Wobble plate engine, Elmer's #14 (finished, with pictures & video)

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Great post MB. Excellent detail and tips.

I know what you mean about small parts. I've got magnifiers all over the place now.
Just had an eye check...time for prescription glasses.
Upside is my daughter didn't use all of the FSA we put aside...so I'm going to get some prescription safety glasses!
 
#37 Hi all. Today I decided to make the 'lever pivots'. Making two on opposite ends of a block seemed like a good way to eliminate too many repeated steps if they were made individually.

Below is a picture of the block with four 1/16" saw cuts. It turned out well with all four blocks measuring up within .001". I was thrilled! When I walked over to the bench to look at the plans something didn't look quite right. After re-examining the plans under magnification, I became painfully aware that the read 3/8" width of the block was actually 5/8" on the plan! My poor eye sight got me again! Turns out that I just spent nearly two hours practicing 'block sizing' and 'slot cutting'! With my adrenalin pumped up, and my experience level enhanced, the replacement block took less than one hour.

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#38 The block needed to hang out one side of the mills vise for slotting. This type of clamping can offset the movable jaw and cause uneven pressure on the work piece that could lead to it shifting. To even out the pressure, the opposite end of the vise needed support. To accomplish this I made up two sets of space blocks to match the dimensions on the work piece. This is the first time I used these blocks, and they turned out to be a real secure time saving way to do this set up.

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#39 To cut the out side profile on the sides of the 'lever pivots' I set up a vise stop block to do all the machining on four sides with one set up. After setting the end mill height, and moving the table over the width of the cut, it was simple to crank through each cut by flipping and rotating the work.

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#40 Using the same flip and rotate stop block method I center drilled and drilled all twelve pivot pin holes. I shut off the mill only once to change out the center drill for the drill.

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#41 To part off the pieces using the same slitting saw I used the same flip and rotate method.

However, this time the edge of the vise became my set up stop.

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#42 Earlier on I decided the two mounting holes would be drilled as a last step. After zeroing out the spindle I randomly set up two pieces in the mill vise on top of two parallels. After each piece was individually zeroed out on the left side, the mill table was moved .0942" and then .5317" to drill the two mounting holes on the work pieces.

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#43 After a little careful filing and sanding the 'lever pivots' are finished. Only three are needed for build #1 and build #2. It would have been more work to avoid making the fourth one, and it gave me a spare just in case one decides to jump off my bench, and commit suicide. The block at the bottom of the picture was my "practice" block. ::)

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#44 It was still early in the day, so I decided to make a few more pieces. I couldn't find the diameter of the crank disc on my copy of the plans and decided that 1" would be about right based on the given 3/4" throw of the crank. Since build #1 is a single piston engine the plans specify a counter balanced crank disc.

To make the discs I machined up an over size round brass bar to 1" in diameter. After drilling and reaming the 'shaft' hole deep enough for two discs, they were individually faced smooth and cut off at 3/16" + .005" for a latter clean up of the less than acceptable surface finish created by the cut off tool.

I drilled a mounting hole in a scrap block mounted in the mill, and then zeroed out both hand wheels. I used a tight fitting bolt and mounted one of the discs faced side down separated by a piece of paper to prevent marring it. After off setting the table .375" the crank pin hole was drilled and reamed through the disc and part way into the scrap block. The second discs crank pin hole was drilled and reamed without breaking the set up by simply bolting it down. After reaming, a pin was pressed through it and into the scrap block to become an indexing pin for milling the counter balance profile needed on build #1. The cuts were made as calibrated moves based on the center of the disc being zeroed out. One cut strait in towards the center and out the right side completed the profile on one side. After returning the cutter to the starting point, the work piece was then flipped and the identical cut repeated on the other side. I found this method to be a simple solution to the problems I encountered in the past with reading hand wheels in reverse or dealing with lead screw back lash. Another example of the simple flip and repeat method I used earlier today.

