Replacement filament guide (bearing?)

g_pwn

Does anyone know where I can find a replacement filament guide bearing? I have been having issues with feeding (stops mid print - new nozzle, tube is good etc) and decided to take apart the motor that feeds the filament.

I found my bearing was made of plastic (not sure if I can upgrade to a metal one?) and it was shaved down causing it not to be able to rotate at all...

 Below is the location of what I'm referring to (its the bit that is opposite to the gear teeth from the motor) Thanks!:

g_pwn

Quick update:
After I got home from work yesterday I went ahead and took apart the filament motor enclosure. What I was initially looking at was a jammed piece of filament in there. I removed it and tried my print again but still jammed a few hours into the print.

After work today I'm going to replace the entire hotend setup with a brand new spare set I have just for this occasion. Hopefully that fixes the damn mid print stops...

g_pwn

Another update:
Replaced the throat, heater block and nozzle last night and left the print running over night. It failed some time this morning after I left for work.

I think this is an issue with the brass extrusion wheel. I've purchased a stainless steel gear which should be in tomorrow. Once I replace the brass one and start the print again, I'll report back here.

Hopefully my pains help someone else! lol

Der_Muck

What do you mean with filament guide?
Maybe your extruder motor gets to hot or your retract is to high. 
If the brass extruder weel looks ok, the stainless steel will not change a lot, I have done that once to increase the printquality but it didnt change a lot.

g_pwn

Hey @Der_Muck
That image is just a sample imagine i found online, its not one I took (sorry, was desperate for an answer)

When I looked my brass extruder wheel it was definitely worn a bit, I just didnt think it was worn too much (I'm new to the scene so had nothing to gauge what it should look like)

In terms of retraction, I've tried it with off, 3mm, 5mm, 7mm same result

If the motor gets too hot, would it stop altogether or would it continue to turn?

Der_Muck

Did you add the TMCs? You can turn the current down to 550mV in the firmware it worked well for me.
My extruder motor was never able to run at 800mV or even higher, it took 5min to get very hot.
In all I would try to change the motor. The normal JG motor is not very strong.
I got that one and its working great with the Bondtech all metal clone which needs 3 times higher speeds.
https://www.amazon.de/gp/product/B07GLMGQB3/

But be aware, with that motor you have to change the 2 middle wires than it works right away.

g_pwn

I mean, would the motor stop spinning if it got too hot? Because mine does not stop at all, it continues as if it was printing.

I did replace all drivers with TMC2130 so adjusting volt. should be easy if needed

Der_Muck

No, PLA has a glas temp. of about 50°C sometimes lower sometimes higher.
Is the extruder that hot, the extruder weel deforms the filament and due a retract the weel cant move the filament forwart or produce enough preasure for a extraction.

Yes a stepper motor can reach up to 80°C that is the max. +- a bit. But for a PLA print you have to keep the temp. down to max. 45°C
You can do that by active cooling, causing noize and you need a fan and wires. 
Or you can step down the motor current. But only with TMCs 
Turn it down. The right way to set motor voltages is to only use so much as the motors needs.
So set it down, the temp. will decrease with every 50mV   beginn using 450mV than try a print and check the motor. Should be little warm. Check your print. If you dont have nice layers, you are ready to go. If you have sometimes open parts in the layers increase the current +50mV to 500 and try again.    Use M906 in PF to see the valves, set it in your startskript with M906 E450 for the testprint.

g_pwn

@Der_Muck What you're saying makes COMPLETE sense. Just didn't think about it since this is the first time this has happened and I've been printing for months now.

I initially used M906 S1 and completely forgot about all of it...

I'm going to try M906 E500 (since you said 550 worked well for you) and go from there.

Will report back once I try my long print again.

I really appreciate your help!

Der_Muck

No Problem, hope it will help you. If not, it can be that your motor isnt good any more because of overheating. 
Overheating cause the motor to produce more heat next time you will use it. The magnets in the motor arent so strong any more after a overheat. Maybe that was also my problem.

g_pwn

@Der_Muck You were spot on with changing the current settings. I did notice previously that the motor was getting too hot to touch. After I made your suggested changes, its a little warm but not the same as before (I can keep my hand on it without becoming uncomfortable).

I started my print last night and will continue to monitor it today while at work. Keep you posted!

Also, would you mind showing me which two wires need to be swapped around in the Usongshine 7HS4401S motor? I might as well upgrade the stock motor

Thanks!

Der_Muck

Great to hear! There are 4 wires on the connector of the motor, just switch the places of the 2 middle wires.
After that, try to extrude some mm of filament. When everything is correct, it will work, when there is anything wrong the motor only vibrates and doesnt move but that should solve the cable swap.

g_pwn

@Der_Muck
Quick update, I'm ~15hrs into the print and it has not failed at all. 100% your suggestion was the fix. Thank you!!!

Thanks for the info on the new motor, I'll be upgrading + swapping pins once I get it in!

Thanks again!!!!

Der_Muck

   Sounds perfect, you are welcome