Monoprice Select Mini Upgrades

I've created this project to make the Monoprice Select Mini 3D a descent and affordable solution. For the $200 Price Range.

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The MP Mini is a super cheap 3D printer with a pretty nice interface and a STM32 based motion controller. I bought one because it was so cheap I had to give it a go.

Also note, that I'd recommend starting at the bottom of my blog and working up.

Task 1 - Level the bed and print the baby.gcode on the MicroSD Card.

I've decided to keep a log here of the costs to fix the printer so far. I don't count filiment because it's an expected cost.

Cooling Fan 40mm1$7.20
M3 Screw Kit115.69
BuildTak 4.5in x 4.5in18.20
Total$231.09 USD

MP Select Mini - Z Bracket.stl

STL for the Z Axis Rods. You need 4 to complete the job. Also uploaded to

Standard Tesselated Geometry - 117.66 kB - 06/26/2016 at 03:12


MP Mini Fan Holder.stl

STL for the Motherboard fan holder. Best to print it upside down. Also uploaded to

Standard Tesselated Geometry - 204.18 kB - 06/23/2016 at 20:50


View all 6 components

  • ABS is Tricky - Use PETG Instead

    Adam M06/27/2016 at 14:55 0 comments

    I tried printing something else in ABS with less surface area and it refused to adhere to the BuildTak even at 80deg C. So keep in mid if you want to print ABS you need to give the model as much surface area on the bed as you can and keep the bottom shell thin as you can.

    I'm not a huge fan of ABS anyways, so I tried PETG at 235C and 60C respectively and had no issue with the prints. I used .2mm height and 35mm/min speed.

    Link to Material Used

  • Fixed The Z, Limit and Tried ABS

    Adam M06/26/2016 at 03:11 0 comments

    I fixed the Z-Axis Rods and added it to the instructions.

    I put Blue Loctite 242 on the screws for the limit. You have to be careful not to get any on switch it can eat the plastic. I'd like to move it in the future to allow me to easily set my Z-offset.

    I also made a test print in ABS, it came out very well for a $200 ish dollar printer.

  • Organizing and Such

    Adam M06/24/2016 at 20:14 0 comments

    I didn't like using the logs for work progress. I did wan't the most important stuff at the bottom, so I moved everything to the step-by-step section. I'll just use the log for general comments going forward.

  • Fixing the Rattling Z-Rods and Loose Z Limit.

    Adam M06/24/2016 at 13:23 0 comments

    My next task is going to make sure the Z-Rods are square with each other and stop them rattling. Also, my Z-Limit switch is starting to rattle loose so I need to fix that as well.

View all 4 project logs

  • 1
    Step 1

    Link to the users Manual: Users Manual

    First look through the manual if you have no idea what you are doing.

    • Start by powering the printer on and homing it.
    • Next preheat the bed to 60 degrees and nozzle to 190 for 15 minutes.

    If it doesn't get close to 60/190 and stay there or fails to home for what ever reason I'd recommend exchanging it. I know this is HackaDay and all but you could have a lemon and you did cough up at least $200.00 for this thing it should work out of the box.

    Check all the screws for being loose, this is common with cheap equipment like this.

    Most of these are assembled by people being payed by the part not hourly. They rush to complete the machine and as long as it passes some level of QA out the door it goes. I found the right rod support set screws on my table's set screws were stripped on both the front and back. I tried to get a replacement but Monoprice is exchange only, I'll just re-tap it with a M4.

    If your machine doesn't sit flat.

    • Place the printer on a known flat surface.
    • Loosen all the screws on the left and right plates by a single turn.
    • If the machine still doesn't sit flat then loosen the screw on the bottom plate by a single turn.
    • It should sit flat then, re-tighten them mirrored on each side. So Left front then Right front

    If the printer won't sit flat either your printer is really tweaked or something else is wrong missing feet? If the printer rocks while it prints, it will effect the pint quality of machine.

      Time to level the bed
      • Right after homing the printer, turn it off and move the head and table into the four corners.
      • Adjust the bed so that a piece of paper slides between the nozzle tip with just a little bit of friction.

      You will tighten the hex keys in the four corners of the bed to increase the gap and loosen them to decrease the gap. If your still unsure look for a video on YouTube about how to level an i3 it's basically the same procedure.


      • Next pre-heat the nozzle, and insert the material through the extruder on the tower. and load the PLA through the tube and into the nozzle. You can look at the manual for guidance.
      • Next you will want to print a test print, from the SD card. Insert it into the right side of the printer
      • Select baby.gcode, It is a pretty challenging print and if it comes out nice, then your good to go.

      This is where I hit my first snag. the extruder started skipping around 50% of the way through the print. I had to crank up the temperature from 195 to 210 to finish the print. It's got some defects but if finished. Thus begins my upgrades to make this thing print consistently and with good quality.

