Fun with gears...

[scottbot]

Hi,
I finally made some time to play with the GearDXF program and cut some gears. I had to play a bit with the GearDXF program to understand how it works but did find it pretty easy to use.
GearDXF only produces to outside profile of the gear so I pulled the DXF into AutoCAD to build the interior of the gear. I also rounded the roots of the gear teeth in AutoCAD.

The other first for me was machining the back side of the gear. The back side of the gear has the same detail as the front.
Eventually I would like to build a wooden clock and now have the confidence to tackle it.

Scott

1049

[khalid]

Very good..i wish you share your progress of clock with us...i will follow you too..can you tell me How small gear you can make on your shopbot?

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https://www.my-woodcarving.blogspot.com/

[mikeacg]

Scott,

I have done several clocks by hand and hoped to someday bring them to my Bot. I am still learning the machine but now you have shown me it can be done! Please continue to update as you make progress!

Khalid,

Lazy? You? Never!!! (P.S. You need to remove the 's' from https://www.my-woodcarving... to make it work)

[bill.young]

Hey Scott,

This is one I made years ago with my original cable drive ShopBot. It hangs in my shop now and still runs after close to 10 years.

http://seasidesmallcraft.com/gizmo3.htm

Bill

[mitch_prest]

Bill

Do you still have the dxf for the gears in that clock..

mitch

[bill.young]

Hey Mitch,

I'll look but I'd be amazed if I did. I just worked from a couple of articles in Fine Woodworking about making wooden clocks that helped in drawing the gears, and then drew a frame in CAD to hold everything together. I didn't really know what I was doing so there's lots of friction all through the drivetrain, but it still works.

Bill

[mitch_prest]

the fact it works is the important point...

m

[scottbot]

Hi All,
Thanks for the comments.

Kahlid,
I don't know how small a gear I can cut on my ShopBot. The gear in the picture has an 8" pitch diameter and was cut from 3/4" MDF using a 1/4" bit. I would think that I could cut a considerably smaller gear. The gear in the picture was my first ever. I had no concerns about being able to cut the gear. The main goal of the exercise was to be able to cut the spokes front and back and have them turn out. They did so I am happy about that. The whole job went very well. Even when I flipped the piece and cut the back.
I am now curious about how small a gear I can cut and I think I will start working on that.

Bill,
Nice clock! I've wanted to do one for years. It still might be years before I actually get to do one although I am encouraged by the results of my test gear.

If you want to see some very cool wooden clocks check this site out.
http://www.lisaboyer.com/Claytonsite/Claytonsite1.htm

Aloha,

Scott

[khalid]

Thanks Michael for correction and thanks for visiting the blogsite
...The wooden clock is in my to do list, but i don't think my machine is that accurate to make gears...

Scott.. I never did 2-sided machining... I will try to do some corbels by machining one side and flipping it and machining other side.. You did it and i think you are now one step ahead from most of us...

Thanks for sharing your work...

[scottbot]

Hey Khalid,
The 2 sided machining wasn't really all that tough.
A little bit of careful thinking and execution was all it took. I was pleasantly surprized at how easy it was.
You should give it a try. Judging from your posts you will have no problem with it.

Scott

[twelchPTM]

how small of a gear really only rely's on how small a bit you can get your hands on. I have engraved 3/64" lettering in brass with crisp detail. I have seen end mills available as small as .001"

[shoeshine]

I reproduced a 1/2" dia. 18 tooth gear in acetal on my bot. It did reqire a 1/64" endmill from precisebits though. Talk about baby-ing a bit along. Not something I'd care to do everyday, but it worked.