Makerbot Replicator 5gen feed gear.

[Bjørn Borud]

hi,

My SmartExtruder (ha!) stopped feeding filament properly in the past couple of days, so I picked the extruder apart, took out the feed gear and studied it under a microscope. Turns out the teeth had worn out.  They were either broken or dulled, not sure which (sorry for not providing a picture, but I don't have a camera on the microscope).

Has anyone tried to buy just the feed gear from Makerbot Industries?  I sent them an email asking about this yesterday, but to be quite honest, I don't expect them to be willing to do this.

Is there anywhere else I could source this part?

-Bjørn

[tramalot]

If you can make a cad drawing, I can make one. I have thought about different sizes also to fool the firmware...

[Ryan Carlyle]

Teeth worn out? That would be pretty surprising unless you ran the printer for thousands of hours, used unusually abrasive filament, or jammed something metal through the drive path.

Although it's possible MBI just used a really flimsy metal on the 5th gen drive gears... That would be interesting.

Does the filament idler hit the teeth when you "dry feed" without filament?

Are you sure it wasn't kind of dull to start with? It would be good to get a comparison of new and old. Extruder drive teeth don't actually need to be super-sharp.

[tramalot]

maybe its a refurb and it was cleared with an allen wrench

[Ryan Carlyle]

Yeah, that's what I was thinking too, Allen wrench.

[Bjørn Borud]

On Saturday, November 1, 2014 2:44:42 PM UTC+1, Ryan Carlyle wrote:

Teeth worn out? That would be pretty surprising unless you ran the printer for thousands of hours, used unusually abrasive filament, or jammed something metal through the drive path.

I think the printer has something like 150 to 200 hours of print time on it on that extruder.  all filament that has been used in the printer was purchased directly from Makerbot and has been stored in a dry place, inside the plastic bags that the filament came in.  I have picked apart the extruder 2 times before to clean it.  The gear was cleaned with compressed air, so there has never been anything made of metal in contact with the gear.

While studying the gear under the microscope I used the tip of a plastic toothpick to run along the endges to better see their shape.  Obviously nothing that could possibly destroy them.

Although it's possible MBI just used a really flimsy metal on the 5th gen drive gears... That would be interesting.

One think I noticed under the microscope was "flaking" one, possibly two locations.  The metal would come off the gear in a thin flake.  I don't know enough about steel to know what this means or if it means anything at all.

Does the filament idler hit the teeth when you "dry feed" without filament?

It won't touch the gear where the damage is so it can't be the idler wheel.
 

Are you sure it wasn't kind of dull to start with? It would be good to get a comparison of new and old. Extruder drive teeth don't actually need to be super-sharp.

The reason I put the thing under the microscope was because the identations from the feed gear on the filament were noticably less clearly defined.  In the beginning, if I ran my fingertips over the unloaded filament, I would feel sharp indentations in the filament.  Now the indentations are shallow and feel much, much duller.

-Bjørn

 

[Bjørn Borud]

On Saturday, November 1, 2014 1:32:28 PM UTC+1, tramalot wrote:

If you can make a cad drawing, I can make one. I have thought about different sizes also to fool the firmware...

Cool!  I'll have a go at it!

-Bjørn 

[tramalot]

ok