# Flapping around... Elmer's Kimble



## arnoldb (Dec 11, 2011)

Elmer's Kimble engine has been on my to-do list for quite a while, and have literally been nagging at me to be built.

I can't seem to find any other build logs on it, and have only found one short Youtube video of one, so this is a bit of a journey into the unknown. The engine seems relatively straight-forward to build, but thinking through the processes, there are a couple of potential gotcha's - most notably that everything thing must be kept very square to prevent binding.

I have found one measurement wrong on the plans so far as well. The sizes for the mortise and tenon joint on the vane shaft does not match... A 1/4" tenon will not go into a 3/16" mortise, so those sizes I'll adjust as needed.

As usual, I'll be using whatever material I have on hand during the build - and will deviate a little from the plans in areas where dimensions does not matter.

I started on the sub-base and base today. The plans call for a 1/8" sub-base and 1/2" base, so I settled for two bits of 10mm hot rolled steel bar :big: :





The thicknesses are not important - as long as they are thick enough together to accommodate the flywheel swing.

Both bits were sawed and then milled to size, and the flat faces roughly fly-cut to get rid of all the mill scale:





A bit of lay-out on the base:





Then I clamped it to the sub-base and started drilling 3mm clearance holes for all the mounting bolts:





I wasn't feeling in the mood to mill out the entire flywheel cut-out, so I chain-drilled the end, pushed some pins through the holes to keep things matched up and then used the band saw to cut down the sides leaving about 0.5mm of metal to remove with the mill:




I just kept a careful eye on the cut to make sure it didn't stray too far. Because of the angle of the saw head, I had to stop early, and finish off the last short sections of the cuts with the saw in vertical mode.

Now, who says a shifting spanner has no place in the shop ;D - I used a small one to break out the unwanted sections from the cuts:





The cut-outs were cleaned up with a 4mm end mill; I just milled to split the mark-out line on the base:




My 4mm end mills are too short to do both the base and sub-base at the same time, so I used pins to align the base with the sub-base again and used a sharp scribe to mark the sub-base off the milled-out section from the base. Then I just milled the sub-base to those lines as well.

Stopped here for today:





Regards, Arnold


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## smfr (Dec 11, 2011)

Pulling up a chair. Looks good so far!


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## Foozer (Dec 11, 2011)

Got my chair and BBQ chips all ready

Robert


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## bearcar1 (Dec 11, 2011)

This is going to be another good one ...... I can just tell. 8)

BC1
Jim


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## lazylathe (Dec 11, 2011)

No rest for the wicked!!!! ;D

You never cease to amaze me Arnold!!!!

Watching with interest again!!!

By the way it was -8 when i woke up this morning!
The dogs water bowl outside looked like an ice rink for all the varmin to use!!!!!
The dogs also kind of gave me the old hairy eyeball when they went for a drink!!! :big:

Andrew


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## Ken I (Dec 12, 2011)

Just signing in to take the ride.

Ken


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## danstir (Dec 12, 2011)

Enjoying the build, keep it coming.


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## arnoldb (Dec 13, 2011)

Thanks Gents  - this one might be a bit slow though, as 'tis the time of the year where a lot of merriment will happen!

 :big: Andrew, the swarf magnets will do that if the water's frozen! It's getting up to a nice and balmy 32-35C here during the day now, but the nights are still surprisingly cool; this morning it was just 17C when I drove to work... I like that; nice & cool in the night, and a liveable temperature in the day. Once it hits 37C I stay out of the shop though :big:

I stole a couple of hours in the shop after work today, and started on the bearing columns. The plans call for 1/4" thick columns, and while I have some 6mm aluminium plate, I decided to rather make them from steel as well. The base will be painted, and keeping the material the same will save some headache when it comes to that. The columns need to be fairly close in thickness, as they will have the flywheel between them, and cranks and linkages on the outsides. I used some more of that 10mm hot-rolled bar:





The edges were milled square and to size, one face fly-cut to get rid of the mill scale, flipped in the vise, and then I hogged down the thickness to 6.4mm with a 16mm end mill:





A 0.05mm fly-cut, and the ugly hog-marks were gone and the bit of plate at 6.35mm ;D:





Split the bit of plate down the middle on the band saw:




And then milled the sawn edges down to size.

One block was laid out and the two were then carefully clamped together - ensuring all edges matched up - and the lot clamped in the mill vise and drilled 8mm:




The main axle will be 6mm, but as it will be steel and the bearing blocks are steel as well, I decided that I'll add pressed-in phosphor bronze bushes.

The last step for today was drilling the columns 2.5mm to tap M3 later for the mounting screws:





Regards, Arnold


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## bearcar1 (Dec 13, 2011)

"........ a lot of merriment....."   is that anything like drunk and disorderly? :big:

It's always such joy to see you hard at work Arnold....


Cheers!

BC1
Jim


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## arnoldb (Dec 18, 2011)

Thanks Jim :big: - not too much drunk and disorderly; 2 weekends ago the bloke in the photo below got what was coming to him - that WAS a bit drunk and disorderly; you should have seen what my house looked afterwards :big: - but it still looked better than what HE did  Yesterday I spent making sure he was looked after & properly attired, and then did some work behind the scenes to make sure the wedding march was started at the right time & that things would go right at the reception hall afterwards...:




The rest of the days just stop at tipsy & merry with a couple of drinks nearly every day with suppliers & business partners ;D. Us lot generally behave ourselves over Christmas, but New Year's might be a different story again :big:.
I think I'm a sucker for doing things the hard way... - You know, work hard and play hard!

Managed a couple of hours in the shop today 

I used the mill vise stop as a kind of parallel to get a good angle on the bearing blocks (the bottom corners of the blocks actually rests on top of the vise stop bar), milled off the angle, flipped the blocks over & repeated:





Then milled the tops close to round:





A quick bit of file-work smoothed off the milled facets:





Tapped the bases M3 for the mounting holes:





Turned up a couple of press-fit phosphor bronze bushes:





Then started on the flywheel. I had a ring of phosphor bronze left over from the Coomber engine, so used that for the flywheel rim. One side and the rim was already true, so I just used two 8mm toolbits to offset the rim to allow me to turn it down to thickness - of course, removing the toolbits before starting up the lathe!:





After a bit of turning and boring, I had the flywheel rim:





Then I turned a bit of 70mm diameter aluminium down for a light press fit for the rim (0.02mm over size)- I had to wait a bit for it to cool down before the final finish pass, as I didn't want it to shrink down too much after machining:





I just left the rim outside in the sun for a couple of minutes; it was a searing 38C here today and the sun was beating down mercilessly, so that heated the rim quite enough to allow me to lightly, but quickly tap it into place on the aluminium, and once it cooled it is staying very much put. A careful clean-up on the rim and a face-off and I left things like that to go inside for a bit of time with the air conditioner. :





I did snap a photo of the base with the bearing blocks mounted; at least that's starting to come together now:




The parts just need a final clean-up to remove the last tool marks and a ding on the sub-base that I haven't noticed before, then some paint.

Regards, Arnold


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## nsfr1206 (Dec 19, 2011)

Looking good!


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## arnoldb (Dec 20, 2011)

Thanks David 

Had a bit more shop time after work today 

The flywheel-in-making was still sitting on the lathe as I left it Sunday, so I drilled and reamed it for the axle, trepanned the face to thin the web and then flipped the whole lot around in the chuck, using bits of cardboard to prevent damage to the finished rim:





Then I faced off the excess aluminium, and trepanned this side as well:





Next up will be a bit of work on the rotary table, but I have to calculate a couple of angles and offsets first...

Regards, Arnold


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## ShedBoy (Dec 20, 2011)

Shaping up to be a nice looking flywheel Arnold.

Brock


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## arnoldb (Dec 24, 2011)

Thanks Brock  I hope today's update doesn't disappoint!

After a merry week, it was nice to get to the shop today.

I first did a C-o-C, then decided on an end mill size and then added a's, b's, thetas and so on, then used sines, cosines and other stuff to make some calculations:




 : Yes, yes, I know... Boring math stuff; I'm a sucker for punishment ;D - but then again, it's really not that hard to do, and very useful 8)

On to machining then. I screwed the chuck to the rotary table and centered it on the mill with a 6mm bar chucked up - close enough for flywheel webs:




The X and Y hand wheels were zeroed here, and I just kept notes on the "boring maths page" (BMP from now on!) to remember which way I was cranking to compensate for backlash.

Then I drilled a bunch of 3.5mm holes according to the BMP:




I want to finish off the webs with a 4m end mill, so I used the 3.5mm drill as it leaves a bit of lee-way for error, and can just be drilled without using a center drill (or even better a spotting drill) for each location. If the 3.5mm drill wanders a tiny bit, that's OK.

