Building Elmers #44 Open Column Twin (Final pictures, and video)
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29) I was forced out of the shop for two days. My riding buddies along with help from "Honey" convinced me to uncover my motorcycle and go riding. I don't like this flip flopping between pastimes but it was fun.
Today I made a little progress shown in the following pictures and post.
After hack sawing out the center shaft on the throw ends of the crank I clamped it in my vise using shims cut from an iced tea can. A light milling cleaned up the remaining material. After drilling for the 1/16" expansion pins they were pressed in along with Loctite.
30) Since the raw steel might eventually rust, I gave the crank a quick dip in tool black.
31) The material for the two piston rods was drilled, tapped, clearance drilled and stamped #1 and #2 on the ends that the end caps will be cut from. After cutting them off a little longer than the finished size they were milled flat and to proper height.
32) Like wise the mating cut ends on the blanks were also trued using an end mill.
33)After installing the cap ends with 2-56 screws, the 1/4" and 1/8" holes were drilled and reamed.
34) Both blanks were milled down to 1/4" width from opposite sides.
35) The piston rods are rough at this point. I used a vise stop to make the cuts to the four sides identical.Further milling on the other two opposing sides is required.
36) A simple fixture was drilled and tapped to hold down the connecting rods for the final milling. The cuts can now be duplicated on the remaining four side with reasonable repeatability, using calibrated table moves.
37) With the milling finished up a few minutes with a file to clean up the milling marks went well. If you look at a copy of the plans you will see that my piston rods are radically different from what Elmer drew up. I enjoy making changes by modifying existing designs.
Could be craziness, creativity, or laziness, who knows! :big:
38) I took a mid day break today and stopped by my favorite scrap yard. Finding some goodies made the trip worthwhile. The round spoke piece looks like it could be a flywheel casting. The find was interesting enough for me to post this picture.
The build is coming along well, with a few tough pieces ahead.
-MB
Today I made a little progress shown in the following pictures and post.
After hack sawing out the center shaft on the throw ends of the crank I clamped it in my vise using shims cut from an iced tea can. A light milling cleaned up the remaining material. After drilling for the 1/16" expansion pins they were pressed in along with Loctite.
30) Since the raw steel might eventually rust, I gave the crank a quick dip in tool black.
31) The material for the two piston rods was drilled, tapped, clearance drilled and stamped #1 and #2 on the ends that the end caps will be cut from. After cutting them off a little longer than the finished size they were milled flat and to proper height.
32) Like wise the mating cut ends on the blanks were also trued using an end mill.
33)After installing the cap ends with 2-56 screws, the 1/4" and 1/8" holes were drilled and reamed.
34) Both blanks were milled down to 1/4" width from opposite sides.
35) The piston rods are rough at this point. I used a vise stop to make the cuts to the four sides identical.Further milling on the other two opposing sides is required.
36) A simple fixture was drilled and tapped to hold down the connecting rods for the final milling. The cuts can now be duplicated on the remaining four side with reasonable repeatability, using calibrated table moves.
37) With the milling finished up a few minutes with a file to clean up the milling marks went well. If you look at a copy of the plans you will see that my piston rods are radically different from what Elmer drew up. I enjoy making changes by modifying existing designs.
Could be craziness, creativity, or laziness, who knows! :big:
38) I took a mid day break today and stopped by my favorite scrap yard. Finding some goodies made the trip worthwhile. The round spoke piece looks like it could be a flywheel casting. The find was interesting enough for me to post this picture.
The build is coming along well, with a few tough pieces ahead.
-MB
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39) To make the eccentric strap a layout was scribed onto a piece of 3/16" thick brass stock. I drilled and reamed the 1/2" hole on the large end and the 3/32" hole on the small end.
