hi, sorry but i'm not sure to post this in the ground ball screw section or the help on buying a cnc section or here.
I have questions that may cover multiple topics.
I've searched the forums about ground ball screws and various websites.
However, i need a more definite answer.
The plan is to buy a CNC from K2CNC and the model is a KG3925 that will be modified with a 4th axis attached to it that will also have indexing capabilities. Attached to the 4th axis will be a pneumatic collet closer from dunham tools. I believe K2CNC uses gecko controllers/drives??
We need our parts to be within +/- .001" for tolerances. The plan is to use this machine for high production of parts. The parts are stainless steel 304 tubes that will have small features cut on them such as slots and circles.
We will be using a laser to cut the parts but it's the motion accuracy that I am worried about. From what I've been taught--> The cnc machine that produces your part should have tolerances that are greater by some magnitude than the tolerance of your parts. i.e. to account for wear and tear of machine, accurate long term production of parts, etc...
Is this correct?
This particular model and most of the other models have a backlash tolerance of .001". So they recommended to use a ground ball screw. They said this would reduce backlash tolerance to .0002".
1. However, will this be good enough for our part tolerances? The total linear travel range of the cnc is 39" by 25"
Based on what I read on another website:
Besides ground versus rolled, ballscrews come in different accuracy grades that you should be aware of:
C0 - 3um or 0.0001" per 300 mm / 12"
C3 - 7um or 0.00027" per 300 mm / 12"
C5 - 14um or 0.0005" per 300 mm / 12"
2. Also this machine will be using servo motors, will the GECKO drives (if that's what K2CNC will use) be good enough? I read somewhere that the quality of the drives/motion control equipment has an effect on the accuracy of the cnc motion.
3. Based on my experience with CNC's at school and industry so far (hasn't been much) I know that CNC motion is suppose to be accurate but how about at the micro level or small features on parts? Suppose my tube has an 1/8" diameter and 1/32" or 1/16" diameter hole will be cut on it using a laser. Will the motion control be good enough at these small increments to give me the part tolerances of +/-.001?
I will continue to search the internet for more answers.
Any input is appreciated. Please let me know if I should post this elsewhere. Thanks!