peter_p

Update: it was the Darlington transistor; the base was always around 4-5V even when turned off. The reason that the transistor died (or better, became sick) is perhaps due to the inductive load of the fan creating spikes. Anyway, I've replaced it plus added a diode between collector and emitter. Peter

yep! And the rest is easy mathematics. Peter

I had the same problem at the very beginning. Did something wrong when mounting the brass pipe upside down with the result of jamming, leakage --> removing, cleaning, mounting again, and finally breaking both the pipe and the nozzle. I ordered a replacement, but the pipe was out of stock. Then I went to our workshop and got a replacement within half an hour: pipe and nozzle in one piece, and all my problems are gone. I guess it is a little design weakness to have two brass parts mounted against each other into an alu-block having a different thermal expansion coefficient: at 200°C they are no longer tight, tightening them at this temperature and removing when cold let them break easily. I have to admit that I haven't read the manual carefully i first place; it is written there to dismount the hot end at high temperature. But my solution seems to be much better. Peter

I just stumbled over your three months old post, which isn't answered yet. Since I'm now dealing with the same issue: have you succeeded to get the info on different ways meanwhile? Best, Peter

Yes Bill, but this was the first I did. Peter

Anyway, have many thanks Joergen! Peter

Ulticontroller says correctly 1 or 0 when these commands are sent, but 255 ~ 19V DC, fan runs at full speed 0 ~ 4,4V DC, fan still runs (at low speed) The voltage is measured at the fan while it is connected, otherwise it is always ~19V (high ohmic). But I don't know if there is simply a DC voltage needed for the fan (?).

Thank you, Joergen! I'll check the Darlington, although I think it was not due to a shortening. Also, the fan reacts on commands, speed up and down. The behaviour is more like an offset: zero isn't zero. Peter

Since a few days my head fan does not turn off completely when switched off either by using the Ulticontroller or gcode M107. Does anyone have an idea why? Thank you in advance, Peter