G540 & Heat

[Bob La Londe]

How hot does it get? I just swapped out a controller and 280 oz steppers I was not happy with for a G540 AND 3 340 oz steppers from CNC Router Parts. As soon as I got the stop limite inputs figured out it worked. I had to go to 40000 steps per inch, but now the rapids scream. Not sure if its a mathematical limitation, but I get about perfect test cuts at that step ratio, but the max speed the software will accept is 52 TPI. In exact stop mode I got a very nice 4x4 test grid engraving.

Running a 48 volt power supply by the way.

Anyway, the motors got uncomfortabley warm, and the bottom of the G540 got almost painfully warm. Is that normal?

My old controller and motors never got anywere near that warm, but then they never seemed to work quite right either and seemed to have very little holding force and would stop and bind easily.

[ger21]

Read this.
http://www.geckodrive.com/upload/G54...Experiment.pdf

[Bob La Londe]

Originally Posted by ger21 Read this. http://www.geckodrive.com/upload/G54...Experiment.pdf

That's pretty straight forward.... MUST HAVE either a cooling fan or a heat sink on the G540.

[rowbare]

Stepper motors run very warm. It isn't unusual for them to be uncomfortable to the touch.

bob

[Bob La Londe]

Originally Posted by rowbare Stepper motors run very warm. It isn't unusual for them to be uncomfortable to the touch. bob

Would it hurt / help to make some aluminum heat sinks and throw them on the steppers?

[Crevice Reamer]

That test is flawed IMO, because it uses a fan in both cooling augmentations. I would prefer to see a test incorporating a passive (no fan) heat sink.

My Keling 48V/381s run at 112 degrees open air



and 127 degrees covered. That is respectively 65 and 50 degrees below max motor temp. Either one is well within normal operating range and requires no heat sinking. I can comfortably hold my hand on the 112 degree motor.

CR.

[rowbare]

I don't think it is worth the effort to try and heat sink the motors. While the motors feel hot, they are well within the design specs.

bob

[Crevice Reamer]

Originally Posted by Bob La Londe I had to go to 40000 steps per inch, but now the rapids scream. Not sure if its a mathematical limitation, but I get about perfect test cuts at that step ratio, but the max speed the software will accept is 52 TPI.

I assume you mean 52 IPM?

1. Why are you running 20 TPI screws?

2. Raising your Mach3 Kernal speed to 45K might get you up to 80 IPM or more.

Best solution is to lower that screw TPI.

CR.

[ger21]

My steppers are pacific Scientific, and they recommend mounting to an aluminum surface to help cool the steppers. The aluminum plates they're mounted to draw quite a bit of heat from them.

[Bob La Londe]

I assume you mean 52 IPM?

I did.

1. Why are you running 20 TPI screws?

Because its what came on the "mill." Interestingly with my previous motors and controller it was close to correct at 32000 steps per inch.

2. Raising your Mach3 Kernal speed to 45K might get you up to 80 IPM or more.

Ok, I'll give it a shot. I'm just very paranoid about changing much at one time. I'm constantly messing with this setup to try and prevent lost steps, and binding, or just dropping out. I'm hoping the Gecko controller and the new stronger motors will eliminate some of that. I was told I should be able to get 60 IPM reliabley with this setup on this machine.

Best solution is to lower that screw TPI.

Yeah probably, but with the issues I've had on this machine with binding and adjustment I hate to reduce the mechanical force.

CR.

Thank you.

[Bob La Londe]

That test is flawed IMO, because it uses a fan in both cooling augmentations. I would prefer to see a test incorporating a passive (no fan) heat sink.

I will have to reread it. I didn't read it as to say that it used a heat sink and a cooling fan in test 3.

My Keling 48V/381s run at 112 degrees open air

I guess I should have thrown my gun on them. My calibrated hand says they are a lot hotter than 112F though. Of course ambient in my shop is probably a lot hotter than in yours too.

and 127 degrees covered. That is respectively 65 and 50 degrees below max motor temp. Either one is well within normal operating range and requires no heat sinking. I can comfortably hold my hand on the 112 degree motor.

It isn't comfortable for me with these motors.

[Crevice Reamer]

Originally Posted by Bob La Londe I assume you mean 52 IPM? I did. 1. Why are you running 20 TPI screws? Because its what came on the "mill." Interestingly with my previous motors and controller it was close to correct at 32000 steps per inch.

Understood. Your previous controller probably had 1/8 micro step setting instead of 1/10.

2. Raising your Mach3 Kernal speed to 45K might get you up to 80 IPM or more. Ok, I'll give it a shot. I'm just very paranoid about changing much at one time. I'm constantly messing with this setup to try and prevent lost steps, and binding, or just dropping out. I'm hoping the Gecko controller and the new stronger motors will eliminate some of that. I was told I should be able to get 60 IPM reliabley with this setup on this machine.

Your 380 motors are delivering 1040 RPM right now. At 48V they can only reliably deliver 1097 RPM. Raising Kernal speed won't really gain you much.

Best solution is to lower that screw TPI. Yeah probably, but with the issues I've had on this machine with binding and adjustment I hate to reduce the mechanical force.

Changing the motors to Keling 381s might help some also. At 48V they will reliably run up to 1320 RPM. That would boost your rapids a bit.

CR.