Problem with Marlin and possible other issues

Hi,

My first post on this forum.
I just completed my Mendel 90 custom build.

I have several problems with printer and sotware.

1) My 100K thermistors are not reading correctly
2) i correctly installed the USB serial port wich uses COM5.
I compiled Marlin and loaded it on the Melzi with no errors.
However I do not get the USB icon when I connect to the printer.
3) when I want to move the x+ motor the printer shuts down due to error:0

Nothing at all is happening on the printer.
What can I measure or do to find the problem?

Edited 1 time(s). Last edit at 03/27/2014 05:48PM by Mendel90.

I think I measured the thermistors wrong since I didn't discnnect them from the circuit.
I disconnected 1 wire from the extruder T and measured 0 ohms.
The same thing with the bed T gave me 200Kohms.
I

Connecting...
start
Printer is now online.
echo:Marlin: 1.0.0 RC2
echo: Last Updated: Mar 27 2014 22:20:17 | Author: nophead
echo: Free Memory: 12982 PlannerBufferBytes: 1232
echo:Using Default settings:
Error:0
[ERROR] Error:0

: Extruder switched off. MINTEMP triggered !
Errorrinter stopped due to errors. Fix the error and use M999 to restart!. (Temperature is reset. Set it before restarting)
[ERROR] Errorrinter stopped due to errors. Fix the error and use M999 to restart!. (Temperature is reset. Set it before restarting)

echoD init fail
Setting hotend temperature to 100.000000 degrees Celsius.
SENDING:M105
ok T:0.0 /0.0 B:17.9 /0.0 @:0%
SENDING:M105
ok T:0.0 /0.0 B:17.9 /0.0 @:0%
Setting hotend temperature to 0.000000 degrees Celsius.
Printer stopped due to errors. Fix the error and use M999 to restart!. (Temperature is reset. Set it before restarting)
>>>M999
SENDING:M999
Resend:1
Error:0
[ERROR] Error:0

: Extruder switched off. MINTEMP triggered !
Errorrinter stopped due to errors. Fix the error and use M999 to restart!. (Temperature is reset. Set it before restarting)
[ERROR] Errorrinter stopped due to errors. Fix the error and use M999 to restart!. (Temperature is reset. Set it before restarting)

Setting hotend temperature to 100.000000 degrees Celsius.
SENDING:M105
ok T:0.0 /0.0 B:17.8 /0.0 @:0%
Setting hotend temperature to 0.000000 degrees Celsius.
Setting bed temperature to 110.000000 degrees Celsius.
SENDING:M105
ok T:0.0 /0.0 B:17.7 /0.0 @:0%
Setting bed temperature to 0.000000 degrees Celsius.
Printer stopped due to errors. Fix the error and use M999 to restart!. (Temperature is reset. Set it before restarting)
>>>M999
SENDING:M999
Resend:1
Error:0
[ERROR] Error:0

: Extruder switched off. MINTEMP triggered !
Errorrinter stopped due to errors. Fix the error and use M999 to restart!. (Temperature is reset. Set it before restarting)
[ERROR] Errorrinter stopped due to errors. Fix the error and use M999 to restart!. (Temperature is reset. Set it before restarting)

If your thermistor measures 0 then you have a short circuit. Marlin would give a MAXTEMP error.

If it is open circuit or if you have 200K thermistors but set the firmware for 100K it will give MINTEMP error, which is what you seem to have.

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[www.hydraraptor.blogspot.com]

I have measured again and my bed thermistor reads 133Kohms on multimeter. The E-thermistor still reads 0 ohms.
I checked the E-PCB for shorts but couldn't find any.

After that I started measuring voltages on the Melzi.
PSU: 12,54V
E-trhermistor: 5,01V
Bed thermistor: 4,84V

When in prntrface the Bed heat is set I measure 0V on the Melzi.
Also the leds I soldered onto the heatbed do not light up.
The extruder does not heat. 0V

The red led on my Melzi does not blink quickly as it did when I fist turned on the PSU. The led is not on anymore.
When I connected in Prnterface , again I didn't receive data from Marlin.
Just Marlin: echo unknown command""

Like you said I think I have a short somewhere.

Update:

I managed to home all the axes.
The microswitches work as they should.
However I can not use the Jog buttons for none of the axes.
They return the error mentioned above.

The heaters still do not work.

It's hard to give answers when you say your bed thermistor reads 200K and then you say 133K. If it is a 100K thermistor 200K would be probably be below 0C. 133K would be an unusually cold room. A 100K thermistor will read 100K at 25C.

You say your E thermistor reads 0 ohms, but the voltage at the Melzi is 5V. If it was 0 ohms the voltage at the Melzi would be 0 and you would get a MAXTEMP error. If it was open circuit the voltage at the Melzi would be 5V and you would get a MINTEMP error. Some multimeters show 0L for open circuit.

Until you fix the thermistor errors Marlin will not drive the heaters or jog the axes.

Marlin does not drive the LED. Some bootstraps flash it before starting the firmware.

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[www.hydraraptor.blogspot.com]

I measured the 200K because I didn't disconnect 1 wire from the circuit as I tried to explain before...
When I did disconnect from the circuit I measured 133 Kohms at 19.6C room temp.
This morning I measured 135 Kohms at 18C room temperature.

