Possible magnetic electricity problem

dexpiste · Posted at 2019-5-8 00:02:03

Hello, I have a very serious problem, it turns out that the controller works very well but with the spindle off, if I turn on the spindle the cnc loses steps, it goes to the left.
I screened the cables (what I could) I put EMI filters and it shows a little but it is not enough, it keeps losing steps.
The fact is that where I have put the cnc electricity (the plugs) has no connection to ground, can this be why it loses steps?

ytliu · Posted at 2019-5-10 08:26:04

I checked your parameters again, please set #416(Time interval between DIR&pulse) to 3000, #420(Z axis pulse signal Electric Level) to High,and try.

jjae6 · Posted at 2019-5-8 00:32:30

Last edited by jjae6 In 2019-5-8 00:35 Editor

Mechanics is also important. Each motor will support an acceleration and maximum speed type depending on the motor size and type and connected mechanics.
If the problem is mechanical, try first the motor engine with nothing connected: spindle, pulleys, etc, etc.

Edited: Oh, reading your question I've realized that it can be an electrical problem derived from the inverter or power supply that makes interferences. Try removing those items from the main box and installing them outside.

dexpiste · Posted at 2019-5-8 00:57:49

If I also think they are either the source or the inverse (or both) but I have already removed them from the box and the investor closes it in a closet and I do not get too good results, I can not think of anything important to try.

Coolers · Posted at 2019-5-8 03:12:59

Hi, I am new to this forum, I am in the process of converting my X2 mini mill to CNC, and am currently waiting for delivery of DDCVS1.1 control.
I have heard of this problem with other control boards, the reported solution was to ensure that the spindle earth is connected to the controls protective earth. maybe this can help?

ytliu · Posted at 2019-5-8 06:10:18

You can try adding a relay between the controller and the investor.

dexpiste · Posted at 2019-5-8 07:29:36

Thank you all for your help, at the end jjae6 gave me to think and move away as a meter the converter boxes and it seems to work, so everything in order.
What happens is that when you are finishing a piece it slows down and steps and I do not think it is a gcode problem because I have tried 2 with the same results, maybe some controller parameter?

It also happens to me that when piece Z ends, it does not rise enough and if you are not careful, it spoils the piece, why does it happen? the home I do not have connected, I say in case that is the cause.

dexpiste · Posted at 2019-5-10 07:30:59

I think I rushed, it seems that everything worked fine but only testing in vacuum, when this afternoon I tried the controller with a piece again lost steps.
I think I'm going to do what the three of you tell me, which is not like putting a relay on the spindle in this controller.

Coolers · Posted at 2019-5-11 02:28:59

Last edited by Coolers In 2019-5-11 02:39 Editor

Have you checked the micro stepping setting on each of your stepper motor drivers? the motor torque (Power) reduces very quickly, the higher you set the micro stepping. If it is too high, the motor will not have enough power to turn the lead screw, and will be like trying to pull away in a car using 5th gear, very easy to stall the engine, without reducing the acceleration.

The better way would be to use a larger timing pulley on the lead screw and a smaller timing pulley on your stepper motor. this will have the effect of increasing the number of steps to complete a full turn, but it will also increase the motors power.

So if you had a 20 tooth pulley on the stepper motor and 60 tooth pulley on the lead screw, the motor will have to turn 3 times to turn the lead screw 1 turn, (you would need to use 600 steps per revolution) setting the motor driver micro steps to 1 will driver the motor at full power, but becouse of the mechanical advantage (Ratio of the pulleys = 3:1) the Motor will have 3 time more torque.
The main reasons for loosing steps are:
Mechanical issue : The machine axis do not move freely due to miss alignment, or poorly adjusted bearings, or Gibbs beaing too tight if using dovetail slides.
Electrical Issue: Steps are lost due to electrical noise from close proximity to other machine parts etc.
Motor Power: Stepper motor Torque is not high enough to turn the lead screw.

I am sorry if you know this already, but i just want to help.

dexpiste · Posted at 2019-5-11 07:00:55

Last edited by dexpiste In 2019-5-11 07:13 Editor

Thanks for your help, but it is an electrical problem derived from the "noise" because I say this, because this same cnc (without the drivers that I have now) was working in another domestic place, when I took it and put it where I have it now I installed it with mah3 but it could not work because of the electronics and the electrical noise, just when I connected it worked fine but when I turned on the inverter and put the spindle on, the cnc would stop and mach3 would freeze, it would not work, that's why I tell you to be sure that this is the problem, also work works very well but when I turn on the investor happens what I tell you.
What I have noticed is that at least one of the drivers I think works badly. this afternoon I have been involved and I have followed the advice you gave me and I have taken a snap shot of the spindle (I also read about it) and I have put it in the box where I have installed the drivers and it seems to work better until I decided to change the driver of the Y axis to put it to the X and X to Y and it seems to be vastly better because in the Gcode that was executing the Y axis did not require much precision instead the X if, therefore I I have to buy some drivers because the ones I have are TB6600 and they do not seem to be very thin.

What drivers could I buy for a cnc 3040 with ACT 76mm motors? If I know it is not a lot of machine but to begin with it is not bad

Edit:
How about DM542 drivers for this cnc?

Possible magnetic electricity problem

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