P802M Prusa i3 Unofficial Support Thread

Ok: Big problems with the dropbox firmware above!
First: home position mismatch (x and y not on the front left skrew, for sure no big problem, could this bet setup in eeprom?)
Second and the bigger Problem: Got a "Heater decoupled" message caused by:
I set the extruder temp for 180 degrees. It heats up and NEVER stopped, going to 220, 230 and then the error!
EDIT: setting extruder heating method to "bang bang" and not to "PID" fixed this issue
Everything can be fixed, for sure. But do not upload this firmware if you are in hurry.

Edited 1 time(s). Last edit at 01/23/2016 05:32AM by madias.

"The Beauty and the Beast", i do not realize how i reach this (in attach) good and disaster result. Have any ideas?
It seems that after half work the extruder have difficult to extrude (but the filament was ok)
(PLA 200/60 layer 0.2, speed 50)

I'm trying to pring my first object in PETG but for some reason I have layer adhesion problems. Could this be because of printing too cold?
I tried increasing the temperature to 245°C already but while printing the printer reads 216°/245°. It looks like it's not getting hot enough.

Any idea why it's not going to 245 while printing?

bed 80 degrees, blue tape plus abs juice if necessary

Quote
ErikL
I'm trying to pring my first object in PETG but for some reason I have layer adhesion problems. Could this be because of printing too cold?
I tried increasing the temperature to 245°C already but while printing the printer reads 216°/245°. It looks like it's not getting hot enough.

Any idea why it's not going to 245 while printing?

I think you need more insulation around your hot end. The filament cooler is probably cooling your nozzle/thermistor down.

And what kind of insulation should I add?
Were you guys required to do this too? Or is it just my printer not being able to keep temperature high enough...

Quote
ErikL
And what kind of insulation should I add?
Were you guys required to do this too? Or is it just my printer not being able to keep temperature high enough...

I used PTFE tape, but kapton tape will probably be better. After I did this my printer was able to better maintain temperature.

There already was kapton tape arround the hot end when I bought this printer so I need to add more layers?

Quote
ErikL
There already was kapton tape arround the hot end when I bought this printer so I need to add more layers?

That kapton tape is there to attach the thermistor. Yes, I'd try adding a few extra layers.

Temperature seems to drop especially when the front fan is running. I don't mean the square fan on the left, which is always running. The blower fan on the front can be turned on / off while printing.
So it seems like this fan is cooling my nozzle down to about a maximum of 220°C

I just measured the voltage of the psu, while printing, and this reads 12.01 so it's still 12V. Insulation is the only option I guess

did you increase the voltage of the PSU to 13.5V? and please do a real temperature measuring. my extruder showed 10 degrees less than the real temp.

I did not touch the psu so it's at default voltage. Should I increase this to 13.5 ?

13 to13.5 is s save.

And increasing it to 13v is required for better keeping the nozzle temperature, or why is it recommended ?

Quote
madias
Good news for printing flexible filaments
The simplest idea was really the best, just an additional guide for the filament prevents loops around the filament gear
Tested with 30m/s working good! More speed give bad results with "soft PLA" even with 230 degrees. But 30ms/s more than the recommended speed.
I have attached a 123D design file and also a STL file for that part.
For myself I used PETG for higher temperature resistance, feel free to experiment.
You also must drill the filament hole a bit (M3-M4, so 3-4mm)
regards Matthias

Hi Matthias,
I modified your design a little bit so it fits my printer and tested printing Ninjaflex filament.
I first had some troubles with it which were related to a too high extruder multiplier. After some tweaking I was able to print ninjaflex at 20mm/s succesfully!

I also attached a picture of my install

Quote
woutwoot

Quote
ErikL
There already was kapton tape arround the hot end when I bought this printer so I need to add more layers?

That kapton tape is there to attach the thermistor. Yes, I'd try adding a few extra layers.

I tried extra layers of kapton tape on the hot end but I don't see a significant difference with it... Maybe I had to tape them with some air between, for added insulation .. I just taped them tight so it won't fall off...

But maybe I should try something like this (printed in PETG instead of ABS?) -> [www.thingiverse.com]
Looking at the pictures it seems like it's going to direct the wind more to the object and not so directly to the hot end...

Maybe this is a better solution than extra layers of kapton tape on the hot end?

Quote
ErikL

Quote
woutwoot

Quote
ErikL
There already was kapton tape arround the hot end when I bought this printer so I need to add more layers?

That kapton tape is there to attach the thermistor. Yes, I'd try adding a few extra layers.

I tried extra layers of kapton tape on the hot end but I don't see a significant difference with it... Maybe I had to tape them with some air between, for added insulation .. I just taped them tight so it won't fall off...

