Problem- Z axis motor over heating

[sitzengruben]

I work with a NH Vanguard 3000. The issue I am having is that the z axis motor is overheating. I have tried to swap the motor and it still over heats on a different motor. I doesn't matter what is hooked if it is off the z axis line of the harness it over heats. I have swapped the cables motors and even the control unit and it persist to over heat. Checked the voltage going to the harness off that branch and it matches that going to the other ones. The volt meter read 25 Volts DC though he motors are rated 5.4 volts DC but the documentation says it should put that out to the motors. In short I am now stumped. any help would be appreciated.

[Torchhead]

Define "overheating". Like it gets so hot the paint starts to smoke or it's just uncomfortable to hold you hand on it. The Z motor will run hotter because it has a constant load (gravity) whereas the other axis do not. Steppers are designed to run hot. They are copper wire and steel laminations. Not much to burn up.

TOM CAUDLE
www.CandCNC.com
Totally Modular CNC Electronics

[sitzengruben]

I define overheating as runs hot enough to burn you, to make a burning smell, and also much hotter than the original motor. Not to mention the other two motors run cool to the touch not even remotely hot even after lots of engraving.

[aminear]

you may have a problem with your driver board. It senses current through the motor and has current limit built into it to limit that.

Take a look at a datasheet for the L297 &L298 stepper motor driver chipset.
It will show a typical setup and the resistor size it uses in the sensing circuit to control the current limit. I would guess you probably use this chipset on your drivers, that is the type on the vanguard 3400.

Arnie

[sitzengruben]

Where can I find the Afformentioned Data Sheet. I don't have a lot of documentation floating around for this thing.

[aminear]

just google L297 on the web, you can also open the machine and look to make sure that is one of the chips on the driver board.

[badger05]

I have just read elswhere in this forum about the bearings on the vertical alignment shafts being gummed up. Has this been checked?