make it to get it spot-on.

Kind regards, Arnold


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## arnoldb (Jun 17, 2012)

Had a bit more shop today - once it warmed up enough for me to stick my nose in there...

The first thing I did was to re-make the valve; this time round it came out better:





On to the valve nut, and I just used the DRO to locate the hole to tap-drill for M2:





After that I tapped the hole, and then used the slitting saw again to slit the valve nut from the parent stock. To prevent it flying off, I used a toolmaker's clamp to tighten down equally on both the parent stock and valve portion before the final slitting operation:





That pretty much completes the entire valve assembly:





I'd decided to go with studs for the cylinder base mounting, so I threaded up some 3mm brass rod, and made nuts from 3/16" hex rod (that was sold to me as 5mm : ). Feeling a bit lazy, I just locked the nuts to the studs with some thread retainer; I'll use them as "bolts" to mount the cylinder:





I quite like how the Kimble's flywheel turned out, and a similar one would go well with the brass/bronze/aluminium mixed theme of the engine, so I sliced off a section of bronze from the section of 78mm OD that I'd bought in December:





A 60mm diameter hunk of aluminium followed:





Then I cleaned up the rim and one face of the bronze:





The aluminium followed suit:





I had to resort to friction drive to clean up the rim of the aluminium - made that 59mm dead nuts:





The bronze had to be bored out for a press fit for the aluminium (58.96mm), but I'd run into the faces of the chuck jaws with the boring bar if I did that, so I used a technique John (Bogstandard) had shown somewhere and used three washers as spacers:




Once the bronze ring was chucked up, I just used the rule to push the washers out; they slid out easily. Can't leave them there, as they're liable to come flying out once the chuck spins up.

The rim hole was bored to size - and I made sure to add a small chamfer on the edge to help start the aluminium slug on it's way later on:





Then I plonked the aluminium bit in the freezer for about 20 minutes, and five minutes before fetching it I used a plumber's torch to heat up the bronze ring nice and hot. Then I fetched the aluminium bit - with a spare bit of ice stuck to it to keep it cold, and plonked it into the ring; a light tap with a small hammer sent it all the way into position:





A quick skim in the lathe, and I left things there to continue next weekend:





Regards, Arnold


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## arnoldb (Jun 23, 2012)

Had a good shop session today; it would have been longer, but a friend I hadn't seen in a while dropped by this morning with a small problem I had to help him with... I got nice payment in the form of a slab of 76% cacao Swiss chocolate he bought in Europe a couple of weeks ago ;D

Work carried on on the flywheel. The spoke section was trepanned out first:





Then I played around with Marv's flywheel generation program, and ended up with this lot - I just added the metric measurements to make life easier for me in the shop:

```
***** NEAREST INTEGRAL ANGLE SOLUTION *****

Number of spokes = 6
Radius on which inner holes are located (R1) = 0.472 in   12mm
Radius on which outer holes are located (R2) = 0.984 in   25mm
Diameter of inner holes (2*r1) = 0.315 in   8mm
Diameter of outer holes (2*r2) = 0.157 in   4mm
Distance from spoke CL to outer hole center (d2) = 0.137 in 3.5mm

Angle from spoke CL to inner hole center (theta1) = 30.000 deg
Angle from spoke CL to outer hole center (theta2) = 8.000 deg
Angle btw two outer holes in same web space = 44.000 deg
Inner spoke width = 0.157 in  3.99mm
Outer spoke width = 0.117 in  2.97mm
Minimum radial web length (W) = 0.748 in 19mm

Assuming that a spoke CL is initially aligned with the mill y axis,
the rotary table must be rotated (phi=) 2.000 deg to bring the spoke edge
parallel to the mill y axis.
The table must then be offset by (x=) 0.092 in plus half the cutter diameter. -> 2.34mm + 2mm = 4.34mm

The rotary table settings (deg) for the inner holes are:
30.000
90.000
150.000
210.000
270.000
330.000

The rotary table settings (deg) for the outer holes are:
8.000
52.000
68.000
112.000
128.000
172.000
188.000
232.000
248.000
292.000
308.000
352.000
```