But maybe I should try something like this (printed in PETG instead of ABS?) -> [www.thingiverse.com]
Looking at the pictures it seems like it's going to direct the wind more to the object and not so directly to the hot end...

Maybe this is a better solution than extra layers of kapton tape on the hot end?

I've printed one of those and I haven't really noticed any difference. I also took it back off the printer because it was obstructing my view towards the nozzle.

add for printing flex. filaments:
Be careful with your slicer program to change every speed value (except travelling speed): In cura there was too much infill speed for me left corrupting the print, so I set ALL to the default speed parameter (is set with "0" in cura). Also reduce the retraction length/speed. A too high retraction lengths results in stress the weak filaments twice. With higher speed it's also good to try about 102-105% flow rate.
@ErikL: Fine that it work for you! On the photo I see a minor gap between the printed object and the nema17-gear. If you got in troubles print it a little bit higher.
About setting voltage to 13V: Much more stable for me (with my old 15A PSU) and reduced heating time for extruder and bed AND: I got the (isolated) bed now to 110 degrees, before there was only 80 possible.

Ok, I think I really solved the issue with the extruder temp:
I have done with the new firmware a new calibration look here: [reprap.org]
I also fixed the (relative) loose thermistor in the hotend.
Another step was to set Max PID to 180 (maybe caused by my new PSU) , so the temp curve is much smoother now and I do not have massive "overshoots". With the original firmware the hotend temperature was fluctuating (if set to 200) between 195 and 205, now it's relative stable.
Everyone should do this, even with the original firmware. It's relative save and you can store the values direct to the EEPROM. So write down (or dump) the original EEPROM values and do the calibration.

@madias; so, you upgraded to the newest repetier firmware? It would be very helpful (for me and others!) if you could just write a short description on how to do this.
Can it be upgraded over usb or do we need an additional device for this?

I wrote every step here in this forum.
For short:
Uploading Firmware via FTDI wont work for me, so I used a cheap USBASP dongle for uploading. You can also use a Arduino UNO as programmer. For further details google for it.

Grab the new firmware from here:
[forum.repetier.com]
[www.dropbox.com]

For newer Arduino IDE (1.6.xx) you must install the sanguino board with this:
[github.com]
easy way: insert the json into the preferences in the IDE so you can choose it via board manager:
[raw.githubusercontent.com]

After uploading the firmware two things happend to me:
x y offset home position not correct.
extruder temperature overshoot while heating up. Do the calibration: [reprap.org], I set max PID to 180 (but maybe this depends on my PSU)

The original firmware you can find here (not verified by me): [drive.google.com]

Warning: Updating the firmware and calibration is very time intensive, so be sure you have time and basic knowledge with arduino IDR avrdude etc....

asked from the seller to send me the firmware upgrade file/tool he used...

he sent me that

[www.megafileupload.com]

i dont know what to do with that or if it any good for Repetier-Firmware use...

anyone know what to do? do i need that for upgrade or just use the Arduino with the firmware posted before ???

thanks !!


edit:

@madias

"x y offset home position not correct" how did you fix that ??

Edited 1 time(s). Last edit at 01/25/2016 08:16AM by dsol.

x y offset: This is easy, insert into the EEPROM settings:
EPR:2 231 -3500 Extr.1 X-offset [steps]
EPR:2 235 -1000 Extr.1 Y-offset [steps]

Edited 1 time(s). Last edit at 01/25/2016 10:47AM by madias.

about your megafileupload link:
Chrome wont download it: Malware!

upgraded to 0.92.5 from the link above and got this on the Repetier-Host when trying to connect

"18:07:10.257 : Serial com errorystem.IO.Ports.SerialErrorReceivedEventArgs"

and this on Simplify3D

"Attempting connection at \\.\COM11...
WARNING: framing error detected by hardware. Please verify that you are using the correct baud rate."

but the com is correct and so is the baud rate (115200)

dont know what to do -.- please HELP ~!

EDIT:

fix it.. but still got a bug

baud rate in the printer is 256000 and on on the Repetier its on 500000 - thats the only way i get it to connect to the pc
will this be a problem ??? what can i do ???

EDIT 2:

printer on 57600 and pc on 115200 also work

just need to know if that gonna be truble soon or can i work like that ???

