stepper motors are super hot!

[zerakren]

hey thanks RocketMagnet I don't think the change in the firmware had any effect but upping the temp definitely did help the prints.

Also i noticed that when I start prints the hotend will drop the temp to 200 despite any settings I have made and I manually have to crank it back up. I have the defualt and max temps set in Config > Printer Settings but every time I hit print it drops the temp and I cannot figure out where to change this setting.

Edit: I was I was typing this out I thought to check Slic3r and that is where its at. First layer temp was set incorrectly.

[Tonkabot]

AFAIK, the increased temperature weakens the magnetic field.

g.

I believe that's true. MRI machines use liquid helium cooling to generate very large magnetic fields.

Actually anybody using liquid Helium is doing it because the electromagnets have superconducting windings, which need to be cooled below some temperature to even be super conducting. Then massive current (100's of amps?) are used without vaporizing the windings to get the very large fields.

If a stepper gets overheated it will weaken the magnetic field, and possibly permanently.

The permanent magnet inside the stepper is only magnitized after assembly, and a video i saw (from a stepper manufacture) said if you disassemble and re-assemble a stepper it will lose 1/3 of it's magnetic field permanently.

[Cortanas]

I just finished up my rostock finally. Made some upgrades to the e3d volcano hot end, 3mm filament and a wade's extruder. I have been noticing heat in the extrudermotor as well. I have the Automation Technologies Inc. Motors. From what I can tell spec wise they are the same as the Kysan (let me know if this isn't correct). I plan on making that change tonight to see if that helps the heat issue. May go ahead and add a fan as well. Something else I wanted to run by you guys. I bought some pla filament that has a melting range of 160C to 170C. Anyone else ran into this? Talked to the guy I bought it from and he said it was PURE PLA so it has a lower melting temp. My thoughts are it isn't PLA at all. Curious about your opinion on it. Thanks! for the feedback!

check the sticker on the motors, if they are not wantai, but the label says Kysan do this.... load up your firmware, go to line 701 of configuration.h

change:

#define MOTOR_CURRENT {175,175,175,200,0} // Values 0-255 (RAMBO 135 = ~0.75A, 185 = ~1A)

to:

#define MOTOR_CURRENT {155,155,155,165,0} // Values 0-255 (RAMBO 135 = ~0.75A, 185 = ~1A KYSAN MOTOR CURRENT SETTINGS )

and your problem should go away... you will have more torque and lower temps!

no need to change anything else, your eeprom will hold all your calibration


Guanu

[Nylocke]

PLA, depending on the manufacturer, can range from 170-220C print temp at times. I wouldn't put it past that stuff you got to be some real pure PLA, when the RepRap project was first getting going and Vik, Adrian, and rest of the gang were trying out PLA for the first time they had some fairly pure PLA (not colored, fairly clearish) that they were printing around the lower end. Sounds about right to me.

[Cortanas]

That is good to hear. I was worried it may be something else all together.

[redbmaster]

I'm having a similar issue with only my extruder motor, and I have already made the change in the firmware. Is there something else I need to change for the extruder motor specifically?

[BenTheRighteous]

For anyone having trouble with a hot extruder motor, I moved mine to the top of my machine and pointed a fan at it. It really helped. The files are available here if anyone is interested.

[redbmaster]

For anyone having trouble with a hot extruder motor, I moved mine to the top of my machine and pointed a fan at it. It really helped. The files are available here if anyone is interested.

Cool, thanks for the stuffs!

My concern is more of having a misconfiguration in the firmware. Or maybe there is a better stepper suited for extrusion.

[dajay23D]

i just measured mine w/ a Fluke thermometer. 86 C!! Using ABS. don't want to jinx it, but been running like that w/ 3hr prints for awhile. I'll change the setting and post it to see if it makes a diff.

[PlasticFolk]

For anyone having trouble with a hot extruder motor, I moved mine to the top of my machine and pointed a fan at it. It really helped. The files are available here if anyone is interested.

Nice BenTheRighteous! We will be incorporating that into our unit. By the way what do you model your design with? We tend to use OpenSCAD.