Next I marked out the sections that must be milled out - just to help prevent a brain-fart later:





And a-milling-we-went. First the insides radial edges closest to the hub, with Y offset for the radius and feeding the rotary table between angles - taking the readings off the BMP; 1mm deep Z for each pass requiring 4 passes per slot; no use to hog things out, as that could just end in heartache or lots of "bad" words from a variety of different languages - or both:





The outside radial edges followed using the same method:





Up to now, everything was done from the mill table's X zero point with only Y feeds for offsets. For the next step, I once again referred to the BMP, offset the mill table in X and Y accordingly, dialed in the needed angle on the rotary table, and started on the straight sections of the webs - with feed on Y only:





More reference to the BMP, other offsets on the mill table, and the last cuts were done:





One side of the flywheel rim was still sharp from previous machining, so I mounted a bit of 6mm silver steel in the collet chuck on the lathe, pushed a bit of cardboard over it to protect and drive the flywheel hub, and then used a cone center with another bit of cardboard on the revolving tailstock center to mount the flywheel:





A quick lick with a file cleared off the burr on the rim, and then I just did some light file-work to get rid of burrs on the flywheel web. A final rub with some emery paper rolled into a cylinder removed some more toolmarks, and I ended up with this:




An OK-sort-of-looking flywheel. I wanted lightly tapered spokes, but not too lightly tapered either. Unfortunately, this is toward the "too lightly" side, so a lesson I can take forward. 4 degrees taper is too little on relatively short spokes like these :-[. I'm not about to use some form of put-on-tool to correct this; in fact the only put-on-tool I have that is suitable for this application is called "re-make" :. 

The BMP did get some additional scribblings on it through the process... Yes, I KNOW... It's still a "Boring Maths Page", but it did help :big::



In fact, if I had to be more mathematically precise, there would have been a lot more calculations involved - but this was good enough for the job on hand.

The flywheel does fit on the base though, and looks OK. I was thinking about painting the webs, but I have a hunch that will not be done; I'll decide about that once the base is painted:





Merry Christmas Everyone!

Kind regards, Arnold


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## Blogwitch (Dec 24, 2011)

And a very nice Christmas present you have made for yourself there Arnold.

Very nicely done. th_wav

But don't let Marv catch you doing it without his little flywheel program, that does all the working out for you, a real pleasure to use.


Best wishes for Christmas.


John


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## mklotz (Dec 24, 2011)

Too late, Bogs, I already caught him. 

"Boring maths" indeed!


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## Foozer (Dec 24, 2011)

Spiffy looking indeed. Tis hard to judge how much taper is 'nuff. Is detectable tho, more might border on obscene. 

Robert


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## arnoldb (Dec 25, 2011)

Thank you John  Marv already caught me *club* - but I'll add in my defense that I Did try Marv's program. Unfortunately it works for only one hole around the hub for each spoke, which would not have worked in this instance. I could have run the program a second time to calculate the dual-holes around the hub though. That would still have left me to calculate the angle for machining the spoke sides manually...

Thanks Marv; i consider myself properly chastised . I guess it's time I climbed into some programming for a change - as you know there's a bit more math than I showed, and I don't think that will be boring ;D

Thanks Robert  I guess I'll have to test with future flywheels... This one has short spokes, but the large hub is needed for the way the eccentric is to be mounted.

Well, zero shop time today - I lazed about and stuffed my pie-hole all day ;D

Kind regards, Arnold


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## mklotz (Dec 25, 2011)

Yes, it's my turn to be chastised. After I looked again I realized that you didn't have a single hole at the base of the cutout "triangle" and my program wouldn't have worked for what you were doing.

Hmm, I wonder if I should write a program for that case? It's a very specialized case and there wouldn't be much call for the program. I'll think on it.


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## arnoldb (Dec 25, 2011)

Marv, no need to feel chastised . Like you said, I don't know if you should spend time on doing a program for this scenario. Your current flywheel program is just fine, and I haven't seen many (if any) flywheels with a similar layout to this one. Elmer's plans does give dimensions for the flywheel for the Kimble, so anybody wanting to build it has that to go on; I'm just bumbling along doing things my own way in areas where deviation from the plans does not matter.

On the other hand, if you do write it, it might get used - people are always on the look-out for different flywheel designs, and this does provide an option. I haven't looked at the source for "FLYWHEEL" yet, but it might be fairly easy to adapt the existing code; the inner holes' position and arc calculation would be pretty much the same as that for the outer holes. The calculation for getting the angle for machining away the sides would be pretty much the same too - unless I'm overlooking something blindingly obvious - which happens often!

Kind regards, Arnold


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## arnoldb (Dec 26, 2011)

Today's little bit...

From this point on, I'll work a bit slower, as this is the start to the more difficult parts of the build.

First, the engine block. It must be 3/8" (9.53mm) thick. I have some 10mm thick aluminium I could have used, but that bit is from extruded bar and very gummy to machine and tap, so I rather dug a bit of harder 12mm aluminium out of the stock bin:






That was then milled square and to size on all edges. As I felt in the mood for some lathe work, I set it up in the 4-jaw on the lathe - just centered by eye and using a bearing shell as a parallel to the chuck body. Some strips of aluminium drinks can were used to prevent chuck marks, and I used wire to bind down the parallel so that it wouldn't rattle around and damage the chuck face if it did happen to come loose:





Faced one side smooth, flipped the block around in the chuck, and faced the other side down to thickness:




There's a slightly rough bit close to the center, but it does not matter, as that's in an area that will be machined away later.
The block needs to be very parallel, and a check with a micrometer gave me less than 0.005mm (that's 2/10ths of a thou) difference measured in a couple of different locations. My old girl (ML7) may be 40 years old, but she can still do it ;D

Some quick marking out for bits that needed to be milled away and the double marking across is 1mm thick where it must be cut with a slitting saw later:





Cut-outs milled away; just hogged it down close to size with the 16mm end mill and then a light final pass either side to clean it up:





I bought a 5mm edge finder quite a while ago, but it was a bit rough and sticky and didn't work well. Last week one evening I gave it a thorough wash-out with methylated spirits to get rid of the sticky oil that was used on it, mixed some Brasso with thin oil and lubricated the running face with that concoction and gave it a bit of a run, before once again washing it out thoroughly and just giving it some light machine oil. Used it today for the first time, and it works beautifully ;D :




At 800RPM it wiggles around a bit, then smooths out, and then suddenly kicks out positively. On the mill dials this was exactly on the same reading each time; I'll test it's accuracy more thoroughly at another time.

I used the vise stop and the mill's dials to coordinate drill the mounting holes 1.6mm to tap M2 later:





Then I slit the top section off:





As I didn't change the vise stop or dial zero-rings when slitting, I just used the same settings and readings to drill 2mm clearance holes through the top:





Next I tapped the holes in the bottom section. I don't have long enough 2mm screws, so out with some bits of threaded rod:





More marking out. The engine block layout on the plan is quite busy, and it's easy to get some measurements wrong. In addition, the tangent sections are a bit difficult to lay out, as Elmer didn't give easy measurements to get to them. As you can probably see, I ended up with a bit of a discrepancy in the thickness of the tangent sections - a combination of trying to manipulate the protractor and forgetting to compensate for the scribe tip's thickness:




Fortunately, the error is not a biggie; I stopped quite a while ago scribing deep lines on the work, as that's too difficult to get rid of later. Both the scribe and the height gauge tips need a bit of sharpening as well; that's why the lines appear so thick. I'll be using the vise stop to mirror the work as I go, so I only need good layout on one side anyway.

I then started drilling the 1.6mm holes for mounting the "cylinder" covers; these needs to be tapped M2 later. Simple process to get the mirroring; locate a hole on the marked-out side and drill, then flip the workpiece end-over end and drill the mirrored hole on the unmarked side. Here it is ready to be flipped to drill the last hole:





After drilling that last hole I stopped for the day. I'm torn between making both the covers from some 2mm brass plate I have, or making the one cover from perspex so that the vane can be seen in operation. The only suitable perspex I have is 3mm thick, and I'll have to check whether this will fit. In addition, the vane shaft uses the holes in the covers as part of its bearing, so if I make a perspex one, I'll have to think up a way to insert a bush in it, and that's not so easy, as the inside part must be very flat as it is part of the sealing surface...

Time to think a bit...

Regards, Arnold


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## arnoldb (Jan 7, 2012)

Wow - what a hot start to the New Year; it's been consistently in the 38C plus range here for the last 2 weeks, so I didn't even bother to venture into the shop and rather spent some quality time indoors upgrading my computer and a lot of software on it. This morning I grabbed an hour shop before the heat got to me again.

I started drilling the port holes in the engine top:





Half-way through the first hole, the mill started making a funny noise; a quick check and the draw-bar had started unscrewing:




I don't know if the heat could have had an effect on it; I don't over-tighten the draw-bar and it could be possible that the heat allowed it to stretch just enough to come loose... That's something I'll have to remember to be on the lookout for.

All set up to cross-drill the long port holes. I used a small square as both a parallel and a way to keep the block square vertically. The wire is to feel when the hole breaks through into the other passages:





As I was peck-drilling these deep 1.6mm holes without any lubrication, so I kept a careful look-out for the drill tip clogging up like this:




Whenever that happened, I stopped the machine and cleaned the tip thoroughly. If one don't, that's a sure-fire way to break off a drill in a deep hole.

At that point, the shop got too hot again, and I moved inside. Out of pure idleness I made a short video on using the wiggle-wire:
[ame]http://www.youtube.com/watch?v=D_XQvD-rRts[/ame]

At least this afternoon some cloud cover came in, and there's the rumble of thunder in the distance. A good rainstorm would help to break the heat spell, so hopefully it might be cooler tomorrow so I can actually get something done.

Kind regards, Arnold


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## Ken I (Jan 7, 2012)

Its hot here in Cape Town as well (33°C) so work in the shop has been unpleasnat - like you I just finished drilling some deep holes - a little nerve wracking.
Your edge finder looks just like mine - I gave it a clean and lube once and it lost its repeatability - cleaned it all out and it was fine - ungrateful edge finder.

