Weird extrusion after Marlin install

Hi,

I´ve just managed to get Marlin running and the axis the switches and the free extrusion work well.

However if I print there is not enough material coming out, it looks like a the nozzle is blocked or the extruder is underfeeding.

Im not sure if this is Marlin related I had a similar issue when I changed the threaded rod at the z axis. There it was the other way around while printing the axis would move normally but while moving manually with pronterface it would stall. It turned out that the new measurements of the rod caused the z motor to turn to fast and therefore stall.
With the extruder here its indeed the other way around. The normal extrusion gives me a nice output while during print it underfeeds.

Any symptoms you recognize?

If you think it is a mechanical problem: put back the old firmware and see if it works again. If not, then yes it's mechanical.

But it could well be that you have to calibrate everything again.

For the extruder... in pronterface, tell it to extrude 127mm of plastic. Then measure how much actually moved. Then adjust the DEFAULT_AXIS_STEPS_PER_UNIT setting in marlin,

new value = old value * ( 127 / measured value)

Here is a video to demonstrate.

[www.youtube.com]

Yes I had already calibrated with the old firmware. The problem went away after i had reuploaded sprinter and then marlin again. I dont know what happened there.

Checking if you have absolute/relative extruder units option matched in firmware and slicer may be worth a try. AFAIK Marlin defaults to absolute - try to issue M83 command before you start the print.