Need help creating these facets in the face of a cylinder..

jcw74801

I wish to create facets into the face of a cylinder like the attached image. The part is one half of an adjustable clamp. I do not have enough experience with CAD to decide which processes to use. Can someone help get me started?

steve_shubin

@jcw74801

Hwere is one way

https://cad.onshape.com/documents/aa9ec76c8565bb88b43a9f93/w/5579493ab30142b7c439532c/e/274f60d24ac83f9cdaad1f48

THE LOFT IS BELOW

mahir

Here's another similar method using a drafted extrude which I think is a bit simpler to implement.

https://cad.onshape.com/documents/d0938c7c1f9f53a416882d38/w/0a898b62540088ea0fc73660/e/37342172147b102dc15901b1

mahir

Umm, there's no attached image.

jcw74801

jcw74801

Ok, hopefully I have successfully added the image...

steve_shubin

@jcw74801

Hwere is one way

https://cad.onshape.com/documents/aa9ec76c8565bb88b43a9f93/w/5579493ab30142b7c439532c/e/274f60d24ac83f9cdaad1f48

THE LOFT IS BELOW

mahir

Here's another similar method using a drafted extrude which I think is a bit simpler to implement.

https://cad.onshape.com/documents/d0938c7c1f9f53a416882d38/w/0a898b62540088ea0fc73660/e/37342172147b102dc15901b1

jcw74801

Thank you Steve, this is wonderful. This was far beyond my skill level. I will learn a great deal from this example.

jcw74801

Thank you Mahir!

steve_shubin

@jcw74801

I like Mahir’s way. Definitely simpler.

Be aware that there are differences in the models

Mahir’s facets are planar (edit - typo correction of planer to planar)

The ones I did are not planar

In my case, the entire flow line at the valley is on the XY plane. Something I thought I was possibly seeing in the picture, where the V’s at each end of the groove were the same depth

But Mahir’s way is slick. Very nice!

S1mon

I haven't dug into the models, but a couple thoughts:

1. Planar facets are going to be easier to inspect and tool. If something doesn't need to be complicated, don't make it so.
2. You'll need to check how the mating part works. I'd have to think for a while about how to make sure that you get all the angled faces theoretically contacting fully. In reality, nothing will be perfect and stuff will contact at points and lines and wear in, but nominally you probably want to start with flat contacts. It's probably best to create the mating part in the same part studio. 
3. Is the angle of contact right for your application? Too shallow and it will be easier to wear and turn when you don't want it to. Too steep and it won't ratchet very well.
4. Depending on cycle life, wear might be an issue. If you can, use dissimilar materials for the two parts so that they wear less.

jcw74801

Steve, I did notice the differences and I think either way would work with my project. I am going to use Mahir's approach for its simplicity. I did learn several helpful techniques from your process. Thanks again for your input

jcw74801

Thanks for your input S1mon. This part will be 3D printed for personal use. I can print prototypes as needed until I get the fit and strength needed. I won't need fine precision with the mating surfaces as there won't be much stress on the clamp. The clamp will rarely need to be adjusted so wear of the mating surfaces won't be a concern.