P802M Prusa i3 Unofficial Support Thread

Maybe too tight or too loose...
Another thinking: Maybe your Z-axis is not calibrated right or had problems above a certain threshold (maybe it jammed about 15 centimeters and do not all steps and the extruder scratch over the printing and the y axis loose steps). Just try to move up the z-axis and examine each height and proof it is smooth enough (disable steppers and wind manually both rods a bit)

I am pretty sure it is not too loose... but could be too tight for the small 5 mm shaft.

I would not think it would be the z axis as looking at the piece closely that failed... each layer is printed properly just not in the correctly y axis location. The z axis appears to keep moving up properly.

If you look at the picture the infill on the right half of the picture its printing nicely then looks like it skips a step, then prints the layer, skips a step then prints a few good layers, then skip a step, print a layer and so on and so forth. Then up near the top it seems to smarten up again.

Thinking out loud here...
If they are over heating why does it take them about 8 hours to get that hot. It was approximately 8-10 hours in to the print when the first y axis shift would have happened... i would think it would happen quicker then that. Perhaps related to the increased mass on the print bed. If I recall correctly when I set my pots for the steppers i think i set them close to max output. Maybe I should turn them back a bit.

Something that just hit me... I did adjust the Jerk settings the other day. I printed a 20mm test cube and wanted the edges a little sharper so up increased the jerk setting... I doubled it. I do not recall exactly what it is set to but i think it might be set to 20mm/s or maybe 40mm/s i wouldnt think either of those numbers should be too high though.

Edited 3 time(s). Last edit at 02/24/2016 11:15AM by jnsbanman.

Unfortunately it's very time and material expensive to reproduce the failue for you ....
I can quiet move the y-axis (the board) without great force forward and backward (with disabled steppers), my belts aren't totally stiff, so I can push my finger on the belt and bend it about 1 cm.
Maybe 0.8V is too high (it's about 1 ampere!) You can choose 0.6V for the X and Y steppers. So 0.8 can produce an overheating after a while. Skipping steps could be a impact of overheating: The stepper reaches a threshold is switching off, cooling below (all within fractions of a second) it, turns on, reach the temp again....
Or - as rtideas said - you have a problem with your cable management upon a certain height? You can do a high test print (like a 2cm round (thickness 1.2mm) with 15cm height).
One silly thing: Are you shure that your filament didn't jammed (a knot in the spool)

I can pretty much guarantee it was not the spool... that would have cause a missed step in the x axis and everything is still nicely aligned in the x axis. I am going to double check my voltage on the y axis and check my y axis belt this evening.

So I started a print this evening and I paid close attention to the stepper drivers... Boy they got hot real fast like under a minute. I can imagine after 8 hours of printing what the board would be like... So I hooked up an 80mm fan with decent flow and pointed it at the stepper drivers. Lets see if this print makes it thru the night. They seemed to have cooled off very quickly.

I checked the voltage and the Y Axis was .77v. That should be fine based on what I read. Would there be any benefit to turning that down to .6? What would be the downside? The board was marked on it as a Melzi V3B by zonestar... although I could find no info on a v3b anywhere.

someone use ABS filament ???

i dont no why not as nice as PLA. it is normal ? i think no.
I tried reduce the extruding no helped
i tried increase the layer high no helped.
i played with temperature, not helped

With PLA the side of the layers are mirror-smooth, but with the ABS is horrible like photos.

what do you advice ? what can i do?

The printouts reminds me of a spool of PLA I bought (I think "BQ" was the brand). Everything I've tried out resulted in ugly prints like yours. So I decided the PLA was the problem.
Are you *really* sure this is ABS? (I heard of mislabled spools) Try to print with 180 degrees (or try to dissolve it in acetone, if it won't dissolve it's for sure not ABS)
You can also proof the diameter of the filament. Maybe it's totally off.
Try one test print with 95% flow rate and with the same settings with 105%. Layer height is for sure not your problem.
In short words: If you can afford it, buy another spool of ABS

ohh, i did not think about of this option. ouh. ..s****t
i tried everithig, just this not!!

i will try it in the next 2 days.

ohh very thak your tip.!!!

