Ok.. I want to use my 3d printer to make a small rotary table for Halloween pumpkin. I’m thinking of printing out something with bearings races similar to an angular contact bearing with an integrated ring gear. I have a couple pinions I could find a use for those raptor gears that I replaced. I rolled them against some 48 pitch gears in my surplus gear box and they it seemed to roll pretty size.. At least I thought they where 48 pitch… I guess I should do a lil calculating…
There’s a nice little sight with a bunch of formula for spur gears. http://www.cage-gear.com/spur_gear_calculations.htm So to calculate DP Pd = (N+2) / OD = (20+2)/ .455 = 48.3 ~ 48
Let me try that the other way… OD = (N+2)/22 22/48 = .458 Ok… Seems like that’s right… So. Ok.. So since freeCAD only does metric (big sigh) we need to bounce around systems. So I’m thinking I want a 48 pitch ring gear some where around 100mm 3.937″ So that means I need about 3.937 X 48 ~ 188.97. Just for fun lets go with 200 teeth.
So.. I need to fill in the freecad input screen. According http://www.engineersedge.com/gear_pitch_chart.htm
48 Dp => goes to a circular pitch of 1.661 MM.
Other Particulars Addenum .0208″
Dedendum .0270″
WD .0478
Circular Pitch .0654
So.. I want to figure how to get that into the gear.py input form which from the repository looks like this(with its fault values:)
I need to look at y, c,&j at bit The problem that I’m having at the moment. Is that if I use the code that’s in the repository and try some subtraction everything goes blank. Not sure whats going on here with that..
(Everything comes to a screeching halt)… I had gotten an alternate script but that seems to take a lot of time.
Well this isn’t going to get solved tonight.
[Edit , wanted to fire up the printer and just print out a 200 tooth 48 dp gear…]
When I tried adjusting the first 2 parameters an this is what I got.. (Looks pretty but not exactly what I was looking for…
Let me drop the number of teeth to 59 and see what happens.
Ok.. This is rather amusing… with 59 teeth generates a gear with a few missing teeth. Ok… Lets try 40 and see if we get something.
- Freecad Export to Stl… Something looking a bit weird
