Thread: Stepper heat

They naturally run hot, if you want to double check things check the current and voltage settings on the driver and check that they don't exceed the motors rating.

If you have a temperature gun check that the motors don't exceed 80 degrees, if everything looks good its normal.

Mine run at about 40-45 degrees, but my machine is also one big heatsink.

Originally Posted by BoomerangInfo

Also had another heat problem with my plugs I made prior to this job, also in HDPE, and using a 3mm, 4-flute carbide bit for the finishing path. I have some single flute bits coming, but I needed to try my design out. Well, it seems the 3mm bit melted the HDPE out of the way, and it formed a solid blob around the bit. I tried to increase the job speed, but no luck. I guess it's just a matter of the wrong bit for the job?

Any suggestions appreciated.

Thanks. Russell.

with 4 flute 1/2 your spindle speed compared to the 2 flute ,i had my 8mm up to 18000 rpm for 12 hours ( to fast for collet ?)
a squirt bottle to call the tip ?

did your HDPE warp ??? ive got a mould that has turned its corners up 10mm each side , its perfect , clamp it down flat , make a carbon fibre part , once its completely hard , release the clamps and the part just pops right of the mould

Originally Posted by SawDustSniffer

did your HDPE warp ??? ive got a mould that has turned its corners up 10mm each side , its perfect , clamp it down flat , make a carbon fibre part , once its completely hard , release the clamps and the part just pops right of the mould

Well, no, but it's still clamped to the table I've routing one bit at a time and perfecting my mould as I go. One of the guys in the pen forum though did report his piece bending when he released it.

Russell.

Hi Guys,

The molds that I cut 300 x 300 x 23mm thick did bow significantly once they were released from the sacrificial board.
What I did notice though is that the second mold I cut did not bow as much, however I left more material between each of the reliefs cut, so I think this needs to be taken into consideration when designing your mold.

Cheers
Tony.

heat stressing one side ? causing one side to shrink or pre stressed HDPE and taking out the stress ?

i think its the internal stress when manufactured , being released when more than 1/2 is removed , cooled to fast , baking to 3/4 melt temp might fix it ?

it melts at 120c to 130c , so i will try and boil a sheet for an hour before my next attempt

Let us know how you go.

Cheers
Tony.

running an x axis heavy program tonight , x axis stepper running at 105c deg , thats at 48 volts , at 3 amps , i checked the old power supply and thats 38 volts under a 3 amp load

i will be lowering the amps after this cut is finished , ant 120c the enamel will melt of the wire inside the steppers

just put a big fan on it and it dropped to 87c

Originally Posted by SawDustSniffer

running an x axis heavy program tonight , x axis stepper running at 105c deg , thats at 48 volts , at 3 amps , i checked the old power supply and thats 38 volts under a 3 amp load

i will be lowering the amps after this cut is finished , ant 120c the enamel will melt of the wire inside the steppers

just put a big fan on it and it dropped to 87c

I don't really have a way of checking the temp on mine. Never thought about the wires melting. That's a worry

Russell

Hello ;
I also had similar heating problem with my stepper motors just after I built my cnc router (Joes 2006 design). The motors (425) got too hot to hold for more than 5 seconds.

I installed little 12 volt dc fans (from old computer cpu ) they are about 2.5" square. I made a little aluminum bracket and mounted the fans about 2" away from each motor this cured the heating problem. I used one on each of the 3 steppers and powered them with a little 12 volt wall wart (110 volt ac to 12 volt dc).

Give it a go....... worked fine for me.

Cheers.Doug