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#45 To complete the crank two pieces of 'shaft' were cut to length and ends were given a ground finish. I pressed them into the 'crank discs' from the faced side .005 short of bottoming out along with Loctite. The crank shafts were returned to the lathe for facing off the additional .005 left on the discs to clean up the sides cut with the parting tool. In the picture below you will notice that one crank disc was not profiled for counter balance. Build #2 is an opposed two cylinder and does not require a counter balanced crank.

I learned quite a bit today, and documented it as best I could in hopes that a beginner like me might find the methods I used today of some use.

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-MB
 
Great post.
Great finish on those cranks!
Beginner? Ha!

I also like that you number your entries. Nice reference. I don't have the discipline for that.
 
#46 For today's post I decided to make the flywheels. I bored out the spoke recesses a 1/2" deep on 1-1/2" and 2" aluminum discs 5/8" thick. Before removing them from the lathe chuck, their 3/16" crank shaft holes were drilled and reamed. Then they were mounted in a 5C spin fixture using a 1/2" mandrel drilled for a bolt to fit their 3/16" bores. using an index of 6-12-18-24-30-36 to equally space the spokes the six holes were drilled and reamed for 3/16" spokes. I center drilled, drilled and reamed all six with one chucking of each cutter by indexing. This helped to make each operation easier to monitor using a dial indicator, and to duplicate each holes depth without breaking through into the crank shaft bore.

The picture below shows two started flywheels, the larger 2" one will be used on build #2, the twin cylinder opposed horizontal.

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#47 To remove the burr's left around the spoke holes by the drilling and reaming, I mounted the discs on a mandrel and chucked it in my 3/8" cordless drill. While the discs were spinning sand paper was applied on the inside recess with the aid of a short 1/4" round bar to sand off the burrs. The drill was run in both directions to De-burr evenly on both sides of the holes. This method does a much neater job than I can do with a Dremel mounted stone or ball end burr.

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#48 Twelve spokes were cut using the band saw. Two different lengths were needed equaling the two different depths of the spoke holes plus an extra .050" for peining them at the outer diameter of the two flywheel discs. One end on each spoke was beveled, and after the addition of Loctite they were driven home and peined as opposing pairs.

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#49 The picture below shows the protruding ends of the spokes being trimmed off. The final machining of the outer diameter will be dealt with latter.

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#50 After the Loctite cured, the flywheel's were returned to the lathe. This time the spokes and recess's were faced inward to machine off the 1/8" excess that held the hub's and outer rim's together during the operations needed to add the spokes.

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#51 With the back side's trimmed off, the flywheels were machined down to the planned width leaving the spokes centered on their rims.

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#52 In the picture below the flywheels were mounted on a "lathe mandrel" to true up their outer diameters. In an effort to reduce or eliminate tool chatter their spokes were packed with "butt putty". This helped quite a bit but I still had some chatter that required re-cutting to produce and acceptable surface finish.

"Butt putty", aka-balistic putty, aka-plumbers putty.

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#53 The sides were trued up by removing equal amounts off both sides. While in this set up a slight bevel to break the sharp edges was added to all the outer corners.

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#54 At last, the final picture. The flywheels are finished except for paint or polish. In the picture below they are shown "as machined" and ready for what ever surface treatment is desired.

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Its approaching two weeks since the start of this build. I was hopping for a two week completion, would have settled for three, fearing four. With holiday preparations its difficult to slip in very much shop time. Oh well, I guess it doesn't really matter. :)

-MB
 
Hi Rick, it looks like you're making great progress on the engine. I have all my shopping done so with the coming Holiday I should get more shop time in. Tomorrow is a music concert so that shoots Sunday.
gbritnell
 
#55 Today I laid out the 'base' plates for build #1 and #2.

