How to scientificially determine best torque values?
I have spent an hour looking here and elsewhere. Has anyone tested to see what torque values should be used on 3d printed parts? I notice that Prusa has been repeatedly asked for torque values. Certainly their engineers must have determined these values to design their parts. But I have never seen answers.
Could anyone suggest a process? I am making this up, but maybe something like this: print ten test blocks with hole sizes like 2.3, 2.35, 2.4, 2.45, 2.5 mm. Measure the torque until stripping of these five holes in the ten test blocks. Find the hole size with the greatest stripping torque and de-rate by 20%.
Now I made all that up out of my butt. But is there a proper engineering method to determine this, or maybe my idea will work with different values, I don't know.
(Engineers: I know the formula is T=kDP, but I don't know the coefficient of friction or the desired tension in kilonewtons. So is there an empirical way to determine the torque rather than mathematically?)
We can all throw out ideas, but I'd really like to hear from a machinist or engineer on the proper or standard procedure.
Cheers, everyone.
Tom
RE: How to scientificially determine best torque values?
You should check out Thomas Sanladerer vids on YouTube as well as CNC kitchen as Im pretty sure Stefan did one on this topic too, think it was this one . For example There are various people on YouTube that have tried to approach this with a semi scientific method.
The trouble with all this of course is that theres so many possible variables, filament type, moisture content, print temps (and so inter layer adhesion), hole orientation, thread size/pitch etc.