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Author Topic: Z zero (plane) moves upwards with every Z dir movement  (Read 2279 times)

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Offline ger21

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Re: Z zero (plane) moves upwards with every Z dir movement
« Reply #20 on: April 08, 2018, 10:28:34 AM »
It depends on the voltage your drives require.

23500 is not ideal, as it should be close to 25,000. But it it's stable, it's probably not the problem.

Other than buying a motion controller like the UC100 to bypass the parallel port, I don't really have any other ideas.
If it still does it with a motion controller, then that tells you that you didn't need the motion controller in the first place.
Gerry

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Re: Z zero (plane) moves upwards with every Z dir movement
« Reply #21 on: April 08, 2018, 11:48:55 AM »
So what you say is I shall buy a motion control board and if it doesn't work then I didn't need to buy it?

Offline ger21

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Re: Z zero (plane) moves upwards with every Z dir movement
« Reply #22 on: April 08, 2018, 11:57:44 AM »
Yes. Not terribly helpful, is it.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
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Re: Z zero (plane) moves upwards with every Z dir movement
« Reply #23 on: April 08, 2018, 12:12:34 PM »
I've been watching the stops and I think that they are too sharp. I mean, the machine stops too fast at the end of motions. It almost clicks when it stops when pulling back up from a drill or a carve path to safe z.

Maybe changing that will help. How can I change the deceleration?

I set acceleration back to 80, but I hope there is an option that sets the sector ration lower while acceleration stays the same.

Does Backlash has something to do with my problem? What is that in the first place?
« Last Edit: April 08, 2018, 12:24:21 PM by norbigazda98 »

Offline ger21

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Re: Z zero (plane) moves upwards with every Z dir movement
« Reply #24 on: April 08, 2018, 07:11:01 PM »
Deceleration and acceleration are the same, controlled by the acceleration setting.

Backlash is looseness in the drive system. It's not cumulative, so it won't cause a loss of position.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: Z zero (plane) moves upwards with every Z dir movement
« Reply #25 on: April 09, 2018, 02:11:59 AM »
Well, I tried setting Z backlash to 0.02, which is a full step, and running the program in the air, and it didn't lose position.
Before that I tried 0.01, because that is the size of a step while microstepping, but the position losing still occured, although it was quite smaller.

So it seems like the backlash setting solved it, but I didn't have time for running the program long, so I might be wrong.

Do you say that backlash has nothing to do with it and these are false results? If so, then I'll have to buy another motion control board to eliminate that failure possibility.

Offline ger21

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Re: Z zero (plane) moves upwards with every Z dir movement
« Reply #26 on: April 09, 2018, 07:11:16 AM »
Have you had backlash compensation enabled the whole time?

Backlash itself won't cause a loss of position, but if you have backlash compensation enabled, and the settings are incorrect, then the backlash compensation can cause issues. More specifically, it can try to accelerate too fast and cause stalling. The shuttle accel setting has a large effect on this I think.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: Z zero (plane) moves upwards with every Z dir movement
« Reply #27 on: April 09, 2018, 08:36:22 AM »
No, backlash wasn't enabled until yesterday's evening (in out country). I set z backlash to0.02 and left ever tithing else at 0 and then enabled the backlash and restarted the program.
Today I'll run several programs in the air to test if it really worked.
Re: Z zero (plane) moves upwards with every Z dir movement
« Reply #28 on: April 09, 2018, 05:02:45 PM »
Yes, you had it right. Backlash has nothing to do with it.

Basically it steps on almost every line of the code a step more in the positive direction than on the negative on a moving axis, regardless of which axis we are talking about.

But then sometimes it works great for 2-3 whole codes and then it is wrong again.

Do you have any other ideas before I buy a new controller board?

Offline ger21

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Re: Z zero (plane) moves upwards with every Z dir movement
« Reply #29 on: April 09, 2018, 07:56:16 PM »
Try changing the active low settings on the step pins.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html