(it is Herz filament, maybe "good quality" ones, but now .... .... )

I read this about Herz: (sorry german, but maybe you are german):

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Abraten möchte ich vom Anbieter Herz auf Ebay (http://www.ebay.de/usr/herzonline). Anfänglich war ich begeistert, Ich konnte das ABS Filament mit dem Soft Temp Mod ohne Probleme drucken. Habe ordentlich zugeschlagen und mir alle verfügbaren Farben bestellt. Leider hatte ich mit allen andere Farben (außer Blau) massive Probleme. Der Durchmesser des Filaments weicht extrem von den 1,75mm ab, sodass ich während der Drucke nur noch ein böses klacken vernommen habe. Das Filament kann nicht eingezogen werden. Teilweise geht der Durchmesser weit über 2mm hinaus, womit mein UP! Mini nicht klar kommt.

So this guy is complaining about the weird diameter of the Herz ABS filament (up to 2mm!)

oh sh*t .... ...
it was middle expensive filament grr..........
i dont understand all of german, i google translated im from hungary and my english is better maybe
but i understand that the herz fila is ................

we have distributor in our country, im going to comlain.

@medias
it's smell abs when i printing. thank you again your tip.

im sad. but never give up

Anyone are using SD Wifi,?
i am thinking to buy one Toshiba Flashair and an Sd to Tf cable.

[es.aliexpress.com]

and

[www.amazon.com]


What do you think?

Thanks.

My Y axis skipping issue...

I got a couple good prints then it failed again... I found that if I engaged the steppers and tried to move the 7 Y axis by hand it was very difficult to move towards the front of the printer... When I tried to move it towards the back the belt would slack a bit then it would slip on the pulley. The pulley is not slipping on motor shaft... That much I am certain of.

The print that failed... I ran it directly after a 10 hour print.. basically back to back. It failed about half way in to the 10 hours. It seems that once it skips it continually keeps skipping as you can see in the pic.

This must be a stepper driver issue I am thinking and not a stepper motor issue. Since running the fan blowing on the board it has been better but obviously still happening. I have a feeling trying to get a replacement board from Aliexpress seller could be fun...

Edit - Just thought of something... could my free movement speed and/or acceleration be too high? That when the Y Axis is moving towards the back of the printer then it goes to move the other way its torquing too much and slipping especially when there is a large mass on the build plate?

Edited 2 time(s). Last edit at 02/26/2016 11:23AM by jnsbanman.

I added a 12 dc fan 6cm and it keeps all the stteper a drivers nice and cool/ warm.
Try just have some old computer's CPU fan tag in to the same line for the cooling fan and it will work great!

While fiddling about with the melzi board and burning a boot loader I found out that my heat sinks where actually stuck to the drivers and mosfets with bathroom silicone glue adhesive :-(.
Proper heatsink glue hardens and isn't like rubber when it cures. If you don't have any heat sink paste go and buy some. Clean the old stuff off the drivers and mosfets. Spread a tiny thin layer of heatsink paste then sandwich it between two "tiny" drops of super glue on the bare surface of the IC. So | super glue|......Heatsink Paste......| super glue| Have some tissue ready to soak up excess glue because you want maximun heatsink surface contact with the paste not the glue. Leave it to cure overnight. Give the heat sinks a light poke the next day just to make sure the glue is holding and you should be good to go. Make sure the heat sinks don't touch any of the small brown smd capacitors!!!! That would be very bad to say the least.

These nozzle: [it.aliexpress.com]

are good for P802M?

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glimpse79
These nozzle: [it.aliexpress.com]

are good for P802M?

They should work fine.

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jnsbanman
They should work fine.

