Jogging problem <solved, noise issues>

[mario.morosavljevic]

Greetings everyone,

So, to summarize the whole story up first, we had our Leadshine DM860 drivers wired according to the scheme where it was wired directly into Acorn motor ports but we had a problem with jogging. For example, when we tried to fine tune our steppers, by giving a command to move G1X1200F200 it was moving but glitching (every here and there it would stop for a second or less but CNC12 kept counting as if axis moved). After that, we gave a command for the axis to move back to X0 and after 200-300mm it stopped moving completely but CNC12 kept counting as it was moving. (Signal was cut from drivers completely, we tested it with a scope). We tried to solve problems ourselves, we scoped and measured everything we could to rule out if drivers or motors are causing a problem and we concluded they work fine (worked fine on mach3 a few days ago as well). Then we contacted Mr. Keith and he suggested that we wire drivers according to other the Leadshine schematics (will attach it here as well) using DB25 port and to change Acorn parameter 968 to 12. Today we wired everything up, changed that parameter and shielded up all wirings in our machine with copper foil and grounded it just to remove as many inducted noises as possible. Then in the wizard, we changed a DB25 signal mapping tab according to the scheme. And then a new problem appeared.

So the first problem today, when we powered everything up and started CNC12, we couldn't home Y-axis (in a negative direction). Then we tried to jog Y axis and it wouldn't move either, then we tried with ALT-J and move it with arrows still nothing. BUT the problem was "fixed" once we jogged our Z axis first. So we jogged Z axis for a small distance in any direction and then Y could move (jog) as well. So that's how we had to home our machine on the very beginning. Then the second problem started when we started to calibrate/tune our Z and X axes but sometimes when we need to jog in Y- direction steppers are not moving (CNC12 is counting as if it moved). Y+ direction is working fine, only - direction is causing a problem which confused as greatly. We can't tune our Y axis at all because of it.

During calibration of the Z-axis, we had the same problem with incremental jogging in 1x mode (it moved in a + direction in x1 incremental mode but not in a - direction). So Z axis worked fine in x10 and x100 incremental same as with continuous. We fixed that problem by restarting CNC12 then it worked fine but Y-axis problem wasn't fixed.

On diagnostic screen (ALT-I) there was no limit tripped or anything which could cause a problem with Y axis in a negative direction. In the wizard DB25 mapping tab we didn't change any signal name, Mapping=enable, Header Selection=db25, drive selection=deafult.

Our gear is:
4xNema 34 steppers
4xLeadshine DM860 drivers, each with own power supply
Chinese 2.2kW water cooled spindle
Ball screw on Z axis and belts on X, Y and slave
We're using slave motor configuration on the Y-axis
Our limit/home switches are NPN NO
We did wiring between acorn and drivers with 1.5mm^2 wire (15awg). All wires are shielded with copper foil grounded to chassis. I will attach a photo of our setup but it's outdated (before DB25 wiring I totally forgot to photo it today again even tho I generated a fresh report zip, silly me...)

Any suggestion what might be causing such a problem?
Thanks in advance and have a blast day,
Mario M.

[cnckeith]

mario,
hello. thanks for posting good information.
the report message logs shows ALOT of limit tripped messages.
Use "Bench Test" mode to debug axis motor movement. once you got the motors moving good..then move onto adding switches etc..

[cnckeith]

and you may want to read this..
viewtopic.php?f=63&t=1801

does the machine really move 37.6991 mm per one revolution of the Y axis motor?
and why is the Z axis steps per rev different than X and Y when you are using the same drives for all?

[martyscncgarage]

You didn't post the screen with your travel limits, nor did you post a picture of the main screen showing us the error messages in the dialog box.
As Keith eluded, my first hunch was a limit switch problem and that you didn't setup your soft limits yet....

[mario.morosavljevic]

and you may want to read this..
viewtopic.php?f=63&t=1801

does the machine really move 37.6991 mm per one revolution of the Y axis motor?
and why is the Z axis steps per rev different than X and Y when you are using the same drives for all?

Hello,
thank you for your time and effort to help us out! Limits are being tripped in a message box which you posted so many times because we were restarting CNC12 and Acorn multiple times out of desperation each time we tried something to fix it. Each time we start CNC12 those messages "limits tripped, cleared" etc is shown. Each time we started a CNC12 we tried to home it but Y negative direction just wouldn't move (X, Z and jogging in Y+ are working fine!)