40) A scrap piece of aluminum was drilled and tapped 4-40 for the large end and 3-48 for the small end of the strap. A 1/2" stepped plug was machined and drilled for a 4-40 hold down screw. To hold down the small end a 3-48 screw was dressed down to .093 for a slip fit through the 3/32" reamed hole on the small end of the work piece. I used two rows of tapped holes on the fixture. The first set was offset to match the proposed taper of the eccentric strap, and the 2ND set of tapped holes are parallel to the vise jaws.
41) The workpiece profile was roughed out and removed from its fixture.
42)After a light cut to smooth things up the work piece was removed and bolted down parallel to the vise jaws. The final step was milling the flat web area down to the 1/8" specified in the plans. This must be a cosmetic step, that does look good when compared to the opposite side.
43) Below is a picture of the finished eccentric strap.
I did a bit of sanding with 600 grit sand paper to remove the machine marks and break the sharp machined corners.
Although the part is far from cosmetic perfection, I'm satisfied with the end result being a usable part.
-MB
40) A scrap piece of aluminum was drilled and tapped 4-40 for the large end and 3-48 for the small end of the strap. A 1/2" stepped plug was machined and drilled for a 4-40 hold down screw. To hold down the small end a 3-48 screw was dressed down to .093 for a slip fit through the 3/32" reamed hole on the small end of the work piece. I used two rows of tapped holes on the fixture. The first set was offset to match the proposed taper of the eccentric strap, and the 2ND set of tapped holes are parallel to the vise jaws.
41) The workpiece profile was roughed out and removed from its fixture.
42)After a light cut to smooth things up the work piece was removed and bolted down parallel to the vise jaws. The final step was milling the flat web area down to the 1/8" specified in the plans. This must be a cosmetic step, that does look good when compared to the opposite side.
43) Below is a picture of the finished eccentric strap.
I did a bit of sanding with 600 grit sand paper to remove the machine marks and break the sharp machined corners.
Although the part is far from cosmetic perfection, I'm satisfied with the end result being a usable part.
-MB
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Wow! Thanks Jack, that quite a compliment!
-MB
-MB
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44) The eccentric was machined from a scrap piece of stainless I had on hand. Due to my lack of a suitable four jaw chuck the offset section was machined using a boring head mounted on the mill/drill. To machine the piece from the out side the cutting edge of the boring bar was turned inward and the boring head was run in reverse.
45) I cut the slot on the slide pin with a 3/32" slitting saw. The piece was mounted in a square collet block so that it could be indexed 90 degrees and cross drilled for the 1/16" pin that will engage the rocker.
46) The picture below shows the slide pin being cross drilled and reamed for a 1/16" pin. It was also drilled and reamed for the 3/32" pin that engages the eccentric strap, (not shown).
47) Below is the finished slide pin.
48) To make the rocker a piece of 1/8" x 3/4" steel was milled down to the required .093" thickness.
49) After milling the rocker blank to 3/4" x 9/16", the 3/32" pivot hole was drilled and reamed.
50) The two slots on the 'L" shaped rocker were milled out with a 1/16" end mill. I took my time and cut .015" deep with each pass. Rushing with this small end mill would result is a poorly finished and over size slot.
51) After free hand cutting out of the excess material, the rocker was milled to final size with a 1/4" end mill.
52) After a light sanding with #600 grit, I dipped the rocker in Tool Black to prevent rust. Also shown is the p rocker pivot pin cut from3/32" s.s. rod. Rather than cross drill it for very thin wire, I cut grooves for 3/32" E-clips. They add a nice neat look, and are easy to remove if needed.
With only a few pins and wooden base to make, the engine should be ready for sanding, painting, assembly, and testing within a few days.
-MB
45) I cut the slot on the slide pin with a 3/32" slitting saw. The piece was mounted in a square collet block so that it could be indexed 90 degrees and cross drilled for the 1/16" pin that will engage the rocker.
46) The picture below shows the slide pin being cross drilled and reamed for a 1/16" pin. It was also drilled and reamed for the 3/32" pin that engages the eccentric strap, (not shown).
47) Below is the finished slide pin.
