Autodesk Inventor

[#1]

Hi,

My question:

How can I create bicycle gears that have different numbers of teeth but all have an intertooth distance (distance between the teeth centres) of 12.7mm?

My attempt at a solution and problems encountered:

I made a bicycle gear by patterning a small circle around a large circle then trimming lines (see attached sketch), but this method requires me to estimate the diameter of the large circle before patterning and then keep modifying this slightly until I get an intertooth distance as close as possible to 12.7mm. So I can't get exactly 12.7mm. In my sketch I have labelled this intertooth distance I refer to by construction lines.

Thanks in advance.

[#2]

Why not use the Roller Chain Spocket Design Accelerator?

[#3]

In any case, I would not create a complex sketch like that.
It is better to pattern features than to pattern sketch.

If you Right Mouse Button - Show All Constraints - you will see that there are too many constraints that would have to be solved. 

[#4]

The shape of the teeth is not the shape I want to use. I also need to model a specific chain type. Though I could try and edit them to suit my needs.

[#5 · Accepted solution]

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AdskInv wrote:

 I also need to model a specific chain type. .

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What is the chain type?

You could examine the attached file and alter it (or start from scratch) using the basic technique.

[#6]

A Shimano CN HG94 chain. It's a very narrow chain and is also not symetrical. I might just pick the narrowest chain with 12.7mm pitch that the design accelerator offers.

Thanks.