To answer your question Mr. Keith, yes machine is really moving around 32mm per revolution (37mm was before calibration). The reason is, we made X and Y axes with a pulley, rack, and pinion. The gear ratio between pulleys is 1:3. The kinematic circumference of the gear is 113.097 mm if we consider that ratio is 1:3 for 1 revolution of stepper machine will make 1/3 of the kinematic circumference which is 37mm (roughly). That's why it's 37 and yes it's really doing around that distance per revolution (now calibrated it's around 32 mm because we've made the machine without gear clearance, check pictures of our system you'll understand how we did it with springs). Calibrated X axis now is working with literally few micrometer accuracy. We were really pleasantly surprised at how accurate Acorn and CNC12 can be.

Today we tried your advice and configured Z-axis step/rev to 4000 like other drivers. We were still having problems when homing Y axis because it's still not moving in a negative direction! After a few tries of restarting CNC12 and few tries to the home machine we finally did it (that's why you'll probably see limits tripped again in the message box because we were restarting CNC12). Y-axis in a negative direction starts to work again AFTER we jog Z for a few mm in a negative direction. That's where the devil lays, why is Y- working after we move Z- first. Before Z movement we can try whatever and it just won't work. When we successfully homed our machine we tried to calibrate Y axis. We achieved rough calibration and Y-axis is accurate in 0.69 mm (on 2000mm of distance, the machine did 2000.69mm). And then we wanted to try with our dial gauge indicator but Y- didn't work again (machine was on 2000mm of distance from limit). When we press to jog Y negative, CNC12 is counting as if the machine is moving but it doesn't (literally no signal towards the driver)!). Well, we got pissed really badly and we gave up because machine coordinates weren't valid anymore and we called it for a day (10 pm here). While Y NEG is not working (malfunctioning or whatever) Y positive works just fine! Soft limits, limit switches or anything didn't appear in the message box. I doubt CNC12 would keep counting if that's the issue.

Incremental jogging on the Y-axis in x1 mode is working weird. It's acting weird and it's moving randomly. We've measured with dial gauge indicator. First click it doesn't move at all, 2nd click it moves 0.015mm, 3rd 0.005mm, 4th 0.02 etc... X axis in the same configuration (and same drivers, gears, rack everything) works fine and very very accurate (I'm talking micrometers here). According to calculation, everything should work fine. I do understand you get and hear a lot of weird and basic questions especially on youtube clips but we're three guys with a master engineer degrees (2 mechanical and 1 electrical) and we really do understand math between whole construction of our machine (which we made) and step parameters.

Mr. Marty, thank you for your response, effort and all of your work on youtube. It's seriously remarkable how well made and informative are your youtube clips. I understand why you suspect soft limits (we thought it too, even though we configured travel limits right in the wizard. Our machine dimensions are 2500x1500mm), but how can you explain, why Y axis won't move in a negative direction (it always works in a positive direction), and after we move Z axis it starts to jog again in negative again. The same thing happens when we jog forward first and then try to go back, forward it works and it's not moving back. Why is CNC12 counting as if the machine is moving but it's not?

I'm attaching photos of how we rewired it, our ballscrew on Z and pulley, pinion, rack system on other axes as well with fresh report.zip and new config screenshots. In the signal mapping tab, we tried drive selection=Leadshine and it's still not working.

Thank you in advance and have a nice day,
Mario M.

[cnckeith]

Mario
please define you idea of machine axis directions.

please draw a stick diagram of your machine and put the TOOL movement x, y z direction arrows showing positive and negative TOOL movement on it so we all know what you consider positive and negative is.

[cnckeith]

its really hard to read huge paragraphs to figure out what the issue(s) are. Please state them like so

1.) Y axis homes in wrong direction..
then put the explanation here...

2.) Limit Tripped messages.
put explanation here.

[cnckeith]

what kind of limit switches are being used?

set them up to use HomeALL rather than individual inputs.

[cnckeith]

Please ALWAYS post a fresh report.zip when asking for help, you might not get a response if there is not a fresh report.zip file since we don't have the info needed to comment.

[cnckeith]

what happens when you swap axis signals from X to Y (disconnect motors from machine) does the problem follow the motor/drive or stay with the axis?