I started drilling holes according to the print-out; the bigger holes around the rim was drilled 8mm final size - taking care to get as smooth a finish as I could from the drill, and the outer ones 3.5mm - as I'd be using a 4mm end mill to make all the cuts. I like to do this, as it leaves a bit of meat to first rough out things and then take a final light pass to full size to get a better finish:





To help prevent a brain-fart, I used a marker to join up the holes and mark the sections that will come out; it's a simple, but convenient way to eyeball things while going along:





For the rough cuts, I also jotted down some new angles on the flywheel sheet - so that all the roughing could be done slightly under-size:





Then I milled out the curved sections - first with the rough machining to the jotted down angles above and leaving 0.3mm on the web diameter for clean-up. It was a pretty brutal - just 2 passes per curve to take the 4mm cutter through the web. Then a finish pass through all the curves to the original calculated angles and final web diameter with the cutter at full depth for that pass. In the next photo you can see on the "inside" of the curves how crude the rough pass was, compared to the nice smooth sections on the outside where it was done to finish:





Next I started milling out the spoke sides - also with a rough pass first to hog things out just below size, followed by a finishing pass:





Five hours later, and all the spokes milled out - with a glaring mistake on the third final pass spoke...:



 : I'd run the cutter in too deep toward the hub; after long concentration my mind was wandering...
The over-run should blend in OK with a file though; it looks worse on the photo than what it really is, as it has a burr standing up that's fooling the eye a bit.

I was hoping to finish the engine this weekend, but I don't think it will be done; The flywheel needs its final touches, there's still a couple of bits to make, and all the parts need to be stripped down for a final clean-up.

Kind regards, Arnold


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## rhitee93 (Jun 23, 2012)

I love the flywheel Arnold!


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## mklotz (Jun 23, 2012)

Arnold (and others who may use the program),

The only thing in this program that makes it Inferial is the fact that dimensions are labeled as inches. Since no internal unit conversions are done, one can directly enter (consistent) metric units and interpret the outputs (labeled as inches) as whatever metric units were input.

To demonstrate what I'm talking about, in the example below wherever the program asked for inch inputs I entered the millimeter values from your example above. Note that the calculated spoke widths and web length values, although labeled inches, correspond with your metric values.



```
Number of spokes = 6
Radius on which inner holes are located (R1) = 12.000 in
Radius on which outer holes are located (R2) = 25.000 in
Diameter of inner holes (2*r1) = 8.000 in
Diameter of outer holes (2*r2) = 4.000 in
Distance from spoke CL to outer hole center (d2) = 3.500 in

Angle from spoke CL to inner hole center (theta1) = 30.000 deg
Angle from spoke CL to outer hole center (theta2) = 8.048 deg
Angle btw two outer holes in same web space = 43.904 deg
Inner spoke width = 4.000 in
Outer spoke width = 3.000 in
Minimum radial web length (W) = 19.000 in

Assuming that a spoke CL is initially aligned with the mill y axis,
the rotary table must be rotated (phi=) 2.000 deg to bring the spoke edge
parallel to the mill y axis.
The table must then be offset by (x=) 2.359 in plus half the cutter diameter.
```


This technique can be used with many of my programs (and other folks' programs). Be careful, though. It will only work if the program does no internal units manipulations.


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## ProdEng (Jun 23, 2012)

Flywheel making seems to be an art on its own, wether you use the mill or saw and file it takes a long time. Rounding the spokes is a bit of a nightmare ;D This must be the one part of an engine where a casting is hard to beat. An alloy hub with a dense rim is a good way to go, my last flywheel was from solid steel and was a pain in the fingers :big:


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## arnoldb (Jun 24, 2012)

Thanks Brian 

Marv, Thank you :bow: ; I actually suspected as much, but didn't want to take a chance...

