Two Cylinder Double Acting Steam Engine Build

Discussion in 'A Work In Progress' started by vederstein, Oct 7, 2018.

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  1. Oct 7, 2018 #1

    vederstein

    vederstein

    vederstein

    Must do dumb things....

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    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.
     
  2. Oct 7, 2018 #2

    vederstein

    vederstein

    vederstein

    Must do dumb things....

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    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.

    DSC02143.JPG

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

    DSC02144.JPG

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

    DSC02145.JPG DSC02146.JPG

    Then I bored it out to 2.75 inches diameter.

    DSC02147.JPG

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

    DSC02148.JPG

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

    DSC02151.JPG

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

    DSC02152.JPG

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

    Attached Files:

  3. Oct 7, 2018 #3

    vederstein

    vederstein

    vederstein

    Must do dumb things....

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

    DSC02153.JPG
    DSC02154.JPG
    DSC02155.JPG

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

    DSC02155.JPG DSC02158.JPG

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

    DSC02159.JPG

    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.

    DSC02160.JPG

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

    DSC02161.JPG

    Until next time...

    ...Ved.
     

    Attached Files:

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  4. Oct 13, 2018 #4

    vederstein

    vederstein

    vederstein

    Must do dumb things....

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    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.

    DSC02168.JPG
    DSC02169.JPG
    DSC02170.JPG

    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.

    DSC02171.JPG

    DSC02172.JPG

    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.

    DSC02175.JPG

    DSC02176.JPG

    DSC02178.JPG

    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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  5. Oct 14, 2018 #5

    vederstein

    vederstein

    vederstein

    Must do dumb things....

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



    ...Ved.
     
  6. Oct 14, 2018 #6

    vederstein

    vederstein

    vederstein

    Must do dumb things....

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    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.

    DSC02187.JPG

    Then parting off...

    DSC02188.JPG

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

    DSC02186.JPG

    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.

    DSC02189.JPG DSC02190.JPG DSC02191.JPG

    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.

    DSC02192.JPG

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

    DSC02194.JPG
     
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  7. Oct 20, 2018 at 8:40 PM #7

    vederstein

    vederstein

    vederstein

    Must do dumb things....

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    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.

    DSC02195.JPG DSC02196.JPG

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

    DSC02198.JPG

    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.

    DSC02199.JPG DSC02200.JPG

    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.

    DSC02201.JPG

    DSC02204.JPG

    And that's enough for the day.

    Next time, machining some aluminum castings I think.

    ...Ved.
     
  8. Oct 20, 2018 at 10:00 PM #8

    johnmcc69

    johnmcc69

    johnmcc69

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    Looks like some pretty good progress! Nice work!

    John
     
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  9. Oct 21, 2018 at 1:49 PM #9

    vederstein

    vederstein

    vederstein

    Must do dumb things....

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    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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