# Matthew Murray's 1802 Hypocycloidal Steam Engine



## Oldmechthings (Feb 23, 2010)

My February project was completed several days ago with a whole week to spare. Now what do I do for the rest of the month?

Actually it is a pretty simple straight forward model to build. The most interesting thing being the internal geared crank mechanism. and that was not difficult. I usually always cut my own gears. Sure it take a little time, but it is so satisfying when I'm finished, and I can make the gears look like the prototype, rather than modifying a commercial gear to try and make it look right. The internal ring gear was machined on the mill, working the quill up and down like a hand powered vertical shaper. The pinion was machined the conventional way. It must have worked, because they turned out ok.













By golly it really runs too!

[ame]http://www.youtube.com/watch?v=zMSlK5nH6HA[/ame]


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## rake60 (Feb 23, 2010)

Beautiful build Birk! :bow:

Rick


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## vascon2196 (Feb 23, 2010)

Really cool...


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## Cedge (Feb 23, 2010)

Birk
There has been a lot of interest in gear cutting of late. Could you elaborate a bit on how you made the cutter profile for the internal gear? Great piece of work!!

Steve


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## ukanduit (Feb 23, 2010)

Wow!! Nice gears!!


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## cfellows (Feb 23, 2010)

Cedge  said:
			
		

> Birk
> There has been a lot of interest in gear cutting of late. Could you elaborate a bit on how you made the cutter profile for the internal gear? Great piece of work!!
> 
> Steve



Me too, Birk. I'd really like to know how you determine the profile of the cutter for the internal gear. 

Chuck


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## tel (Feb 23, 2010)

Let me add my voice to the call - that set of gears is just totally mind-blowing!


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## kustomkb (Feb 23, 2010)

What a beauty!

I really enjoy the hypocycloidal motion.


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## Maryak (Feb 23, 2010)

Birk,

Fantastic build, :bow: :bow: :bow: just to add to the clarion call more on your internal gear cutting please.

Best Regards
Bob


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## zeeprogrammer (Feb 23, 2010)

Me too! Me too! What everyone said.
Fascinating build. Thanks for posting it.


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## vlmarshall (Feb 23, 2010)

Great work! :bow: I really enjoy watching those things run. 




			
				Oldmechthings  said:
			
		

> The internal ring gear was machined on the mill, working the quill up and down like a hand powered vertical shaper.


Excellent! I've cut internal splines like that, but never a gear. :bow:


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## slick95 (Feb 23, 2010)

Very NICE :bow: :bow: :bow:

Internal gear cutting training...I'm in.

Thanks for sharing...

Jeff


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## Powder keg (Feb 23, 2010)

That was all done on a manual mill ;D That reminds me, I need to get over and see Birk's stuff again. Might even visit with Birk ;D


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## Oldmechthings (Feb 23, 2010)

SHAPING GEAR CUTTERS
  On this particular model the draftsman had done a pretty good job, so I enlarged the drawing to full size and then ground a lathe type tool bit to fit the drawing.
  On occasions I will make my own layout with a sharp pointed compass and pencil, and grind a bit to fit the contour.
  Another way is to use a commercial gear of the same pitch and near the same size (number of teeth) and use that for a template.
  Those methods work for shaping a one tooth fly cutter or shaper type cutter like was used on the ring gear for this model.
   Of course you can also use a commercially made standard multiple tooth gear cutter, and I have a limited selection of those, but to have enough to cut all sizes would cost a fortune.
   I'll try to add a picture showing the set up for cutting the ring gear. I thought I had it included this morning, but I was having some real problems getting anything to work.


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## Deanofid (Feb 24, 2010)

What a beautiful engine! Very interesting motion.

Dean


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## hammers-n-nails (Feb 24, 2010)

thats a very interesting design, i think i could watch it for 10min, i dont think ive ever seen one move, just pictures. very nice. is it still 1 up-down stroke=1rev? dumb question, how did you lock the mill from rotating as you where cutting the ring gear teeth?


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## Diy89 (Feb 25, 2010)

Super NICE! :bow:


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## Xlmyford (Feb 26, 2010)

Hi.
Here you can see another one in progress

http://dampfundmehr.de/im-bau/Hypocycloidal/hypo_1.htm

click on "Seite 3" at the bottom and so on..

One should take a look at this beauty:

http://randomron.com/cycloid.htm#top

and look at 2:28"

[ame]http://www.youtube.com/watch?v=-rIRmj5FqgY[/ame]

Cheers,Ralph


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