# Two Cylinder Double Acting Steam Engine Build



## vederstein (Oct 7, 2018)

Now that my (failed) Essex Stirling is over, I'm starting my next project.

This steam engine is of my own design.

90 degree, two cylinder, and double acting.  It will use barstock and aluminum castings.  The castings will be the crosshead frame, cylinder, and steam chest.  The rest is aluminum, brass, and steel barstock.

Bore is 1-1/8 inches with a 1 inch stroke.

I've shown this animation in another thread, but it's appropriate to show it here:



Let the build commence!!!

...Ved.


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## vederstein (Oct 7, 2018)

I started with the engine block which was a 4 inch diameter x 4 long piece of solid 6061 aluminum.  It took 45 minutes to cut this think on my 4x6 bandsaw.





First I faced it off and turned down 0.20 to clean up the outside.




Next was to progressive drill out the center so I wouldn't have to bore out as much.





Then I bored it out to 2.75 inches diameter.




I flipped the part in the lathe and the machined out the rear boss.  I took some very heavy cuts...




Then I bored out the opposite end for the rear crankshaft bearing.  (1.125 diameter)




The amount of chips after hogging out this chuck of aluminum was significant.




Then off to the mill (next post in this thread)...


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## vederstein (Oct 7, 2018)

After indexing the part into the rotary table, I cut the two faceted sides 90 degrees apart.








Then on one face, I drilled out the holes to mount the crosshead frame and the milled a pocket for connecting rod clearance.





Rotating the part 180 degrees, I milled out the slots for access to the connecting rod bearing caps.




Rotating to the other face, the same operations were then performed.  The operations were offset from the first set though because the 2nd cylinder is offset from the first.  Then I drilled and counterbored the holes to mount the front crankshaft bearing housing.  Rotating the part 180 degrees to do the same operation to the other side.




With the lathe work in the previous post, this was about 4-1/2 hours of work.






Until next time...

...Ved.


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## vederstein (Oct 13, 2018)

I could've make the front bearing housing simple, a round disk with a bored center hole.  But nope.  Let's make it DIFFICULT!!!

I found a piece of scrap on the shelf. (Not scrap anymore) and after blueing the approximate center, I chucked the part into the four jaw.  The I commenced to drill / bore the bearing journal.














Then I switched the four jaw to the three jaw and made a mandral to slide the bore over.  I held the part against the mandral with a live center and a piece of scrap.  Then I could commence with turning the outside radius.











At this point I could've had a useable part.  But this is where I made it difficult:  Off to the mill:

Using my rotary table, I milled the perimeter close to print.  It's just for looks and access to oil the connecting rods, so I wasn't super careful on getting the dims exactly right.  The result looks pretty good through.
















There's some holes to drill/tap into the ends of the bearing housing, but I'll wait on putting those in because I have my mill set up with the rotary table and I don't want to tear it down when I have more parts there will require the table.

So that's it for this part.

I also made some crankshaft components, but they're pieces of stepped roundstock and aren't really interesting.

...Ved.


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## vederstein (Oct 13, 2018)

Today I had an apparently successful pour of one of the two cylinders and crossheads:



...Ved.


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## vederstein (Oct 14, 2018)

Much of the order of parts has to do with what material I have laying around and not wanting to tear down my rotary table.   So on to the eccentrics.

I had a small piece of 1" diameter 12L14 barstock (perfect for the eccentrics).  So first it was facing off the stock then turning the diameter.






Then parting off...






Then the part was flipped and the opposite side cleaned up.






After making a second part and some discs for the eccentric covers, it was off to the mill.  The shoulder on the eccentric made it easy to hold in the rotary table.  Then it was a matter of drilling / tapping / reaming the part.  When I started tapping, it just didn't feel right.  I tried a new tap and it was still stiff.  I was afraid of breaking the tap so I changed the design for a through bolt and nut design.  I may not be a pretty, but the risk was too high.






The Eccentric covers had the same drilling and reaming operations.  The only thing noteworthy is that the "teeth" in the rotary table's jaws made it pretty easy to hole the thin disc.






 There's a drilling / tapping operation still to be done, but that's for later when the rotary table is torn down.


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## vederstein (Oct 20, 2018)

Today I worked on the cylinder heads and piston rod glands.  Both are very similar (2.125 dia x .25 thick plates).  I had a chunk of 2-1/2" aluminum round form which to make the parts.  So I turned the material to the correct diameter then parted off the two cylinder heads.





