Backlash Compensation
14 Aug 2015 23:19 #61401
by fc60
Backlash Compensation was created by fc60
Greetings,
I have inspected and corrected any mechanical backlash in the X, Y, and Z ball screws via the purchase of some nicely machined German hook spanners. While the adjustment on the tapered bearings of the pillow block is correct, I still have some mechanical backlash in the ball nut itself.
Fortunately, LinuxCNC has a BACKLASH parameter in the INI file. When I insert the value determined via my indicator and testing, it does a nice job of correcting the error.
I would like to understand how the computer detects and applies the compensation.
Does it work only via MDI or while running a program?
Cheers,
Dave
I have inspected and corrected any mechanical backlash in the X, Y, and Z ball screws via the purchase of some nicely machined German hook spanners. While the adjustment on the tapered bearings of the pillow block is correct, I still have some mechanical backlash in the ball nut itself.
Fortunately, LinuxCNC has a BACKLASH parameter in the INI file. When I insert the value determined via my indicator and testing, it does a nice job of correcting the error.
I would like to understand how the computer detects and applies the compensation.
Does it work only via MDI or while running a program?
Cheers,
Dave
Please Log in or Create an account to join the conversation.
16 Aug 2015 02:59 #61419
by andypugh
It works when running a program, but it can only know about the direction of movement not the direction that the cutting forces are acting in. So it is only a partial solution.
You might be able to re-ball your ballscrew, or replace it with a pre-loade version. I did the latter, there was no extra cost, just a longer leadtime.
Replied by andypugh on topic Backlash Compensation
Does it work only via MDI or while running a program?
It works when running a program, but it can only know about the direction of movement not the direction that the cutting forces are acting in. So it is only a partial solution.
You might be able to re-ball your ballscrew, or replace it with a pre-loade version. I did the latter, there was no extra cost, just a longer leadtime.
Please Log in or Create an account to join the conversation.
16 Aug 2015 22:13 #61443
by fc60
Replied by fc60 on topic Backlash Compensation
Greetings Andy,
Thanks for the reply.
Where does one go to purchase new balls for the nut?
Looking at where it is located, it seems a major effort to remove and replace.
Cheers,
Dave
Thanks for the reply.
Where does one go to purchase new balls for the nut?
Looking at where it is located, it seems a major effort to remove and replace.
Cheers,
Dave
Please Log in or Create an account to join the conversation.
17 Aug 2015 01:57 - 17 Aug 2015 02:03 #61457
by andypugh
Bear in mind that replacing the balls is a bit of a game, and also that I haven't actually done it...
One source is a specialist on Amazon: www.amazon.com/s/ref=lp_5737159011_nr_sc...0568ffba88daab4ed518
There is a video here showing the way to do one type of ballscrew (ones with a tube are easier)
Replied by andypugh on topic Backlash Compensation
Where does one go to purchase new balls for the nut?
Bear in mind that replacing the balls is a bit of a game, and also that I haven't actually done it...
One source is a specialist on Amazon: www.amazon.com/s/ref=lp_5737159011_nr_sc...0568ffba88daab4ed518
There is a video here showing the way to do one type of ballscrew (ones with a tube are easier)
Last edit: 17 Aug 2015 02:03 by andypugh.
Please Log in or Create an account to join the conversation.
Time to create page: 0.164 seconds