Ken


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## arnoldb (Jan 14, 2012)

Ken, I was once in Cape Town when it went up to 35... Camping in a caravan... High temperatures in CT is really unpleasant :wall:
 :big: I'll have to keep an eye on this edge finder then; if it get ungrateful, I'll just clean out the oil.

 ;D It's been cooler here the last couple of days, and after a run-around to shops this morning I got some more done on the Kimble, though I fluttered around all over the show. Must be residual heat-stroke or something...

Instead of checking exactly where I ended off last week, I jumped in with a bit of perspex hacked off a salvaged old line-printer "window":





The perspex is 4mm thick, but that's not a problem as the one side of the engine where I want to put the clear engine cover can accommodate it. I'd decided to make an insert from 2mm thick brass plate to act as the bearing.

To protect the perspex, I just coated it with masking tape, leaving the section that I wanted to mill out for the insert open:





The mill was still set up to drill holes all over the engine's top, and fortunately I thought to check if I'd finished all the holes in the top last Saturday. Good thing I checked; I'd forgotten to drill the exhaust ports; in fact, I'd never even laid them out on the top. So that was done first. Then I had to drill the holes. There was no way to get in close enough to spot drill first, so I just had to take the plunge and drill with the 1.6mm drill and hope it wouldn't wander:




As I couldn't drill straight through for both ports in one go, I had to flip the workpiece and drill from the other side as well. I don't know if I was purely lucky, or if I'd spent enough time to set up accurately, but both holes intersected perfectly. Looking through it, it's impossible to see that it was drilled as two separate holes.

With all the holes ( :) in the top completed, I started on the brass insert for the perspex cover, purely because I'm lazy and it's easier to make it first and then mill away the perspex cover and use the insert to check the fit. Holding smallish bits of plate is always a bit of a problem, so I opted for the tooling plate to hold it down to mill to width:





The perspex cover followed to cut out the insert space:





While I was set up on the tooling plate, I also looked for a nice piece of flat 2mm brass plate for the other side-cover, and squared up two sides of that as well:





I nearly started tapping all the 2mm side-cover mounting holes on the block and top, but then remembered that it would be easier to spot all the holes in the side covers using the block and top. Then I saw some more holes I'd forgotten in the top; the 1.6mm mounting holes : - So I drilled those first:




Three down & one to go; just a flip away...

And done:





Cleaned the burrs off all the holes, and then glued the insert to the perspex plate. I wanted to use epoxy glue, but when I found the tubes, all the hardener had leaked out, so I used superglue. I hope it bonds with perspex. Stopped for the day with this bunch 'o bits; not much to show for quite a bit of work ::





Regards, Arnold


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## arnoldb (Jan 15, 2012)

This afternoon I clamped the covers and block together. The perspex cover is sandwiched between the brass cover and the block, and the masking tape on it helps a lot to keep things from moving:





Off to the drill press to drill the 1.6mm holes. With a small drill like this, I'm comfortable, yet very careful, to keep the workpiece firmly pressed down on top of the vise jaws with my left hand and operate the quill with my right. Because of the different layers in the sandwich, I peck-drilled the holes to keep swarf in them to the minimum while drilling:





When needing to move the clamp to a different position without letting things come apart, I just clamp the lot in a spot where the old and new clamp position wouldn't interfere. Sometimes I do that with another toolmaker's clamp or in this case I used my small milling vise:




Here I wanted to flip the clamp from the left to the right to be able to drill the holes on the side where the clamp was before changing.

Next off to the mill to get rid of excess stock on the covers:









Silly me... I'd put the studs and nuts on the top on the wrong side. That made milling excess stock off the top more difficult, as I'd originally planned to just remove the nut and stud on the alternative top parts to finish to size. The nut was too big to rotate, so I had to go around its back:





Next I turned up 1.6mm pins from some 4.3mm aluminium rod I have. The toolbit is set up to leave a very slight taper on the aluminium, and the entire thickness is turned down in one go. I used the small ER11 collet chuck, as it has a 4.5mm collet that can easily clamp down to 4.3mm - thus saving strain on my 5mm ER 25 collet:





The four completed pins/plugs. As you can probably see, I just used a side-cutter to clip them off at just over the approximate length needed. The two longer pins are to plug the holes right at the top of the engine top; they need to be long enough that their inside ends will be machined flush with the valve bore later on:





Here I installed one of the side plugs - a tiny dab of loctite on it, and hammer it into the hole with a small ball-peen hammer. I knocked it good and flat, so that the plug will properly fill the hole, and once the excess is filed off, the plug will be completely invisible:





The two top pins knocked in and then filed flush; as you can see, they "disappear":





Same with the pin on the side; just lightly cleaned up here:




There are still tool marks on the sides of the block; these will be removed later in the build.

At this point I called it a day, as a big thunderstorm with high winds broke. I'd left a lot of doors and windows open in the house, so I had to go and attend to a bit of mop-duty ;D: 





Regards, Arnold


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## arnoldb (Jan 21, 2012)

A bit of a boring update today...

The cover plates were still sticking together after last weekend's work - this was a result of using some old gummy masking tape to protect the perspex cover, so I lightly clamped them together just to make sure they didn't come apart, then opened the holes to 2mm for clearance for M2 screws, and then countersunk all the holes - easy to do by getting one hole to the correct depth and setting the drill press depth stop:




I had a bit of chatter in the holes; after a careful check,I found that these holes are actually a bit small for the countersink I have and it can barely open them up, so I'll have to buy a smaller countersink at some point.

Next up, tapping the M2 holes in the engine block. My M2 taps are too short to tap the holes right through, so I had to tap the holes from both sides. I used my tapping guide to limit the depth to tap too to half of the engine block depth (Apologies for the out-of-focus photo):





Then I set about tapping all the holes. For aluminium I use methylated spirits (rubbing alcohol) as tapping fluid, so I poured some into a spray-can top to make life easier. The meths easily washes off any chips stuck to the tap, so it's easy; tap the hole; swash the tap in the meths and it gets both cleaned off and "lubricated" for the next hole:




The dark bits in the meths are chips that were washed from the tap.

Next a quick check, and as I thought, the shortest M2 screws I have are too long for the thin cover:




They are OK for the perspex cover though.

I've had to shorten M2 screws in the past, and it's a bit of a pain in the rear :. Usually it was just one or two screws at a time so I'd fiddle along, but I was in no mood to fiddle ten of them... So I diverted and built a little tool.
I just chucked up some 8mm hex brass, drilled it 5mm diameter (for M6 threading) 15mm deep, and followed the 5mm drill with a 2mm one another 4mm deeper. Then I tapped it M6, and parted the piece off 17mm long. On to the mill, and with a 2mm slot mill, I milled a slot to the center of the 2mm hole, and a perpendicular slot wide enough to allow a 2mm screw's head to pass through far enough from the end to leave the cone section left by the 5mm drill intact. 





To my horror I discovered I'm out of 6mm silver steel to make the rest of the tool , so I used a cap screw with the head sawn off and the end section of the thread relieved to clear the last bits of thread in the brass bit:





I wouldn't recommend using the above tool under power on the lathe, as the screw will easily deflect into the slot while machining. I just used it chucked up in the lathe (with motor off) to saw off the excess length of the screws with a junior hacksaw with a fine blade:





It is convenient to have the tool in the lathe, as it's easy to clean up the cut face with a small file, and also file a slight taper around the cut face by rotating the chuck by hand. These screws are stainless steel, and just outside the size for my favourite electronics cutter, if they were within it's size I would just have clipped off the ends with it and cleaned off with the file.
Ideally, I should have "relieved" the seat for the screw in the brass bit to 90 degrees rather than using the 118 degree cone left by the drill bit - but that would have meant making up a d-bit reamer and I wasn't in the mood for faffing around with that today. 

The little tool works quite well. Slip a screw in, tighten up the brass section on the arbor, saw off the little screw, file the nose flat to remove the burr from sawing, file a slight taper around the end of the treads then loosen the brass nut with a hand under it to catch the screw as it falls out... It took me less than a minute per screw to get this lot shortened:





All the little screws in place - I need to make all the countersink holes about 0.1mm deeper though ::





And the perspex cover screwed on:




To compensate for the thickness of the masking tape that was on there, I countersunk the holes slightly deeper. Unfortunately, I over-compensated : - these are slightly too deep.

Hopefully, I'll have more interesting progress to report tomorrow.

Regards, Arnold


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## bearcar1 (Jan 21, 2012)

Looking good as always Arnold Thm: You have provided me with something new to try next time I am tapping Ali, rubbing alcohol. (who knew) I've used WD-40 in the past but will definitely have a go using your spirit of choice. You have the hot temps to deal with while I just came in from ridding ours and the neighbors drive way of the 5-6" of snow that dumped itself on us yesterday and last night. Have I ever mentioned how much I hate shoveling snow? %&^$%# the stuff anyway.

seasons greetings .... bah humbug ;D

cheers

BC1
Jim


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## arnoldb (Jan 22, 2012)

Thanks Jim 
 :big: The alcohol's not my spirit of choice, but it works on the ali. I wouldn't waste my spirit of choice on tapping - after all, it has to be imported from Scotland at great expense. Fortunately it arrives without bagpipe music, haggis and snow 

We had a beautiful day here in Windhoek today; cool with light rain. Great for shop time... Unfortunately, my tummy decided it wasn't taking any part in a great day, so it was a bah-humbug for me too :

Kind regards, Arnold


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## Blogwitch (Jan 22, 2012)

Arnold,

Your little device that you made for shortening your screws is in fact called a LANTERN CHUCK.