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#56 The picture below shows the bushing holes drilled and reamed on the front blocks ('bearing') for both builds

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#57 I drilled and tapped all the holes on the 'column' for build #1

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#58 The three major structural components of build #1 were assembled for a test fit. In the picture the parts are a little sloppy looking but don't let that fool you. All of the dimension and locations of the holes were done with a high degree of accuracy.

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#59 Shown below are the three major components of build #2. There's still quite a bit of work that needs to be done on the #2 'column' (the large piece).

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#60 I'm developing a drafting style that you may find (at least) difficult to understand. The important thing is that it all makes sense to me, and guides my way through build after build with out to many problems. Well.. usually anyway. Below are some of the calculations I do to convert the fractions on the plans to decimal figures, and also to generate machine coordinates.

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#61 Four more pages of calculations needed for today's machining session.

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#62 Below is the drawing ("blue print") of the column for build #2. Its not complete at this point. It will be used to generate another 8 to 10 pages of calculations I need to finish up the column for the #2- Horizontal Opposed Twin.



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The small amount of photos don't seem to show much progress, but I did have a busy and productive day. :)

-MB
 
MB,

If I send you $5, will you promise to use the money to buy yourself a scientific calculator?
 
mklotz said:
MB,

If I send you $5, will you promise to use the money to buy yourself a scientific calculator?

Thanks for the generous offer Marv! You really do care! :bow:

If I sent YOU $10 you wouldn't be able to teach me how to use it. Trust me! Remember that old dog new trick thingy, from your past experience. :big:

Even if I wanted to, I'm too busy doing the work to stop and learn new ways to accomplish the same goal.8)

-MB
 
#63 After drilling and taping the holes on the face of 'column' for build #2, the four taped holes on its opposite ends to hold down the valves needed to be done. When I tried to set up the column in the vise it became apparent that there was not enough room between the work piece and chuck. The set-up I used was stable enough to drill and tap the holes without disturbing the vise and took only a few minutes. A little "odd" but it worked, (feel free to laugh).

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#64 I set up the three 'lever guides' to drill their two clearance holes, and afterward clamped them with their saw cut slot facing up to drill and tap for the two 2-56 screws that go through the column from behind, and hold them in place. Setting up three pieces in a vise this way will not work unless the outer dimension of all three pieces are identical.

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#65 To mill the angled profile on the column, I scribed guide lines and determined by eye ball comparison that a 15 degree angle would be appropriate. The smaller 'bearing' shown on the left side of the picture was previously milled using a 14 degree angle block.

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#66 In the picture below the 15 degree angle on the side of the 'column' is being cut using a 1/2" end mill. A brass shim was needed on the work piece since it was thinner by two thousands than the angle blocks.

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#67 The column profile turned out as well as could be expected. There is a minor discrepancy in the measurement on the flats at its base mounting point. The plan shows 1/2", but mine ended up 7/16". Apparently 15 degrees is not the "exact" angle created by following the dimensions in the plans. With out the angle specified in the plans I gave it my best shot and it turned out with except able results.

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#68 A quick test assembly of the four parts that make up the structure showed that the parts match right up, with no problems. I just love it when ever thing fits the way it should.

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#69 Below is a shot of the set-up I used to mill the angled sides on the 'column'. Trying to line up and locate two stacked angle blocks, the work piece, and a brass shim accurately to make duplicate cuts on both sides would have been impossible. By using a work stop, and taping the angle blocks from shifting, the milling became a simple cut-flip- cut, making both sides equal. Two sided (double stick) tape is a good way to solve a shifting problem like the one I encountered in this set up, and having some in your collection of tools is a good idea. :)

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-MB
 
Boy you're making good progress on your engine. The documentation is first rate. It takes a lot of time to machine, take picture, machine, take picture, download to server, copy to site with text. You'll have another one knocked out in no time.
Maybe after the holiday bustle we'll have to get together and see each other's shop.
gbritnell
 
gbritnell said:
Boy you're making good progress on your engine. The documentation is first rate. It takes a lot of time to machine, take picture, machine, take picture, download to server, copy to site with text. You'll have another one knocked out in no time.
Maybe after the holiday bustle we'll have to get together and see each other's shop.
gbritnell

Sounds good George! I was thinking the same thing, after the holiday recuperation. ;)

-MB
 
MB,

The documentation is first rate. It takes a lot of time to machine, take picture, machine, take picture, download to server, copy to site with text

I agree with George. Just know that the extra effort is much appreciated.

