E value has multiplier of 7

The GCode files I'm generating using Skeinforge (version 36 I think) have E values that are 7 times the distance moved by the extruder e.g.

G92
G1 X3 Y4 F1800 E35

The physical distance travelled is 5mm, but the extruded length is 35mm. From my understanding the extruded value should match the distance travelled (give or take some tweaking) i.e.

G92
G1 X3 Y4 F1800 E5

If this is true it would explain a lot of the issues I'm experiencing with very fat lines with varying thickness in my printed objects.

I imagine the multiplier of 7 I'm getting is due to a setting somewhere in Skeinforge, but I can't figure out which one and would greatly appreciate a nudge in the right direction!

Thanks,

alianmac

The parameters to change are feed rate and flow rate setting in the Speed tab. You need to raise your feed rate or decrease your flow rate until your infills and perimeters on the 3 outermost surface layers are touching each other (solid surface).

I think a good starting point is to make the Feed Rate and the Flow Rate the same.

For example, I (when my extruder was working) had feed rate and flow rate both at 30. That seemed to be working for me.

Quote
AgeingHippy
For example, I (when my extruder was working) had feed rate and flow rate both at 30. That seemed to be working for me.

What happened to your extruder?

hmm..

well initially the thermal break inner diameter was 3.5mm and my barrel internal diameter was 3.1mm. I got failures pretty quickley as the pressure on the softened plastic in the thermal break was causing the feedstock to swell to 3.5mm in the thermal break just before entering the barrel. This caused feed failures.

I fixed this by drilling out my barrel to 3.5mm to a depth of about 7mm so this swollen area would be melted down by the barrel.

Then I think I did not screw the barrel in tightly enough and I got some leakage out by my PEEk threads. I opened the assembly and had to drill out the blockage. Stupidly used 4.5mm!! so that screwed up my hot end totally.

I now have some PTFE (10mm) and a 3.1mm drill bit so need to drill it out, cut it down and insert it into the PEEK housing. Unfortunately I completely mangled the 10mm internal circlip and am having problems finding a cost effective replacement. Also, the PEEK replacement is 10mm for a 3/8ths original, so I will need to sand the PTFE rod down a bit to fit the PEEK.

I must admit I am browsing mini lathe sites a lot in the last week or so because I don't have the correct tools to do the required repairs. I know - spending 400+ quid to repair something I can buy for 30 quid or so is maybe over the top... but there you go - tool envy. Like a sweet shop I tell you

I'm not sure if you saw my other post, but I found out that with Adrian's geared extruder, I have to blow air around the PTFE thermal break for the retract/restart option in Skeinforge to work in preventing ooze. It seems that the it gets hot enough in there to soften the filament and the air cools it down enough to prevent that.

@alianmac: I forgot to tell you that the value for the extruder stepper per mm must be set in firmware correctly in order to get the E value to be about equal to the distance travelled. This depends on parameters like extruder design and filament size. How you do this depends on what firmware you're using.