If you have more than a dozen screws to shorten or modify, it pays you to make one as you did. But you made the mistake of cutting away the side so that you could put the screw in. Normally, you just have a hole in the end and the screw is fed in from underneath the hole.

I'm sure that if you put a search in and look for images, you would get a few pictures of what I am on about.

Looking good.


John


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## arnoldb (Jan 23, 2012)

Thanks John  - I knew I'd seen something similar somewhere, but could not remember it's name or precise design. Now I won't forget; the next one I make will be a proper lantern chuck, as it's obvious that one can be used under power.

Kind regards, Arnold


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## arnoldb (Jan 28, 2012)

Finally, a bit more done. I'm taking things a bit slow on the engine block, as I don't want to make a mistake.

Last weekend I ended off with the countersink screws on the brass cover side still sticking out a bit. For some of the machining operations to follow, I needed them flush - or just a tiny bit below the surface, but I also didn't want them countersunk too deep, as I think that looks plain ugly.

So after a careful measurement, I determined that they are sticking out just about the thickness of a business card. So I used the plate just lying on top of the drill press vise jaws to set the drill press depth stop with the countersink bit engaged in one of the holes, then shoved a business card below the plate and touched up each hole:





Screwed up, all the screws are far enough below the surface; I could even rub the block over some emery to clean up the face a bit:




It would look even better if all the screws were "timed" so that their slots lie the same way... That's a project for one day when I try and do an "advanced" build :big:

On to one of the most important holes for the project; the main pivot hole. This has to be very square to the engine body, otherwise the engine will be near-certain to bind as the vane will twist around in the block... When I built my tooling plate, I marked it so that it go back in the mill vise in the same orientation that I faced its top, So I used that - did a quick check with a DTI to make sure that it was still level and square, and clamped the engine block to it, leaving it over-hanging just enough to clear a 6mm reamer passing through:





Then I drilled the hole through with a 3mm drill. This was followed by a 5mm end mill. The reason for the end mill is that it will true up the hole in case the 3mm drill had wandered a bit. This was then followed by a 5.9mm drill; my theory being that it would follow the hole left by the 5mm end mill and not wander off course. Finally I ran the 6mm reamer through the hole to get it to size and smooth:





Next the perspex cover was removed, and I set up the piece in the mill vise so that I could drill and ream for the rotary valve. It was left raised enough out of the vise so that the cover plate could be removed without disturbing the set-up - then I drilled 2.9mm and reamed 3mm through the lot for the valve shaft:





The cover was removed, and I drilled the 3mm hole out to 9.8mm:





Next it was reamed to 10mm. The plans call for a 3/8" hole for the valve, and I could have done that by boring the hole, but I had a careful look at the valve plans, and its easy to adapt it to 10mm:




The plans call for the "plugs" in the holes that were inserted from the top of the head to go in deep enough into the valve hole to be machined flush when reaming/boring the valve hole...  ;D I must have done something right, as they did "disappear". 

I left off there for today. Another important bit of machining is next, and I'd like to do that in one full shop session.
Back of block:





Front:





Overall progress... I never coated the base with some oil, and it picked up a bit of surface rust from the damp weather we've been having. Fortunately, nothing major, as it still needs some surface finishing and paint:





Regards, Arnold


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## Ken I (Jan 28, 2012)

Damp weather ? - it thought it only rained steam in your neck of the woods.

Ken


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## Foozer (Jan 28, 2012)

Very nice so far, countersinking can be fun. gizmo to get em nuts on 

http://www.panamericantool.com/countersinks/micro-stop-countersinks-cage-needle-bearing.html

I'm gonna gain 20# with the chips and Twinkies watching this build 

Robert


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## bearcar1 (Jan 28, 2012)

What terrific therapy it is to watch as you work Arnold. (cheaper than a trip to the dentist as well ;D) It's going to turn out to be another fine piece of art, I just know it. Thm:

BC1
Jim


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## arnoldb (Jan 29, 2012)

:big:, Ken, that's the problem... It doesn't make puddles and run off; it just permeates the air and hangs around rusting things... 

Thanks Robert  - I like those doo-dads you linked to, but at that price, I might just make my own at some point! Hmm... Chips & Twinkies... Is the weather still keeping you from your shop; I thought you had a rotating cylinder engine going stickpoke ;D

 :big: Thanks Jim. Don't mention that Den... word; I'm not scared of many things in life, but of them Most Definitely :

 ;D Today was one of those golden days in the shop that makes me love model engineering so much. Just the right amounts of challenges, head-scratching, problem solving, lots of chips, and that whole kaboodle coming together in a nice end result. Not really much to show as the end result, but the journey was the fun part.

For the next step in the machining process, I needed a sacrificial plate. A bit of flat wood would have done as well, but I wanted slightly more accuracy than the wood would have given. A while ago, the storage term for a whole lot of these ran out at work:




Anybody remember those? As I'm responsible for IT Security at work, I signed them off for responsible destruction - told the bosses what would happen to them, and brought them home. Taken apart, it's easy to snip the tape into thousands of pieces, and I get nice bits of tempered aluminium plate and a lot of precision pins out of them to use in projects. Bosses are happy, and so am I.

I was spoilt for choice on how to do the next part... Work on the lathe face plate, or boring head on the mill... As there was quite a bit of milling to come, I decided on the face plate, as it's fun to change between machines for different jobs.
With a suitable bit of plate sawn from the old tape, I started setting up things on the face plate. I find it easier to start setup on a table, and then mount the face plate to the lathe later:





For the next step, the lot had to be mounted on the lathe, with the workpiece centered on the reamed hole. Normally that would be done by sticking a pin in the hole and using a dial indicator or DTI to clock it up, but I know a pin chucked up in my lathe's tailstock is spot-on, so thats the method I used. Face plate mounted on the lathe and the pin in the chuck:




Not a bad job of eyeballing on the table before-hand ;D

With the workpiece loosened slightly, it was easy to lightly tap it into position to fit the pin:





Then I added one more clamp - just to be safe, and to allow me to remove either of the side clamps so that I could get at the screws holding the engine body to the top:





 : I'd forgotten to lay out the cut dimension for the top... Not so easy with a hole where the center should be either... The small lathe is not mounted properly yet, but this is a very light job, so I fired it up and faced and lightly center drilled a bit of 6mm rod:





That was then sawn off and inserted in the hole in the block:





Next, I set my compass to 31.75mm. Well, the photo shows that it was slightly less than that, but the camera's macro mode is much better than my eyeballs. The reason the reading on the rule is 41.75mm is that the other end of the compass is sitting in the 10mm groove of the rule:





Target cut-line scribed:





Then I added some counterweights to the face plate; No fancy math was used; just the fact that I have a fairly good feeling for how heavy the bunch of clamps and retaining nuts are - the gears were selected to approximate that. And a final check from the top as to whether there would be any clearance issues:





And a view from the side - with the cutting bit set as deep as it would go:





Then I started putting some cuts on... The cutting bit was honed super-sharp, but on the second cut I heard the dreaded sound... A high-pitched squeal each time the cutter cut... Chatter... Stopped, and yes there it was (you can click on the image for a larger picture):




The finish in this cut must be smooth as silk; there would be no easy way to lap it accurately once done... So I tried a stiffer toolbit; same thing - slightly finer chatter, but still there.
As the chatter was very fine, it would not take much to damp; I tried pressing on the back of the toolbit during the cut with a toothbrush handle, and the chatter went away ;D:





After the final cut with the toothbrush in position (once again, clickable for a larger photo):



 ;D That's the finish I was after ;D

Some more lay-out followed:





Then a quick bit of hogging in the mill:





I just used some threaded rod screwed into the mounting holes to set the piece to mill out the angled sections:





A little while later:





Then with both covers mounted on, a bit more lay-out:





More milling - a bit more careful this time so as not to break out chunks of the perspex - and lots of brass, aluminium and perspex chips all over the show:















Finally I ended up with this:




I left the outer edges of the block slightly thicker than the plans show - they are purely cosmetic, and the extra thickness is to help prevent the perspex from cracking.

Overall progress:





 ;D Looks more like it. There's still some work left on the block - a hole to drill and tap in the top for air supply, and a bit of clearance milling on the bottom for the vane - then a final flat-lap and cosmetic work, but the hardest part is over.

Regards, Arnold


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## Foozer (Jan 29, 2012)

arnoldb  said:
			
		

> Thanks Robert  - I like those doo-dads you linked to, but at that price, I might just make my own at some point! Hmm... Chips & Twinkies... Is the weather still keeping you from your shop; I thought you had a rotating cylinder engine going stickpoke ;D
> 
> Regards, Arnold



 Took a left turn from the rotating cylinder, had this Airpot sitting around, and well,

Robert


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## Ken I (Jan 30, 2012)

Arnold, I always get something out of your posts... a toothbrush handle as a harmonic damper - who'da thought :bow:

Ken


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## arnoldb (Feb 5, 2012)

Thanks Ken - that was just one of those "Oh well, let's try this out of desperation" moments.

 : My work life has been keeping me pretty busy of late, so shop time is hard to come by.