[draw-tech]

Hi all
I just had a problem of the hobbed gear eating the filament at about 8 Hours into a 14 hour print. The stepper motor was so hot all the teeth on the gear turned into hot knives. I went out into the shop, and came up with these haet sinks. If they work I will let you know. I also intend to produce them.
Jack
Draw-Tech

[BenTheRighteous]

By the way what do you model your design with? We tend to use OpenSCAD.

I started learning on OpenSCAD and it's a really great tool. However lately I've been preferring DesignSpark Mechanical. It's straightforward to use, powerful, free, and did I mention straightforward?

OpenSCAD can do some really cool things, but IMO the proficiency curve is extraordinarily steep.

Novice: "I can make a shape with holes in it in about an hour"
Intermediate: "I can make a shape with holes in it in about 20 minutes"
Expert: "I can make a shape with holes in it in a few minutes"
Master Jedi Wizard: "I can make a dragon's head that breathes fire with some nested loops and some gnarly matrix transformations on these lookup tables!"

Powerful, but really only once you've fully mastered all its features!

[dajay23D]

well, literally the very next day after I posted, first failed print. Print failed from extruder slipping. I'm not sure what it is, i'll need to take it apart to find out.

[draw-tech]

well, literally the very next day after I posted, first failed print. Print failed from extruder slipping. I'm not sure what it is, i'll need to take it apart to find out.

Hi dajay23D
A few days ago I posted about the high heat of the extruder motor, causing the hobbed gear to eat the filament instead of pushing it at the correct speed. I was printing a disk about 5” in diameter and found the problem, the stepper motor was at 68 C which says the gear is the same temp. I made these heat sinks that will fit the Max2 without modifications, attaches with tie wraps. I did the same print which took 9 hours. I painted the hobbed gear black so I could get a good temp reading. Without any heat transfer paste or Fan the temp went from 68C to 38C. After the print I checked the gear, absolutely no plastic in the gear. Heat transfer paste should be even better.
Jack
Draw-Tech

[Tincho85]

You can use an old cpu cooler, I don't remember what socket.
It's a 40mm fan with a small heatsink.

https://farm1.staticflickr.com/363/2010 ... e88a_b.jpg
[img]https://farm1.staticflickr.com/363/2010 ... e88a_b.jpg[/img]

https://farm4.staticflickr.com/3825/200 ... 68ea_o.jpg
[img]https://farm4.staticflickr.com/3825/200 ... 68ea_o.jpg[/img]
You don't need to use bolts, it comes with some 3M tape.

https://farm1.staticflickr.com/506/1991 ... 991f_o.jpg
[img]https://farm1.staticflickr.com/506/1991 ... 991f_o.jpg[/img]
Perfect fit!
and it's cheap.

[lumpy_potato]

I bought a northbridge cooler + heatsink for ~8$. Still need to mount it, its a little long so I think I have to adjust the extruder 'forward' a little bit to clear the delta arms fully. With the changes to voltage it sits at ~55-60C, which is still a little to hot for my tastes, so I'm hoping to bring it down to the 30s and 40s and see whether that reduces the biting into the filament.

[draw-tech]

I bought a northbridge cooler + heatsink for ~8$. Still need to mount it, its a little long so I think I have to adjust the extruder 'forward' a little bit to clear the delta arms fully. With the changes to voltage it sits at ~55-60C, which is still a little to hot for my tastes, so I'm hoping to bring it down to the 30s and 40s and see whether that reduces the biting into the filament.

Hi lumpy_potato

As Tincho85 said you can buy a fan cheap. But the way it;s mounted at the end of the stepper motor, which make's about a 20% contact with it. The place that needs to be cooled is the hobbed gear end. The fan also uses energy. The system that I have designed is designed to fit right on the stock Rostock Max 2, with tie wraps or leather string to shrink it tight, now contact is about 80%, now without a fan I have checked it constantly through over 20 hours run time. Used an inferred thermometer, Rear staying below 39C Front face average 2C lower, and hobbed gear average 34C. and in all the hours, no build up in the gear. The sinks are about 3" sq, to gain as mush surface area as possible.

[lumpy_potato]

If I had access to a machining setup I could probably experiment with a heatsink like that but in NYC access to such spaces is terribly limited.

That said, I might be able to buy some aluminum plate at a hardware store and cut it down by hand...

[BenTheRighteous]

There are lots of good suggestions in this thread that will all do the job well! Past that, it's all personal preference.

