z axes looses about 0.01mm when moving down.

close to killing myself now. Spend a lot hours again. Changed all the wires and even used another arduino. Again disassemled the Z for a final check.
Why why why did i spend 1500 euro's for a piece of hardware which is not working properly. Why doesn't this stepcraft standard has a usb port is a time that computers does not have LPT anymore.
Did several runs again without cutting any material and it always ended 0.7 to 1.5mm above the startpoint

Today i messured the coils in all the three steppermotors. I hoped this would indicate that the Z motor was defect however, all the motors are perfect.
I used the stepcraft 600 for allmost a year now and the Z problem i noticed some month ago. The last parts of a job were not milled all through the material.
Now at this time when i want to make the first 2.5D parts the Z axes is crucial.
I'm hopeless
Anyone a suggestion?

https://youtu.be/Y6UVyX-EGK8

Please take a look at this

https://youtu.be/Y6UVyX-EGK8

Hello,
did you verify there is enough lubrication on all required parts of the Z axis? Did you try lower acceleration or maximum speed on this axis?

Sebastian

Yes i did both. And it worked fine for several month.
Today i will change the Z and X port if then the Z axes works fine and the is a difference in the X it is a problem with the driverboard.
I do not know if Stepcraft has a garantee on it otherwise i have to buy a new one :angry:

I made a lot of changes and nothing seemed to work first but now the first test are looking promising agian.
There were two possible causes.

I reduced the startspeed in Estlcam to 1mm
There was a TL light tube very close to the driverboard. I noticed a buzzing sound on the motors when i turned the light on.
After adjusting both possible factors its working now.

So it was caused by lost steps?

yes. i'm gonna test it this week and if its stil working this weekend i am a happy user again

I keep my fingers crossed !

Well the problem is still there. What i discovered today after so many tests
The Z axes makes every now and then a spontaneous step. I was milling a mold and noticed that on a path when there was no action on the Z axes it made sometimes 1 step. You cant see it of course but you feel it when you hold the axel of the motor. Not every path just every now and then. There is no step in the code .....
What could be the problem here ???

But one step ist only 0.0075mm; a lot of steps would be necessary to result in >1mm (like shown in above video).
Could it be caused by backlash?
Is there a difference if you move the axis 'up from below' or 'down from above' to zero?

Please take a look at this.

www.youtube.com/watch?v=r4I-JYcZRXo

www.youtube.com/watch?v=r4I-JYcZRXo

I'd like to ask Christian Knüll (EstlCAM)
if it would makes sense to place some 10k pulldown resistors
from arduino PIN A3, A4, A5 (should be step x, step y, step z) to ground.

Maybe there is some noise and stepping motor end phase generates a step from the noise.
Or you try to measure with an oscilloscope if arduino generates real steps.

Hello,

things like this can unfortunately be really really difficult to sort out.
But from past experiences I'd try out 2 things first:

1. Get an active USB hub with external power source and plug the Arduino into this hub...
   Some USB ports are really weak and supply voltages way below the nominal 5V.
   This has caused exactly this kind of behaviour on different machines before so it is really worth a try.

   Alternatively you can also supply the Arduino with an external power source.

2. Check the ground wiring. If your step lines float at undefined levels due to high resistance ground connections they will become very prone to interferences.
3. Do NOT put resistors between Arduino and Machine - they massively worsen the signal to noise ratio.
   The signal behind the resistor is much less powerful and therefore more susceptible to be altered by interferences.

Christian