    • 2
      Step 2

      Based on my experience with my Rostock Max and small stepper drivers, I believe the skipping issue is caused the stepper driver shutting down. When the driver overheats it faults and shuts off power the pressure from the filament pins the stepper backwards and then it recovers and repeats. Which leads to what is shown in the video.

      I removed the bottom cover and found all the drivers are linked together on a strip of heatsink material. With no airflow it would seam if the drivers are all working hard this would cause things to overheat. So I drew up a bracket and mounted a 40mm fan blowing onto the PCB.

      I soldered the power wires from the fan to the main power so the fan turns on with the power to the printer.

      Here is the fan mounted, I should have made the fan clip onto the mount instead of screws, but I had the hardware and this required less trial and error. For the fun of it I used the MP to print the part.

      I zip tied the power wires to the existing harness to provide strain relief.

      Link To STL

      The results of the baby.gcode object.

      Next I Printed baymax.gcode

      I'd say the problem is solved!

    • 3
      Step 3

      Install BuildTak, I run this on my Rostock Max, XYZ 1.0, now this little guy. Playing with tempratures, tape, and hairspray become a thing of the past.

      To Install

      • Remove the tape that comes with the printer and place.
      • Mark the four travel extents of the nozzle onto the bed with dot via a sharpie marker.
      • Place the BuildTak centered between the dots you made.

      Note: The BuildTak is super sticky so make sure it doesn'tt touch down until your ready. Also make sure to lay it down with no air bubbles.

    View all 4 instructions

    Enjoy this project?



    arygeotv wrote 04/27/2021 at 09:19 point

    Nice one, it will be much helpful for the small business needs.

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    kockphilips wrote 01/29/2021 at 07:42 point

    yes i like the way you shared this informative article with an attractive project i am also working on the same topic you can see here

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    messenger1316 wrote 04/22/2017 at 20:41 point

    What slicer do you use? And can you upload your profile?

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    Parkwoodrehab1 wrote 04/05/2017 at 17:49 point

    Don't use that bracket to mount  a fan over the MB !!!!...  The right side foot dimensions are wrong and you will likely crush the 3 leads on the SMD - LCD controller chip there.   That happened to me and the MB is now a door stop.   Also the bracket is 60 mil too wide and  interferes with the side panel.  Better to use a flat bracket and 3/4" standoffs from the PCB mounting holes.

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    Adam M wrote 04/05/2017 at 18:10 point

    Can you show me, I didn't have any issues on my board. I can rev the part if that is the case.

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    Parkwoodrehab1 wrote 04/05/2017 at 19:10 point

    It was the right-side square  foot where it contacted the MB - there is a couple small R's nearby and a quad flatpak IC with 0.25m pins.   The rightmost 3 pins got crushed together by the inner edge of the foot.  I think it would be better to make those legs just smaller round 13mm barrels and use a 20mm long M3 screw from the top.   Also the bracket sticks out into the side panel space- the side panel with the two cutouts for the uSD and uUSB ports.

    I've had to order a new MB anyway, but thought I'd warn all about the fit.

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    wheedal wrote 07/01/2016 at 13:36 point

    Thanks for publishing the fan mount!  The driver board definitely works better being actively cooled.  I did run into a snag --and it was totally my fault --I only had a larger extra deep server style 40mm fan in my junk box, which pressed on the side of the case, so I had put a little torque being pressed on the fan mount legs.  Over time the vibration caused the leg near the CPU to shift and I ended up shaving off R17 and mangled a few pins on the processor.  I'm pretty sure I can repair the physical damage if I didn't short something permanently.   Worst case I've got a board to do some reverse engineering on for custom software.  The last print was perfect though!  

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    Adam M wrote 06/23/2016 at 20:55 point

    Thanks for the pointer, I didn't notice that on the logo. I figure for $200.00, an ARM based controller and nice LCD it's worth trying. 

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    Pete wrote 06/23/2016 at 17:25 point

    I'm curious to see how this goes.  Reviews indicate that there are temperature stability issues on this one that affect bridging.

    FWIW, I bought the MP Architect a few months ago and I love it.  It's a basic MakerBot Rep1 clone right down to the MightyBoard controller.  On the plus side, that makes finding replacement parts easy.. I'm wishing I'd bought a second just for the parts before MP pulled the SKU.  The neg is it's a single head and no heated bed, and adding them would require a new PS.
    BTW, the "IIIP" is a sytlized "MP" not a model number.. it's on all their printers.  :)

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    Robert Gouge wrote 06/28/2016 at 23:00 point

    Temperature stability issues have been resolved by manual PID tuning.  The most common values that provide good stable temps are M301 P20 I0.02 D250

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