P802M Prusa i3 Unofficial Support Thread

mine is 220x220x230
from 3d star aliexpress
P802M black
Melzi by Zonestar V3b

@BobbyNi: I have no problems with x-y-z axis, this belongs to other persons here (I need the 1600 steps) . You are right with the temp table. The exercise I have done with various firmwares on the melzi board is only caused by my step upgrading to RAMPS 1.4. So every firmware I uploaded has a source code. My problem is, that for my printer (hesine m505 or so f*** whatever name they use) I have only a *.hex file. So I tried all of the firmwares (with SC) if they matches to my printer, but no one does. Calculating x-y-z axis steps is a easy thing. But temp tables are a lot of work, but it seems that I didn't found the right one. BTW: I wont use the 5key display anymore, I have a 12864 with encoder works like a charm on my "dry build" RAMPS setup. I'm not in hurry. I'll use the melzi board till it burned out, because my printer does his job excellent (with original FW). I don't really need autolevelling at the moment (and I think it's better to wait, because autolevelling (and bug fixes) is a big thing in every new version of repetier)

Quote
Bobyni
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

yes.. i have the lead screw and i manual measure i got to the ~400 i needed, but still good to know the settings are good
and i used 0.92 firmware for the 5 bottoms and everything works fine

also i have the same printer
mine is 220x220x230
from 3d star aliexpress

but mine is p802m transparent , had the Repetier V0.91 and now on 0.92.5


and:

how can i do PID to the bed ?? when printing ABS it take more then 10min to get it to 100c (but when ig get is stay level very good)

Quote
dsol

Quote
Bobyni
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

yes.. i have the lead screw and i manual measure i got to the ~400 i needed, but still good to know the settings are good
and i used 0.92 firmware for the 5 bottoms and everything works fine

also i have the same printer
mine is 220x220x230
from 3d star aliexpress

but mine is p802m transparent , had the Repetier V0.91 and now on 0.92.5


and:

how can i do PID to the bed ?? when printing ABS it take more then 10min to get it to 100c (but when ig get is stay level very good)

What is your hotend current PID settings? (yesterday I made PID autotune and settigs for hotend (extruder btw ))


the bed PID autotune way is same: M303 E-1 S60 C8
but i didn't tried it, maybe today i will.

so,

Better idea would be to heat isolate the bed on the bottom side, you are on limit with PID more is not possible while heating up (I guess output is 100% - unless max drive is not set to 255, but I don't believe that). Gives me massive benefits (I wrote some pages ago: Thermal compounds between heat bed and alu plate and a 5mm styrofoam wrapped in alufoil and the downside of the heat bed and set the PSU to 13 Volt).

Quote
dsol
how can i do PID to the bed ?? when printing ABS it take more then 10min to get it to 100c (but when ig get is stay level very good)

The speed the bed heats up has nothing to do with PID. PID is like cruise control on a car. You set the value and PID does it's best to compensate for hills and valleys. But getting to speed, the gas pedal is floored and can only go as fast as the motor--or the heating element of the bed will take you. You can try insulating your bed with something non-flammable.I've used thick cardboard on one bed and that helped a bit. Trying silicone caulk the the back of the bed of another printer. Standard silicone caulk should be able to handle the temperature up to 200ºC (~400ºF). It gives added insulation to get it up to temp a bit faster, and might help is minimizing the the carriage plate from warping from heat of the bed.

As far as the PID for the hot ends fluctuations at higher temps, there is a grounding fix for the Melzi board--used by the Wanhao Di3--that is supposed to give a more stable temp for the hot end. I have not tried it yet, but hearing good reports from the Wanhao google group.
Video here: [www.youtube.com]
I believe the fix is derived from here:
[alex-avr2.livejournal.com]
Translated to English:
[translate.google.com]

I have Zonestar P802M from aliexpress too

and i made this:

PID tuning knowhow

what is your Kp Ki Kd numbers?

Differences between the tuned and factory settings was very big. I changed to tuned numbers, but it not be better.

what is the good settings do you think for P802M, melzi with v0.91 ???

what you advice?