48) To make the rocker a piece of 1/8" x 3/4" steel was milled down to the required .093" thickness.
49) After milling the rocker blank to 3/4" x 9/16", the 3/32" pivot hole was drilled and reamed.
50) The two slots on the 'L" shaped rocker were milled out with a 1/16" end mill. I took my time and cut .015" deep with each pass. Rushing with this small end mill would result is a poorly finished and over size slot.
51) After free hand cutting out of the excess material, the rocker was milled to final size with a 1/4" end mill.
52) After a light sanding with #600 grit, I dipped the rocker in Tool Black to prevent rust. Also shown is the p rocker pivot pin cut from3/32" s.s. rod. Rather than cross drill it for very thin wire, I cut grooves for 3/32" E-clips. They add a nice neat look, and are easy to remove if needed.
With only a few pins and wooden base to make, the engine should be ready for sanding, painting, assembly, and testing within a few days.
-MB
R
RobWilson
Guest
Hi MB
Just found this thread ,, GREAT photo build and VERY nice machining :bow: :bow: :bow: :bow: :bow: :bow: :bow:
Regards Rob
Just found this thread ,, GREAT photo build and VERY nice machining :bow: :bow: :bow: :bow: :bow: :bow: :bow:
Regards Rob
zeeprogrammer
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Great stuff MB. Thanks for the detail and pics.
Why did you set the collet block on a parallel in the vise?
Why did you set the collet block on a parallel in the vise?
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zeeprogrammer said:
Its a combination of a bad habit and laziness? Bad habit = I have done this before and gotten away with it. Laziness= It's a whopping 3 feet to the roll away were my parallels are stored.
A better way, I should say the proper way, would have been to set it on two low parallels.
Balancing it on one of the jaw slides might not be accurate since the collet blocks chosen offset took it off one of those top slide ways.
Do you follow what I,m tying to say Zee?
-MB
zeeprogrammer
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Metal Butcher said:
Uh...no. I was wondering why it was on a parallel in the first place (why the collet block simply wasn't on the floor of the vise). Now I'm wondering why you say the proper way is to set it on two low parallels. Was there a height issue you were trying to reach? And either way...why are two low parallels better? (Other than, from some recent reading, I'm suspecting that parallels are spec'd for parallelism to height...not their width. Is that right?)
I'm asking out of complete ignorance...I'm not questioning your method.
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zeeprogrammer said:
My vise "floor" is basically like two rails, paralells are used to bridge these so called rails and set a work pieces at a proper work height. Setting the collet block off to one side clears one of the rails leaving the block suppoted on only one side, with two thirds of it unsupported in mid air. The ideal set up is grabbing hold of as much material as possible with the vise jaws and exposing only enough of the work piece to safely complete the machining task at hand. As such hiking it up on parallels should be ovoided.
There was no real height issue with me clamping the collet block in the vise. By laying one parallel on its side raising the collet block up high and outside the jaws of the vise was avoided. Two low ones mentioned would have given the proper side to side support with out raising the collet block to an uncomfortable height above the top of the vise jaws.
Parallels will flex when laid on their side without center support, they should be used standing up were they offer a sound structural method of raising work pieces to a safe and ideal work height.
-MB
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53) Yesterday I made the last of the parts to complete my version of Elmer's #44. The original plans do not include the flywheel I added.
54) To give the project a finished look I cut and routed it's wooden base. As usual I applied four square rubber feet under neath for stability. According to "Honey" the wood bases make my projects suitable for display in the living areas of our home.
55) The picture below shows the intake side with its 3/16" model pipe used for connecting the air supply line.
56) This macro close-up shows the pivot pin and the E-clips I used to hold it in place. The two 1/16" linkage pins were not pinned in place. Instead I used low strength loctite and longer pins. Their longer length gives me something to grab onto in case they should ever need to be removed.
