Migbot Prusa i3 Unofficial Support Thread

I figured out what my problem was with the z motor. The wires for the z motors ohmed good, but someone switched the location of the white and green wires on one end of the cable. Thanks for the suggestions. Here is everything I found wrong.....


The AC power cord to PSU is too small to handle more than a couple amps. (careful if you use this and the PSU actually puts out 20 amps it could get hot and melt)
PSU is too weak to handle powering heat bead/nozzle (when you turn head bed on power pulses in and out)
Linear bearings falling apart(you could see little balls come out when you insert smooth rods)
The printed parts for the x-axis are warped, which causes the the brass nut on the z-axis thread rod to not be parallel to smooth rods and bind. (I had to loosen the bolts holding the brass nut)
Two wires for the z-motor were reversed (should be black, green, white, red)
The x-axis belt rubs on supports, pulley on the motor is not in line with the rest of the belt. (Need to install pulley backwards, setscrews positioned aft)

I am still working on tuning...if/when I am happy with things I will post my Marlin config.h

Edited 1 time(s). Last edit at 05/20/2015 08:26AM by tkin.

Thank you all for sharing the information and uploading the manual/software. Very grateful.

I will start constructing the Migbot prusa i3 tonight

n/a

Edited 1 time(s). Last edit at 05/19/2015 01:05PM by magiske.

this y axis grinding when homing is driving me nuts. i'm afraid the motor or belt is going to get destroyed. i've checked to make sure all the moving cables are out of the way. the limit switch "appears" to be operational physically. any ideas anyone?.....anyone?...Bueller?....Bueller?..(sorry, i had to say that)

First step is to check for binding of the slides. You will want to disengage the belt for this. The y axis should move with no resistance. If it is smooth, then it could be the acceleration settings in firmware, or the motion settings in the host software for homing, or the stepper driver current adjust.

Edited 1 time(s). Last edit at 05/19/2015 06:13PM by jcabrer.

the y axis slides just fine. i wondered if the accel settings in the firmware was the culprit.


EDIT: just an fyi...i had read about sending an M119 command to the printer to check limit switch states. i just didn't know what to use to try it. i found out about Pronterface and tried it. it was a bad limit switch. luckily i had a spare since i ordered my migbot with the auto leveling function. still can't get the print to center on the bed though..but i'm getting there slowly.

Edited 1 time(s). Last edit at 05/20/2015 01:26AM by rejaak.

So are you guys just using the aluminum plate the printer comes with and some painters tape or have any of you picked up a sheet of glass?

If you want to try glass, get Borosilicate glass 6mm thick. Thinner sheets are not great at providing stable temperature.

Also, avoid using clips to hold the glass down. Use silicone adhesive, but only on the edges, not under the glass.

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jcabrer
If you want to try glass, get Borosilicate glass 6mm thick. Thinner sheets are not great at providing stable temperature.

Also, avoid using clips to hold the glass down. Use silicone adhesive, but only on the edges, not under the glass.

I guess unfortunately some were saying early in the thread that there may then be a sensor problem, due to the sensor not sensing the glass and then the glass being too thick for the sensor to read the plate below. Perhaps a better sensor doesn't have a problem with glass?

Leveling takes place on the edges of the bed. If in fact the glass is difficult to measure (I doubt this), you can place a small piece of adhesive tape at each location.

The proximity sensor is an inductive sensor that senses the presence of the aluminum plate. The sensor included has a sensing distance of 2mm, so anything non-conductive needs to be less than that or the sensor will crash into it. You could try 1/16" glass, get a sensor with a longer range, or maybe glue a piece of metal to the corner .

I'm just using blue painter's tape on the bed. Things were working great when the printer was in the warm garage, but I've been dealing with bed adhesion issues since moving the printer inside with the A/C.

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Invictus
The proximity sensor is an inductive sensor that senses the presence of the aluminum plate. The sensor included has a sensing distance of 2mm, so anything non-conductive needs to be less than that or the sensor will crash into it. You could try 1/16" glass, get a sensor with a longer range, or maybe glue a piece of metal to the corner .

small squares of aluminum foil on the corners perhaps? metal, but thin enough not to cause miss detection

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gatorNic
small squares of aluminum foil on the corners perhaps? metal, but thin enough not to cause miss detection

I'm surprised, but foil seems to trigger the sensor at about the same distance as the bed. You can test any material by holding it under the sensor to see if the LED comes on.

