My feedback on M201 printer after 3 weeks

[stado65]

Hi everybody,

It has been around three weeks since I received my M201 and I want to share some experience after long evening (and sometimes nights) spent on this machine...
First of all, the assembly is not so easy. I am quite experienced in DIY but as there are some inconsistencies betwwen videos and pdf guide I had to do, undo and do it again some operations (especially the hotend carriage). Finally I managed to have it finished and ready to print !

The first prints were not really beautiful but it worked. During this 3 weeks, I encountered various problems, solved some but there are still many issues with this printer.
Here is mylist :

• hotbed : the hotbed was not at all at the temperature indicated but much lower : I solved this by turning the hot plate the other side (the resistance on the aluminium plate side), put an insulator in order for the connections not to touch the aluminium, add thermal paste in between and and a cork layer below ; now the temperature of the plate is really the one displayed by the LCD
  z-wobbling : thi sis a very well know problem with Prusa due to misaligned or bended Z-threaded rods, I solved it by replaced the original Z-couplers by couplers I have printed (
  ball bearings : after a few prints, one ball bearing of Y driving wheel was very noisy and finally, it exploded ! They are of very poor quality : I bought new ones and replaced them on all the wheels
  X-axis bearings : the LM8LUU were very noisy (the balls inside were moving) : I had to put grease inside to remove the noise
  A4988 drivers : X and Y axis were missing some steps, creating shifts on the object : I had to increased the current in the motors by adjusting A4988 voltage
  X axis endstop : I had to screw a piece of plastic on the X carriage to reach the X endstop...
  firmware : that is the biggest issue !!! the printer is only usable with Repetier host. I tried Repetier server : does not communicate at all. I tried Octoprint : it works but there are many com errors and, according to Octoprint's author, this is due to the firmware. Finally I tried to print from SD card but the print stops after 9 hours around 50%... Moreover, when printing from SD card, the printing speed decreases automatically down to 15%, then increases and decreases once again without any reason !!! I will open a new topic on this issue

To conclude, this printer is very promising but still has got many problems that need to be solved and especially firmware related ones...

[Mark]

the firmware, have you tried the latest V1.0.3?

[stado65]

Yes Mark, I upgraded to 1.0.3
The stops during printing happened very often with the previous firmware.
With the new one, it almost never happens except sometimes and especially on long prints (which is even more frustrating because you loose time and material...).

[Mark]

seems the latest firmware still have the pause problem, will keep on debugging it.

[stado65]

OK, Mark.

I suppose it is linked with a communication problem with the firmware : Octoprint always complains about resending each line :

Send: N18886 G0 F7200 X121.847 Y116.447*76
Recv: Error: Line Number is not Last Line Number+1, Last Line: 18886
Recv: Resend: 18887
Send: N18887 G0 X124.567 Y103.801*46
Recv: ok
Recv: ok
Send: N18887 G1 F2400 X132.821 Y105.473 E1954.99487*49
Recv: Error: Line Number is not Last Line Number+1, Last Line: 18887
Recv: Resend: 18888
Send: N18888 G0 X123.351 Y105.044*42
Recv: ok
Recv: ok

Moreover, I have to push the reset button on the LCD before each print. If not, it does not start.

Finally, please have a look to the issue with the bug for accessing the SD Card I already mentioned in a previous post.

Thanks.

[Mark]

I can see this error every time I connected the printer, but it will not affect the print job in the I3 series and also my own M201. Anyway will forward this issue to the software engineer later.

[Malaka]

I've had similar issues. I replaced the bed bearing and even rods to prevent it from causing layer shifting. The bearings for the belt wheels surely need replacement. I've had clogging issues but a brand new hotend sent from support works flawless(Thanks Geeetech). Firmware issue is a problem but so far v1.0.3 has fixed my problems. I am receiving the same error about the line+1, I've been precompiling my g-code on my main computer and transfer it to the computer handling the printer, haven't had that error for a while. Only during prints 12hrs+ would I have issues with killed prints due to that error. Very slight z-wobble, I will try replacing the coupling and see how that works. The X endstop initially was unreachable by the hotend mount because of the locking rings on the rods, I used a leftover long screw and ziptied it to left 3 upper holes and it works fine. I haven't had a hotbed issue, seems to be accurate enough. I haven't tried increasing the current to motors, I've had layer shifts but I put a fan in front of control board and it seems to fix it most of the times, but long prints might have small shifts.

[neilcoggins]

I've had several issues with my M201:

• GTM32 overheating (cutting out USB randomly) - improved, but not cured, by blowing an 80mm fan at it constantly
• layer shifting (seems to be related to the A4988, although I've tried 3 replacements with no change, and the X-axis belt being too tight which is now fixed)
• every print over 1M gcode instructions failing at exactly line 1,000,001 (I've tried 3 different STLs multiple times - it fails every time
• backlash on Z-axis (I'm going to fix this by printing replacement XZ-axis motor & idler ends, and fitting anti-backlash nut traps)
• Z-axis wobble (caused by a bent 8mm threaded rod - I'll fix this with the replacement XZ-axis idler end and some surgery to the top mount of the rod)
• inaccurate X/Y/Z steps/mm in the firmware (which can't be entirely fixed in the LCD settings, and the GTM32 ignores the M92 command - I have to scale every print by 102% for sizing to be correct)
• bent aluminium heatbed plate, making levelling impossible (I've fixed this by using some borosilicate glass, and holding it in place using bulldog clips)
• nozzle clogging all the time (tried several different brands of PLA, only Excelvan flows smoothly all the time, so I'm sticking to that for now)

Ho-hum. Knowing the issues at least allows you to work around (most of) them - my M201 is busy most days printing parts for my next 3d printer - a Mostly Printed CNC with an E3Dv6 print head and a print volume of 50x50x20cm...

[stado65]

Hi

I forgot to mention the bent aluminium heatbed, you're right !! It makes almost impossible to make a good Z calibration over the whole plate...

Regarding the firmware issues, I really think about getting rid of the proprietary GTM32 board and replace it with a good old RAMPS 1.4 with an OpenSource firmware.
I do not understand why this printer needs such a board. The E3D Cyclops hotend (which is the one sold with M201) is supposed to be compatible with RAMPS and Repetier firmware.
Moreover, the GTM32 is supposed to be more powerful and quicker than RAMPS or GT2560 but in fact, it seems to be less reactive and more buggy...

Mark, what's your opinion ?

[Mark]

yeah as you said it should be quicker than GT2560 or Ramps, might be the buggy firmware, the latest version 1.0.4 is released today you can check it later.