Well, after a lot of research and hesitation, I bought a 3D Printer kit, MakerGear M2
It took a while, but finally the printer has been delivered.

While it is strictly speaking not RC, I intend to use it mostly to make RC-related parts, so it is RC-related after all.

Here in this thread I'd like to document my journey in assembling, tuning and using this 3D printer.

Strangely enough, USPS delivered the box on Sunday, did not expect that. My poor wife had to carry the heavy box upstairs. It weighs 39.6lb (17.9kg). A couple of those kg are the two spools of PLA plastic I ordered. I also ordered some nylon elsewhere and need to get some ABS as well.

It was a perfect timing - the package was delivered just before my birthday, making it a great present for myself.

Upon opening - everything is very well and carefully packaged, with individually labeled bags.

Time to start RTFM !

The manual claims that mounting the Z-Stage/Platform is the most complicated part. Thankfully, that part has already been done and all the steps related to that should be skipped.
The only thing needed to be done was to align the Y-rail.

Since the Z-Stage is already mounted, it would make sense to mount feet so that the printer can stand on its feet properly, even though this is step 8 in the manual.

All the hardware such as screws is carefully sorted by size and put in separate bags and carefully labeled. Each length is in a separate bag, and then all hardware of the same diameter is in a bigger bag. Very easy to find what you need.

Next, I mounted the knob on the Z acme screw, so that I can raise and lower the Z axis easily.
The knob was a tight fit. Had to sand around a little and use some light tapping.

Now we can back to the manual and start doing the recommended steps in order, skipping the parts that have already been done.
So, the next step is mounting the X-rail.
The manual warns not to let the carriage off the rail.
Looks like in two of the holes on the rail, a special brass alignment pins should be inserted instead of the screws. The photos and drawings indicate that these pins should stay there.

The rails seem to be a little tighter than I'd hoped for. I need to find out if I'm supposed to adjust this somehow.

There is another guy who documents his M2 building.
Might be a good resource
http://rara993.smugmug.com/Electroni...9776&k=HmfXgLS

Next step mentions "Previously Assembled X Stage Assembly". Go back to a separate PDF for the X Stage Assembly.

Took a few minutes to gather all the parts - for some had to search out which bag a part is supposed to be and then which part is which.

After that it is pretty easy. Just a little bit of cleaning and sanding the printed parts.

I noticed some people mentioned some gaps in the manual. I wonder what they are, have not encountered one yet. But if I do, I'll document the solution here.

Next step also requires going to separate PDFs for the lower and upper spool holders.
Pretty straightforward, just needs a little cleaning/sanding to fit the screws in.

Switch to Full Filament Drive PDF.
I might later rethink which corner of the fan the fan bracket is attached to and the fan wire location - just to optimize wiring.
EDIT: the fan mounting had to be revised, see post 13.

Now going back to the main assembly PDF.
Mounting the X motor and idler are fairly straightforward. Just need to carefully adjust the height of the pulley on the motor shaft and make sure the motor mounted with its connector on the back.

I wonder, though, how tight is the belt supposed to be ? I tightened as far as I can with my bare hands, but I can still touch the belt sides together, not like on an RC helicopter.
OK, from the assembly animation, it looks like there supposed to be a screw pushing the motor to create tension. Need to find out which screw it should to be.

Yet another separate PDF - Y Stage Assembly.
Here the manual gets a little messier - it lists an extra screw on every page; that screw (M3x18) is apparently already installed on the first page and should not be mentioned any more. EDIT: should have looked at Z stage Assembly PDF

I also could not find the listing for the screws to attach the assembly to the rail. Will have to guess by analogy to the X Assembly (M3x12, which are indeed listed as 4 screws on the Z Stage Assembly Full Hardware List, thus confirming the guess).
Wrong. Need something much shorter. There are 4 M3x8 and 4 M3x8 LowHead. The letter ones are also listed in that list - plausible. It also seems that's where I'm supposed to use split-lock washers - 4 are listed right next to the screws.

EDIT: OK, I'm an idiot. I completely missed the Z Stage Assembly PDF that clearly shows all those steps, and also confirms my guess. That's because the Z stage assembly is already pre-installed and overlooked this PDF initially and did not bother checking its existence for the missing steps.

Installed the Y idler and the Y motor.
The build platform was a little involved to fit into the rubber corners.
I suspect that whenever I need to clean the glass, it will take some efforts to put the glass back.

Mechanical part is pretty much finished at this point. Now it's time to start with the electronics, beginning with end switches.

Started wiring by installing end switches and immediately encountered a problem.
If the fan is installed like in the instructions, it hits the wall, and as a result, the X end switch is unreachable, and the extruder stays fairly far from the platform edge.

I re-mounted the fan on its left corner instead and that solved all of the above problems.

I also installed a crew (I used M4x18) for X belt tensioning. The screw is shown on the animations but not in PDFs.

The electronics box is not covered in the instruction diagrams. So we have to guess by looking at the photos at the makergear site and their flickr channel.

The fan can be installed either extracting blowing up, or intaking blowing onto the board. I decided to blow onto the board. In this case the screws that fit are M3x18. (if doing extracting fan shorter screws can be used as the fan has indentations for the screw heads).

The same M3x18 screws are used for the SD card reader.

To install the box onto the printer I used M4x16. They are a little too long but the shortest M4 remaining, and seem to match the photos.

There are a couple of questionable parts.
The first one (actually two) are apparently the fan covers. They are not mentioned anywhere, but it is fairly obvious that they go on top of the extruder fans. And they can be seen on the picture on the assembly instruction page http://www.makergear.com/pages/m2-assembly-instructions

The real question here is whether they serve anything more than purely decorative function. They require extra screws and nuts to install, and those are sticking out not very gracefully. And it just creates extra weight of the moving part. As such, I think I'll skip them.

EDIT: These things are actually labeled in the list of included parts as "fan guards". So that's their function. I'll probably still leave these things off.

The second is more interesting. It is a piece of black shrink wrap. In the list of parts it is labeled as "1.5cm pc 3/32 heat shrink for Y Mounting Plate". I could not find any other reference to either the shrink tube or the Y Mounting Plate, so I have no idea what I would use it for. But it was included for SOME reason. There are some spare/replacement parts, that I understand. But this one is a mystery.