@Robkadett

after PID test i use hotend PID
P - 6.65
I - 0.15
D - 72
big change from 0.91 factory firmware, but better result for me

that from the reprap PID page, try it out for fine tune

"For manual adjustments:
if it overshoots a lot and oscillates, either the integral gain needs to be increased or all gains should be reduced
Too much overshoot? Increase D, decrease P.
Response too damped? Increase P.
Ramps up quickly to a value below target temperature (0-160 fast) and then slows down as it approaches target (160-170 slow, 170-180 really slow, etc) temperature? Try increasing the I constant."

@madias

thanks for the tip, ill try to get some thermal insulation material and try, but i think about build a enclosed box for the printer before that

@rtideas

thanks for the info, didnt know that!
and my hotend works very good so i wont try the link you gave for now

----

I ordered this sensor a few weeks ago
[www.aliexpress.com]

anything i sould do before it arive to get the installation quick and easy ??

im gonna use this tutorial
[www.hkepc.com]
[translate.google.com]

Quote
dsol
@Robkadett

after PID test i use hotend PID
P - 6.65
I - 0.15
D - 72
big change from 0.91 factory firmware, but better result for me

that from the reprap PID page, try it out for fine tune

"For manual adjustments:
if it overshoots a lot and oscillates, either the integral gain needs to be increased or all gains should be reduced
Too much overshoot? Increase D, decrease P.
Response too damped? Increase P.
Ramps up quickly to a value below target temperature (0-160 fast) and then slows down as it approaches target (160-170 slow, 170-180 really slow, etc) temperature? Try increasing the I constant."

Thank you!
i think now, my numbers will be good, P 11.73, I 0.6, D 57.37, but i will run autotun min twice again.

What are the kind of upgrades you can do to this printer besides upgrading the printed parts, upgrading the frame, adding a sensor?

Can you upgrade the build area? What would you need to do to be able to do that? Is there a larger build plate you can get with a heated bed part? or if you got a larger build area (alum or glass)
Can you use the smaller heat pad or is there a larger version you would need? Longer rods, plus would you need to just salvage parts and just build a whole new frame, etc? Or would it be best just to buy 100% new parts and build a 2nd printer?

Quote
kmjee
What are the kind of upgrades you can do to this printer besides upgrading the printed parts, upgrading the frame, adding a sensor?

Can you upgrade the build area? What would you need to do to be able to do that? Is there a larger build plate you can get with a heated bed part? or if you got a larger build area (alum or glass)
Can you use the smaller heat pad or is there a larger version you would need? Longer rods, plus would you need to just salvage parts and just build a whole new frame, etc? Or would it be best just to buy 100% new parts and build a 2nd printer?

as far as i know... you could add a lases cuter/burner to you 3d printer just as you add a sensor for auto level - but that is not recommended !! the laser is very dangerous if not enclosed properly

anyway, you can install a larger bed if you have the space for that, but its is recommended that you replace the heat element also. i have a 220x220mm bed but the frame enable a 265x220mm (265 on the X) i can find and install bed fitting that size but that will give me an uneven heat across the bed... ill say thats only good if printing with no heated bed (pla or something like that)

other then that, everything need a new frame/rods/etc.

you can salvage the electric parts and build a new printer, but i dont see why would you need a big printer... bigger rod= less accuracy (unless you invest in some very good stainless steel rods or some aluminum profile or something like that)

Can you turn this into a dual extruder setup? I would imagine it would require something in the firmware of the unit? Maybe not if you print through the USB cable?

Quote
kmjee
Can you turn this into a dual extruder setup? I would imagine it would require something in the firmware of the unit? Maybe not if you print through the USB cable?

Short answer: Not with the melzi board. There is no additional output for a secondary extruder/stepper. With RAMPS 1.4 it is possible.

Edited 1 time(s). Last edit at 01/30/2016 12:36PM by madias.

say.. when printing ABS
haw do you make the print stick to the bed ???

didn't had any problem till yesterday with warping on staying on the bed while printing... but didn't had to print anything big till yesterday also

i use ABS juice, but i think i use it wrong
the heat platform connected to the aluminum bed.. on that i use masking tape and on the tape i apply ABS juice.. but last print the tape just rip off by the warping on the edge of the print...
is the blue tape better ?(its sure is way more expensive)
or even... is that that right way to use ABS juice ? or should i put the ABS juice directly on the aluminum bed ???