Then I drilled/reamed the material for the Piston Rod Glands.




The design calls for a .375 x .030 countebore for the O-ring pocket.  On other projects I've had variable success with boring tools and endmills.

A couple of years ago I was visiting a garage sale and the guy was selling old counterboring tools.  I purchased the entire box for $20 or something like that.  Until now, I've never used them.

Rummaging through the bag of tools, I found a .375 cutter that worked wonderfully.  If anyone can tell me what this tool is actually meant for, I'd appreciate it.





Then I parted off the part.  Do this three more times and off to the mill.

I used my rotary table setup to drill the bolt circles.  Unfortunately, I assembled the jaws incorrectly and the first part's bolt circle was jacked.  So I re-drilled it.  I can use the part in a position on the engine where the error won't be noticeable or impact engine performance, so the part isn't totally ruined.  Repeat five more times.









And that's enough for the day.

Next time, machining some aluminum castings I think.

...Ved.


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## johnmcc69 (Oct 20, 2018)

Looks like some pretty good progress! Nice work!

 John


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## vederstein (Oct 21, 2018)

I'm glad to see that someone is watching.  I was wondering if anybody had interest in this thread or if I was documenting for no purpose whatsoever.

...Ved.


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## reubenT (Oct 21, 2018)

It's nice work.   I'm glad someone is still interested in steam engines.   I want to make a twin double acting someday,  maybe 20 HP in size,  and pretty much all in cast iron.  (put the charcoal cupola to work)  Haven't decided on exact configuration, whether side by side or opposed or V twin.  And what kind of valves to use,  maybe invent my own style valve.  Maybe a modified gridiron type would fit my ideas.     One to drive another steam truck with a yarrow boiler.   I just love the whole concept of driving around and doing work on firewood power,  and blowing off steam.


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## vederstein (Oct 22, 2018)

20HP is a big engine.  The steam tractors I've seen in that power range typically have a single, double acting piston around 10" diameter.  But they ran quite slowly.

Given a project as you suggest, It would seem prudent to have a smaller, but high speed engine.  The pistons pistons should be oriented in such a way to minimize vibration (horizontally opposed, inline at 180 degrees, or something like that).  A high speed engine (~2500 rpm) would allow the use of power transmission equipment from automotive sources lessening the issue of the rest of the machine.

As for valves, again look at automotive technology.  Poppets which are well suited to higher speeds would be my first thought.  Second thought would be a rotary valve.  Third would be a D-valve, but those aren't the most thermally efficient.

Just a few comments...

...Ved.


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## reubenT (Oct 22, 2018)

Yah.  The old medium size engines usually run around 250 RPM.    I've considered many options.   Kind of settled on about 5" piston size and maybe 1000 RPM. Direct coupled to transmission of a 4x4 truck. Thought about using poppet valves too.     Slide valves don't like much over 200 PSI.   If I use slide or rocker valves I like independent intake and exhaust controls.  Tied together as in the various forms of D valves it's hard to control inlet cutoff while maintaining full exhaust venting.    I have a book full of all manner of creative solutions the steam engineers came up with in the 1800's.   The original gridiron valve minimized valve motion but still had intake and exhaust actions tied together.   I thought about doing the gridiron with independent control for each end,  although it's still a slide valve.  Poppet might be better.  The truck I just got working has the old Westinghouse high speed engine on it,  2 cy single acting.   (600 rpm is high speed when everything else was much slower)   I will have to start using it to see how well it pulls the truck.  I had it going once and it seemed to drive around on the level OK.    If it doesn't climb a hill with a load I will lower the chain ratio to the transmission to give it lower gears.   Been busy rebuilding a semi transmission, haven't found time to play with it.

  Now on the original topic here,    I've heard that aluminum and steam don't mix very well.   But I'm assuming that has to do with wear surfaces in valve and cylinder.  I'm assuming everything but cylinder and valves would be fine in Al.  Even an aluminum cy would probably be ok with a cast iron or brass liner.    I was going to try using an aluminum piston once, since ideally the piston doesn't really bear on the cylinder wall,  only the rings do.   but didn't get further than collecting the parts for that one.    (the Westinghouse engine came along before I put it together, so I used it instead)


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## vederstein (Oct 23, 2018)

For what I'm doing, aluminum will be fine.  We're talking about an engine meant to last for hours, not even tens of hours before requiring a rebuild.  If wear does become an issue, I'll press in a liner and have a slightly smaller piston.

Your project, requires real thought to those items.

...Ved.