This afternoon I drilled a 2.5mm hole through the center of the engine top:




That was tapped M3 for the air inlet.

I next milled out the excess metal that was still left on the bottom of the engine:





The bottom mounting holes were not tapped yet, so I also tapped those M3, and gave the block a final flat-lap on both sides. That pretty much completes the engine block part of the build.

Next I started on the vane; I milled a section of 4.8mmx12 brass flat bar down width of 9.65mm - that's the same thickness as the engine block. I didn't quite get it, and ended up at 9.7mm. I wanted the vane 0.01mm thinner than the engine block, so I sat down and flat-lapped it down to 9.64mm on some 600 grit paper, frequently checking with a micrometer that I was keeping it parallel and not lapping one end down more than the other. Quite a bit of manual work, but it turned out well in the end:





Next I faced the one end square, cut it of just over length (the bit of flat bar was more than twice too long), and then squared up the other end as well. The vane top needs a slot where a seal with a small spring will be installed, so I started cutting that with a 2mm cutter. after about the 7th pass, a bit of a disaster; just a second of inattention and I increased the rate of feed just too much:




Oh well, that poor end mill has been doing duty for more than six months now, in everything from plastic to a bit in stainless; it was getting a bit blunt. So I fetched a new one from my stock and finished the job. There's only one left now, so it's time I fired off an order to RichOn - I need some other cutters as well...

Back when I started this project, I mentioned the fact that Elmer's plans has a measurement error with the mortise and tenon joint. I was still undecided whether I was going to use this method for joining the vane to the main shaft. 
This joint is most likely the weakest link in the engine, and would see quite a bit of torque transferred through it, so just soft-soldering the vane to the shaft without some form of additional strengthening would very likely lead to failure.
Many moons ago, John Bogs suggested that silver soldering the joint would be his way to do it - I agree, but then there's one teeny little problem for me; this joint has to be done ultra-neat as any excess would be very difficult to clean up, and that's something I'm still having problems with when silver soldering.
So it was either the mortise and tenon for me, or I had to find another solution. I did the latter, and decided that three pieces of 1.5mm piano wire running between the shaft and vane would be just as strong - if not stronger than - a mortise and tenon made from brass. The main loading on the joint is radially, and the wire would cope well with that - while loctite would be more than adequate to keep things from coming apart.

I drilled three 1.5mm holes spaced 2.5mm apart in the bottom of the vane:





Next I cut a section of 6mm silver steel to length (  I restocked earlier this week) and cleaned it up on the lathe. Then I drilled matching 1.5mm holes in it - offset to compensate for the one thicker cylinder cover so that the ends sticking out from the engine would be equal:





I used the Dremel with a cut-off wheel to slice off three sections of 1.5mm music wire, and pressed those into the vane with some loctite, and with more dabs of loctite, pressed the lot into the shaft. The middle hole on the shaft had wandered a tiny bit, but this actually helped things; I had to use the mill vise to press it together the last bit - and the vise aided in getting everything nice and square. It won't come apart easily, but if needed, I can get it apart again with some heat. Some of the excess loctite running between the two pieces also help to make the seal air tight:




and





A quick assembly, and things are looking good; some oil smeared on the vane gets distributed evenly everywhere on both the rear and front covers, and there's no binding ;D:





Regards, Arnold


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## lazylathe (Feb 5, 2012)

Another great build thread with lots of pictures and problem solving!!!
Excellent as usual Arnold!!

Looks like another winner on the go here!!! ;D

Andrew


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## arnoldb (Feb 11, 2012)

Thanks Andrew  - I'm having quite a bit of fun building this one; I just hope it runs when I'm done :big:

Got to the rotary valve today. The plans for the valve itself is a separate chapter in Elmer's book.
I went about making it quite differently from the way Elmer describes - in fact, I did not do a single bit of marking out...

As I'd made slight dimensional changes to the engine block in the valve area to suit my available reamers, I had to re-calculate some of the dimensions of the valve. Most importantly, it's slightly bigger at a close 10mm fit compared to the 3/8" (9.53mm) the plans call for. This meant that some of the porting cut-outs had to be slightly deeper than those shown on the plans - all by 0.235mm ~ 0.24mm. The 1/8" shaft section was re-sized to a running fit for 3mm.

First I turned down a bit of 1/2" brass rod. A 8mm long section 2.98 mm thick to match the 3mm reamed hole in the the back engine cover and the next section 9.99mm thick for a close fit in the reamed 10mm hole the engine top:




 I got a nice smooth finish just turning to size, so no lapping needed here.

Off to the mill with the dividing head mounted in the vise, and the edge finder and hand-wheel zero-rings used to locate things - from this point, all operations were done according to mill dial readings:





The valve needs a 1.6mm hole drilled accurately through it's center, but on one side, the hole is connected to a 2.4mm slot. Rather than have the drill bit wandering on a curved surface, I first milled the slot, and then drilled the hole - much easier this way:





Another small change to Elmer's design follows - this time to correct a booboo that crept in when I drilled the port holes in the engine top; the drill wandered a bit on both holes, and they are pretty far off axially compared to the valve center line. The original valve design uses just the 1.6mm through-hole to supply air to the ports in the engine top - meaning everything have to align pretty darn accurately, and I don't have that... So to compensate, I milled a short slot 1.6mm deep axially on the other side of the workpiece (rotated 180o since the last operation):




After milling the slot in the photo above with a 1.5mm cutter, I followed it with a 2mm cutter - which might be a mistake... I'll see if this is OK later.

The exhaust cut-outs followed - taking care to cut them both from the correct side; one had to be done feeding in on Y, and the other feeding out on Y:





Back to the lathe, and parting off - an action photo for a change:





The finished valve:





Well... not quite. Seeing as I have this one transparent engine cover, and one of the most difficult things to explain to people when they're looking at my little engines is always how and where the air or steam goes inside the invisible bits of the engine, I decided to add a cross-section of the valve cut-outs on the "visible" face of the valve. I just free-hand milled this lot with a 1.5mm cutter 0.1mm deep:




The 1.6mm drill bit sticking through there is what I used to estimate level and orientation when I clamped up the workpiece :big:

With the milled out bits on the valve face coloured in with a permanent pen, it'll look like this in the engine top:





Regards, Arnold


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## Foozer (Feb 11, 2012)

Getting fancy there, I best acquire another bag of BBQ chips, detect a video coming up shortly

Robert


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## Blogwitch (Feb 11, 2012)

Arnold,

I think the Kimble is one of the most difficult engines that Elmer decided to show how to build.

He showed one way to make it, and I am sure, like you are doing, there are many ways to achieve the same result in the end.

That is what model making is all about, finding ways to achieve a final result. If it works at the end of it all, then you have done it correctly.

You are doing great on this one, and I can't wait for the next installment. :bow: :bow:


John


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## arnoldb (Feb 12, 2012)

Thanks Robert  - there's still quite a bit to do though, so the video won't be too soon.

John, thank you  I have to agree; Kimble is not an easy engine - maybe that's the reason why there's not more examples of completed ones. I think it's a good example of an engine that first have to be understood before one start to build it... 

Today's little bit, the eccentric. It's not a difficult part to make at all - in fact all the difficult bits of the engine are now done - but once again I made a slight change to it. 
If made as per plans, the eccentric is bolted to the flywheel, and when the engine is assembled, the eccentric ring is retained between the flywheel and the bearing column. 
I don't want the eccentric ring to touch the bearing column when the engine is done, simply because the column will be painted, and the ring will either rub off the paint, or the paint will add quite a bit of friction while running - or both. 
So I decided to add a step to the eccentric and eccentric ring to prevent that. The ring will still run against the flywheel on one side, but that's OK, as the flywheel won't be painted. 
I'm also going to make the eccentric ring a split assembly rather than one piece. This is mostly for ease of assembly; this engine will be finicky to assemble when done, so I'd rather do a bit of extra work up front. It will also add some visual appeal - I hope.

Started turning up the eccentric - a bit of 20mm silver steel turned down to 17.5mm, and a 1mm long step turned down to 16.5mm diameter:






Off to the mill and mounted on the rotary table - purely for the fact that it's easy to center the RT to the spindle, plonk the chuck on it and dial in the hole locations. The two holes needed drilled - the most important one is the 6mm hole on the right, as that determines the eccentric offset. The hole on the left is 2.5mm - that will be transferred to the flywheel and then drilled out to 3mm:





Back to the lathe with the chuck, and parting off at thickness:




It looks like the lathe is running hell-for-leather in that photo, but actually, it's only running at 110rpm - I can't do much faster than that on parting steel. The lathe's spindle bearings is a bit worn, and I have a load of backlash on the cross slide feed nut as well. To top that lot, the "parting" blade I'm using is actually a HSS wood plane cutter that I ground down, and anything faster than that on steel would just toast the cutting edge. Not to mention the fact that this was an interrupted parting cut because of the two holes in there :big:

Once parted off, I spent some time and energy to file away the tool marks on the parted face, thereafter a bit of rubbing on emery, and the parted side of the eccentric is all nice and shiny. Shoved a bit of 6mm silver steel through it and the flywheel, and clamped the lot together with a toolmaker's clamp, and then clamped the clamp in the mill vise and transferred the 2.5mm hole into the flywheel - taking care not to have the hole exit on the other side of the flywheel:





Off to the drill press, and with the same toolmaker's clamp trick, opened up the 2.5mm hole in the eccentric to 3mm, and countersunk it for a nice fit for some 3mm countersink screws I have:





Next I tapped the hole in the flywheel to M3, shortened one of the M3 countersink screws for a proper fit, and this is what it looks like assembled together:





Regards, Arnold


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## arnoldb (Feb 18, 2012)

A bit more progress; this is turning into a weekends-only project it seems...

