Strange heaters behaviour, after repetier-server wizard

K8200 3D Printer K8200 - Printer software (repetier, slicer, ...) a
1

hello,

I recently bought a K8200 as DIY kit, a quite complete report of what I did is here:
servicemix.eu/_3DRAG

For starters, it was not behaving as expected (homing movements and fan on right after powering on):
servicemix.eu/_3DRAG/step3.php

Let alone this, I could not connect to it with the non-std baudrate, so I uploaded the firmware (updated to 115200 bauds), after having to burn the bootloader in:
servicemix.eu/_3DRAG/step4.php

After this, all seemed to work fine, at least basic behavior:
I then loaded the PLA wire and tried a printout, but it failed.

After this, I tried the repetier-server wizard, and since then (as far as I can recall) the heaters started misbehaving.

Indeed, while motors and temp sensors seems ok, there the heaters are not working:
servicemix.eu/_3DRAG/step5.php

It seems like they’re using too much power, which brings down the voltage, that’s why the board blinks and buzzes that way. Even the led on the power supply blinks the same way.

is there something broken on the board, so that the power supply looks too weak?
or
did some config changes in the firmware make the controller use too much power?

at the moment, it could only be used to move pieces on a chessboard…

any hints?

thanks
corrado

2

UP…

no posts so far… not enough doc, not a clear question?

also, no news from velleman support…

3

here’s an update with measurements…

thermo resistor of extruder is around 84.4 K Ohms:

thermo resistor of heated bed is around 107.2 K Ohms:

extruder heater resistance is around 8.4 Ohms:

heated bed heater resistance is around 5.8 Ohms:

but then, if you try turning on any of these 2 heaters, something bad happens:

(full video is on my website)

it seems the power is not enough, right?

4

I think the resistances look correct there. But it is definitely not right that your supply voltage is dropping

I had a similar experience with one of my printers after re-flashing the firmware. Maybe you need to reset the flash settings? In Repetier control panel, send the following two commands to the printer:

M502; M500;
The M502 will instruct the printer to initialize all settings to their “factory default” values, and the M500 will write those settings into non-volatile flash.
If that doesn’t help I would try disconnecting all fan and motor outputs from the controller to see if it still happens. Something is drawing too much power.

5

Make sure you use Arduino software 1.0.6 or below.