topic Re: Notches on a internal splined cog in Inventor Forum

Notches on a internal splined cog

igers562WV — Thu, 04 Mar 2021 14:50:05 GMT

Working in a .ipt file, the attached shows a internal splined cog that has a notch on each tooth. I am trying to get the notches to change in count to match the count of teeth and still remain centered on the tooth.

I got the notches to constrain to the minor diameter so when I change the minor diameter to a larger or smaller number and back the notch follows suit.

The issue is when the count of the teeth change the notches do not remain constrained to the center of the tooth. I believe they are clocking from the original position which is based on the the angle of rotation origin.

The drawing is based on space width instead of tooth width therefore I had to start the notches using a formula of half the angle of rotation based on number of teeth, if that makes sense.

Re: Notches on a internal splined cog

mcgyvr — Thu, 04 Mar 2021 15:14:06 GMT

Can you post the ipt file?

I'm not sure what variables you have between versions but why aren't you just sketching a single tooth with the notch included/constrained to the middle of the tooth profile and a circular feature pattern to array them around the internal.

Re: Notches on a internal splined cog

igers562WV — Thu, 04 Mar 2021 15:44:15 GMT

I did not draw the original sketch. It is from a template designed by a previous employee.

I was told when drawing up prints for internal teeth we use the space width measurement instead of the tooth width measurement. Which explains why the space width is at 12 o'clock and not the tooth.

I have included the .ipt file

Re: Notches on a internal splined cog

JDMather — Thu, 04 Mar 2021 22:21:12 GMT

Sketch5 is not fully defined?

Re: Notches on a internal splined cog

igers562WV — Fri, 05 Mar 2021 14:00:28 GMT

Forgive me, I am still a novice at this. Which part is not defined?

Re: Notches on a internal splined cog

JDMather — Fri, 05 Mar 2021 14:17:21 GMT

What is the purpose of these two dimensions at the Origin in Sketch1?

Re: Notches on a internal splined cog

JDMather — Fri, 05 Mar 2021 14:21:42 GMT

First thing I would do is sketch 3 circles at the Origin as shown...

Re: Notches on a internal splined cog

JDMather — Fri, 05 Mar 2021 14:24:49 GMT

Then I would sketch a line of symmetry and the two angled lines as shown.

Re: Notches on a internal splined cog

JDMather — Fri, 05 Mar 2021 14:29:51 GMT

Note the simplicity of the sketch thus far...

Re: Notches on a internal splined cog

JDMather — Fri, 05 Mar 2021 15:21:37 GMT

Examine the Attached.

You will have to determine if you want to add a relation between the Number_of_Spaces and the ID.

Re: Notches on a internal splined cog

igers562WV — Fri, 05 Mar 2021 20:45:26 GMT

I cannot answer that question, I did not draw the original sketch. It appears to be "half_space_width_origin"

Re: Notches on a internal splined cog

igers562WV — Fri, 05 Mar 2021 20:53:18 GMT

This seems to be working. However, I need to be able to suppress the notches and notch fillets. Not all cogs will have notched teeth.

Re: Notches on a internal splined cog

JDMather — Fri, 05 Mar 2021 21:48:30 GMT

The do that feature as a separate feature and feature pattern.

You can then alter the pattern or suppress individual occurrences.

Re: Notches on a internal splined cog

igers562WV — Tue, 09 Mar 2021 20:02:37 GMT

JD, I finally figured out how and where to use the formula you supplied: 180 deg / number_of_spaces.

I also had a template for a internal involute spline that was a little trickier to resolve, but I did manage.

Thanks so much for your help.

I will mark your solution as accepted.