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## Rickl (Oct 24, 2018)

Have enjoyed your work. Looking forward to your progress.

Rick
Sth Australia


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## vederstein (Oct 28, 2018)

On to the first cylinder casting.

I used the nub left over from the casting process to hold the part and then I could center drill the opposite end for a live center.  Then I could machine the outside diameter and face off the first end.





I left a bit of material so I count grip on it for machining the opposite end.






I then gripped the part in the lathe chuck via the OD and drilled / bored the cylinder.





Off to the mill.  I set the rotary table to zero degrees then eyeballed the steam chest porting face.  I then used a long endmill to cut the face 1.75" off the center.






Then I could drill/tap the two flanges.  Note that when I flipped the part, I used a dial test indicator to locate the casting square.










And that's the first cylinder until I tear down the rotary table.

...Ved.


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## swarfrat (Oct 28, 2018)

vederstein said:


> The design calls for a .375 x .030 countebore for the O-ring pocket.  On other projects I've had variable success with boring tools and endmills.
> 
> A couple of years ago I was visiting a garage sale and the guy was selling old counterboring tools.  I purchased the entire box for $20 or something like that.  Until now, I've never used them.
> 
> ...



That tool is, indeed, a counterbore without a pilot. Normal usage would have a properly sized pilot in the end to keep the cutting tool aligned with the existing hole.
Craig


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## vederstein (Oct 28, 2018)

I also tried to machine the first crosshead casting.  When I flipped the part, I didn't use a live center to support the end.  I should have and will next time...

(The video is about four minutes.  If you want to see all hell break loose, go to time 3:40.)


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## vederstein (Nov 3, 2018)

I made another crosshead casting and machined the second part up to the point in the video (prior post) where I screwed up.  This time I ensured I used a live center to support the end.  I also placed some thin brass between the casting and the jaws to protect the machined casting finish.  It helped, but I still have some marks on the OD of the surface.  






 Then I could flip the part and drill out for reaming.  This is the same 1.000" reamer I used for the Essex Hot Air Engine cooling fin castings.  On that engine I had a terrible finish, but I didn't know if it was the material or if the reamer was just plain shitty.  Here I had a better finish with far less (but still some) chatter.  So I guess my previous bad finish was mostly due to the material, but my setup also can have some blame.










Next was off to the mill for drilling the holes in the flanges.  This process was similar as on the earlier parts, but here, the clocking of the holes in both flanges is critical.




To do so, I drilled through the clamped (lower flange) in one position.






This allowed me to pin-locate the casting for drilling the opposite side when the part was flipped.  (I couldn't drill all the way through in one setup because then I'd be drilling into the chuck jaws in some of the positions.






From there, I stopped for the day except I felt the need to do a dry fit before I machined the 2nd cylinder parts.  All holes appeared to line up.  Yea!!






That's all for  now...

...Ved.


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## vederstein (Nov 18, 2018)

I machined one of the connecting rods today.  It was surprisingly difficult and my results are serviceable but certainly not where I wanted it to be.

After squaring the material destined to be the upper and lower ends of the conrod, I drilled/tapped and bolted the two pieces together.






Then I indicated the big end center and drilled/reamed the upper and big end journals.







I shifted the part over in the vise and milled the "neck" down.  Then I rotated the part and milled the necked portion the remaining length.





 I disassembled the big end and milled it down to the proper thickness (.500")




After a bit of filing, I have a serviceable connecting rod.  (Proper length screws will come later).






The description here doesn't fully convey how hard this part was to make, but it's the general idea.

...Ved.


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## vederstein (Nov 18, 2018)

Today I also finished up the outer bearing housing.  First I located the first threaded hole per the print.  Then I installed the bearing in the housing and the block.






With one end secured to the block and a solid shaft going through both bearings, I transferred punched the other end of the bearing housing to locate the thread.  I figured is anything was off, this procedure would compensate.






 Then I could drill/tap the punched side.  The bearings were just a bit loose in their housings, so I reassembled the parts and secured the bearings in the housings with some red loctite.

...Ved.


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## Cymro77 (Nov 18, 2018)

Enjoying watching your progress and techniques.  I am very familiar with your cleanup mistake - made it more than once!!


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## LorenOtto (Nov 19, 2018)

vederstein said:


> I'm glad to see that someone is watching.  I was wondering if anybody had interest in this thread or if I was documenting for no purpose whatsoever.
> 
> ...Ved.