i know i need an enclosed box to keep the air temp stady around the model.. but still, any advise on how to keep to print flat ??

and..

anyone here use PEI (Polyetherimide) Sheet as a print bed ?? or glass ? acyclic ?
did you put it above the aluminum bed or remove the aluminum and install the glass / PEI / acyclic ??

blue tape is FAR better. With the "normal" yellow tape I got only bad results.
How about your bed temperature? more than 100 degrees? 110 would be perfect. It's also a wise idea to proof the temperature with an external one (there are cheap IR thermometers on ali). On my printer the results were totally off especially with the bed (makes a "jump" after 79 degrees to 90 degrees, so bad thermistor values).
You can try to print directly on the alu bed with the juice. Also try to turn the fan off or to 25% and keep in mind that the room temperature should be steady and no wind.

so... small update

built myself a box for the printer
order from ali some infrared Thermometer to see if my printer read correct nozzle/bed temp
and some digital Thermometer to see how hot/steady the temp in the box is
and connected my printer to my wifi with octaprint

Edited 1 time(s). Last edit at 02/03/2016 02:52AM by dsol.

Looks good!
Maybe just two suggestions:
A big (slow) fan in the box for cooling the mainboard
Some damper material (loudspeaker mat) between box and printer. I guess the whole wooden box acts as noise amplifier without damper.

I have an idea about getting rid of the toxic fumes while printing ABS
I bought some times ago a cheap extracter for soldering works (from local store, I think Conrad):, like this

This device has a real big fan and a filter texture (activated carbon) on the back. So this can be easily insert into the back of a printer box (with little modifications of the extracter housing).
: This is the link for the german store costs about 30 EUR: [www.pollin.de]

Edited 3 time(s). Last edit at 02/03/2016 03:32AM by madias.

actually the wood absorb sound and the print noise is way down then before....

found some old thermometer like that [globe-views.com] and is shows 30c steady in the box. not as high as i wanted it to be but maybe ill preheat the box with some hair dryer
and the filter seem very good... ill see if i can get one locally or ill order online, the ABS fumes are awful

with all that.. still cent get the print to stay on the bed =/ i think ill get some glass and try printing on that

dsol: about sticky prints: I see on the photos you haven't isolate your heatbed right now. I would do this first, as I wrote before heating time is really speed up and I got about 20 degrees more. Working with ABS is all about the heatbed....and a really slow first layer. And invest in a roll of blue tape. I use blue tape for nearly everything: PLA, ABS, PETG, soft-PLA.... with best (sticky) results.
For the filter system: Just google "Zd 153" (I'm not sure if the product is only Europe related - I don't know where are you from) and do not pay more than 30 EUR

insulation is the next step... i need to go the the hardware store to get some isolation
for now i got some plywood/cardboard/ acrylic/polycarbonate that i can laser cut... ot some silicone hot plate (form the kitchen) an some car sunshade (aluminum like that [www.dhresource.com])

do you think any of them will work good ? or just go out and but some real hardcore insulation material ??

and i found this one on aliexpress [www.aliexpress.com]
seem the same fan

I would prefer the car sunshade and the silicone hot plate
You can test it easily with your iron! Setup the iron about 150 degrees (should be enough with headroom) and leave it on the sunshade and/or slicone plate for some minutes. If it smells bad or burn, leave it.
I don't know how thick your silicone plate is - the overall thickness should not be over 5mm (otherwise you get in conflict with the bord levelling skrews)
So:
============
-----alu_plate--
-----heatbed----
---sunshade---- ... and/or
---silicon plate-
============

If you are going out go into a car supplier shop and buy the cheapest exhaust isolation mate. Something like this: [www.amazon.de]

Edited 1 time(s). Last edit at 02/03/2016 06:11AM by madias.

so... added a insulation to the bed
had to buy some acetone and found in the dollar store some aluminum bubble roll for the kitchen.. and didnt really wanted to cut my car shade
so.. it look like that [www.radiantbarrier.com] 1 side aluminum bubble 1 side anti slip something (non flammable)
anyway 2 layers or the aluminum bubble+1 layer of compressed cardboard (http://img1.exportersindia.com/product_images/bc-full/dir_57/1704666/cardboard-1310622.jpg)
cut to the size under the heat bed

