[solved] Only 7 steps per mm extrusion?

I have an older reprappro mendel that I just finished putting together. I updated the firmware on it to the latest marlin. I also have the latest pronterface. When I tested the extrusion, it extrudes 90mm for every 1mm. That is, if I try to extrude 1mm at 300mm/sec using pronterface, it extrudes 90mm very slowly. The settings in the firmware are still default (660 steps per unit for E axis). According to the calculation on the calibration wiki page, the steps should be

(current setting * expected length) / actual length = new steps per mm.

That calculation gives 7.333 steps per mm, but when I try that, I get an error saying that I am trying to extrude too much. It seems that 7.33 steps per mm is awfully low. Does anyone have any clue what could be going on?

Thanks.

Edited 1 time(s). Last edit at 08/25/2013 06:54PM by bob.

The steps per mm is for filament going into the extruder. Your figures look like you are measuring what comes out.

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Thanks for the reply. Actually, I disconnected the hot end to make the measurements (it is a bowden tube style design). It is just the extruder motor/gear assembly at this point. If 100mm goes in, 100mm comes out. So, in other words, I am measuring what goes in to the extruder.

Edited 1 time(s). Last edit at 08/24/2013 08:16PM by bob.

Check your microstepping. If you are running full steps, then 7.33 becomes about 117 steps/mm when you enable microstepping. That sounds more reasonable, especially if you are running direct drive.

Thanks. I found my problem (sort of). I found a different version of the firmware and installed it. Now things are working. I don't know what was going on, but it all seems to work now. Now I just have the issue of trying to get prints to stick to the bed. The extrusion just curls up onto the nozzle and rolls around on the bed when the hot end moves around.