Matthew Murray's 1802 Hypocycloidal Steam Engine

[Oldmechthings]

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]

 

[rake60]

Beautiful build Birk! :bow:

Rick

 

[vascon2196]

Really cool...

 

[Cedge]

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

 

[ukanduit]

Wow!! Nice gears!!

 

[cfellows]

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

 

[tel]

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

 

[kustomkb]

What a beauty!

I really enjoy the hypocycloidal motion.

 

[Maryak]

Birk,

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

Best Regards
Bob

 

[zeeprogrammer]

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

 

[vlmarshall]

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

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:

 

[slick95]

Very NICE :bow: :bow: :bow:

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

Thanks for sharing...

Jeff

 

[Powder keg]

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

 

[Oldmechthings]

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.

 

[Deanofid]

What a beautiful engine! Very interesting motion.

Dean

 

[hammers-n-nails]

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?

 

[Diy89]

Super NICE! :bow:

 

[Xlmyford]

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