Bondtech LGX extruder binding
I have two LGX extruders. One is on my VCore 3.0 500 that has worked great with no issues even when the enclosure gets a little toasty (~70c).
However, I have another extruder that is brand new that I was upgrading my Pruda Bear with. Just finished FINALLY getting around to the Prusa 2.5'ish to Prusa Bear upgrade and moved to a HeroMe Gen 7 carriage and Revo hotend. Got everything going and was pushing plastic getting ready for test prints.
I noticed that the printer would stop extruding after a short amount of time. Chased several normal problem solutions (bump up temp, bump up current, slow things down) and nothing seemed to work. Took the extruder apart and lubricated everything. By hand it seemed to function just fine. Put it back in the system and back to not extruding again. Took it apart again and put it back together. Started testing movement by hand again and I noticed that there is a point where the gears seem to bind. Fairly repeatable at the same spot. Seems more related to the large gear rather than the stepper spur gear.
Has anyone run across this and found a solution?
I have a new LGX on the way to in theory get the Bear up and running. Just wondering if the misbehaving unit is salvageable.
I have a new LGX on the way to in theory get the Bear up and running. Just wondering if the misbehaving unit is salvageable.
4 Replies
did you inspect the teeth? any damaged? crap stuck in between teeth?
Nothing damaged and literally brand new out of the box. But it took so long to get the project going that I have no idea if Matterhackers would even swap the extruder under warrenty.
🫤
flat-fuchsia•2y ago
I've seen binding issues when the screws to attach the extruder are too long and push into the gears
Nope, still have the original bolts. Thinking it miight be the pressed on gears are a little out of true. Will have to chase it later...
Can't see any obvious problem with the press fit parts. Seems to take more force to turn by hand when the tensioner is at the lowest setting. which doesn't make a lot of sense...
I think I finally sorted it out. I was doing an upgrade to my old Prusa MK2.5/3 moving to a Prusa Bear config. Upgraded the system to 24V and Mini 5+ Duet controller. That turned out to be a bigger hassle than I was expecting.
I got everything back together with all the new parts (new carriage and heated bed, lots of other small bits...) and everything seemed to work.
What I didn't do was pay close attention to the voltage for the fans. I didn't realize that there are TWO jumpers for fan voltage. One for one set of pins and one for another set. Turns out I was running the extruder fan at 12V not the 24V I thought I had it at. So I was getting heat creep in the hot end. Once I got that sorted out I found that I was still having a little under extrusion. That was a volumetric flow mistake. Turned that back down and everything seems to be behaving finally.
One curious side note: In testing the various fans I had kicking around I found that one of my older 12V fans actually did better than the 24V fan I was going to use. I thnk the 24V was optimized for noise not flow.