I'm sure there are many of us lurking who are to dumb to comment.  I for one am fascinated to learn new techniques and tool usage.  Keep it up.


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## vederstein (Nov 25, 2018)

I made biggie mistake on some of my castings.  I _thought_  I could keep track of what was cast aluminum and what was cast zinc on the shelf.

NOPE!

Well I found that if you alloy aluminum and zinc together you get complete and utter crap.  The material is brittle and cracks easily.  It doesn't cut well and the finish is garbage.  One of my cylinders and crossheads are of this crapinium.  So I guess I need to make some more castings.  I also realized my pattern for the cylinder casting was missing a boss.  So both of those are garbage. Ugh.

So I went onto some of the other components.  There wasn't really any rhyme or reason for the order of these parts, they just need made.

First I completed the machining of the (good cast aluminum) crosshead.  I used the bolt heads to index the part along the parting line so the parting line would get cut away.





Then I indexed to the centerline then drilled and milled out the crosshead slot.










..Ved.


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## vederstein (Nov 25, 2018)

I then made the pistons.  To keep things simple I had a piece of 12L14 steel of the correct diameter.  So I just used that.  The pictures should be self explanatory, this was a fairly simple component(s).








The crosshead "piston" required a bit more thought.  Again, since I had a piece of 360 Brass of the correct diameter, I used that, but first I need to ensure the part fit onto the crosshead frame.  The fit wasn't quite there, so I used fine grip sandpaper in the lathe to get the brass to a slip fit to the crosshead frame.




Note that I kept the part in my 5C collet holder throughout this part to keep everything in place. It was off to the mill where I milled the conrod slot and drilled/reamed the pivot joint.




Back to the lathe.  After parting off the part I cleaned up the opposite side.  TADA: a crosshead piston!









I'll have to wait until the other crosshead frame is made to create the second crosshead piston due to the slip fit requirements.

...Ved.


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## vederstein (Nov 25, 2018)

I created the piston rods but are so simple it's not worth documenting here.  (They're simply lengths of 1/4" rod tapped 10-32 at both ends).

I couldn't resist putting a few parts together.  I had some interferences with the connecting rod which I resolved. and the bottom end of once cylinder is complete.






...Ved.


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## Cymro77 (Nov 25, 2018)

Cool stuff - will I ever get the skill?  Too much to learn, too little time!


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## vederstein (Nov 26, 2018)

I'm a hack (a practical one though) compared to many of the people on this forum.

But then it's just a hobby.  If you enjoy doing it and it's not screwing up the rest of your life, don't worry about your skill level.

A side note:  I document the builds the way I do so people can see how (not) to make a part.  Much of the time, I'm doing it for the first time myself, so I have no idea if what I'm doing is "correct" or not.  Trial and Error Baby!!!

...Ved.


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## vederstein (Dec 8, 2018)

I've been away for some time.  This is not because I haven't been working on the engine, but I've been making duplicate parts.

Anyways, I made one of the steam chests (valve body) today.  Because my castings have lots of flash, there was a lot of flipping to get the thing square.





When I have four "square" sides I positioned the part for drilling / milling the mounting holes and steam chest.  Being a casting, there isn't a foolproof way to find the center, it's an educated guess with some measuring equipment to back it up.  I've had better luck whittling out pockets via multiple plunge cuts with the end mill instead of milling progressive slots.  I had some undesirable scalloping.  It's doesn't hurt the functionality of the part and it's covered so I'm not too worried.  I'll make adjustments on the second one when I get around to making it.






Drilling/Reaming the hole for the valve rod is a bit tricky.  First I used a 123 block to position the valve body square.  Then I found the "center" of the boss where I drilled/reamed the hole.






...continued on the next post...


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## vederstein (Dec 8, 2018)

Because the casting had lots of flash, I put a 3/16" rod through the part and held it in the lathe. Then I could turn the flash away.






The casting then needed milled to the correct thickness.  I kept the 3/16 rod inserted into the casting and used the paper slide technique to find the tangent of the rod radius.  Then I could calculate my position relative to the rod center and mill off the extra material.





The last operation was drilling/tapping the steam supply port.





And the final part:






That's all for now...

...Ved.


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## vederstein (Dec 16, 2018)

I re-cast the cylinders and crosshead frames out of aluminum instead of crapinium.  Then I machined them back to where I last showed them.  So consider these steps a continuation of those parts.

The porting on the cylinders are probably the most cringe-worthy part of this engine because a screw up here isn't recoverable.  The part is scrap.  Gladly as far as I can tell, I didn't screw them up!   (I'll find out later when I try to assemble/rotate/run the engine).