Thanks Jan;  - yes, flywheel making does seem to be an endeavor of it's own... I'm not even going to attempt to round the spokes on this one; this build has already taken more time than I anticipated :big:

Had a good session in the shop today ;D

The flywheel was drilled and reamed out for a 6mm axle, and then I clamped up the dividing head at a suitable angle in the mill vise - not to be used for dividing, but purely as a convenient way to hold the flywheel to drill for the grub (set) screw. I first used a center-cutting mill to drill down a bit to allow the M3 tapping drill to start without wandering:




After drilling the 2.5mm hole through, I tapped it M3. That little straight-shanked ER11 collet chuck I turned up is proving to be extremely useful all round - here I just used it to chuck up the tap, and let it slide in the Mill's collet chuck as tapping guide:




Clean-up followed. The bronze ring on the flywheel proved to be a real [email protected]@rd to get a nice finish on... I eventually gave up and left it at this:




Actually the photo makes it look worse than it is. From a bit further away with a quick try-out on the partly assembled engine, it looks slightly better:




Some 2mm bronze brazing rod volunteered to be threaded on both ends - these are to mount the cross-head arms to the columns:





The steam/air adapter was a quick job:





At that point I ran out of bits to make 

So, I disassembled everything, except for the bearing columns:




All the parts got a final once-over; there were still some tooling marks on the bearing columns that were removed with emery, and the "shiny" bits got a final run past the buffing wheel.

Then everything jumped back together again in slow motion - and after a solid hour of careful re-assembly, I ended up with an engine. The photos are not that great, as I don't have a nice setup with adequate lighting :-[






























Does it run ?.... You Betcha ;D ;D

I didn't mess around too much with setting the timing. Before fitting the steam chest cover, I set the valve to slightly favour the bottom part of the cylinder as the connecting rod assembly isn't very well balanced, so a bit more power on the up-stroke and gravity helps a bit with the down-stroke. The slip-eccentric was just set to have the grub screw in line with the "pointy" bit of the crank. The engine runs slightly better in one direction than the other, so the eccentric still needs a bit of adjustment.
During assembly I tested each and every moving part for minimum friction. The packing nuts each had a bit of plumber's PTFE tape rolled up and coiled around the valve and piston rods with the nuts snugged down on that, and then loosened up slightly to get free movement.

OK, enough rambling; this video really is the engine's first run on air - without any fine tuning or running in. I'm a happy chappy ;D:
[ame]http://www.youtube.com/watch?v=b06vloxS7oQ[/ame]

This was a really fun build - if I re-read my starting post, things seemed to have mushroomed along the way, but maybe that's a good thing. Not only did I get to simple grips with the DRO, but I fairly successfully tested a couple of new-to-me techniques along the way and added a very handy bit of tooling to my steadily growing shop.

Many thanks to everyone who followed along and added voices of support, advice and inspiration :bow:

Kind regards, Arnold


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## Don1966 (Jun 24, 2012)

I just read your thread Arnold and you have made it into a fun built. I really enjoyed reading it and super job on the Elmer #32. That is one beautiful engine and a must on my list to do. Thanks for sharing. 
 Don


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## rhitee93 (Jun 24, 2012)

Congrats Arnold! It's got a great sound Thm:


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## ProdEng (Jun 25, 2012)

It's a nice looking engine with those links. Love an engine that runs on next to no pressure. Enjoyed following along and learned a heap, thanks for the trip.

Jan


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## steamer (Jun 25, 2012)

Oh that's a sweet one Arnold!
Nicely done!


 :bow:
Dave


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## Blogwitch (Jun 25, 2012)

Lovely build Arnold, just what we expect from you nowadays, like a swiss watch.

 th_wav th_wav th_wav th_wav


John


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## Ken I (Jun 25, 2012)

Really great build Arnold - enjoyed this thread from start to finish and as per usual picked up a few tips along the way.

Great looking & running engine.

Regards,
       Ken


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## SBWHART (Jun 25, 2012)

Great Job Arnold you got a real fine finish on it and it runs very well

Regards

Stew


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## vcutajar (Jun 25, 2012)

Thanks Arnold for the detailed build notes and great photos. A sweet runner.

Vince


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## arnoldb (Jun 25, 2012)

Many thanks Gents for your positive replies :bow:

Time to sort out my shop a bit to make space for the T+C grinder that will be arriving in the next couple of weeks, and thoroughly service all the machines. I haven't selected my next project yet, but I'm really feeling in the mood for a live steam project, so things might just go that way. And I have a favour to do for a friend as well 

Kind regards, Arnold


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## clivel (Jun 25, 2012)

Another excellent build Arnold.

