FADAL VMC 4020

[dmac88]

We just obtained a used Fadal which looked to be in great shape. However, once started we noticed the z axis motor is getting very hot. We measured the case with a temperature gun and it is running around 150 f - not good as I am told the motor will fault at around 155 f. This motor model (Glentek 6000B) does not come with a brake. We think it may be something mechanical or perhaps the backlash. All advice would be most welcome in solving this problem.

[Neal]

A over heated motor may be a bad motor (ohm out the motor to clear it). It may also be a mechanical binding some place such as gibbs, straps, or ball screw. Measure the amp draw on the motor and with no load around 9 amp max should be the reading if no excess binding is there. Also what is the voltage output to the sevro motor.

Neal

[Mark Hockett]

I know this is probably not the problem but I have to ask, did you remove the pins that hold the Z axis counter weight for shipping? and is the weight, chains and sprockets moving freely?

Mark Hockett

[dmac88]

The counter weight is moving freely and the chain and sprockets seem to be ok. However, it seems that to properly check to sprockets we will have to remove the counter weight. We are not sure how to accomplish this.

[dmac88]

Thank you for your advice. We have checked the current to the z axis motor and are getting between 8 and 12 amps. We checked the current at the axis amplifier to the z axis motor. When we checked the x and y axis motors we only saw 4 to 5 amps. If the motor is drawing excessive amps it would seem to confirm that it is working too hard - am I correct in thinking this or is it an electrical problem in the motor or the amplifier?

[andyb4]

With my experience with these machines, very small movements will cause the motor to run very hot. We were programming point to point with very small z axis movements causing the excessive heat. This is a problem with these machines. We used a pedasal fan to help cool motor.

[DareBee]

It is simple to check.
Block the spindle and remove the Z motor (leaving it wired).
Power it up and check amps.
If it is still 8 - 12 it is not a mechanical problem.
BTW, mark the couplings so you reinstall the motor with the correct orientation for CS.

[Drassk]

I had an X axis motor running really hot on my 4020. It turned out to be a combination of a worn shaft and a bunch of gunk in the motor (powder from worn brushes, etc). If the tach gets dirty then the motor will stutter and heat up, as well.