After indexing the cylinder port face to center, I drilled out the slots prior to milling because I've broken too many tiny endmills.  I've always had better luck with plunge cuts then finishing the perimeter.





Then I drilled & tapped for the steam chest.




I rotated the part 90 degrees and drilled/tapped the exhaust port.  I made sure to only go as far as the port face and not over drill the depth.






Then, again flipping the part, I milled out the pilot slots for the pressure porting.





...Continued on Next Post..


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## vederstein (Dec 16, 2018)

...Continued from Previous Post:

I couldn't figure out a way to fixture the part reliably in the vise with the tooling I have, so I resigned myself to tilting the milling head.  I really didn't want to do this because tramming this thing is a PITA!! 




So I positioned the part and drilled to the pressure port.  I visually confirmed I only drilled to the port and not through the port where I could've cross drilled and ruined the part.  (This operation was nerve racking.)




Do this four times (two sides & two parts) and I have finished cylinders.






That's is for this session.

...Ved.


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## vederstein (Dec 25, 2018)

It's Christmas!  What better day to be out in the garage?  (Actually due to my work, I did the family stuff over the weekend, so on Christmas day, it's just the wife and myself.)

Before any work could commence, I needed to tram the mill due to my previous cylinder porting operation:




Today I worked on a some smaller parts.  The first was the valve port face.  The part was simple and the picture should be self explanatory.




Then I worked on the two D-valves.  Before doing the hard stuff, I needed to mill the parts to the final size.  After that I milled the valve rod slots.  Due to the small endmills, some of my cuts were plunge cuts (think like drilling) then a final pass to clean up the sides.  In the past I've broken far too many tiny endmills by being too aggressive.





...Continued on post...


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## vederstein (Dec 25, 2018)

Next was to flip the part and gingerly cut out the port face.  My cut depths were shallow (~.015").




Flipping the part on its side, I could mill the four corner chamfers:




After a little deburring, two D-valves: 






That's it for today.

...Ved.


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## Cymro77 (Dec 25, 2018)

Coming along nicely!  Merry Christmas - I hope the Fat Bearded Gentlemen brought you some new toys for your shop!!
Thanks for sharing.


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## LorenOtto (Dec 26, 2018)

Cymro77 said:


> Cool stuff - will I ever get the skill?  Too much to learn, too little time!


You can say that again brother.


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## vederstein (Dec 29, 2018)

Well,  I was 3D printing the casting pattern for my flywheel.

Needless to say, something went wrong...






...Ved.


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## Cogsy (Dec 29, 2018)

I feel your pain. I've printed my share of those as well and it's always disappointing.


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## vederstein (Dec 30, 2018)

The second try went without any problems.  The issue had to do with positioning of the model.  I printed the pattern vertical to keep the outside surfaces free(ish) of support material.  The software positioned the print crossways to the Y-axis meaning that the print wobbled the taller the print got.  Apparently it wobbled so much that it lost position and you see the photo above.

All I did was rotate the print 90 degrees, and the print went just fine.

(It's not a traditional looking flywheel, but then this engine isn't a model of anything.  It's just a small steam engine.)

...Ved.


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## vederstein (Dec 30, 2018)

Today I worked on some more valve train parts.  Note that every operation shown here was doubled because this is a two cylinder engine.

I turned a piece of 3/8" brass barstock to the round dimensions per the print.  Then drilled/tapped the end.





And off to the mill.  I put the part into my 5C collet and after indexing the part, drilled/reamed the cross hole.





Turning the part 90 degrees, I cut out the slot.  I used my slitting saw for this operation.  I hate, Hate, _*HATE*_ these things.  They scare the hell out of me.






It sucked anyways.  I don't really know what I did wrong, but as you can see from the following photo, the tab was totally screwed up. 






So screw it.  I'll start over with another technique (next post)...


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## vederstein (Dec 30, 2018)

...so back to the slitting operation.

This time I went with a known technique: plunge milling whittling out the slot.  This technique worked.











With that part completed,  I made the valve rods.  These weren't too difficult, just getting the part to the correct length.  Then cross drilling per the print and threading the end.





I made the 3/32 diameter pin (no pictures) to move the D-valve and put together one valve assembly.  It all fit as intended.  (steam leakage is a whole other issue that may or may not exist).






That concludes this session.

...Ved.


