extruder problem

I have prusa i3 printer and have alot of trouble with extruder.
Every third item I print is unfinished because extruder is clogged or something happends that printer not print anymore.
I hear alot of ticking from extruder motor which can not turn gear for filament and goes forward and backward with ticking noise.
I have turned motor driver to full to 1,3V and it is still the same a little better but not much that ticking noise is still present.
And filament not coming out from nozzle until i pushed it with my hand, it is alot of gaps in print.
After that I have changed and mounted on J head nozzle with bowden extruder and again it is the same.
I am really frustrated and don't know what to do to make this printer works as it should so I can print something and it prints whole object like it should be.

I had issues with mine too. I wasted a lot of time on this and in the end, I think it was the replacement of the driver board that fixed it. I went with a DRV8825 for the extruder only. I kept the full set of jumpers for 32 microstepping, and changed the firmware to reflect it.

Other than that, I replaced my thermistor with a known type (no idea what it shipped with) and available table in the firmware, and I sealed it into the block with silicone RTV, so I'm more certain that the temperature I set is the temperature of the hotend. I don't know if this helped as I have/had no way of knowing what the actual temperature was.

I also ditched the spool of PLA that came with the machine and got a fresh roll from Microcenter (Inland brand) heat-sealed and with a desiccant pouch so I know it is dry.

I really don't know if the latter two things had any effect as they were done concurrently while trying to deduce the problem. The board change was the last thing I tried and it seems to have eliminated the stutter in my extruder.

What did you change in firmware for DRV8825. I have it but still didn't change driver

The A4988 board with all three jumpers applied (as is normally the case) only provides 16 microsteps. The DRV8825 has 32 so you need to double the esteps/mm in the firmware. Mine was set for 105 in the original firmware (direct-drive extruder) so I upped it to 210. After doing a calibration, I backed that off to 207.

I assume you're using Marlin. Find and change DEFAULT_AXIS_STEPS_PER_UNIT in Configuration.h.

Ok I have changed driver and for now looks good! No more ticking.
But DRV8825 heats alot and also motor heats alot!

I trust you have a heat sink on that chip. They do seem to run hotter, but I think my motor doesn't get any hotter than before.

Yes of course I have heatsink, and heatsink is hot alot, when before was not.
Motor before even get warm and nwo it is hot

None of my 4988s had heat sinks so I thought I'd ask. I never checked the temperature before so I don't have a reference. It is definitely hotter than the other steppers, but it is doing a lot more work and is very near the hotend. Mine runs cool enough that I can hold my hand against it at any time which means it is probably below 50C. The sink on my 8825 is also not too hot to hold my finger against.

I can not hold finger on my 8825 it is too hot, stepper motor also!
S I lowered voltage of stepper driver from 1V to 0,89V and now driver and motor are ok, I can hold finger on it!

Edited 1 time(s). Last edit at 02/18/2016 08:47AM by Blisk.

Good deal. I hope it still runs stutter free.

yes runs ok, it should be around 100 oC to damage driver or motor!