EDIT 3:

im erally starting to get annoyed with the firmware upgrade =/
for some reason everything seem way to fast, i think that the "move 10mm up in z" is not a real 10mm and so is the x+y
this is my eeprom, do you see anything wrong ? didnt saved the old one before the upgrade

EDIT 4:

LOL im talking to myself... nevermind that
what im here for is to share my troubles and fixes

so ! im still dont know if its is ok to work with the baud rate as is.. but im trying anyway, if anything happend ill tell you guys

and !! i was not mistaken to think that my steps per mm is off... i asked for 10mm and got almost 25mm in Z... !! anyway.. i just used the same thing i use for my extruder --> (what i asked / hat i got) * the current step per mm = the new step per mm
for me --> (10/25)*1600= 640 .... i just mark with a sharpie on my steel rod and use a caliper to measure till i got 10mm for the 10mm i asked

Edited 4 time(s). Last edit at 01/25/2016 04:28PM by dsol.

Hi there,

I hope anyone can help me out. I also bought the P802M Prusa i3 from alie express
The problem I have is with the size of the printed items and the place on the bed

Below there are 2 links to movies I have made from the terrible outcome


[goo.gl]

[goo.gl]

There is something wrong with the settings. I have made many adjustments to the Slic3r software. Nothing is helping

Kind regards
André

ok. I'm done with my experiences with the melzi board. Neither firmware I installed is better than the original installed one and for this I do not have the source code. I have my ramps 1.4 on my desk with minimum connections (not to a real printer) and I'll invest my time for it (nearly configurated the firmware from zero). Remember: You can never install a secondary extruder on melzi, it`s not possible, if one stepper burned out, you can trash the whole board. So some calculations:
Melzi board: 4 Euro
Arduino Mega Clone 6 Euro
5 pcs DRV8825: 7 Euro
So you can get a far better RAMPS 1.4 based system for 17 Euros. So my suggestion: Save your time, use the melzi until it will burn out and have a RAMPS system in reserve.

@ dedi... : Did you try the gcode example shipped on the sd card? there are massive mismatches with the x-axis (if not all axis)
@ dsol: Sorry, I haven't got the baudrate problem. Maybe a driver issue? Remember that on this melzi board there is a FAKE FTDI. About the Z-axis steps: 1600 is correct. What I've done before upload any firmware, I've done a backup of all eeprom settings and compared them after flashing a new one. Not every entry was the same, so I edited them manually.
Even if you won't got in driver hell, they are less functional than the original one. You got the problem with the z-axis, I got the problem with the hotend temp...so:
I think there are many printer variations out here with minimal changes, but this minimal things prevent us "working on the same horse"

Anyone tried these ? [pinshape.com]
Wondering if it's worth something or just better don't try

Quote
ErikL
Anyone tried these ? [pinshape.com]
Wondering if it's worth something or just better don't try

I think it is a great thing to do...
the guy is out from Quebec, Canada.
I saw his post on the FB and it really looks good and should be included on every Zonestar....
but, at $13... I resist to

If he shared in Thingiverse, I would definitely have done it!

Quote
madias
ok. I'm done with my experiences with the melzi board. Neither firmware I installed is better than the original installed one and for this I do not have the source code. I have my ramps 1.4 on my desk with minimum connections (not to a real printer) and I'll invest my time for it (nearly configurated the firmware from zero). Remember: You can never install a secondary extruder on melzi, it`s not possible, if one stepper burned out, you can trash the whole board. So some calculations:
Melzi board: 4 Euro
Arduino Mega Clone 6 Euro
5 pcs DRV8825: 7 Euro
So you can get a far better RAMPS 1.4 based system for 17 Euros. So my suggestion: Save your time, use the melzi until it will burn out and have a RAMPS system in reserve.

@ dedi... : Did you try the gcode example shipped on the sd card? there are massive mismatches with the x-axis (if not all axis)
@ dsol: Sorry, I haven't got the baudrate problem. Maybe a driver issue? Remember that on this melzi board there is a FAKE FTDI. About the Z-axis steps: 1600 is correct. What I've done before upload any firmware, I've done a backup of all eeprom settings and compared them after flashing a new one. Not every entry was the same, so I edited them manually.
Even if you won't got in driver hell, they are less functional than the original one. You got the problem with the z-axis, I got the problem with the hotend temp...so:
I think there are many printer variations out here with minimal changes, but this minimal things prevent us "working on the same horse"

I think you are having issue with the MELZI board cause you did not have the right firmware.....
Is your P802M uses threaded rod or lead screw?
Threatened rod most likely is using the step revolution at 1600, but if your kit uses lead screw then it would be 400....
also, remember that the Zonestar's MElzi board, the manufacture is using their own temp table the sensor is under 501 type

also, the LCD with 5 bottoms uses its own coding within the Repetier firmware and MArlin...

so, If you are downloading from the net, certainly it would not work correctly....

I have mine Repetier V0.91 and Marlin V1.0 w/ABL both working