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## vederstein (Dec 31, 2018)

On my first attempt at the crankshaft, I used bits and pieces I had laying around.  The truth is, I entirely forgot I purchased material to make the crank.  The first one sucked anyway.

I'm amazed by the folks that turn a crankshaft from a single piece of barstock.  It looks very difficult and I've always been to intimidated to try it.  This engine is no different.  I make my cranks from built up pieces.

The round pieces are just pieces of 1/2" roundstock where I turned down a shoulder.

The trickier part is getting the crank webs correct.  So I drilled/reamed a single piece of barstock that was destined to become the two webs.






Then I marked the approximate center and saw cut the two parts in half.






From there I could index the hole locations and clean up the ends:






All this is fairly normal, the next step will probably send the "proper modellers" cowering under their bed in fear because what I do is so, so wrong.  I weld it!

I pressed the ends together then plug weld the ends.









Then I put the two ends into the lathe to face off the extra weld.






So I have two crank halves.  To join them, I clamped the two parts together with the crank throw installed.  Then weld it up!











I assembled the engine and worked it in with the lathe.  Believe it or not, the crank was about as straight as I ever get.  After some fiddling with piston/crosshead alignment, I can turn the engine with my hand on the crankshaft.  This was a big milestone.






I has planned on making two castings on this New Years Eve (flywheel & 2nd steam chest), but it's raining and to cast material today would be beyond dangerous stupid.  So that's it for 2018...

...Ved.


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## vederstein (Jan 6, 2019)

I have two videos here showing the flywheel casting and machining for this engine.  The first, which is the heavily edited version is for most people.  You can see the creation from making the sand mold to the final clean up in about 3-1/2 minutes.

The second version is for the masochist.  It shows all steps in real time with limited editing.  It's over twenty minutes long.  At least you can listen to the background and guess my music preferences.

Enjoy (or don't)...


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## vederstein (Jan 12, 2019)

Spent some time today working on getting one of the cylinders running.  I wanted to check the design prior to making any more components.

First I realized that my design is a pain in the ass to time.  So I removed the eccentric ring and drilled out the opposite end.  This allowed me to make timing adjustments without removing the eccentric.  I seem to remember that steam engines like their timing with the eccentric 180 degrees out of phase with the crank.  On this engine, 90 degrees was what really worked.  I spent far too much time re-learning this.





Second, my engine had a lot of drag.  After some investigation, my oring seals have swelled.  I guess EDPM doesn't like something.  I replaced the seals, but I'll probably need to get seals of a different materials.

Third, it was a bit troublesome getting the valve rod length correct.  It took several tries, but I got there.  Below is a video of the engine running on one cylinder.  The first part I had the valve rod too short and you can see the engine reversing. The second part of the video has the engine running. Pressure was about 25 psi. I hope this will improve once the second cylinder is active and the engine is broken in.

...Ved.


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## vederstein (Jan 13, 2019)

With one casting to pour and a snowy day outside, making that particular part was out of the question.  So I worked on the engine base. This design was totally based on material I had laying on the floor.  After I made it, I documented (created drawings) of what I created.

I found a length of 3/8" thick by 3" long aluminum.  Looked good to me.  So I cut a four inch long piece and after some squaring and guessing the pilot hole location, I drilled & bored the pilot.  I usually don't have much luck with my boring head.  This time things went well though.





Then I drilled the hole pattern for mounting the plate to the engine block.




I positioned the plate on the engine and used a transfer punch to locate the holes.  Next was to drill/tap the corresponding  threads in the block.




There were some "ears" left over on the material, so I scribed the location and then milled off the ears.  I also drilled/tapped mounting holes of the plate to the base plate.






 The base was made from the same material.  Other than a cut out to engage the vertical plate, it was pretty easy.









...Ved.


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## vederstein (Jan 20, 2019)

Another weekend another snowstorm.  How the hell can I finish this engine when I can't cast the last component!!!!

<GRRRRRRRR>


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## vederstein (Jan 27, 2019)

Last Friday evening it was very cold, but the weather was dry, so I froze my butt off and cast the last component - the steam chest for the second cylinder.

Today I machined said component and installed on the engine.  No need to document, since I already documented the first one.  Then it was about six hours of fiddling getting the engine to run at lowish pressures.

If you remember from my previous video, the engine was running on one cylinder at about 25 psi.  In the video below, I managed to get it to run at 8psi on both cylinders and will sometimes tick over at 5psi.  Good enough for me!!!

