If there’s a shortcoming with the Monoprice Select Mini 3D printer, it’s that the instructions are… well, lacking. And a new printer with poor instructions can be very intimidating to the newcomer to 3D printing. So the MP Select Mini users community wrote this guide to help you with your first print.
If you have questions after reading this guide, head over to the forums and ask our user community there.
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Step 1: Unpacking
Your Monoprice Select Mini 3D printer will come in a sturdy corrugated cardboard box from Monprice. Open this box, and inside you’ll find another box. This suggests to us that Monoprice isn’t the manufacturer of this printer, but that they’re simply reselling the printer under their own brand. Most of us are okay with that, though, because Monoprice offers returns and support that no-name Chinese online retailers typically don’t offer. Even if you could find it for less from a no-name Chinese merchant (and I don’t think any of us have yet), it’s probably just not worth it.
Open the second box, set it on its side, and slide out the styrofoam insert. Open the two styrofoam halves and you’ll see your new printer and two cardboard parts boxes. In one box is the power supply. In the other is the power cable, a plastic spudger tool, a micro SD card, and an Allen wrench.
There will also be a sample length of filament that is, for all practical purposes, useless.
Set up the printer on a sturdy surface near a computer (within a USB cable’s length). Though it’s not strictly necessary to tether the printer to a computer, it can be quite beneficial to do so, and if you have the option, I highly encourage you to do so. Plug the power supply into the printer, and plug the power cable into the wall. Turn on the switch on the back of your printer and the display should come to life with this:
Note that if you don’t have the USB cable connected to your computer, the display will read “No Connection” instead of “USB Connected.” Unlike most 3D printers, the MP Select Mini can print from a memory card even without a USB connection to a host computer. Upon powering on, the printer will be silent and the fan won’t be spinning.
At this point, the motors won’t have power going to them, which means you can move the print head and the bed by hand. Ensure the bed slides forward and backward freely. Ensure the print head will move left to right easily.
Step 2: Make it move!
You won’t be able to resist this any more than any of us could. Use the dial to move the pointer to “Move” and press the center of the dial in to select the Move menu.
In the Move menu, you can select X Axis, the Y Axis, or the Z axis by highlighting the axis and pressing the dial in. You can then use the dial to move the printer parts. Press the dial in again to stop moving that axis.
The “Extruder” axis on the page will move the motor at the top of the tower. Since you don’t have any filament loaded, you can play with this axis as well. (Tip: draw a line on the motor shaft with a magic marker so you can easily visualize movement of this motor.) However, once you have filament loaded in the machine, you should only move the extruder axis when the hotend is hot.
Step 3: Level the Bed and Adjust Bed Height
Getting the bed properly adjusted is THE KEY to successful prints. While having a suitable bed surface ranks right up there, even the best bed surface isn’t going to do you any good without a properly zeroed and leveled bed.
Getting the bed dialed in can take some trial and error, and it can be frustrating. Get a comfortable chair, work under good light, have a beer at the ready, and do it methodically. The work will pay off. On the other hand, if you don’t get this done right, nothing else will matter, and all of your prints will fail. (Did you see that? I used bold, italic, and underline all on the same words. That means it’s important!)
Start by using the LCD screen and command dial to home the three printer axes. Unlike some other printer models, the Select Mini does not have an adjustable zero. This makes things just a bit more difficult, but still possible.
The extruder should be over the front left of the bed. Take a regular plain ol’ sheet of copier paper, and slide it between the extruder nozzle and the bed. The paper should slide in there freely, with just the faintest hint of drag from being pinched between the two surfaces. If there’s no drag at all, your bed is too low and must be raised. If you can’t get the paper in there, the bed is too high and must be lowered. Using the Allen wrench that was included with your printer, make any necessary adjustments. You can slide the bed out by hand, make an adjustment, then slide the bed back in and test again with the sheet of paper. You may have to peel back the masking tape that ships on the bed surface (leave it on there; just peel back enough to expose the screw head), or force the Allen wrench through the tape and into the screwhead. Either way is fine.
When this corner is adjusted, move the extruder head to the other side of the bed and repeat. Then move the bed forward and repeat. Then move the extruder head back to the starting position and repeat.
Continue to work all four corners of the bed until you get the same slight drag on the sheet of paper in all four corners. This can be an iterative process, so be patient and do it right. (Did I mention that getting this right is important?)
