New to M200, having some problems

@dealen, please fill the support form , attach these photos and short movie that shows how filament is extruding during filament loading. Probably you will need to clean or replace the nozzle.

caesar I think you have just write a very intelligent response.

Every mod is possible even in closed environment machines, you just have to know how ;)

Thank you for sharing the knowledge.

and for telling everyone if you want to mod go ahead and try yourself, if not please get informed and try getting responsible fot the probable consequences.

its the orginal one

I found out that -30C is a little too much, at some points it wasn't hot enough to print with success.

So I used -20C to get better prints. The hotend temp fluctuates a lot between +20 and +30C, probably because it is moving. Definitely something wrong with the thermocouple.

Here is a side picture of my hotend. Note: I scraped the nozzle at some point so it is pretty clean now.


I will try to take it out and see what's wrong with it.

I wonder if I can buy just the thermocouple?

Sidenote: the Up works the same way. Nozzle and temp block are dirty as a pig but almost no burn marks in the prints.

Both printers use high temp ABS + perfboard + raft. Up uses 260C to print ABS.


Edit: thermocouple is fixed inside a metal tube. There is no way for the fastener to damage it. The problem might be inside it, at higher temps it could touch the sides and throw off the temp readings.

The thermocouple assembly looks like it is protruding farther from the block than normal. Typically its case sticks out only about 5mm or so.

It is completely pushed in.

How long should it be?

To see if the difference is in hotend hole or thermocouple length.

Edit: mine is 40mm long while hotend block is 33mm


Interesting point caesar, I also have an uop and it's dirty as a pig too and no burn marks.

The crimp connections (assuming your printer has them and not the screw-terminal block) of the thermocouple to the electronics could be an issue - might want to check those if you haven't already.

Hi Caesar,

Can you tell me how to find out what temperature the hot end is at?

I am also getting burn marks on white ABS, and wanted to check the temp.

Could you also let me know the mod you did to set the temp correctly?


ssangster, it is not easy without any electronics skills.

First, I isolated the small chip on the extruder PCB so the heat from the stepper is not perturbing the reading. Just put something there to cover the hole in the plastic under the PCB - I used some paper tissue.

The temp convertor chip uses its own sensed temperature to offset the one read inside the hotend. Basically the chip must know the temperature of the place where the thermocouple is connected to the extruder PCB. If the chip is hotter than the connection place on the PCB, it will read a lower temperature than real inside the hotend, forcing the printer to heat the hotend more.

This can add 5-15C of error.

Second, the inherent errors on the mainboard from components (1% in resistors) and the power supply's error in 3 Volts rail (up to 3-5%) can also add to this, raising the total error to about +20C. For these there is no direct solution.

As I said before, if you are skilled enough to do the change then it is not a problem to make the mod by just using a 200k trimpot.

The temperature is reported in 5 millivolt per degree Celsius on the output of that chip. You need to solder on the PCB to be able to read temps while printing.