Centroid Community CNC Support Forum

I located a larger sheet of Delrin and plan on machining these forks two at a time. Since they are only held in place by four M6 screws I am concerned that if I machine to aggressively, the forks could move out of registration.

I have a Shear Hog (.75 inch single flute index cutter) that I use for adaptive tools paths for rapid stock removal. In aluminum I typically run around 40 ipm, .125 DOC, and .45 WOC. I was thinking of taking a lighter pass at 35 ipm, .125 DOC and .3 WOC and leaving lots of stock left behind for the next tool path to remove.

Do you think this large tool may still push the Delrin out of registration?

Richard

I would use CA and 3M blue tape in addition to the screws

Uwe

Thanks. I will give it a try.

RJS100 wrote: ↑Sun Mar 02, 2025 11:39 am Will CAl stick to the Delrin? Is it easy to remove the part from the fixture?

Blue Tape on the fixture and on the Delrin. Z depth part + one tape thickness, remove with a long slim cutter blade.

Uwe

I usually use flat head screws when holding parts like this for a more secure hold.

I used the CA approach and only added the glue to the tip of the forks. Worked great!! Made it really easy to remove once done.

Tom. That is a great idea! Because these parts are not faced, you could actually just use a couple M3 socket screws. If I run these again... I will surely use screws!

Here is a great video on the painters tape and CA glue fixturing. I like it because I hate turning parts over to deck the back

The idea of the flat head screws is that they seat in the clearance drill sized hole and take up the slop. A 6mm screw in a 6.2mm hole allows room for the part to wiggle while machining.

Thanks Tom.

The video of the CA approach is the one I used to machine the parts. Small world!