Ultimaker 2 Extended Feeder Problem

[ELLOMS 3]

I've bought my Ultimaker 2 Extended about half a year ago and I am very happy with print quality, ease of use and flexibility. Most of the time I am printing with UM PLA, Pearl White and Silver and Colorfabbs Bronzefill, Copperfill and Woodfill. I print often so i tuned my printer very carefully to the filament I am using and I didn't run into any problem I couldn't solve with looking for someone in this forum who had a similar issue until now. Which is great!

Nevertheless, I started a print with bronzefill 2 days ago and forgot to increase flow rate on the printer. So i found my printer being clogged mid print the next day. I stopped it immediatly and cleaned the nozzle with atomic pulls. I then tried printing with PLA which worked fine for two test prints. Next I tried to print bronzefill again which failed due to no extrusion happening at all. It seemed like the feeder was to weak to push the filament through the nozzle, which I didn't encounter before. So I thought about some possible unwanted residues in the nozzle and a deformed PTFE Coupler so I replaced the whole Hot-End (Nozzle, Teflon Insulator and PTFE Coupler). I tried printing with PLA Pearl White again and everything worked fine. So I tried Bronzefill again, running into the exact same problem as before.

Now that I could be sure that there was no problem with the Hot-End I took a closer look at the feeder.

I dissassembled it and noticed something quite strange. I don't know if this is supposed to look like that?

[media-thumb=6825][media=6825]

(marked red in the picture) It seems to be sort of carved in by the filament. I reassembled the whole feeder mechanism and now I can't even print PLA anymore. I really need my printer to be up and running again for i run a small buisness and clients are waiting for their product. I hope you can help me with this problem!

Thx in Advance!

[Labern 774]

Bronzefil is abrasive stuff.

Are you sure you assembled it correctly. As long as its staying on the bearing it should be fine. can you see if the filament is coming off?

there other feeders you can print like THIS one but you need to get it printing first.

Make sure the filament is on the knurled part of the drive wheel.

[ELLOMS 3]

Bronzefil is abrasive stuff.

Are you sure you assembled it correctly. As long as its staying on the bearing it should be fine. can you see if the filament is coming off?

there other feeders you can print like THIS one but you need to get it printing first.

Make sure the filament is on the knurled part of the drive wheel.

 

I am quite sure that I assembeld it correctly for I didn't take the wheel with the carved housing apart. As far as I can tell the filament tends to bend into the carving (which is exactly as wide as the filament) and so the knurled part of the drive wheel has to work against the fricition created by the bend. I also noticed that there is no skipped back steps by the feeder motor which i heard often when the filament can't advance. The knurled wheel just bites into the filament until its completly grinded and there's no contact at all.

The carved in part is located at the backside of the feeder so I can't really see how exactly things get messed up. I wonder if I could print with PLA before because it is stiffer than Bronzefill and doesn't bend into the carving as much?

When theres little to no friction to the filament like when changing material, the feeder acts normal, but as soon as it is pushing through the nozzle the filament gets grinded.

[ELLOMS 3]

+ I saw this alternative feeder and tried to print it when everything messed up.

Thank you for your help!

[Labern 774]

The filament shouldn't bend in the feeder . Maybe there is to much pressure build up or the wear has weakened the arm so it bends slightly.

It's a hard part to temporarily fix when you can't print.

[ELLOMS 3]

The filament  shouldn't bend in the feeder . Maybe there is to much pressure build up or the wear has weakened the arm so it bends slightly.

It's a hard part to temporarily fix when you can't print.

 

Ok so how can i reduce pressure? I will try to fix the carving by filling the void with epoxy resin or something. Could there be a problem with the stepper motor itself? Not having sufficient strength?

[Labern 774]

not really unless its getting to hot. but normally it will deform the filament if its hot.

Skipping back means its not slipping (good) but there is 2 much pressure build up.

if the feeder is 2 tight it can squash the filament 2 much and be tight in the bowden.

or there could be something wrong the the hot end like blocked nozzle etc.

If the feeder is to loose then in will slip and grind. but in your case if the filament is moving to the side its possible that it could grind even with good contact.

what material, temps and speeds are you trying to print at?

[ELLOMS 3]

not really unless its getting to hot. but normally it will deform the filament if its hot.

Skipping back means its not slipping (good) but there is 2 much pressure build up.

if the feeder is 2 tight it can squash the filament 2 much and be tight in the bowden.

or there could be something wrong the the hot end like blocked nozzle etc.

If the feeder is to loose then in will slip and grind. but in your case if the  filament is moving to the side its possible that it could grind even with good contact.

what material, temps and speeds are you trying to print at?

 

PLA settings

Temp 210-215

Speed 40-50 mm/s

L Height 0.1 -0.2 mm

Perimeters 0.8 mm

Infill 0-20 %

Top Bottom 1 mm

Retraction 4.55mm at 25 mm/s

Bronzefill settings

Temp 215-220

Speed 40-50 mm/s

L Height 0.1 -0.2 mm

Perimeters 0.8 mm

Infill 0-20 %

Top Bottom 1 mm

Retraction 4.50mm at 25 mm/s

Flow Rate 104-108%

I can't find any spare parts for the feeder mechanism in the UM Shop. Aren't they selling them? Is replacing the bowden tube worth a try?

[Labern 774]

You will have to contact support to get one.

Give them the part numbers from here: Part 1 Part 2

Pull one end of the bowden off and push the filament through, it should be pretty easy to push. if there is a tight spot then it may need replacing.

[ELLOMS 3]

I checked the bowden tube and it seemed to be ok. I got my printer running with PLA. Trying to print the alternative feeder again and facing heavy under extrusion. I raised the temp to 225 and the speed to 50mm/s and now it runs ok. But this is by far exceeding my usual settings.

I also did a few atomic pulls and i noticed strange shapes on the filament around the area of the PTFE Coupler. Could this be a sign of incorrect assembly?

I assembled the Nozzle following this guide from ultimaker:

https://ultimaker.com/en/support/view/253-re-assembly

It says:

"Screw the hot end isolator on top of the nozzle, with the aluminum plate in between. Make sure to screw the hot end isolator back on until it just covers the screw-thread of the nozzle."

I don't know if I understood this correctly? (not having english as the native language) I made a photo of how I assembled the teflon isolator with the nozzle.

I marked the area red where I didn't thighten the isolator against the nozzle.

Thanks again!

[DidierKlein 729]

Actually you have to leave a space of 2mm between the Teflon isolator (white) and the steel isolator.

[ELLOMS 3]

Actually you have to leave a space of 2mm between the Teflon isolator (white) and the steel isolator.

 

Well I did that, but this was just the nozzle I had laying around and I didn't pay much attention on getting the space right in this photo.

So i should screw the metal part into the nozzle until it sits thight? Or leave the space as it is?

Thanks!

[Labern 774]

it doesnt screw all the way down. you screw it till you have the 2mm gap between the white and metal bit as DidierKlein stated

[ELLOMS 3]

Oh ok now i got it. Thanks for the help!

I will try to print the alternative feeder and see how this changes things. I will update you as soon as I have it installed.

[ELLOMS 3]

I installed the alternative feeder and it works perfectly. Very happy with design and ease of use! I tried to print a few things including an extrusion test.

It turned out pretty good I think. Only some tiny little holes next to the writing at 10mm3/s and 9mm3/s but the rest of the layers have a solid bond.

Thank you for the nice Tips and Tricks!

[Labern 774]

Awesome. Glad you got it fixed