FYI guys..if a peep with the handle "Leo" or "Lion" starts posting in here, its the guy in china from migbot tech support. i was emailing him last nite about some bearings he was supposed to send me since i was missing them when i got my printer. apparently sarcasm is lost on him or he just didn't care when i told him that i wouldn't have this printer running except for my research on the web and scanning the forums (especially this one). he immediately shot back with "tell me which one..i need to know so i can post".

Yeah. it goes without saying this thread is not about that kind of support. The topics that I'm trying to address here are firmware and those things that make the mig bot prusa I3 different from others.

Hey do you guys know, do you no longer need the Z limit switch installed in step 6 of the manual if you have the auto leveling sensor? If I am reading this right it seems like you install the plug for the autoleveling (proximity) sensor into the port that would be normally for z limit switch. I see no other port to have both

You do not need the Z limit switch if you plan to use auto-leveling. The proximity sensor plugs into Z- on the board in place of the switch.

Edited 1 time(s). Last edit at 05/21/2015 06:48PM by Invictus.

Hi, would anyone please share the "Auto leveling Instructions and Manuel.rar" file dropbox/googledrive/ect ??

Thanks u Invictus, as does anyone have a idea of better Sensor that can be mount on it, as while printing there will be issue using this sensor, why? Because when you are doing multi printing, the sensor will knock on the other print and it really useless to have this sensor, which i give this up.

Hello,

I'm going to apologise for my newbness beforehand.

I've bought and assembled this printer and plugged it into my PC. It's installed the automatic drivers but I'm unsure where to go from here.

The LCD screen does not turn on, the power supply fans spin up and the red LED on the board lights up to say it has power.

Any attempt at using a slicing software says the printer is offline regardless of whichever port I use.

Any help will be appreciated, I'm sure this is all pretty basic stuff for you guys.

[imgur.com]

The google drive link is posted higher up

First thing to look at changing is the Baud Rate setting in the software. 250000 and 115200 are common values there. Im not sure what the lcd behavior should be. Is it possibly connected backward? Double check.

Quote
evetanlm
Thanks u Invictus, as does anyone have a idea of better Sensor that can be mount on it, as while printing there will be issue using this sensor, why? Because when you are doing multi printing, the sensor will knock on the other print and it really useless to have this sensor, which i give this up.

For multi print, where you print more that one layer on a part before starting the next, you will need to set a limit less than the clearance of the sensor. 1.8mm maybe?

Hello, I've fixed the LCD. It was the cables. However I'm now getting the trouble with getting the motors to move.

Edit, I think it may be the power supply. The square fan which is hooked directly to the 12v isn't spinning up.

Edited 1 time(s). Last edit at 05/22/2015 11:09AM by freshpine99.

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freshpine99
Hello, I've fixed the LCD. It was the cables. However I'm now getting the trouble with getting the motors to move.

Please provide more details. the more info you can provide, the quicker the silution will come.

I am having problems with the firmware i cannot seem to get it loaded on the mother board and i d not have the original that was loaded to begin with. Does anyone have a copy of the firmware so i can reload it on the main board?

uggh, pissed. Just fried the board.

1.Quadruple checked all the wiring before hand, tested the voltages of the power supply with a multimeter, all good.
2.Plugged in just the USB, lights come on, lcd on, recognized by my PC, mattercontrol found printer, all good
3. Stopped, unplugged USB. Plugged in just power cable. Power light comes on, extruder fan comes on, looking good.
4. Next plug back in usb, zzzzzzzz, fries out I think a transistor next to usb connector. No clue. FML

Now I can plug in just USB, no longer recognized by PC and lcd doesn't come on. Power cable alone also still works, lcd turns on. Not sure what else to do. Doubt they would send me a new board, since they'll think connected something wrong. Its possible, but I don't see where. I have checked it over and over.

Only thing I changed, was I changed out their crappy 2 pronged power cable to a 3 pronged cable for the ground. But again I tested and ran the power supply with the new cable for twenty minutes on the new cable. Multimeter reading was 12.1-12.2 volts, which should be great.

any suggestions on what to do next? test individual parts?

Bummer, sorry to hear that

look on page 1 of this post there's a link to a Google Drive account in the firmware is in there

Can any of you snap a closer/better photo of the spot I circled? Its location 'L3'. Its the part that burnt out and if I identify it might be able to solder on a new one. long shot, but parts of the board are still working since when I hook up power I am still getting the lcd working which is showing the temps. Thanks