AND the heat stay !! from 0 (not really, but around 15c) to 80 in no time... to 120 took less then normally do 100c when printing ABS
at 120c cant touch the bed.. too hot ! but can freely touch the insulation bottom (its warm, but not hot)
the bed is off for ~20-30min now and its only got down to ~50 so i think it safe to say the insulation works! not the best, but works...

cleaned the aluminum print bed.. i think that some adhesive glue residue from the masking tape prevent my ABS juice to stick to the Aluminum bed and so the part didnt stay put all the way.. will give it a try later

thanks for the help so far =]

Quote
dsol
AND the heat stay !! from 0 (not really, but around 15c) to 80 in no time... to 120 took less then normally do 100c when printing ABS
at 120c cant touch the bed.. too hot ! but can freely touch the insulation bottom (its warm, but not hot)
the bed is off for ~20-30min now and its only got down to ~50 so i think it safe to say the insulation works! not the best, but works...
thanks for the help so far =]

The simplest and cheapest solution is often the best - and: If it works, it works ... and your electricity bill will say "Thank you!"
and you are welcome
Maybe you could try to give more ABS into your juice this could be also a reason, why it won't stick on bed.....and think about the blue tape. Hint: There are rolls out with the width of 100cm. So you only have one "cut line" in the middle of the plate. About the yellow tape: Use it for what is was made: For your next painting job
I'm a little bit worried about your closed box without active cooling the electronics. With heatbed on 110c and closed box the temperature could raise critical. Mabye one of those bigger PC PSU fan's would do the job?

wont the active cooling will defy the purpose of the hot box ??

at max.. i believe the temp in the box will be around 40-50c, is that so hot ? will moving the psu out help ??

Has anyone attempted to upgrade the wimpy 8mm X and Y axis rails to 10 or even 12mm?

I think I might definitely do the y axis as that should be pretty simple and straight forward...but the x would require modifying the whole x axis.

Edited 1 time(s). Last edit at 02/04/2016 10:55AM by jnsbanman.

for what? imho the x/y axis rails are the most robust parts on this printer. Before doing this you should think about building a complete new frame.
dsol: moving the PSU out of the box is a good idea, moving the mainbord out of it also. But you'll need a big multi-connector for all the cables, otherwise the whole thing isn't really hackable anymore. Background: the stepper drivers are under room temperature conditions nearly stressed, but in a closed box with ~50c they'll tend to malefunction without active cooling.

Edited 2 time(s). Last edit at 02/04/2016 11:01AM by madias.

Quote
madias
for what? imho the x/y axis rails are the most robust parts on this printer. Before doing this you should think about building a complete new frame.
dsol: moving the PSU out of the box is a good idea, moving the mainbord out of it also. But you'll need a big multi-connector for all the cables, otherwise the whole thing isn't really hackable anymore. Background: the stepper drivers are under room temperature conditions nearly stressed, but in a closed box with ~50c they'll tend to malefunction without active cooling.

The 8mm rails seem a little flexible imo. But now I have re enforced most of the frame with 1" aluminium angle. I have not had a chance to test prints since the upgrade as I am waiting on a replacement part. The whole frame 10 times more rigid then the factory setup. I am also changing the Z axis to use the 1 stepper.

I do not use the included PSU I have a 700 watt bronze psu I have modified for this. I have considered move the board out or changing to a RAMPS but under normal printing my stepper drivers are nice and cool. And I have read the Melzi is a better solution if you do not plan on changing or adding anything to the printer.

Edited 1 time(s). Last edit at 02/04/2016 12:43PM by jnsbanman.

here is my update for my enclosure

After the first ABS wrap, I decided to get an enclosure for my printer.
moved the Melzi out
have added several control on/off switches for
- Main power
-SSR to run the hpt bed
- dedicated 110V AC fan for the ctrl board
- nozzle fan
- 12V RBG LED strip lighting
- 24V LED white light
- temperature prove to the inside of chamber with LCD
- USB/VCC select switch
and added also
- USB connector
- 110 V AC female connector

I was too busy with work and progress is slow...

hope I get it done sometime next week...

Little offtopic:
While browsing about some ideas of wireless printing I got to this:
[creatorbot.com]
Looks like a nice alternative for BT-06 bluetooth serial modules and thoose ESP's are awful cheap (2-3 USD)