Bontech gears griding?  

Re: Bontech gears griding?

I have the same on mine and have seen the same on one or two other MK3 Pictures. No Idea what it is....

Re: Bontech gears griding?

I have the same on mine and have seen the same on one or two other MK3 Pictures. No Idea what it is....

Weird.... my fear is that the brown dust gets into the PTFE and down to the hotend.... that will be a clogged nozzle for sure =/

When i saw it from the outside it almost looked like rust.... xD

Re: Bontech gears griding?

I have the same on mine and have seen the same on one or two other MK3 Pictures. No Idea what it is....

........
When i saw it from the outside it almost looked like rust.... xD

I was thinking the same thing... Take a magnet to it...

Re: Bontech gears griding?

Here is a better picture.... it really looks like rust.... Right ❓ ❓

EDIT: That is already cleaned.. those spots are not coming off easily

Re: Bontech gears griding?

I have the same on mine and have seen the same on one or two other MK3 Pictures. No Idea what it is....

........
When i saw it from the outside it almost looked like rust.... xD

I was thinking the same thing... Take a magnet to it...

Already cleaned it =/.... Maybe someone can test it out?

Re: Bontech gears griding?

3 Things:
1) Loosen the gears a bit, it may be too tight
2) Make sure the gears are aligned, the wear seems to be on 1 side, could be misalignment that you can't fix though
3) Maybe use some grease to lubricate the gears.

Re: Bontech gears griding?

@leonardo.g3 how are those IGUS bearings working out for you? I was tempted to go with them but our supplier hooked me up with THK bearings and rods for my upcoming build...

Re: Bontech gears griding?

3 Things:
1) Loosen the gears a bit, it may be too tight
2) Make sure the gears are aligned, the wear seems to be on 1 side, could be misalignment that you can't fix though
3) Maybe use some grease to lubricate the gears.

1) To properly tighten the screws i left them a bit loose, to the point they wouldnt grip the filament all that well, then i started slowly tightening them until there was no more slippage so i dont think they are really that tight, but i can loosen them a bit.

2) Alignment is perfect =), i checked and rechecked this, i usually take a look after a few hours to see if anything is out of place.

3) Lubricate the bearings.... yes!! Thats what i'm doing it now to see if i can prevent this from happening again.... at least until my new pulleys arrive (support said they will send me new ones).

Re: Bontech gears griding?

@leonardo.g3 how are those IGUS bearings working out for you? I was tempted to go with them but our supplier hooked me up with THK bearings and rods for my upcoming build...

They are working out great... it really makes the printer quiet... it adds a bit of drag but the movement is bind free and smooth.

I have the softer rods and they are already scratched from the other bearings... when the new rods arrive i will test them out with the new bearings.

Re: Bontech gears griding?

I have the excact same thing on mine

Re: Bontech gears griding?

I have the excact same thing on mine

I suggest cleaning it up.... if it ends up on the Hot End you will have problems for sure.... 😡

I applied a bit of machine oil to the pulleys to help reduce friction aswell.

Re: Bontech gears griding?

Are those Bondtech gears made from steel then plated so they don't rust? Those gears are not meshing properly and wearing down just the bit that is. That plastic idler gear cover looks like it was printed at .3mm+, why so bad? The plastic idler gear cover looks like it is twisting due to weakness in the plastic cover. Trying to squeeze the 1.75mm filament on one side while bottoming out and not propery mating the gears teeth on the other end. Not sure I am liking all this plastic parts for durability. Some of these parts should be aluminum.

How long will the $50.00/set of Bondtech gears last at this rate? $$$$$$$$

Re: Bontech gears griding?

Looks like rust marks. The bondtech gears are made from hardened steel, so they should be lightly oiled.

Edit: Thought about this statement a little bit. Not sure that using light oil would be a good move here because it could get on the filament and pass through the hot end. I'll go by Prusa's instructions and if I run into any issues, I'll contact warranty.

Re: Bontech gears griding?

That BROWN looks to be rust. If you look at the picture, you can see the chrome plating on the gear is wearing off.
put a tiny amount of grease on the teeth to lubricate the gears. Be sure to not put too much on there, as you dont want the grease anywhere near the part that grabs the filament. Don't use oil as that will travel around. You want just enough grease to let the gear teeth slide with a thin coating of grease between them. You never see gears in other devices/mechanisms without grease because the gear teeth would wear out prematurely.

Ty Hoeffer
Palmyra, VA

Re: Bontech gears griding?

Bondtech's assembly documentation shows you should add lubrication to the gear and shaft:

https://drive.google.com/file/d/0B7A1MEUY39HCZmlFYW5oc3Rvcjg/view

Re: Bontech gears griding?

I might make this idler gear mount from aluminum. Simplified for CNC. Needs to be printed first to check out modifications fit.

Re: Bontech gears griding?

making a version of the "dust/light" cover that sits in the middle, but has the bolt threads through it with a circular profile so the door can swing past it without removing/losing the little blighter would also be a nice touch.

Re: Bontech gears griding?

Bondtech's assembly documentation shows you should add lubrication to the gear and shaft:

https://drive.google.com/file/d/0B7A1MEUY39HCZmlFYW5oc3Rvcjg/view

Well.... Support told me they shouldnt need any type of lubrification but didnt advice against it and said i could do it with care and not too much....

I've done it... I'm gonna print 100 or 200 hours or so and check again if the gears are still griding each other!

I will replace the gears anyways when the new ones arrive.

Re: Bontech gears griding?

I might make this idler gear mount from aluminum. Simplified for CNC. Needs to be printed first to check out modifications fit.

Let us know how it goes!! I agree that the whole extruder is way too much plastic everywhere....

At least it's PET and somewhat resistant... only time will tell (i have about 410 hours of printing time).