Stepper motor cooling

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smarterengineering
Posts: 41
Joined: Sun Jul 08, 2012 3:32 am

Stepper motor cooling

Post by smarterengineering » Tue Aug 21, 2012 7:20 am

Gday all,

Just thought i would post up what i finished today.

I bought an Ebay VGA heatsink with a Fan attached.


I fitted it today using the original 2x black bolts that go through the stepper motor. I had to buy some that were 5mm longer but that wasnt an issue.

I run it just from a 240vac to 12vdc variable transformer.

After initial inspection i tried a few things

1. No heatsink

As we all know this burns if you touch it

2. Heatsink without fan running

Can touch the stepper motor and its hot if you have tough skin not a problem

3. With the fan running


Was trying this now, with the fan running and the printer printing i can happily hold the stepper motor (black sandwich plates as well as the silver ends).

I just thought people might be interested to know how this set up would work.

Was very easy and i didnt need to print any other mods, just drilled one hole in the heatsink to make sure it fit.

Here is a photo, the Cooler cost me 2 dollars i think from ebay with the fan, its very lightweight also.

As weith all of them i think this will make a huge difference to the heat of the extruded gear side.
20120821_150440.jpg
20120821_150440.jpg (71.94 KiB) Viewed 11722 times
Thanks

eyUP
Posts: 230
Joined: Thu May 24, 2012 3:23 pm

Re: Stepper motor cooling

Post by eyUP » Tue Aug 21, 2012 8:33 am

Great idea (just what I thought of doing)

I'd like to know if it helps with extrusion issues...
Are you going to try with PLA next ?
Have you got a reel of material which wouldn't work previously ?

smarterengineering
Posts: 41
Joined: Sun Jul 08, 2012 3:32 am

Re: Stepper motor cooling

Post by smarterengineering » Tue Aug 21, 2012 9:21 am

Nah,

As im quite busy with paid jobs i only use the UP ABS from Bruce, less time fiddling around and wasting plastic.

Now they have the other colours etc i most liekly wont try printing with other manufacturers stuff (unless i wanted cheap plastic to muck around with).

PLA i dont think so, i dont see a lot of benefit for me to use it thats all.


I think the fan combined with compressed air cooling would make a huge difference.

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JuliaDee
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Location: Connecticut
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Re: Stepper motor cooling

Post by JuliaDee » Tue Aug 21, 2012 2:15 pm

BTW there is 12VDC available right there for the existing fan. No telling how much extra current is available though.

smarterengineering
Posts: 41
Joined: Sun Jul 08, 2012 3:32 am

Re: Stepper motor cooling

Post by smarterengineering » Wed Aug 22, 2012 1:18 pm

Yep, I just wanted to steer clear from modifying the electrics used for normal operation as i have had some problems.


INTERESTING NEWS FLASH

My heatsink with the fan going actually wont allow the nozzle to get up to temperature before printing.

It takes ages and i was watching it then, it got up to 255 and then hovered there and actually started dropping.

Appears the heatink works too well when its heating up by sucking away a lot of the heat...


I had the fan off and just then i got a "nozzle too cool" error down the bottom, the print has paused mid print...

because of the bad coding i cant see the temp when its running so now i have no idea whats going on...bit weird...

eyUP
Posts: 230
Joined: Thu May 24, 2012 3:23 pm

Re: Stepper motor cooling

Post by eyUP » Wed Aug 22, 2012 1:37 pm

Is it blowing over the nozzle/heater ?
There should be a thermal barrier between the motor and the nozzle and heater so cooling the motor shouldn't effect the nozzle temperature by much (if it did, the whole thing would be sapping heat from the nozzle)
I bet you could stick a sheet between the bottom of the fan and the heater and it'll get to working temperature again!

smarterengineering
Posts: 41
Joined: Sun Jul 08, 2012 3:32 am

Re: Stepper motor cooling

Post by smarterengineering » Wed Aug 22, 2012 2:57 pm

Its not blowing on the nozzle,

Even when i turned it off the temp kept going down.


I also had a barrier inbetween the V7 wind barrier so there wasnt any win blowing on the nozzle...interesting.


I found the quickest way to heat the nozzle up to temp was to turn the normal heat sink fan off for a few seconds, that extra temp in the block heats it up quickly

eyUP
Posts: 230
Joined: Thu May 24, 2012 3:23 pm

Re: Stepper motor cooling

Post by eyUP » Wed Aug 22, 2012 3:29 pm

hmm, strange you'd have to do all that to get it to temperature.
Possibly the RTD or heater element isn't making good "thermal" contact ?

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wilsonj
Posts: 569
Joined: Tue Feb 28, 2012 10:26 pm
Location: Australia

Re: Stepper motor cooling

Post by wilsonj » Wed Aug 22, 2012 11:07 pm

Good work!

It certainly looks like air from the fan can blow through the fins on the heatsink, and cool the heaterblock. I did experience exactly this problem a while back.

I also had the same issue you are having with the block not heating up (without extra fans either). What I did was unplug the machine from the back, so it gets no power at all, and leave it for a while. For whatever reason the problem went away and now it works again as it should.
Regards
Jamie
3DPrinterGear.com.au

Eurisko84
Posts: 38
Joined: Wed Feb 08, 2012 5:56 am

Re: Stepper motor cooling

Post by Eurisko84 » Wed Aug 22, 2012 11:32 pm

JuliaDee wrote:BTW there is 12VDC available right there for the existing fan. No telling how much extra current is available though.
smarterengineering wrote:Yep, I just wanted to steer clear from modifying the electrics used for normal operation as i have had some problems.
Just as a note - I have been using the 12VDC off the extruder board for almost 6 months now without a single hiccup.

Im using the fans off a G.Skill Turbulence II ram cooler (see here http://www.gskill.com/products.php?index=296) - with an individual fan rated at ~35mA (with LED).

I wouldn't be too concerned that the board is so power drawn that an additional load of 35mA will kill it... hell, a stubborn filament will cause the stepper to pull more than that!

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