As I was setting the timing on the second cylinder, I realized its eccentric was exactly the same position (clocking) on the crank as the first eccentric.  The 90 degree cylinder offset takes care of the timing.  I'll update my design/drawings to reflect this.






Other things I changed.  I changed the piston seals from EDPM to Teflon orings.  The EDPM was near wear resistant enough.  It was difficult to get the valve train free, and much of my tweaking had to do with this aspect.  I started painting the thing.  After the fact, I'm not too thrilled with the purple, but I guess I'm stuck with it now.

This engine is destined to power a spin art machine of my own design for the 2019 Maker Faire season..  Though the spin art machine is only about 40% complete, I was able to test the engine on the spindle.  It works just fine.

Now for the video:



Bye,

...Ved.


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## davidyat (Jan 28, 2019)

Since this is of your own design, can I buy a set of plans from you?
Grasshopper


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## vederstein (Jan 28, 2019)

davidyat said:


> Since this is of your own design, can I buy a set of plans from you?
> Grasshopper



Once I'm completely done with the engine, I'll post the plans on this website, no charge.  This is hobby and I'm flattered if someone else uses my designs..  As I've made the engine, I've caught some print and design errors.  Therefore I don't want to pass those errors on to the next person.  I intend on posting PDF drawings and the solid models (step format) of the engine and the casting patterns.

This engine _can_ be built entirely of barstock if you choose (and it would probably look better), but if you want the castings instead, we can discuss and come to common terms.  I won't gouge on price, but it will expect to be re-imbursed for my material and labor.   I'll probably take orders for one casting run only.  Also, I do the castings in my driveway and honestly they're not great quality.  I tend to have lots of casting flash.

Wait a couple of weeks and I should be completely finished with the engine and I'll  post the drawings.

...Ved.


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## johnmcc69 (Jan 28, 2019)

Really nice build Ved! Nice of you to share your plans & castings here.

 John


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## davidyat (Jan 28, 2019)

Looking forward to getting my hands on this build design and plans. I like to do things from bar stock.
Thanks,
Grasshopper


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## vederstein (Jan 29, 2019)

I've gone ahead and posted the design in the Plans forum

https://www.homemodelenginemachinis...double-acting-steam-engine.30980/#post-319664


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## vederstein (Feb 3, 2019)

I just couldn't get over the paint coverage of the purple modeling spray paint I used on the engine.  I found an alternative paint that I used on my last engine project.  The color is blue, but this paint is much thicker and works quite well when it comes to filling in the nooks and crannies of the casting finish.  You can still tell it's a casting, but the sand cast bumps are much smoothed out.  This paint also adheres to the aluminum barstock components, so they can be painted as well if desired.




I disassembled the engine for painting this time.  It's a risky prospect.  It took so long to get the engine running to my satisfaction that I was hesitant to do it over again.  But so be it...






After reassembling and getting it running ok again, I touched up a few places.  I intentionally left the block raw aluminum.






I did realize that I need to re-make the right hand steam chest.  It simply leaks too much through the valve rod gland.  I used a 0.189 reamer, I guess I should have used a 0.1875 or even a 0.0187 and lapped the valve rod to the housing.  The left side housing is much better than the right.  I just can't let the leakage go.

The leakage isn't a big deal on compressed air, but when I run this engine on live steam, it will create one hell of a mess.

To be continued...

...Ved.


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## johnmcc69 (Feb 3, 2019)

Nice work Ved!
 It looks good in blue.

 John


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## vederstein (Feb 17, 2019)

Sometimes I just don't get it.  I remade the right hand steam chest and reamed the valve rod gland 0.1875.  When I assembled the engine, the new steam chest leaks worse than the old one.  I reamed through both ends of the part in one pass.  After assembling, I can see the gap between the valve rod and the gland.  Perhaps this reaming set I have is just complete junk.

Well, I'm out of castings so I'm out of work for awhile.  Perhaps next week I can get the leak resolved.  Next time I'll go to my -.001 press fit reamer and lap the two parts together?

...Ved.


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## davidyat (Feb 18, 2019)

Ved,
   Looking at what your problem is, what's the reason the valve rod exits the top of the steam chest? When you saw my 1890 Model Machine shop, I finished the Coke Bottle steam engine from PM Research and it has the same type steam chest and no exit at the top for a valve rod. It is much smaller than your design and works fine with only one entrance hole for the valve rod. It uses a round rubber doughnut that is squished a bit to keep it air tight at the only inlet for a valve rod.  There is a hole at the top for air not a valve rod. If you'd like to see the blue prints of the coke bottle, let me know.
Grasshopper


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## vederstein (Feb 18, 2019)

The reason for the exit is to show more moving parts.  It's there entirely for looks and has no real purpose.

