# Elmer's #46 Comber Rotary Engine



## weez (Aug 18, 2013)

Finally got started on my fifth Elmer's engine today.  Here is the start of the cam ring.


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## weez (Aug 20, 2013)

I finished the cam ring today.  To make the inside cam profile, I did a series of 180 plunge cuts in two degree increments using a Excel spreadsheet to determine the offset from center for each cut.


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## Herbiev (Aug 20, 2013)

Looking great. Keep those pics coming


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## weez (Sep 18, 2013)

Finally got in some shop time tonight and finished the base.


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## Hat56 (Sep 19, 2013)

Speaking of  Elmers engines I saw a two cylinder wobbler geared to a single shaft presented by Tubalcain on youtube and he suggested it was a number 115? made by Elmer. I would like to get the plans for this if anyone can help.

   Thanks  Mark


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## Thivoth (Sep 19, 2013)

It's getting there, can't wait to see the final product


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## weez (Sep 21, 2013)

Next up is one of the two bearings.


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## brian13b (Sep 21, 2013)

What Kind of mill is that?  thanks


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## weez (Sep 22, 2013)

brian13b said:


> What Kind of mill is that?  thanks


It is a Central Machinery item #44991 from Harbor Freight.


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## weez (Sep 22, 2013)

Finished the second bearing today.  Next up will be the cylinder.


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## Inky Engines (Sep 22, 2013)

Weez...

Looking good ... this log brings back fond (and some frustrating) memories of my build of this engine - it's not the easiest of Elmer's engines to build and get running well, but it is worth the effort.

Good luck and kind regards

Geoff at Inky Engines


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## brian13b (Sep 23, 2013)

Is it a good one?  What would you recommend? thanks


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## weez (Sep 25, 2013)

brian13b said:


> Is it a good one?  What would you recommend? thanks


I have had this mill for about a year and am very happy with it.  I am new to machining and this is the only mill I have ever used so I cannot compare it with anything else.  It would help if you would post an introduction in the Welcome section with information on what you currently have or what you are looking for in a machine and what you are looking to make with it.  There are tons of very knowledgeable people on here who are willing to answer questions and help out beginners.


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## weez (Sep 27, 2013)

Here is the start of the cylinder.


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## weez (Sep 27, 2013)

I made a 15 degree angle block that I will use for drilling the steam/air passages.  I used CAD to figure out the coordinates of two holes on a 15 degree angle.  Then I used two drill bits to position it in the vise to mill the angle.


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## vascon2196 (Sep 27, 2013)

Great job with this build so far!

This engine is on my bucket list...with about 30 other Elmer's engines!

I saw a 2X scale version of this engine over the weekend...it was done completely on a rapid prototyper.

Good luck with your build!


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## weez (Sep 29, 2013)

I drilled the air/steam passages and milled the two slots in the shaft.  Then Locktited brass plugs in the holes in the end and faced it off to make the plugs nearly invisible.


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## weez (Sep 29, 2013)

Made two cylinder heads.  Also made the piston and piston rod.  I Locktited the piston to the rod instead of soldering it.  I assume that the Locktite will hold good enough.  I also made the two rollers.  All that is left are the two forks and a flywheel.


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## Philjoe5 (Sep 29, 2013)

Very nice build.  It's looking good.  The bearing profiling work looks great!

Cheers,
Phil


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## weez (Oct 2, 2013)

Finished the flywheel today (other than the threaded hole for the set screw).  I should have spent more time with the hacksaw cutting the corners off of the chunk of aluminum I had on hand.  It took a long time to turn the rectangle down to a circle.  I really should invest in a band saw.  I think that I have all the parts made now.  Now time to polish them up a bit before assembling.  Hopefully I will have a runner in a couple of days.


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## weez (Oct 4, 2013)

Here is the completed engine.  I did run it for a short time yesterday.  It requires about 15 psi to run.  I will post a video after I do a little fine tuning to get it to run a little smoother.


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## jwcnc1911 (Oct 4, 2013)

That looks very good!  I can't wait to see the video.

I don't quite get how these work.  The center line of the bearings are offset to the bottom of the ring?


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## weez (Oct 4, 2013)

jwcnc1911 said:


> That looks very good!  I can't wait to see the video.
> 
> I don't quite get how these work.  The center line of the bearings are offset to the bottom of the ring?



Yes, the center line of the bearings is 1/4 inch lower than the center of the ring (which is equal to half of the stroke).  The ring is sort of an elliptical shape.  I just finished up making brass bushings for the rollers.  I was getting some binding and I hope the bushings take care of that.  Will reassemble after lunch and hopefully it will run better. If it runs good, I will take a video.


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## weez (Oct 4, 2013)

Here is the video of it running.
[ame]http://youtu.be/AliXNUD3EYA[/ame]


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## ausdier (Oct 5, 2013)

Just like a wobbler you have ports that lineup and give a power stroke and then exhaust on the return stroke.
So here is a more liniar version of this.
Just add another roller to the other side and imagine the outter track is round.
As you can see the two circles, pivot and track are offset to give the taper needed.
Hope this helps.


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## vascon2196 (Oct 6, 2013)

weez said:


> Here is the video of it running.
> http://youtu.be/AliXNUD3EYA


 
Great job!!!


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