[SOLVED] Need help creating serations

[gone_bush]

I'm trying to create a model with serrations similar to those in the attached images but I have not been able to do it. Note that the serrations are radial - that is my downfall.

How can this be done?

tia
Kevin

[edwilliams16]

Cut one groove then https://wiki.freecadweb.org/PartDesign_PolarPattern

[gone_bush]

OK, but I've got a mental block on how to draw the first groove. I can do it if it's straight bit not radially.

[edwilliams16]

I made two nested polygons and lofted a triangle between two corresponding faces, then did a polar pattern. To make the edges circular, I pocketed them. I've no doubt there's a better way - I'm still a neophyte.

Screen Shot 2021-06-17 at 6.08.34 PM.png (105.14 KiB) Viewed 692 times

[chrisb]

I remember at least two other discussions on this topic; you may search for Hirth joint.

[papyblaise]

one more idée

[gone_bush]

I remember at least two other discussions on this topic; you may search for Hirth joint.

Hirth joint - never heard of it before but that is exactly what I need.

For the record, I found this video that explains it very well: https://youtu.be/SEnCLU8moN4

Thanks for you help, much appreciated!

[mario52]

hi

How to make a hirth joint?

Work project is kicking my butt

Hirth joint (macro)



Repeating pattern on a cylinder (macro)


mario