Dennis
 
#70 I managed to do a little work this morning ("Honey" was at work), and decided to post my progress since the builds are nearing completion.

I cut the 45 degree angle profiles on the front 'bearing block, and cut out the square profiles and 30 degree angles on the horizontal 'column' for build #2. All that the pieces need now is final filing and sanding.

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#71 After the final sanding the pieces were wiped down with solvent in preparation for the paint finish. I sprayed on a thin 'base coat' of my favorite color on each piece, one side at a time. The picture below shows the pieces after a 'finish coat' of dusted on 'clear laquer' was applied.

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#72 I forgot to mention that I cut and routed the wooden bases for both builds over a week ago. Every day I applied at least two coats of Tru-Oil using my finger. Prior to applying each coat of the oil finish the bases were buffed with #0000 steel wool. There must be at least twelve coats I applied that the 'Leopard Wood' needed to fill in it's strange grainy surface.

I still need to make up some plumbing to connect the two cylinders on build #2 giving it one air/steam connection, make a few little pins, and probably some other little piece(s) long forgotten that will become apparent when I start assembling the engines.

Hopefully my next post and progress report will show at least one build finished, and maybe running too!. :)

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Merry Christmas everybody!

-MB
 
#73 Hi all, Today I assembled my modified single cylinder, and double cylinder version of Elmer's #14 'Wobble Plate Engine. After a quick eye ball set up of the wobble plate on the single cylinder version, it started to run with a little nudge after the the air supply was connected. I duplicated the wobble plates orientation on the Horizontal Opposed Twin version, and it also started right up. Both engines are set up to run in a clockwise direction facing the flywheel. Surprisingly, neither engine required any note worthy break-in period. Both builds will run slow on less than one pound of air pressure. At 3 to 4 psi they run much faster than I feel comfortable with. When I connected them in to my air supply in tandem they ran at one pound of air pressure. After about an hour of mindlessly watching them run I realized its time to stop, and post the results.

Below are the final pictures of my modified versions of Elmer's #14. I would like to think that Elmer would be pleased to see the pair I built and smile, the way that his work puts a smile on my face.

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#74

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#75

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#76

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#77

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#78

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#79

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#80

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#81

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#82

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#83

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#84

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I hope you enjoyed watching my build, as much as I enjoyed sharing it with you!

[ame]http://www.youtube.com/watch?v=AhAMFF5C10w[/ame]

-MB
 
MB

Those turned out wonderful :bow: :bow:

Do you ever sleep? You went from "What's next?" to DONE in less time than it takes me to decide the machining order for my next part. I really like that shipside grey paint as well.

Cheers, Joe
 
Great job on two fine engines MB. I likt the paint job too!!

Bill
 
Metal Butcher, that was a wonderful job you have done, love the detail and the colors, sure run sweet, thanks for the someday to do projects, got it all saved to file, thanks again, Lathe Nut
 
They look goood, Rick! Interesting motion, and fun to watch when running slow. Especially the twin.
I enjoy that caddywhumpus action of the valve disc.
You have a talent for picking a song to go along with the engine, too.

You referred to the wood that you used for the bases as "Leopard wood". Is that what it's really called? I don't know wood from worms, so, just curious.

Again, good looking engines!

Dean



 
MB,

2 beautifully finished engines. :bow: :bow:

Best Regards
Bob
 
Beautiful job, MB. Love your work.

Chuck
 

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