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Apologies - somewhat out of context. My reference to "noise" is related to babble rather than advice and to the value (or lack thereof) to the continued thread, and not a suggestion at all of electrical noise.
For absolute clarity - I do not mean electrical noise, for the reasoned evidence that Jazz gives.
12.68mm I just doubled checked it now.Quote:
Originally Posted by JAZZCNC
Ah ok my apologies also, now I read it again in this context I see it, I didn't before and just saw electrical noise and with you being an electronics Wizz and the other electronic bull shit that's going on in another thread I thought OH NO please don't go there...:joker: :loyal:Quote:
Originally Posted by Doddy
Have you tried with a different vernier caliper or always the same one?
Always the same one but you can see a mm on a ruler which I also tried, the bit is a 1/2" trend router bit, and it's in a 1/2" collet so I think my calipers aren't the issue here.Quote:
Originally Posted by phill05
The pocket even using measuring tape I can see are 1mm undersized.
BUT this gap is meant to be 100cm so the only thing I can think off is the controller is offsetting the tool.
Attachment 27729
Thinking I might need to connect the X, Y & Z to a breakout board and do a test cut from linuxcnc super slow to see if that shows the same size issue.
This is a wild shot but suppose must be asked.! . . .You have trammed the spindle haven't you.? Does the bottom of the pocket measure same as the top.?
I can't remember if I did now, I've had the Z off a few times including changing the gantry rails, did I tram it last time?Quote:
Originally Posted by JAZZCNC
Will go check shortly.
Actually, on reflection, it wouldn't make any difference the size would still be correct it's just your pocket walls would be a parallelllllll gram or what ever they are called..:thumsup:Quote:
Originally Posted by Desertboy
Have you measured your backlash? You need to check backlash.
A couple of experiments for you to try.
*** CAUTION: Hand coded G-Code and un-tested. Sit next to your E-Stop!!! ***
Attachment 27730
This should slowly rock the X-axis by 0.5mm (or 18 degrees on a 1610 screw) - wrap a bit of tape around the x-axis screw with a visible tail and run this g-code through the controller and observe the tape. The G-code has got a feed rate of 10mm/min so my poor maths suggests around 3 seconds to go 0.5mm (18 degrees) and 3 seconds to go back to 0 (0 degrees). It repeats... a few times. No spindle and no z-movement.
This is just to verify that there's no backlash compensation active erroneously or not in the controller. You'll have to eyeball the 18 degrees rotation on the screw/tape.
Remove tape.
Attachment 27731
This one cuts two pocket outlines - with your 12.7mm milling bit, starts at (0,0) and cuts a 3-tooth comb with a positive displacement on X, 50mm between teeth. After the 3rd tooth it reverses and cuts another 2 teeth offset in Y 30mm back the other way also 50mm apart. This to verify again that there's no backlash effects or compensation in operation.
Sorry, that's all I can think of at the moment.