They work fine. I've got them at home.

well i was changing my fw for the new extruder and was going successful for multiple updates then I suffered what may have been a brownout and the upload only partially completed. Now i have melzi board with no valid bootloader don't want to wait a month for a usb programmer so going to try and pick up ramps 1.4 locally unless someone possibly has a quick fix for this?

Do you have an UNO or MEGA (or something else Arduino like) at home? So you can upload the code (or bootloader) via arduino as ISP ---> [www.arduino.cc]
But sadly I guess that's not only the bootloader is affected, because the code for the bootloader is on the first sectors of the flash and won't be overridden with a new sketch code (via bootloader upload method). You can try the "push fast the reset" method: Click upload and hit the reset button once on the melzi in the right time (It's the magic moment beween completing compiling and before the real upload procedure begins).
: OK, if you have RAMPS at home you should have a MEGA also. Try to upload a the bootloader first

Edited 2 time(s). Last edit at 02/29/2016 11:03AM by madias.

Hi madias

I did exactly that - I got myself an UNO R3 kit and successfully used it to save the board . It uploaded no problem and after powering up the melzi it started first time without any need for reset - thanks!

Attached is my new extruder from thingiverse and how the UNO was used.

X

Edited 1 time(s). Last edit at 03/04/2016 02:50PM by Scottjar.

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Gatchaman

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Scottjar
I'm after some help after printing in PLA I've come to use the printer again and it wont feed the PLA out of the extruder in program. When I feed it manually from the menu in the LCD it will feed no problem leaving a mess on my desk but wont on previously printed programs. Please help

The reset button on the board works a treat. Don't know why I didn't try that before

Never got feedback from you for this issue [forums.reprap.org]
So what fixed your printer? It might help somebody else if you post your fix.

And to everyone else this might not come as a complete shock but I have a horrible feeling the heat sinks on the Melzi board are stuck to the IC's using silicon glue. The stuff you use in the bathroom.
I've had to burn a bootloader as my board was just blinking and wouldn't talk to the PC which left me with, yep, a blank LCD. So I did this [reprap.org], and while I was checking I pulled off a heat sink to check the paste/glue. I found the paste it to be very very rubbery. Cleaned off the silicone glue with acetone and will sandwich some proper heatsink paste in between two spots of superglue which I'll leave to set over night.

Hi I got a new board from aliexpress as nothing that I tried seemed to work. Think that it was a bad board. Sorry should have posted that. S

Hello friends. something like I read a forum (with English bad-I) and realized that ABL do with the sensor. And who do probyval ABL with servomotor. (No sensor and servo available) Can knows where to connect? Printer P802M. Melzi 2.0 1284P Reprap Control Maynboard
THX

Sadly, my bed support got "melt"down due to
Printing in ABS!
A combination of failure cased my H base acrylic softened and beyond repair.....
Well, I have successfully "repair" it but due to the heating process, the acrylic got shrank and it is smaller than the aluminum plate.... Consequently,
Unable to attach the hot bed.

Now
, trying to make a metal base to support my heated bed....

Edited 1 time(s). Last edit at 03/04/2016 08:03PM by Bobyni.

Hi,

- Marlin source code
- Update Utility
- Firmware hex with auto level (I have compiled a version without auto level)
- Documentation

[www.dropbox.com]

Quote
jfd
Hi,

- Marlin source code
- Update Utility
- Firmware hex with auto level (I have compiled a version without auto level)
- Documentation

[www.dropbox.com]

THX. Very useful information . But everywhere I see uses proximity sensors , and I would like to connect a servo , which he had hidden , and took out a trailer .

Just saw that Zonestar put up on YouTube a hiw to install their auto leveling sensor

[youtu.be]

Hope this helps

Someone that use CURA 15.10 ? have a good profile?

I´m using BQ Hephestos Profile and the problem ...... The hot Bed....


Thx.

Quote
Bobyni
Just saw that Zonestar put up on YouTube a hiw to install their auto leveling sensor

[youtu.be]

Hope this helps

Where's possible to buy the upgrade kit?

Aliexpress I think.