I want to share my experiences with the Monoprice Mini Delta printer, because I learned a lot that will help others. I haven't really found the right place to do it, but I'll right it up and post it here for now. If you can think where else I should post this, let me know. (There's a very active Facebook community but I don't do Facebook, and there's a subreddit but that's another thing I don't do.)
TL;DR – I got two bad ones before I got a good one, but now I'm printing all the time and having a blast with this great little machine. The included instructions are not adequate, particularly for Mac users, but once you get that sorted out the machine is great. I have printed several things useful for gaming as well as for around the house, and expect to do a lot more in the future. If you want to tinker with 3D printing without spending a lot of money, this thing is the ticket.
I was attracted to the machine not just because of the low price, but because it had the right features: heated bed, ABS capability, self-leveling, web interface, high resolution. good reviews. Also, the delta design is very rigid, leading to good print quality. Most other low price printers are cantilevered, a design so prone to vibration and wobble that affects your prints that I don't understand why they make them.
Let's see if I can make the boring part short. I ordered one, it wouldn't work at all. Talked to tech support, sent it back. I now believe that with what I learned trying to fix the second one I could have fixed the first one. Second one worked great for a few prints, then the fan on the hot end died, and the filament started folding up inside the heat break (inside the hot end) and it jammed *every* time I tried to print. This meant disassembling and reassembling part of the hot end each time, teaching me a lot. Talked to tech support, they gave me a diagnosis that I now feel was wrong. Sent it back, got a third one. This one is awesome.
I pasted in the starting gcode from the manual into the software, and since that code starts by moving the print head to the corner of a *cubic* print volume (when this printer has a cylindrical print volume) it plowed the heated nozzle directly into the plastic clip that holds the print bed, carving a big old gouge in it. This has not mattered, but I'm still unhappy that the included instructions tell the printer to damage itself.
I did some research, there's a wiki specifically for this printer at mpminidelta.com that was particularly helpful. I looked at other examples of start code and then ended up re-writing mine myself (see below to save yourself this step).
I had a lot of trouble with build plate adhesion at first. Everyone says to use blue tape. I went to Home Depot and bought a roll of tape for $10 USD (ouch). It was horrible. I dug deeper, read more, turns out 3M makes *many* kinds of "blue tape". I had purchased #2080EL, which is expensive and useless. I went to target and bought a roll of #2090 for $4 USD, and it has worked brilliantly.
Sometimes I put a little glue stick on there to help, and if the thing I'm printing does't have a *lot* of surface area I use a raft. This requires clicking on Custom instead of Recommended on the right side of the Cura window, which gives you a lot more control over the printer. If the surface gets gummed up I wipe it with some alcohol. I replace the blue tape every few weeks, basically only when it is damaged during removal of a print. Print bed adhesion is pretty much the only problem I have now, and it's only occasional.
I also have some trouble with warping – the edges of objects large enough to reach the edges of the print area often peel up a millimeter or two. This means I have an otherwise successful print with a bottom that's not flat. Often this is fine, sometimes it's not. I have tried enclosing the print area by taping pasteboard over the three openings, but I don't think it's helping. I've talked to tech support about this and they recommend printing PLA at Extruder = 205 Platform = 45. This is pretty different from my 200/60, so I may try that. They said the idea of enclosing the sides is good, since drafts and cold air cause print failures. They did say to punch a few holes in the tops of the panels so there would be some air circulation. They couldn't give an ideal temperature for inside the enclosure.
I have printed dozens and scores of items, big and small, without a jam. I have printed several things that have become part of gaming terrain (gargoyles, mirrors, idols, columns, all from Thingiverse.com). I have printed and painted a couple of figures, and while they are definitely not great some poses come out good enough to use. I have hopes of doing naval ships and spaceships in the future.
I have printed several "torture tests" and am very pleased with the results. I have printed several "print in place" items with multiple moving parts and they have always worked great.
Neat trick: you can pause printing, switch filaments, and restart and the results are great. This lets you change colors part way through a print. The two colors will be just as well bonded as any other layers. The can produce neat effects.
Tech Support: I'm sorry to say it's hot and cold. sometimes you get someone who has worked with the 3D printers a lot, and they can provide great help. Sometimes you get someone who, well, they've probably seen the printer, but you wouldn't know it.
Downsides:
The web interface to the printer is useful for seeing how far along the print job is, but the gcode upload is SO SLOW that it's more or less useless. I just carry the micro SD card back and forth. There are ways to tweak and replace the web interface and I have not yet played with that part of the printer.
Speaking of microSD cards, the one that comes with the printer is SO SMALL that it's nearly worthless. Luckily it's easy to get another.
Third downside: this thing is a little loud. It's not table saw loud, but it's louder than a bread machine and the noise isn't a smooth, healthy-sounding machine noise. If anything else made this kind of grinding and chunking I would think it was time for a new one. Apparently you can reduce this by putting the machine on a firm foam surface, I haven't tried this yet.
Fourth Downside: the resulting prints seem to come out 3% small. If you print a little spaceship you won't care. If you print something that is supposed to interface with something in the real world, like a battery or utility knife blade, be prepared to print, test, scale, print again. It's not clear to me if every printer is off by the same amount or what that amount is. Some people or Reddit were talking about experimenting to find the number for their own printers. It's a nuisance to remember to scale things up, but while you can't always get what you want, if you try, you just might find, you get what you need.
I have not tired ABS. PLA works great for almost everything. I'm really not sure I need ABS. I have not experimented with any flexible filaments, but that's something I hope to try one day.
Here are the settings I am using. I am not saying they are the best settings, I hope I learn more as time goes by. I am not saying these settings won't blow up your printer, but they are better than the settings that come in the manual or software and I have been using them successfully for months.
I am using AMZ3D PLA at 200°C with a 60° bed. I am going to be experimenting with 205 and 45, and one tech support guy said that sometimes darker colors of PLA, because they have more pigment, print better at 210 or even 215.
Ultimaker Cura 3.2.1 for Mac OS X
X=110mm/20mm
Y=110mm/10mm
Z=120mm/10mm
Elliptic
Origin at Center – checked
Heated Bed – checked
Gantry 9999999999
# of Extruders 1
Gcode flavor = Marlin
Nozzle size = 0.4mm
Compatible material diameter = 1.75mm
both nozzle offsets = 0
Start Code:
—————————————————————————————
G21;(metric values)
G90;(absolute positioning)
M82;(set extruder to absolute mode)
M107;(start with the fan off)
G28 X0 Y0;(Home the printer)
G28 Z0;
G29 Z0.4; (autolevel)
;G1 Z15.0 F150; move the platform down 15mm
G1 X0 Y0 Z15;
G92 E0; zero extruded length
G1 F200 E3; extrude 3mm
G92 E0; zero extruded length again
G1 F150; move the platform down 15mm
M117 Printing
—————————————————————————————
End Code:
—————————————————————————————
;End GCode (from cat gcode file)
M104 S0 ;extruder heater off
M140 S0 ;heated bed heater off (if you have it)
G91 ;relative positioning
G1 E-1 F300 ;retract the filament a bit before lifting the nozzle, to release some of the pressure
G1 Z+0.5 E-5 X-20 Y-20 F4800 ;move Z up a bit and retract filament even more
G28 X0 Y0 ;move X/Y to min endstops, so the head is out of the way
M84 ;steppers off
G90 ;absolute positioning
—————————————————————————————
learns to drill with a screwdriver.