With all the hard-to-do parts done, I don't know how long the yet-to-be-made parts will take to do, but soon I'll have to start assembling bits and pieces to see if everything fits. The base and sub-base picked up a bit of rust earlier on, and there were a couple of dings in them as well. The dings were my own fault - I didn't follow the rules of scrupulously cleaning the mill vise each time a part was moved, and some swarf got trapped and made dents.

So first I cleaned up the dings - had to lightly mill away the sides of both the base and sub base to get rid of them:





Then I set to with a file and some scotch-brite to remove the last major machining marks and all the rust from the bits, and gave them a coat of primer:





In the previous post I mentioned I might make the eccentric ring a split one, so I grabbed a bit of 3mm brass plate and roughly laid it out:





After picturing the finished part in my mind on the completed engine, I decided against making the split eccentric ring; it would look a bit "chunky" against the rest of the engine. The smallest taps and screws I have are 10BA, and even If I used these to close the eccentric ring, I'd have to turn down their heads just to fit, and they'd still look overly large.
I do have 1.4mm taps, but no die nut, and if I want to single-point turn screws for these, I first have to make some tools, which have to wait for another day.

So, back to a simple ring for the eccentric ring, and a bit of phosphor bronze turned down to outside diameter - I nearly grabbed a bit of aluminium bronze I have for this part, but remembered in time that I had to silver solder on it!:





After a bit of drilling, and boring, things were to size, with the step turned in to match the one I made on the eccentric:




There was nearly a brown-pants moment while drilling the bronze... I'd forgotten I recently bought a new 10mm drill bit, and it's still very nice and sharp... It grabbed into the bronze, pulling the tailstock chuck right out of the tailstock taper. I grabbed the old chipped 10mm drill, and roughly stoned its cutting faces to a more suitable profile for bronze and finished the job.

The eccentric fits a treat - turning closely, but smoothly in the ring, with the eccentric face _just_ protruding a bit:





Next I parted the ring off:





It was about 0.05mm too thick after parting off, so I flat-lapped that off on some emery, and ended up with this:





Elmer's plans call for 1.6mm (1/16") plate for the valve rod and connecting rods. I thought I had 1.6mm brass plate - well I thought wrong :. I have 1.2mm and 2mm. For a while I sat debating with myself whether to maybe make the rods from round rod, but decided against that as well. So, I'll use the 2mm plate, and I cut some strips from it:





Then trimmed the valve rod to width - 4mm in this case, leaving it about 0.02mm over size for final finishing:





I love my digital camera to bits; it takes fairly good photos without even trying hard, and it'll take 500 to 800 photos on a single full charge, but one thing I don't like about it is the fact that it'll suddenly show the low-battery-of-doom indicator, and only take *two* photos before shutting down completely on low battery. The last time the batteries ran out was last year when I was finishing the second Coomber, and I didn't give the batteries a full charge... You have three guesses what happened today, and the first two don't count.

Without photos while the batteries were recharging a bit, I silver soldered the eccentric ring to the eccentric rod, and cleaned it up a bit:



I didn't notice it in the shop; but the photo shows some interesting things colour wise. Both the eccentric ring and flywheel rim are phosphor bronze, but of two different compositions - I say that because they behaved a bit differently while machining. The rim has a bit of patina on it already, but is more yellow than the eccentric ring which is more copper in colour, suggesting a higher copper content in the alloy of the ring. Next the yellow of the brass eccentric rod follows. There's also the different grays - ranging from the darker shade of the silver steel eccentric (maybe indicative of it's high carbon content) to the zinc colour of the galvanized screw, then the aluminium approaching "white" and finally the silver sliver of high-content silver in the joint between the bronze ring and brass "rod".

Regards, Arnold


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## arnoldb (Feb 19, 2012)

Today's bit...

One thing I didn't do when I made the vane shaft was mill out flats on it for the vane arm setscrews - that was easily done:





Then I spent some time with the base - flattening the primer a bit with some 1200 emery, and gave everything the first coat of paint:










Next I marked out the vane arms on some brass flat bar:





And drilled and reamed the vane rod holes:





Then I sawed both bits off the parent stock, and with a bit of 6mm rod trough the holes clamped them together in a small vise, then removed the rod and clamped them up with a toolmaker's clamp that's narrower than the workpieces:





The clamp could then be clamped in the mill vise, with the bits lying flat on top, and I drilled a 2.5mm hole trough to tap M3 - this keeps the connecting rod offsets exactly the same for both vane arms:





 Elmer's plans use 2mm pins here - cross drilled for using a piece of thin wire as a retainer, but I had enough fun with that method on my Grasshopper engine; I prefer screws and bolts.

I used a bit of rod and the 2.5mm drill to keep the pieces aligned, and clamped them up in the vise so that the center line is horizontal to the vise jaws:





Then drilled the top 2.5m mto thread M3 for set screws:





While I was about it, I just tapped the holes as well:





Next I used some bits 'n bobs to get things set up to mill away the sides:





And off to the big vise to file the rounds; it takes me longer to set up something to machine curves like these than it does to just file them to the line, and where it's a cosmetic feature like here, a file's plenty good enough:





After a quick rub on emery, things look presentable:





The arms needed a bit taken off on the one face of each; rather than set up the rotary table for this, I did it on the lathe:





Arms finished:





And where they fit on the vane; I'll have to shorten the set screws a bit:





Regards, Arnold


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## bearcar1 (Feb 20, 2012)

Looking real good Arnold, it won't be much longer until yet another work of art can be placed up on the mantle. (top shelf in the shop maybe? :big

BC1
Jim


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## arnoldb (Feb 26, 2012)

Jim, thanks my friend  This one's a bit slow - once it's done it'll join the others on the side-board in the lounge to trap unwary visitors :big::



There's some missing there; I've given away a couple, and others are paperweights in my office. The office ones might join this crowd at home soon though, as I'm at a bit of a turning point in my career and might not have a permanent office in a month or so... Guess I'll have to break out the woodworking tools soon - to build an add-on shelf :big:

Yesterday was a dead loss in the shop; "work" work all day interfered...

This morning I started off with the crank webs - digging through my stock I had a choice between aluminium and bronze in the approximate sizes needed. As the flywheel web is aluminium, I decided on the aluminium to match it; all the linkages will be brass anyway, and I like a bit of contrast. Cleaned off, and drilled and reamed to 6mm:





Next, turned the step on the first web:





And parted of with a bit of oiled 6mm rod in the tailstock chuck to both help support and catch the web:





The second one followed - using the same measurements. I'm slowly starting to get better finishes on parting cuts - it still looks horrible though - I wonder if it's possible to get a really smooth finish on a parting cut ? :




I'll just keep on trying harder :big:

Cleaned up the ugly parting marks:





The webs must be made as a left and right-hand version, and to prevent binding on the engine later on, their crank offsets must match exactly - so I shoved a bit of rod through them held back-to-back, and clamped them together and clamped them flat on the mill vise:





Then I used the edge finder to locate the center line in Y and also the X edge of the pin; then I just dialed in the hole position on the X handwheel - it takes a simple bit of work on a calculator to calculate  crank throw - (half the pin thickness + half the center finder thickness) and dial that in . A quick spot with a center drill, and drilled a 2.5mm hole to thread M3 later:





While I was busy drilling holes, I drilled the 2.5mm holes to tap M3 for the grub screws (set screws) as well:





After sitting down and playing around with the set of M3 taps, I had the finished webs:




There's some scuff marks on them; those I'll remove at a later stage.

I did a bit more paint work on the columns, and COMPLETELY stuffed it up  :hDe: :rant: :




Hopelessly over-sprayed, and there must still have been some contaminants on there to boot. As the bushes are slightly proud of the column faces, there was only one way to recover; I dunked the lot in acetone and got rid of every last vestige of paint on there, and started anew - right from primer.

While waiting for primer to dry, I started on the valve arm - pretty much the same method as the main crank arms:





Rounding over with facets before filing:





Thinning it down - I used a bit of 3mm rod chucked up in the ER11 collet chuck. Just filed a flat on it for the grub screw to hold onto, and turned it down. You'll see that the grub screw was a bit long, and I'd turned a bit of that away in the process as well:





To get more use from that same grub screw , I just screwed it half-way into a 3mm nut, and with a 3mm cap screw turned in from the other end of the nut to lock up against it, I had enough to hold on to to go to the bench grinder and grind off the excess:





The grub screw was still a bit long, so I plonked it on the end of an Allen key and carefully ground down the other end as well to shorten it further making a slight point on the end:





A bit of work with a fine file and emery, and the valve arm is done:





The bits left to make are getting less now, but some things depend on getting the engine assembled partly to take some measurements. I did start to clean up the two bits of brass plate cut in an earlier post - that's the start of the connecting rods:




 : I guess I'd better start putting drill bits back in the index - before they slip into the fourth dimension.