And so many useful techniques to learn from 

Clive


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## Maryak (Jun 25, 2012)

clivel  said:
			
		

> Another excellent build Arnold.
> 
> And so many useful techniques to learn from
> 
> Clive



YES :bow: :bow: :bow:

Best Regards
Bob


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## arnoldb (Jun 26, 2012)

Clive & Bob - Thanks Gents :bow:

Kind regards, Arnold


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## RCGUY (Jun 28, 2012)

A great running engine with nice detail and beautiful finish. As a beginner in this hobby I appreciate your photo's and explanations, it has helped me a lot with my build.

Looking forward to your next build,
Ed


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## Brian Rupnow (Jun 28, 2012)

WELL DONE!!! I particularly like the Watts link type of centering device for the piston rod.---Brian


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## arnoldb (Jun 28, 2012)

Thank you Ed :bow: - I'm glad that you found my posts useful; that adds additional satisfaction to having a finished engine 

Brian, Thank you :bow:. I think when Elmer designed this engine, it was his intention to showcase the Watts straight-line motion linkages. And when the engine's running slowly its very satisfying to watch the movement in that area.

I've run the engine in for another about 20 minutes, and it runs easily on breath power now. Some technicians at one of my work sites walked by as I was showing photos of it to a colleague on my laptop today, and insisted that I bring it along for a show and tell, so tomorrow it's going to work.

Kind regards, Arnold


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## Brian Rupnow (Jun 28, 2012)

Arnold---As I'm sure you know, I've spent a goodly portion of my life building street rods as a hobby. There is something very compelling about following a street rod that has a Watts type linkage designed to hold the rear axle centered in the car. If the rear of the body is built so that this suspension component is visible when the car is being driven, it is fascinating to watch as the car drives over a bump in the road and the rise and fall of the rear axle sets all of the arms in motion.


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## danstir (Jun 29, 2012)

Very nice. Thanks for sharing your build and knowledge.


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## hopeless (Jun 29, 2012)

Nice work as always Arnold :bow:
Pete


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## Ogaryd (Jun 29, 2012)

Beautiful job Arnold,

I really enjoyed watching this build.

Show us some more.

                                                 Thanks Gary


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## bearcar1 (Jun 29, 2012)

A SPLENDID piece of work Arnold Thm:... So graceful. 'Watching' you work is very enjoyable, at least for me it is and I learn a few of your tricks along the way as well. What's next? More tooling? or another engine perhaps ???? Can't wait to see whatever it turns out to be .


BC1
Jim


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## arnoldb (Jun 29, 2012)

Brian, yes, I've been drooling a bit over your yellow 'rod :bow: - I love 'rods and would love to own one. A two-tone '37 Chevy in dark blue and silver would do me just fine; this one would be a good starting point for me, but with different rims and the silver added... 
I didn't know some of the 'rods used used Watts linkages for the suspension though; something I need to investigate!

Danstir & Pete, thanks very much :bow:

Thanks Gary :bow: "Show us some more." You Bet! - I'm not about to stop having fun, and sharing a build brings a satisfaction of it's own; besides, no one seems to complain about a build log getting shown ;D

Jim, thank you :bow:. I don't know about "graceful" though... You obviously have never seen me trying to dance :big:.
"What's next?" - A thorough service of all the machines, and tidy up AMESS with some slight re-arrangements and additional lighting. I wish I had Pete as a neighbour, so I could get him to build me some cabinets as well; I need storage space... Some tooling coming up as well; not for myself though. A handful of Myford change wheels and a calibrated Myford leadscrew handle for a friend. Our currency is rock bottom against international ones at the moment, so it's actually worthwhile making these rather than buying them, and anyway, I'm in the mood for a bit of gear-cutting. I might have to make up a slotting attachment to broach the keyways in the gear hubs though... So, LOTS to do, and I haven't even picked my next engine yet.

Kind regards, Arnold

Edited to fix the link to the Chevy - Thanks Don!


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## SBWHART (Jul 2, 2012)

Hi Arnold

Bin away on holiday in you're neck of the woods Tanzania, great holiday, so a little late to congratualte you on another great build

Stew


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## arnoldb (Jul 2, 2012)

Thanks Stew :bow:

So, how was Tanzania; I'd forgotten you mentioned you were going there on holiday 

Kind regards, Arnold


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