Routine Problem

[MauricioTakano]

Ok, I tried to swap the X and the Z axes drivers.
The Z axis continued to be the problem.
So I got the Z axis motor tested.
The motor itself was working, however when I applied 6V it was consuming 5A. The specifications say that by applying 84V it should consume 3A.

[angel-tech]

with steppers you must limit the current, rather than let it draw what it wants.

[MauricioTakano]

Is it possible that by solving the current problem the machine will start working fine?
I tested the motor without the break, does it make any difference in the tests?

[Denford Admin]

If you just put voltage onto the coils then they will observe Ohms law and take whatever current (A) the coil resistance (R) needs at a particular voltage (V)
The stepper drives chop the output to the motors so that they use whatever current they are supposed to. The higher the drive voltage, the quicker it puts current into the coils...until the average chopped current it is supplying is 3 Amp

If the Z motor does not run properly from it's own drive, or another axis drive, and you have removed the brake mechanism then I'd suggest replacing the motor. They aren't that expensive

[DavidB]

I noticed the discussion about USB to RS232 converters and they can run reliably at 115k baud as I used to work on an application that did so and effectively streamed data back from an instrument to a PC at that rate. The caveat that one had to remember after the driver install is that it defaulted to a long latency time and that prevented reliable operation at 115k baud. The latency setting is located via control panel in the settings for the virtual com port and when set to the minimum latency worked fine. IIRC the chipsets used in the converters we used were from FTDI.

[Denford Admin]

I noticed the discussion about USB to RS232 converters and they can run reliably at 115k baud as I used to work on an application that did so and effectively streamed data back from an instrument to a PC at that rate. The caveat that one had to remember after the driver install is that it defaulted to a long latency time and that prevented reliable operation at 115k baud. The latency setting is located via control panel in the settings for the virtual com port and when set to the minimum latency worked fine. IIRC the chipsets used in the converters we used were from FTDI.

That's interesting to know..we never had much luck with them a few years ago. I guess the drivers and electronics have improved since then.