57) This is the business end that shows all the small linkage pieces used to transfer motion from the rotating crank to the single slide valve that operates the two cylinders. This fascinating part of the design compelled me to build this model.
58) This side shows the added exhaust manifold that I made late last night. It was created due partly to a problem I encountered during a feverish attempt to see it run. When I connected the air supply the engine refused to run. I tried setting the eccentric in every conceivable position. No go! All the engine would do is hiss. Then it dawned on me! I had mistakenly connected the air supply line to the exhaust side! This is what can and does happen when I get excited. After switching it, and a few adjustments of the eccentric the motor began to run! Wow, what a relief. The engine Runs well on less than one pound of air pressure!!! At three to four pounds its screaming fast! As Ripley would say, "Believe it or not".
59) With the added exhaust manifold I won't make that silly mistake again. Admittedly though, I also added it for its visual interest.
I hope you enjoyed following my build, as much as I enjoyed sharing it with you!
Below is a video I added to finish off this post. During its production I adjusted the air pressure a few times to demonstrate the engine running slower and faster.
If a picture is worth a thousand words, "then a video tells it all." -MB
[ame]http://www.youtube.com/watch?v=Ld4ca2aha1E[/ame]
54) To give the project a finished look I cut and routed it's wooden base. As usual I applied four square rubber feet under neath for stability. According to "Honey" the wood bases make my projects suitable for display in the living areas of our home.
55) The picture below shows the intake side with its 3/16" model pipe used for connecting the air supply line.
56) This macro close-up shows the pivot pin and the E-clips I used to hold it in place. The two 1/16" linkage pins were not pinned in place. Instead I used low strength loctite and longer pins. Their longer length gives me something to grab onto in case they should ever need to be removed.
57) This is the business end that shows all the small linkage pieces used to transfer motion from the rotating crank to the single slide valve that operates the two cylinders. This fascinating part of the design compelled me to build this model.
58) This side shows the added exhaust manifold that I made late last night. It was created due partly to a problem I encountered during a feverish attempt to see it run. When I connected the air supply the engine refused to run. I tried setting the eccentric in every conceivable position. No go! All the engine would do is hiss. Then it dawned on me! I had mistakenly connected the air supply line to the exhaust side! This is what can and does happen when I get excited. After switching it, and a few adjustments of the eccentric the motor began to run! Wow, what a relief. The engine Runs well on less than one pound of air pressure!!! At three to four pounds its screaming fast! As Ripley would say, "Believe it or not".
59) With the added exhaust manifold I won't make that silly mistake again. Admittedly though, I also added it for its visual interest.
I hope you enjoyed following my build, as much as I enjoyed sharing it with you!
Below is a video I added to finish off this post. During its production I adjusted the air pressure a few times to demonstrate the engine running slower and faster.
If a picture is worth a thousand words, "then a video tells it all." -MB
[ame]http://www.youtube.com/watch?v=Ld4ca2aha1E[/ame]
mklotz
Well-Known Member
Beautiful work, MB. Very professional looking.
Like you, I too was drawn to build the engine by the unusual valving and the interesting linkage motion.
I love the exhaust 'muffler'. I think I'll add one to mine. (If it makes you feel any better, I tried to pump air into the exhaust a few times too.)
Like you, I too was drawn to build the engine by the unusual valving and the interesting linkage motion.
I love the exhaust 'muffler'. I think I'll add one to mine. (If it makes you feel any better, I tried to pump air into the exhaust a few times too.)
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Thanks Marv for the wonderful compliment!
Did you notice that it (muffler) matches up with the style of the guide spigots on the stuffing box?
I used a little creativity in the past to eliminate the unnecessarily simple exhaust pipes on a few previous builds. I made all of them with out any drawing or measuring.
-MB
Did you notice that it (muffler) matches up with the style of the guide spigots on the stuffing box?
I used a little creativity in the past to eliminate the unnecessarily simple exhaust pipes on a few previous builds. I made all of them with out any drawing or measuring.
-MB
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