Actually I went as far as to consider making the valve covers out of a clear plastic, but reconsidered knowing that I'm eventually going to run this thing on live steam.

Now for a bit of engineering knowledge:  In mechanical engineering circles, a sliding plain bearing requires the length of the bearing to be at least 2 times the diameter.  Otherwise, there's the chance that the rod may bind in the hole.  Being that the rod is 3/16 diameter, the bearing surface needs to be at least 3/8" long.  One one side of the part we have that, so all is good.  Two short bearings spaced far enough apart will also meet this requirement.

On your version of this engine, you don't need to drill all the way through if you choose not to.

Thanks for the inquiry.

...Ved.


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## Andy Munns (Feb 19, 2019)

On most actual small steam engines (<5" bore?) the lower valve rod guide and gland does all the guiding, but over many years wear leads to slop. Larger engines often have a tail rod guide - these are mostly blind and therefore capped to stop leaks. You could thread the OD and fit a cap. Also could fit a cap nut on bottom guide and build a gland.  Sometimes engines have a packed tail rod gland but I have never seen this in practice. Steel valve rod in aluminum not ideal with steam so you could sleeve with bronze bushes, perhaps also incorporating grooves to create a tiny labyrinth seal.


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## vederstein (Feb 23, 2019)

I keep finding new and inventive ways to screw up.

I created two steam chest castings and of course started with the better of the two.  As I was making a finish pass, the endmill slipped in the collet and I created a sloped surface.  CRAP!!!!

So I machined the other one.

After re-assembling the engine I saw that I have a porosity issue.  I'll plug it with some JB weld after the RTV sealing I use to seal the steam chest "sandwich" cures.




Anyways, my excessive leak around the valve rod is gone.  This time I reamed the gland .1870 and then used a piece of 3/16 brass roundstock to lap the gland to size.

In the end, the engine will run (no load condition) on 5 psi.  It will run the Spin Art Machine at 10 psi, but a bit too slowly.  15-20 psi seems to be the sweet spot when running the Spin Art Machine.







Although my casting certainly isn't the prettiest.  I'll look less bad when I paint it.  I'm considering this win (especially after trying about five times getting this component not to leak profusely).

...Ved.


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## davidyat (Feb 23, 2019)

Grasshopper here,
   I'm working on Ved's 2 cylinder engine. Working slowly and following Ved's blog so as not to make the same mistakes. Pictures of my progress so far. When I get to the steam chest, I will probably machine it close to size out of CRS steel I have laying around. Then I will bore a hole length wise while it's still solid and insert a 3/8 " solid brass insert and braze or silver solder it with plenty sticking out either end. Then bore the brass a bit smaller than the valve rod diameter. Then hog out the valve chamber taking the brass rod out of the inside. Lap it when finished to the valve rod. The future engine block is in the 
background. Will be a lot of aluminum on the floor for future melts and pours


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## vederstein (Feb 23, 2019)

David,



davidyat said:


> following Ved's blog so as not to make the same mistakes



That's a lot of mistakes to account for....  

You seem to be flying through this thing.  Being my version has taken about 5-6 months now, you're making great progress.  I see the giant chunk of AL round for the block.  This will be a good use for the dividing head you recently procured.

On a side note I see that you're a "Well known member" with 109 posts.  I have 583 and "Must do dumb things..."  (Years ago I figured out how to manually change the member description to say whatever I wanted it.)  But as for defaults, this makes me wonder what the various criteria for various levels?

...Ved.


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## davidyat (Mar 6, 2019)

Ved,

   As I was going through your build, I came across the problem with angle drilling for your steam ports and having to tilt the mill to do the drilling. I highly suggest getting an angle cube. I use mine a lot and don't have to tilt the Bridgeport head and re-tram it every time. Those angle cubes are pretty accurate to a hundredth of a degree. I use the angle cube with a tiltable vise that I have.
Grasshopper


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## davidyat (Mar 6, 2019)

Oh, and I started a separate thread for my build. It's titled "Vedersteins' Two Cylinder Double Acting Steam Engine.
Grasshopper


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## davidyat (Mar 8, 2019)

Ved,

   Could you e-mail me again. Somewhere, Spectrum has decided on its' own to delete some e-mail addresses from my contact list.
Grasshopper


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