But earlier test show that actual position can be lower after a carve.
Lost steps are a symptom, finding the disease is the tricky part as it can be several factors weighting in or cause is intermittent.
Typical culprits:
Mechanical slipping due to excessive friction/ or lack of enough power
Feed rates / acceleration rates too high for the job asked
Intermittent connection on one of the four Z-motor wires / circuit
Bit slipping in collett
Overheating of the driver cause intermittent pauses, which driver you have?
could my dip switches on my driver be at the wrong place ?
are you talking about the stepper motor driver or the software im using to run the motor
thanks for your time
The stepper driver. Maybe your current setting dip switches are too low? Whatâs switch #4âs value?
As @HaldorLonningdal said, there are many possible culprits.
My motors are NEMA34 and those motors are driven by Wantai DQ860MA 2H microstep driver. The specs for those motors are 5.6amp and 1.8deg/step, im not quite sure what the DEG of 1.8 mean but after some research on the internet i configured my switch like that.
SW1:ON SW2:ON SW3:OFF SW4:OFF SW5:ON SW6:OFF SW7:ON SW8:ON
I tried both setting for switch #4 half current/full current, no change at all. As @HaldorLonningdal said im wondering if my motor are well tuned in velocity and acceleration. But can`t figure out how to tune it right.
UhâŚYes i know its degrees⌠but what does it means
Youâre set for 1/4 stepping at 5.2A. I think thatâs ok.
The settings for your Z axis are $112 (max speed) and $122 (acceleration). There is some trial and error to get those right.
I had this happen when the set screw on the top pulley for the Z axis was getting loose. Tightening it fixed the problem.
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Ok, so you have:
Nema34âs configured for 5.6A - good
Set switch #4 to ON for now on Z-driver
What powersupply (V and W) do you use?
Your micro stepping is set to 1600pulse/revolution => 1/4step
Your motor/driver combination should be strong enough to not miss steps. I think we need more details about your machine.
Also, we need to know what acceleration / rapid values you have for Z, I dont know Mach3 so can not assist on how to do that. Google may be your friend 
As Larry, I had a big problem I didnât realize when the screw that holds in the lead screw (or in my case knob) wasnât tight, and there was about a quarter inch of play in the Z direction. Oops!
Hi
I use 3 power supply âŚone for each driver and they supply 120vac to 60vdc
Ok, then what we still dont know is your current feed rates (rapid and cutting) and acceleration values.
Your system is strong powerwise and I really dont think it is loosing steps from lack of power. So I am more certain this is mechanical or excessive rapids/acceleration values. Only you can tell ut those.
It could also be due to RF noise, causing minute false steps to Z during carve but that is much less likely then mechanical issues.
ok right now my z axis is set at 12816.18steps per inches with a velocity of 43.14 inches per min and acceleration is 5.0 inches per sec
Oh and also the feed rate is set at 50.00
Its strange because when i move my z axis up and down several times it goes back right on zero
During a 3D carve Z may move up/down hundreds, if not several thousands times over.
Jogging a few times up/down will only show a problem if it is consistent.
Reduce acceleration to 50% and run an âair carveâ, as in running in air, spindle off.
If it return to the exact physical spot as before the carve, try running once more with the spindle running.
If still good, use the old acc. settings and run once with motor off, then again with spindle on.
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@ConradCaron - I didnât see you respond earlier, so Iâll bug you again. On my X-Carve, I was shocked to see that I could literally take my hand and push up on the X-Carve and move it a quarter of an inch or so because the lead screw wasnât on tight. If thatâs whatâs happening with yours, I could see maybe that the extra force on the Z during roughing is driving the lead screw upwards, and the relatively smaller Z forces on a finishing pass, combined with gravity and vibrations are allowing the lead screw to fall to its lower limits.
With the motors locked pushing up and down, even with moderate force, should not move the Z axis.
no everything is tights but i have to tell you that i did machine the nut for the acme rod that drive the z axisâŚit was machine with epoxy and i expect this to be the problemâŚnot sure yet still troubleshooting
