Heating problem

Hi,
I have a problem which I don't understand. When I run the heat profiler or the extruder exerciser, the nozzle always stops to heat at 138

Ok,I made another test and the thermistor is the problem.I use the first Generation electronics and a 100K Ohms thermistor. I didn't build the electronic card, because of this my knowledge about this is not so big. I have read in the forum that I have to replace a capacitor, but I don't know which one.SORRY

kind regards

Mathias

C3 is the one that needs to be changed... I used a .22 uF polyster cap. Then in the preferences for Extruder0 the setting for Extruder0_Capacitor(F) needs to be changed to 0.0000022. That should take care of your problem.

The build instructions for the Extruder controller board is here...
[www.reprap.org]

Just ignore their value for C3 and use the .22 uF polyster or similar cap I mentioned above. Several of us have had this problem and this fixes it.

After this you should run the extruder profiler and use that data with this site

[www.wessa.net]

to get a simple linear regression for your Extruder0_hb and Extruder0_hm settings in the Extruder0 preferences settings. I detail how I did that here:

[objects.reprap.org]

with my Gen 1 electronics.

Hope that helped some. Keep pluggin at it and it'll get done!

Demented

Thank you very much,

I replaced the cap and it solved the problem!!!

I have done the heat profiler and everything went fine. My nozzle heated up until 280

There are two sets of jumpers on your extruder board after you get done testing it. They are both on the three pin headers. One says Min/Speed the other says Max/Empty. Take the jumper off of the Max/Empty header and your problem is solved.

You don't need to be at 280

I do something similar. My routine goes like this:
1. open the extruder exerciser and turn on the heater
2. open the model and position it on the build area
3. home the Z axis and make sure it's the right height
4. home X and Y
5. run the extruder for a bit to get it pushing filament
6. print

I've found that the two things that are most likely to ruin a print are a) not having the nozzle close enough to the bed and b) not having enough filament coming out at the start of the build.

To remedy the first one, I check the nozzle height at four corners of the bed using a sheet of paper as a gap gauge. Not sure what the best practice is but I set it so that the paper just barely grabs. Seems to be best to do this when the extruder's hot.

The second one can be avoided by running the extruder for a bit immediately before the build. If you've got an extruder with a nozzle valve, this shouldn't be necessary.

Steve,

Yeah, the nozzle height seems to change for me based on a bunch of factors...heat being the main one...

I just use that period where it is drawing the line up and back before it prints the part to position the height by hand...a very dodgy method but it works.

Demented

Thank you very very much "Demented"!!!

I took of the jumper and it worked. You are really a big help.

Mathias

Glad to save you trouble.

Demented

Hey Demented,

I still have some heating problems:-(
When I want to start to print there are only 5.8Volts on my nicrome wire. Because of this, it heats up very slowly and the nozzle is not able to hold the 230