Feeder pressure on UM2+

[Shinao 0]

Hello,

My UM2+ feeder was grinding my filament so I wanted to loosen the feeder.

Nothing happens, the indicator stay on the top, I decided to unscrew everything and see what happens inside and I don't get it : how does the screw will loosen/tighten the pressure ?

I screw and unscrew all the way but nothing happens.

Am I missing something, maybe my UM2+ is not mounted properly ?

Also, is this a good alternative feeder for the UM2+ ? https://www.youmagine.com/designs/alternative-um2-feeder-version-two#activity

Thanks in advance

Edited May 16, 2016 by Guest

[gr5 2,267]

Lol - you didn't go "all the way".  Unscrew it some more and it will start pushing down on the spring making the spring more compressed.

In both photos you show it as loose as it can go.

Edited May 16, 2016 by Guest

[Shinao 0]

Oh wow, how did I miss that ? Thanks.

Hm, if it's already as loose as it can go then that's bad for me, as nobody ever had this problem, and if so, is the only solution to change feeder ?

Thanks anyway

[gr5 2,267]

Sometimes grinding is caused by feeder too loose (slipping). Sometimes too tight. But usually not too tight. Sometimes it's just too many retractions. I have had prints that had 40 retractions on the same spot of filament - could that be your problem? Or if you print too fast or too cold then the pressures are amazing in the print head and some filaments result in grinding.

How hard or soft your filament is in the feeder can also affect grinding.

Try printing at half speed or thinner layers (what layer height, nozzle size, temp and print speed were you at?) and also if you have lots of retractions (from another post):

One simple solution is to reduce the amount of retractions. I was printing "big ben" and it kept failing in a particular section. I found that slice and there were 40 retractions. It was one retraction every .159mm or 24 retractions for every spot of filament on that layer. So I set the minimal extrusion parameter to 0.32mm. I had 19995 retractions in the resulting gcode instead of 34300 retractions. That was enough that I was able to print big ben and the stringing appeared to be no worse visually.

[Shinao 0]

Not much retractions on this particular model that I try to print (don't hear the sound much of the time), but I did have a strange result in quality with this filament, like it didn't heat enough. Gonna try to heat it more.

I will try your parameters also, nothing to loose but time

Thanks for the informations gr5 !