Before I left shop for the day, I gave the offending column another coat of paint; it still does not look great, but I'll let it dry for a couple of days and give it a rub-down with some 1200 emery before a final coat of paint:





Kind regards, Arnold


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## steamer (Feb 26, 2012)

Arnold,

Read through the whole thread...it's clear your a "Faceplate" guy! :bow:


Fabulous workmanship friend!

Dave


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## bearcar1 (Feb 26, 2012)

Progressing well A', and it is always nice to see Fred and company once again. 

Jim B.


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## zeeprogrammer (Feb 29, 2012)

Howdy Arnold! Very happy to find another thread from you. Always a good read.

By the looks of your mantle you've been a busy guy. And that 'new' mill shows a lot of use.

Looking forward to seeing more and knowing you...that won't be long.


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## arnoldb (Mar 3, 2012)

Thanks Dave - I tend to do some things a bit "old fashioned" :big: ; my face plate is a good bit of kit to use!

Thank you Jim ; the "paperweights" I have in my office will also have to come home now, as I accepted that new job that will leave me office-less :big:

Carl, Thanks  - I'm getting to grips with the mill - though it still needs some sorting out; a power feed is definitely in the pipeline, but I must first get my small lathe installed properly as well. LOTS of tooling work to do once this engine is done ;D. 

This afternoon I made some small bits. As I mentioned earlier, I'm not going to use Elmer's "pin with hole and soft wire" method for retaining the connecting rods and valve rod. So it was time to start making screws.

First up, a small screw for linking the valve rod with the valve arm. I started with some 4mm silver steel and turned a 2.5mm step on it to match the hole in the crank arm, and then a 2mm step to thread M2:




If you look carefully at the photo, the first section of the smallest step is undersize; I'd overshot and turned it down to 1.8mm - which wouldn't do as that is too small for an adequate M2 thread. It's great for getting an easy and straight start to the thread though 

After threading with the tailstock die holder, I turned off the excess 1.8mm bit, and parted of the screw. It just needs a slot:





Next, some 5mm silver steel - turned with a 4mm and 3mm step, and threaded M3:




That was parted off, and repeated another 3 times.

If you look carefully at the previous photo, you'll notice that the 3mm thread does not run to the shoulder. Normally, one would make an undercut there for a crank screw like this, but I'm a lazy rotter and didn't want to grind up a narrow enough cutting bit for the undercut. Anyway, the crank rods need some slight spacing off the webs and crank arms, so I rather set about making some 0.5mm thick brass washers - ID 3mm and OD 6mm.
If one first drill the brass rod and then part off the washers, each is left with a burr on the side that must be filed down; a real pain. So I used a method that leaves much less burrs in a case like this.
I first made all the parting cuts - leaving the core at just under 3mm. The first section was a bit thick ::





Then I center drilled the end, and drilled a 1.5mm pilot hole through - the pilot hole is needed to prevent the 3mm drill from wandering around for the next step. Then I just drilled down the lot with the 3mm drill, and all the washers are left on it with a minimum of burring:





This is what the bunch of washers look like without any clean-up whatsoever:





Next I slotted all the screws - not the ideal setup to do it with, but it worked:





For today's shop session, I ended up with this lot:





Not as much as I'd hoped to get done, but I spent about 1 1/2 hours at one point searching for my ER11 collet closer nut after dropping it, the collet that was in it and the screw that was in that :wall: :wall: I never knew these things were made from rubber; everything bounced all over the show, and not having chameleon-like eyes it's impossible to follow the flight paths of three madly bouncing bits at the same time :
I eventually found the nut - there's an old V6 engine standing between my lathe and mill at this point, and the nut had lodged between the water pump and its pulley:




 :big: I've found another entrance to the fourth dimension!

Kind regards, Arnold


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## AussieJimG (Mar 3, 2012)

Thank you Arnold, you have just solved yesterday's problem: how to make a thin washer without that annoying burr on it. This forum is great stuff. :bow: :bow:

Jim


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## zeeprogrammer (Mar 3, 2012)

Nice tip making the washers. They look great.

My favorite 'where did it go hide-y holes' are the cuffs of my pants.


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## lazylathe (Mar 3, 2012)

As usual full of good info!!!!

Maybe for your next project you can build a frame for the V6?
At least that way it will be out of the way!!! :big:

Andrew


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## arnoldb (Mar 4, 2012)

Thanks Jim  - that's exactly what HMEM is all about 

Carl, thank you  - ??? why do you wear pants with cuffs in the shop ? - that's a sure-fire place for swarf to collect and get you in trouble with the better half :big:

Thanks Andrew  - That's an old Ford Essex engine... No frame needed; just a long chain to make a boat anchor out of it; I just need the boat as well :big:

Today's bit; more fiddly stuff and making screws.

First a teaser  - I had to assemble things well enough to judge how to bend the front connecting rod, as the perspex engine cover is quite a bit thicker than the cover from the plans:





I then bent the connecting rod to match:




The back one was bent to plans, as I didn't change any measurements there.

Then I drilled the big end holes in both rods:




 :Sorry - out of focus photo!

Next I located the hole against the vise stop and set the mill x handwheel to zero on location:





Then I dialed in the con rod length on the x axis and prepared to center drill:




After center drilling and drilling through at 4mm on the one rod, I flipped them and drilled the other. This made sure they had exactly the same length hole-to-hole in each even though the are bent. It's crucial to get this measurement the same for this engine.

Next I rounded over the ends with a file, and cleaned the lot up with some scotch-brite:





I turned up the main shaft, and loctited the flywheel to it before taking a bit of a lunch break - that gave enough time for the loctite to cure, as it was a nice and warm day today:





One more part required was the vane seal - I prepared some 2mm brass plate for it, and drilled a 0.8mm hole to retain the spring in it:




I need to buy some smaller drills at some point :

The vane seal was then sawn off from the parent stock, and filed and lapped to size. Elmer specifies some very thin stainless wire to make a spring from. I don't have that, and I was thinking of using a bit of thin high "E" guitar string for that, but I couldn't find the bit I stole off the guitar - till I remembered I used it to repair the cheese slicer. Then my eyes fell on the big wire brush, and I clipped one of it's bristles off and bent that to the spring shape - that's the thin black part in the photo:





The valve rod still needed a hole drilled and tapped M2 for connecting to the valve arm - that followed:





I'd originally intended to use some 2mm all-thread "studs" and nuts to mount the engine top to the body as I didn't have long enough M2 screws for the job, but as everything else on the engine now use slotted screws, that would look a bit out of place. So I chucked some 4mm silver steel in the ER11 chuck, and turned it down to 1.95mm diameter 13mm long, and filed a good cone on the end to allow the M2 tailstock die to start easily Then I turned a short section down to 3mm - that will make the screw head:




When turning down thin long sections like this, it's imperative to hone the toolbit to a very sharp edge on all cutting edges - then lathe max RPM (~640 for my Myford) and a smooth and steady hand feed to keep a consistent thin chip coming off. Works a treat, but seems to take a bit of practice. I need to build myself a box tool like Tel showed.

Thread, part off & repeat 3 more times, and I had this lot - just needs slotting:




 : The one on the right's head is a bit big... I forgot to turn it down to 3mm :big:

Easily fixed:




I'm *really* starting to enjoy the ER11 collet chuck working along with my ER25 chuck like this for small jobs!

I slotted them the same way as yesterday's screws. Next I turned up the steam connector from some 5mm hex brass:





Then I laid out all the bits and started giving them a once-over to remove the last tooling marks and to make sure everything was there:




Regards, Arnold


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## zeeprogrammer (Mar 4, 2012)

arnoldb  said:
			
		

> Carl, thank you  - ??? why do you wear pants with cuffs in the shop ? - that's a sure-fire place for swarf to collect and get you in trouble with the better half :big:



True enough. When I do wear pants in the shop...they don't have cuffs. ;D
But I'm getting shorter and occasionally have to fold the ends up.

That's a fine looking engine Arnold. I'm very much looking forward to the run.
Got your celebratory drink ready? I'm thinking that bottle you showed me some time ago must be gone now. :'(


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## vascon2196 (Mar 4, 2012)

Your work is amazing....the engine is looking sweeeeet.....

Chris


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## arnoldb (Mar 5, 2012)

Thanks Carl  - Your wish is my command :big:.  :-X That bottle is LONG gone - Doctor's prescriptions: Start the course and finish it :big:.

Chris, thank you  I hope today's photos are OK!

 ;D ;D ;D Well, the Kimble is a runner, but it didn't come without a fight. Actually I had it running yesterday evening, but I was too dog tired to get a video and shoot a couple of photos.

After I assembled the engine, I had some troubles with binding. 

The way the engine gets assembled is awkward to say the least, with a major fiddly bit being trying to hold the columns with the flywheel, main shaft and valve rod all in place and getting the column mounting screws in place from the bottom - all the while trying not to scratch things and damage the paint. This played havoc with trying to get the bearing columns aligned for the least amount of friction.
If I can provide some advise in this respect for anyone contemplating a build of this engine: Make split bearing blocks! - You'll save yourself a lot of hassle.

I found another source of binding eventually; I couldn't figure out where it was coming from initially; the vane would "stick" on one side - even though I'd taken great care in keeping tolerances close but not tight. I finally traced the source to the one crank arm on the vane shaft; it had a high spot on the rounding that I didn't file down far enough, and that was touching the base at one end of the throw : - a quick lick with a file and some emery cleared that up.