You may have to repeat this process after a few prints, or when you change the bed surface, or when you change filament, or sometimes for no apparent reason at all. It’s one of the things that goes along with owning a FDM 3D printer.
Step 4: Load Filament
You did buy a spool of filament when you bought your printer, didn’t you? If not, STOP. There’s not much you can do with the printer without filament, and trying to make do with something is just going to cause problems. And that sample length of filament that came with your printer is still useless.
There are two main types of filament on the market: ABS and PLA. I highly encourage you to start with PLA filament and not ABS. PLA has some properties that make it easier to get a good quality first print than ABS does. In any case, get a spool of 1.75mm PLA filament in the color of your choice. There are all kinds of online and even brick-and-mortar retailers selling filament. Remember: 1.75mm PLA is what you want.
Install the spool holder on the tower and hang your spool of filament from the spool holder. If the end of the filament has any sharp bends in it, use a pair of scissors to cut off the end.
Use the control panel to raise the printhead a few inches above the bed, and preheat the extruder to 195 degrees. Wait for the extruder to reach this temperature before proceeding.
Open the pinch rollers in the extrusion feeder by squeezing the black clamp. Feed the filament by hand into the tube (known as a Bowden tube) until it gets to the hot end. You can eyeball how much filament this should take, and you’ll definitely feel resistance when the filament gets to the hotend. Release the extruder clamp and allow the pinch rollers to grab the filament.
Leave the extruder preheater on. Go to the Move menu and select the Extruder motor. Use the command dial to feed filament into the hotend. I suggest you take a black magic marker and make a vertical line on the shaft of the extruder motor; this makes it a lot easier to see when the shaft is turning. Hold the filament to the left of the extruder motor so that you can feel whether filament is being fed in or whether the pinch rollers are slipping.
Observe to ensure that melted filament comes out of the nozzle. Feed a few centimeters of filament through the extruder, and remove any extruded filament with a tool such as tweezers or needlenose pliers. (And keep the tool with your printer; it should be a permanent fixture next to your Select Mini.)
Step 5: Print!
In the interest of getting up and running quickly, insert the Micro SD card that came with the printer into the slot on the printer’s right side. From the menu, select “Print.” The printer will read the contents of the SD card and present you with a list of files. By default, the printer card comes with “baby elephane.gcode” and “cat.gcode” preinstalled.
Select the file and click the dial to begin printing.
For a while, you won’t see much happening. If you print the cat, you should see the extruder target temperature set to 195 degrees C, and the extruder temperature will start climbing. At some point, the cooling fan will turn on. The printer will home itself on all three axes, and the printer will begin printing.
The printer will first print a ‘raft’ of lines a few mm apart, and then will lay down the second layer that has a complete fill. The first few centimeters of filament might not stick to the bed of the printer. As long as the model ‘grabs’ the bed on the second layer or so, things will be fine. If no filament comes out of the extruder after ~30 seconds of extruding, or if the print doesn’t stick to the bed after a layer or two, use the command dial to cancel the print, troubleshoot, and try again. If filament isn’t sticking to the bed, re-zero and re-level the print bed. A properly leveled and zeroed bed is paramount to getting a successful print! Don’t worry if it takes you 2 or 3, or even 11 or 15 or 20 tries, to get this right. Properly setting bed height is part art, part science, and part luck. After canceling any print job, be sure to remove any filament from the bed before trying again. I use a utility knife for this purpose, but the included plastic spudger is a good tool as well.
Watch your printer as it does its first few prints so you can learn its behavior and be on the lookout for any problems. Once you gain some confidence in your printer you’ll feel comfortable walking away as it’s printing.
3D printing is fun, and it’s cool, but it’s not fast. Here’s what happened when I printed that cat file:
That’s two hours and fifty six minutes worth of cat there.
Step 6: Remove the print from the bed, and clean it up
I use a utility knife to pry my prints of the bed of my printer. Some prints can really get stuck on there, and you may find that when you remove a print you take the bed surface up with it. No problem; just get yourself some 3M blue painter’s tape and put down another protective layer over the metal print bed. (And re-zero and re-level the bed when you do.)
You’ll notice that after the print finishes, the cooling fan stays on, even though the extruder and bed heaters are off. That seems to be the design of the printer currently. To shut off the fan, you’ll have to turn your printer off and back on again.