I built an aluminum extrusion UM2. This one:
http://www.thingiverse.com/thing:811271
I am using UM2 main board and the UM2 feeder knurled sleeve, I've set the filament diameter to 1.75mm in the on-screen setup and in Cura. When printing, i am getting massive over extrusion. I have to set the flow rate to 55% to get normal flow. I did a 100mm test extrusion using Pronterface and it extruded 180mm which agrees with the 55% above. When I do an "Insert Material" it tries to push way too much material through and ends up chewing through the filament when it can't push that much.
If I set the filament diameter to 2.85m, it gets closer to proper extrusion but still not correct.
Is there a way to set the steps per minute somewhere in the software? I know how to do it with my Prusa i3 but adjusting firmware in the Ultimaker seems to be a mystery. Can I do an M92 command in Pronterface to adjust it?
I have tried the latest firmware, an older version and the Tinker firmware with the same results.
Thanks.