chainring demensions?

[xHOBOPHOBIAx]

I am trying to design a chainring in an autocad program, but can't find any measurements on one, can i get some help, preferably a 44 or 46 tooth ring.

 

[xHOBOPHOBIAx]

i mean just outer diameter and the diameter of the inner hole please.

 

[Korporal]

For a one or three piece crank? If you don't have the crank, these methods won't work, and require somebody else do some measuring for you.

For a three piece crank, you can measure the number of bolts, and distance on center. The number of bolts dictates the shape of the holes (like a constellation of stars), and their distance from one another determines the rest of the geometry. To cheat on the circumference, each roller is 1/2" on center. Therefore a 44 tooth chainring will be 22" in circumference plus a bit for roller width. To compensate for the roller width, add twice the diameter of the roller to each side of the overall diameter (one for each side of the sprocket).

For a one piece crank, measure the diameter of the crank arm at the bottom bracket for the hole diameter, and measure up the crank arm for the little holder peg thing. Figure out the circumference as outlines for a three piece crank.

WARNING: I have never worked with CAD and HIGHLY recommend checking to make sure my guesstimate is somewhat accurate before cutting up something expensive.

 

[xHOBOPHOBIAx]

oh, sorry, no just one for a single piece crank. I have one ordered, just a cheap one, that i can cut and file a design in, just trying to figure out what it will look like.

 

[B607]

Here's for a 46t Schwinn cloverleaf. Center hole, .940". Drive hole, .400". Holes, center to center, 1.345". And the overall dia., 3.90". Show us the results if your program works out. Gary

 

[xHOBOPHOBIAx]

thanks man, right now i'm just trying to get an idea of what i want to do with it. I'm going to try to cut a flur de leis into one since i couldn't find one to buy.