3D Printing Soft jaws for CNC milling machines

Just curios if anyone has used the PAHT-CF carbon fiber nylon to print soft jaws. The kind of soft jaws that are used to hold parts being milled on a CNC milling machine?

I frequently print fixtures to hold parts at specific angles/orientations. Just PLA. no crazy tolerances. also no experience with coolant (guess that´s the question?) but John from Saunders Machine Works mentioned that some prints that he has in his machines for months/years to deflect/direct chips and coolant hold up well.

Thanks… That is interesting… I thought the pla would crack from the pressure of the vise. I use mist coolant and it never bothers petg. I have been told that carbon fiber nylon is far more rigid. Guess I’ll have to experiment.

PLA, is actually one of the strongest filaments. Rigid and strong, but not very durable or heat resistant.

Nylon is probably not the best filament to use around moisture. It tends to soften up a little as it absorbs moisture. Not sure if carbon fiber helps with that, but I probably wouldn’t use a Nylon/PA around coolant useless I wanted a little flex. I used some PAHT-CF as a temporary spindle holder on a homemade desktop CNC router and had no complaints. So, if you keep the moisture out it is very rigid. Also note, PA12 works better in moist scenarios than PA6’s, but PA6’s are stiffer when dry.

I would think PLA would probably be the best if you are using coolant, but Nylon/PA6 could be great if you are not. I’m thinking an ABS-GF would be good, but the best that I can think of would probably be PET CF. It takes moisture well and is very strong and stiff. But it’s also very expensive.

1 Like

Very interesting. There are a number of videos with folks using the Markforged with carbon reinforced nylon. Have to do some testing.

Here is a PolyMaker video on some of the advantages and disadvantages of PA/Nylons. As stated before, PA12’s will definitely be better if you plan to introduce moisture, but their video suggests the fall off on the strength shouldn’t be too bad with a PA12. They give a quick and easy to understand reason why moisture is problematic for PA’s and subsequently why PA12 is better for moisture/humid applications. But honestly, I would still look to a PET CF (not PETG CF, these are significantly different) or test in PLA to see if it’s worth worrying about. I’ve seen PLA used to form steel sheet metal in presses. When printed solid, PLA has pretty good compressive strength.

Thanks for the nice video. I recently ordered a few rolls of VOXEL Pla. It is super cheap, (16.99/roll) and is a toughened pla. I am certainly going to test this first. Here is a video you may enjoy:

Best… Richard

Yeah, I like Clough42’s channel. Lots of good info on all sorts of projects. Found his channel last year and have been enjoying it ever since.

I can attest to that: just recently had to make a custom bending die for 3mm aluminium. Plain PLA. Held up great: der ProtoTyp on Instagram

Thanks… I’m going to give it a try for sure.