Ballscrew pitch compensation in MASSO?

[mkuivamaki]

Hi!

Is there possibility to compensate ballscrew pitch error? Let's say I tell machine to move 500mm but in reality it moves 500,30mm. Is it possible to map ballscrews with MASSO?

Thanks,

Mikko

 

[tmtoronto]

Would the axis calibration tool be what you are looking for?

 

[mkuivamaki]

Actually no. Some cheaper ballscrews are for example 5mm pitch but the real pitch can be something else. Pitch errors are really small but in long distances it could be quite much. Ofcourse if the pitch error is linear then calibration tool can work.

I have used in my current machine EdingCNC controller. There you could compensate the pitch error like this (software reads a notepad table):

X100.00 100.15

Left value is commanded and the right value is measured movement. Then software does then all the calculation and adds or reduces the steps. As result the commanded and the measured distance are the same. The pitch error can be also non-linear, you can add measuring points as much you want. I made a video years ago:

 

[mkuivamaki]

Found some old picture where I mapped that cheap RM1605 ballscrew. I measured the real distance every 10mm and here you can see the pitch error in each position. The error is roughly 0,1mm / 100mm. After compensation I got my machine super accurate

 

[tmtoronto]

If I understand correctly, Masso calibration compensates for linear pitch error, but you need it to compensate for non-linear errors caused in your linear motion hardware?

Is this the reason precision lead screws are more expensive - they reduce or eliminate this type of introduced machining error?