[dajay23D]

Hi draw-tech,

That's a good idea. Seems like you reduced the temp by almost 50%!?? Either way, even if I read wrong, the temp is lower. So with the lower temp, was the noise reduced? Mine squeaks and is pretty loud. BTW, i figured out my problem. it's the RED TAB on the filament tensioner. I didn't think much of it at first, but there was a small crack that was starting to propagate in the clear cover at the middle screw area. I noticed it shortly after assembly and printing. I didn't think much of it because I just thought the screw was too tight. After about 1.5 days on the LCD print time, filament started to slip (after my post). I decided to take off the clear cover to see what's going on. I tugged on it and it pretty much just separated, so i removed it. Turns out when it's retracting, the RED TAB would move out at an angle. Only does it when it's retracting. Continuous retract would cause the tab to move out enough to have the bearing slip from the filament and would not contact it at all. Small "pop" noise. Assuming, the extra heat played a role, the tab also pushed out and bent the clear cover for it to crack. My solution? Zip tie!!

On another note, I did use Gene's commands and it seems like it did lower the temperature, somewhat. It did help. I noticed reduced temp, but when printing for a couple hrs, it's still close to 80C. But now, it's more like 70-75C and it doesn't just climb to 80C right from the beginning. Temp would actually fluctuate from high to low. Before, as soon as I turned on the the machine and extruded, it'd shoot straight to 80C.

[draw-tech]

Hi dajay23D

Still running at below 39C no fan just tie warped to the motor, front and rear. I also noticed the red lever deflecting, maybe make one of aluminum, may help to cool the bearing.
I have noticed that the hobbed gear runs only about 3 degrees C lower than the rear or front of the motor. Take a black sharpie and coat the shaft of hobbed gear the inferred thermo reads better. My solution for the cracked cover, trash it now we can see the filament feed.

Draw-Tech

[EL Cuajinais]

well, literally the very next day after I posted, first failed print. Print failed from extruder slipping. I'm not sure what it is, i'll need to take it apart to find out.

Hi dajay23D
A few days ago I posted about the high heat of the extruder motor, causing the hobbed gear to eat the filament instead of pushing it at the correct speed. I was printing a disk about 5” in diameter and found the problem, the stepper motor was at 68 C which says the gear is the same temp. I made these heat sinks that will fit the Max2 without modifications, attaches with tie wraps. I did the same print which took 9 hours. I painted the hobbed gear black so I could get a good temp reading. Without any heat transfer paste or Fan the temp went from 68C to 38C. After the print I checked the gear, absolutely no plastic in the gear. Heat transfer paste should be even better.
Jack
Draw-Tech

You had me at "fits without modifications". And at 30 C less. And at no additional power consumption. How much for a set? I live in Puerto Rico which gets the same rate for USPS as anywhere in the US.

[Eaglezsoar]

You can use an old cpu cooler, I don't remember what socket.
It's a 40mm fan with a small heatsink.

https://farm1.staticflickr.com/363/2010 ... e88a_b.jpg
[img]https://farm1.staticflickr.com/363/2010 ... e88a_b.jpg[/img]

https://farm4.staticflickr.com/3825/200 ... 68ea_o.jpg
[img]https://farm4.staticflickr.com/3825/200 ... 68ea_o.jpg[/img]
You don't need to use bolts, it comes with some 3M tape.

https://farm1.staticflickr.com/506/1991 ... 991f_o.jpg
[img]https://farm1.staticflickr.com/506/1991 ... 991f_o.jpg[/img]
Perfect fit!
and it's cheap.

Does anyone have a source for the old cpu cooler?

[Eric]

Well, if you truly want an OLD one, as in torn out of some defunct computer, that means you need to scrape off the previous thermal coating (it's not meant to be reused) and either apply new thermal tape or thermal cement.

Or you can buy a new one from any of the usual computer sources. Here's one on ebay: http://www.ebay.com/itm/New-Adhesive-Al ... 1755319920

Or you can buy a heatsink meant to mount to the nema 17 frame. e.g. http://www.walmart.com/ip/43803852 No fan, but you can add one if you think it's needed.

[Tincho85]

Uhmm it's weird, I can't find the one I bought by googling it.
I bought it in a local electronics store.

It might be for 486 mothers but I'm not sure.