Once I'd gotten all the binding sorted out, I connected it to air, and it would try to run, but only go through three or so revolutions and stop. I tried upping the pressure a bit, and when I got to 30psi I stopped - I didn't want to blow off the perspex cylinder cover. I traced the problem to the timing - and this part was definitely my own fault for messing with some dimensions on the rotary valve. Earlier in the build I'd made a slot in the bottom of the valve to compensate for the holes that had wandered into the engine top - but I made that slot wider than the diameter of the original port hole. As it turned out, the slot would very nearly connect both steam ports at the same time, but once I really fine-tuned the valve on it's drive arm, the engine started running.

OK, enough blubbering - some photos and a video ;D





















[ame]http://www.youtube.com/watch?v=WXH6AFwspUw[/ame]

I must say, this was a really fun build - even though it took me a lot longer than any of my other engines before to complete, and to see the engine running is a real treat!


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## mklotz (Mar 5, 2012)

Ausgezeichnet. A truly curious engine and you've done a superb job modeling it. My congratulations.


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## Blogwitch (Mar 5, 2012)

I've never seen one running before Arnold, and always wanted to make one, but never go around to doing it.

Your model is absolutely wonderful and is truly an extraordinary engine.

Very nicely shown and made, a real credit to you.


John


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## Ken I (Mar 5, 2012)

As per usual Arnold, you have intrigued me with this thread.

As per usual completeted perfectly.

As per usual it adds one more thing to my to do list.

Well done.

Ken


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## moconnor (Mar 5, 2012)

Hello Arnold,

You have done a superb job building the Kimble Engine and documenting it. This must be one of the rarest of Elmer's engines, I too have never seen one running before. Congratulations on a fine running engine.

Kind regards,
Mike


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## vcutajar (Mar 5, 2012)

Arnold

Congrats for your running Kimble. Thanks for all the photos.

Vince


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## zeeprogrammer (Mar 5, 2012)

That is one beautiful engine and well worth your fine collection.
I love seeing the action!
I'm breaking out my jelly jar and raising a toast to you.
Okay...the jelly jar was already out...but here's to you Arnold.


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## RMO (Mar 5, 2012)

Arnold,

Let me add my congratulations. Inspiring! Thanks for showing. :bow: :bow:

Mike


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## larry1 (Mar 6, 2012)

Arnold, Great work, Great engine, Thank you for the pictures. larry


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## arnoldb (Mar 6, 2012)

Vielen Dank herr Klotz  

John, thank you very much . I know you've mentioned a couple of times that you'd like to make one of these engines; it seems a shame that there are so few of them around.

Thanks Ken  - I'll hold up with engines for a while; time to catch up with tooling - that is unless I get a bee in my bonnet one weekend :big:

Both Mikes, Vince and Larry, thank you Gents; it was a pleasure sharing the build.

Carl, thanks & Cheers *beer*; I'm in a hugely celebratory mood (not just because of the Kimble build), so I'll treat myself to some special liquid of Scottish origin this coming weekend. I'll be sure to toast you as well; it's good to have you active on the forum again ;D

Kind regards, Arnold


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## danstir (Mar 6, 2012)

Very nice engine. And I really enjoyed your construction thread. Thanks for all the tips!


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## vascon2196 (Mar 6, 2012)

I have to say that is a great engine...I enjoy building and viewing Elmer's engines. This questions has to have been asked in the past but how many Elmer's engines have you completed? Do you or has anyone built all of them from his book?

Is this your goal?

I have only (3) Elmer's engines completed.

Just curious...thanks again for posting those great pics and the awesome video!

Chris


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## b.lindsey (Mar 6, 2012)

Great work Arnold...like others have said, I've never seen one running and it certainly whet's my appetite to make one now. The use of the clear cover will make it perfect for display and showing just how it works too! Very well done indeed!!!

Bill


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## arnoldb (Mar 6, 2012)

Danstir, Chris & Bill - thanks very much Gents 

Chris, I'm not aware of anybody that has built all of them. MetalButcher here on HMEM has given the list a good go though!
I want to build them all ;D - I've got 7 so far:
#15 Fancy, #23 Tiny, #8 Scotty, #37 Grasshopper, #46 Comber, #43 Horizontal Mill, and the Kimble.

I have also made another slightly larger Comber, and a turbine roughly based on the #12 Turbine & pump, but I don't count this one as an Elmer engine. I'll build the real Elmer turbine and pump later.


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## Blogwitch (Mar 6, 2012)

Only another 40 odd to go then.

That should keep you busy for a couple of weeks : :


John


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## bearcar1 (Mar 6, 2012)

Now *THAT*, is truly dee-lightful! I've only seen photographs of this model and never witnessed one in operation. Way cool! 8) Arnold, it is always a pleasure to see you in action. Another fine model under your belt. Now then, get cracking on expanding the display arena ;D

BC1
Jim


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## AussieJimG (Mar 6, 2012)

A lovely engine Arnold, congratulations. :bow: :bow:

The finish is superb and your idea of outlining the valve worked a treat.

And thanks for all the instruction on the way. It was a great journey.

Jim


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## vascon2196 (Mar 6, 2012)

arnoldb  said:
			
		

> Danstir, Chris & Bill - thanks very much Gents
> 
> Chris, I'm not aware of anybody that has built all of them. MetalButcher here on HMEM has given the list a good go though!
> I want to build them all ;D - I've got 7 so far:
> ...



Something to look forward to right? This is good stuff! Thanks for the reply.

Chris


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## arnoldb (Mar 7, 2012)

> Only another 40 odd to go then.
> 
> That should keep you busy for a couple of weeks : :


 :big: 43 to go John; good to keep me occupied for at least twenty years with tooling and some other builds interspersed ;D

Thank you Jim BC1  - Display has to wait a bit; some tooling first 

Jim AussyJimG, thank you.  It's very good to hear that some of the things I show are useful, but please don't think of it as instruction - it's just the way I happened to do it Thm:

Pleasure Chris  - I'll be sure to annoy everybody with more Elmer's Engines build in future 

Kind regards, Arnold


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## ShopShoe (Mar 8, 2012)

Arnold,

I would like to add my congrats to the others. Your build logs are an inspiration and your completed engines are so nicely detailed and finished. You also manage to include enough new ideas on shop techniques to keep us learning.

Good One! :bow:

--ShopShoe


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## reFlad (Mar 10, 2012)

Arnold,
Very, Very, nice work - as usual. Thanks for sharing the build with us! Looking forward to your next build...

Ronald


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## Maryak (Mar 10, 2012)

Arnold,

Don't quite know how I've missed this  Too much time flapping around and missing more than hitting.

Anyway congratulations on yet another magnificent build and build log. :bow: :bow: :bow:

Best Regards
Bob


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## arnoldb (Mar 12, 2012)

Shopshoe, Ronald & Bob - many thanks Gents 


Kind regards, Arnold


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## lazylathe (Mar 12, 2012)

WHOA!!!!!! th_confused0052

That perspex cover really makes the engine!!!
I could sit and watch the rotary valve all day long!!! 
With some of the Dr's prescribed medicine of course! :big:

Another beauty to add to your collection Arnold!!
Great build log and a smooth runner!!
Just like the quality muti!!!

Andrew


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## arnoldb (Mar 14, 2012)

Andrew, thanks Boet  - the little engine has been amusing the heck out of my colleagues at work... The FD pops into my office regularly, sits down and turns the flywheel looking at the mechanism. Seems to take his mind off work things a bit, which is a good thing. I'm really glad I went to the bit of extra bother to make that see-through cover!

Kind regards, Arnold


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## lazylathe (Mar 14, 2012)

So you still have a desk at work??
Not working from home yet?

Maybe the boss will keep you around to amuse him for a while longer.
As long as you keep machining interesting engines! ;D

Andrew


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## Foozer (Mar 14, 2012)

An air powered Finger Engine. There ya go

Like how you paused on the rotation to show the flywheel had no wobble.

Very nice work.


Robert


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## arnoldb (Mar 15, 2012)

;D Andrew, I have a desk till the end of this month... The bosses are a bit sad to see me go, but the new job I'm moving on to from next month is quite a big career step-up, and unfortunately they can't match it. I'll still deal with them regularly though; the IT community in Namibia is pretty small. In my new job I'll be providing highly specialised consulting and development services to a variety of companies, and due to the nature of this I'll be working on-site in restricted areas for these companies - so no more permanent desk; my car will become my office pretty much :big:. 
I'm not about to stop building engines though  - in fact I really treated myself today and ordered a DRO for my mill ;D

Thanks Robert  - LOL - I never thought of the Kimble as an air powered finger engine. The pause on the rotation wasn't intentional. I'd have given myself a sound hiding with a carefully selected bit of cane if the flywheel wobbled on this build - before publicly owning up to that fact and re-making the flywheel to run true ;D

Kind regards, Arnold


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## hunter2008 (Oct 18, 2015)

I love the engine you built.  It reminds me of a musicians metronome.
I'm thinking of trying one myself but looking through the plans available on the Elmer Verburg site there seems to be a page missing (page 91?)

Since you have built the engine I'm assuming you have details of the missing page.  I've tried searching the web to find it but no luck.  I would be grateful if you could send me the web address of the missing page or email a copy of it.

Thanks.

Andy K.


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## romartin (Feb 15, 2016)

Thank you Arnold for this masterly build and its build log, which I discovered in November and which inspired me to try a Kimble build myself.


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