Both my thermistors should be 100K ohm from the type B57560G104F as it was mentioned on the 2 seperate vendors sites since I got 1 thermistor with the heatbed and 1 with the hotend I bought. This corresponds with thermistor #8 in Marlin wich I selected before compiling with Arduino.

Thnx for the info about the leds. I have allready desoldered them from the heatbed.

I can only see what the multimeter is reading. It measures Voltage but no resistance on the thermistor in the hotend. (measured 2 times)
If I don't find the problem I will order a new thermistor for the hotend.
Thnx alot for your help.

I don't think you are interpreting your multimeter properly. You can't increase a resistance by connecting something in parallel with it (assuming the Melzi was not powered) it could only make it lower. For example the Melzi should have a 4K7 pullup resistor to 5V. When not powered that 5V rail should have a lowish resistance to ground, so I would expect something close to 5K across the terminals. I just measured one and got 6K. There is no way it could read 200K with a 135K thermistor wired across it.

The voltage measurement and Marlin both indicate your E thermistor is open circuit, not 0 Ohms.

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[www.hydraraptor.blogspot.com]

I was indeed first measering with an analog multimeter but changed to an digital multimeter.
As soon as i've found and fixed the bad connection on the PCB on the extruder I could measure the E-thermister at 112Kohms.
So, after all my wiring was good!

I struggled two evenings wit an unstable Y-endstop wich makes it nearly impossible to calibrate and print.
This is because I do not have printed clamps but smaller clamps in metal I managed to get the same length as the printed ones.
I finally fixed the endstop with two zipties firmly attached to the clamp.

The problem I'm having now, trying to do my first print.
Is bad reading from my SD card in the Melzi.
My file is named correctly 8+3, RIBBOONC.GCO

Sometimes the file is read correctly but mostly I get the SD init failed error.
I have formatted this card at least 100 times the past 2 days as FAT16.
I just have to keep trying an half hour to make 1 print attempt.
Then I can do a little adjustment in lowering the Nozzle to try again an half hour later.

Is this normal?

No it isn't normal. Must be a faulty SD card or Melzi. SD init should always pass with a card inserted.

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[www.hydraraptor.blogspot.com]

I'm pretty sure it's the SDcard.
When I re-upload marlin.ini it's fixed but soon after it goes wrong again or
when I manage to launch a print after a few seconds I discoonect the printer it will stop printing because the card can't be read properly.
Unfortunately my only other SD card is a 2GB wich can only be formatted to FAT 32/64 KB.

I'll buy another one tomorrow.
Thnx.

Why can it not be formatted FAT? I use 2GB cards and Windows gives me the option of FAT, FAT32 and exFAT.

Edited 1 time(s). Last edit at 04/03/2014 09:56AM by nophead.

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[www.hydraraptor.blogspot.com]

I guess you are right.
I can load and start a print from pronterface.

Unfortunately I don't have the budget to buy a new Melzi.
For the time being I 'm going to print from the PC. I hope I don't get to many failures this way.

I still have the problem with my hotend heating in the corner (on the screw in the back on the right) instead of the center.
I've put -100 for x and y in the options in pronterface but ii'm unable to change it's position.
It's not a big problem however since i'm using the Z-offset setting in pronterface to start my print at the correct height.

Now I'm able to print a new problem has come up.
The first layer doesn't stick to the bed.
I have increased the bed temp for my 1,75 ABS, from 110 to 120C wich helps a little bit but not enough.
My hotend is at 225 first layer and 220C from then on.

I have now prepared an ABS solution with acetone to make the first layer stick to the printbed.
Using the solution on glass is not ideal maybe but I will see what happens.

Use PET tape on the bed to print ABS. Printing ABS direct on glass needs 130C surface temperature for the first layer and you can't get that from a 12V PSU. Also it needs a very very very dilute ABS in acetone solution which needs to be baked on the first time you use it.

The start position is determined by your slicer, not pronterface.

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[www.hydraraptor.blogspot.com]

I've ordered PET with deal extreme.
For the time being my first layer sticks sufficiently to the bed with the acetone soltion I made yesterday.

The last thing preventing printing is inconsistent extrusion.
While the filament extrudes quite well when testing, it doesn't go so well during printing.
I'm printing a small Mendel90 ribbon clamp and while it starts off good, it goes wrong when the infill starts.
That's also when the printer shifts to high speed.

I have fastened the grub screw on the extruder pulley and fastened the springs on the idler.
Alltough it has improved a bit extruding sometimes completely stops.

The only thing I can think of is checking the hobbed bolt.

What are your toughts?

My printing position is centered.

The problem is when the hotend has to heat up after homing.
Instead centered it goes to the screw in the back of the bed on the right.

Could be a faulty hot end, temperature too low, or not enough spring tension. Try removing the bolt and see if you can extrude at a reasonable speed pushing it by hand.

The bolt should look like this: [forums.reprap.org]

If the nozzle is in the wrong place when it heats up then your start.gcode must be different from the one I use.

Edited 1 time(s). Last edit at 04/04/2014 06:53PM by nophead.

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[www.hydraraptor.blogspot.com]

I have put more tension on the springs and I have added more Kapton around the hotend.
This helped and I finally have my first print.

2nd print extruding stopped again after 2 or 3 layers.
I make sure now to do a 50mm extruder test before I start a new print.

I haven't modified start code from the ribbon clamps I'm printing but it's not really an issue for me.

Thnx for your advice!
Jim