350mm 2.4 with afterburner extruder getting way too hot.

[Mark]

I have been printing on my new 2.4 with good consistent quality,however noted the extruder pancake motor would get really hot.

I tried to print a full bed of parts for my next build, and after about 2hours in thr extruder started slipping and under extruding. When I pulled the motor out water still sizzle on the brass motor gear and the motor was very slightly impesses itself into the extruder body by being softened.

I pu a complete new extruder into the printer,all new printed parts bonded assembly and stepper motor. It printed all the parts for a new clockwork2 extruder perfectly. But when I tried my full bed of parts again everything got too hot and soft and not extruding proper again.

In config file the motor is set to .5 and out of ideas, thinking of trying cw2 assembly. The pancake steppers are Moon from a Formbot kit.

Any suggestions would be much appreciated, I am in NZ at 2.51am so might not reply straight away.

Cheers Mark

[beachtec]

Hi Mark,

 

The first thing I would so is carefully check your motor settings. I am not sure how experienced you are, so please do not take offense if your a highly skilled builder, but if the motor is running that hot, it seems likely your settings are incorrect. There are lots of good sites that show you how to calculate these values. If your max current, idle amperage setting, stepping is set incorrectly, even slightly, you will have problems. I am not sure what you are extruding, but perhaps your extruder temps are a tad low as well, making your extruder work extra hard. Finally, I would consider swapping the motor; the can and do overload or develop shorts that yield weird problems. Is the motor making any noise? Try replacing your Stepper chip (is this configured right? Jumpers all correct?).

 

Good Luck

[Simon2.4]

Just as an addon to this thread:

https://docs.vorondesign.com/community/howto/120decibell/calculating_driver_current.html

The motor that came with my kit has a current rating of 0.8A so according to this article, 0.5A is the right setting. What rating is the "pancake motor" ?

 

[Mark]

9 hours ago, beachtec said:

Hi Mark,

The first thing I would so is carefully check your motor settings. I am not sure how experienced you are, so please do not take offense if your a highly skilled builder, but if the motor is running that hot, it seems likely your settings are incorrect. There are lots of good sites that show you how to calculate these values. If your max current, idle amperage setting, stepping is set incorrectly, even slightly, you will have problems. I am not sure what you are extruding, but perhaps your extruder temps are a tad low as well, making your extruder work extra hard. Finally, I would consider swapping the motor; the can and do overload or develop shorts that yield weird problems. Is the motor making any noise? Try replacing your Stepper chip (is this configured right? Jumpers all correct?).

Good Luck

Thanks for you're reply, no offence taken, even though I have been doing this a longtime, any suggestions are appreciated. I am printing ABS at 250c and print quality is great until extruder gets so hot it slips and under extrudes. If I am correct the only alterations for the tmc2209 is in the printer config. Originally set at .5 I tried .8 now back at .5.

There is no noise and the stepper motor still works but won't drive filament as the gears wont bite the filament anymore. I have put in a completely new afterburner from my new 2.4 I am building and once again awesome prints if just a few hours. Tried printing a full bed of parts and 2 hours in it starts slipping.

I "think" there is an inherent weakness in the design given it is a motor not even passively cooling from the enclosure perspective, actually believe it's something obvious I have got wrong. Both the stepper motors I have tried are Moon branded (both faulty?) and as specified. Hence now thinking of putting in the stealthburner, clockwork 2.

I've got one more new no name(unknown specs) pancake I will quickly try first, can't do any harm at least. Also got everything for stealthburner printed now.

I double checked the driver pins and even replaced the driver while I had it out. Thanks, at least you have got me looking at even the seemingly simple things.

[Mark]

8 hours ago, Simon2.4 said:

Just as an addon to this thread:

https://docs.vorondesign.com/community/howto/120decibell/calculating_driver_current.html

The motor that came with my kit has a current rating of 0.8A so according to this article, 0.5A is the right setting. What rating is the "pancake motor" ?

It is the specified rating as you say, but is the config file the only option to change the current, put a meter on it anyway and not an obvious meaningful output. 

It is strange as it looks exactly like the uneven layers from where people are asking about inconsistent extrusion (something about number "6") I don't follow. However I can clearly see this is the extruder heat issue for me. Thanks

[Buurman]

Hi @Mark did you solve this somehow? Just curious, using the same bot to build often and pancake is about 65 degrees C after an hour print, doesnt really go up from there. But still curious, what is normal, I mean, its already 50 degrees at least in the closed off chamber, so 65 is pretty close to this and doesnt seem worth worrying.

What temperature you think your pancake was? 

And yes on the Moons pancake 0.5 is correct, but some run the LTO's as low as 0.3 to keep them from slipping/heating up.... guess you can try 0.4.

[Mark]

Hi

No, I ended up building the Stealth burner with Clockwork two, now no problem. same wiring and setting etc, only different motor, and now runs well.

Wish I knew what it was. Thanks for the follow-up though.