This is the 7th post in an ongoing series detailing my efforts to build a RepRap Mendel, an open source desktop 3D printer. For the rest of the RepRap build progress, see here.

The X, Y, and Z stage blocks were put together successfully, the extruder was constructed, the electronics were tested (everything moves or heats up), it’s time for the most exciting part of the build: putting it all together!

To start, the X-axis blocks were put together into a completed X axis. The smooth bars that came with the Mendel-parts kit were a little wider than the stock Mendel design, so some drilling/filing was needed to get all of the parts to slide onto the rod. The finished X axis is shown below:

Once the X-axis was constructed, it was time to assemble Mendel’s distinct triangular frame. The Mendel includes 6 curved vertex pieces (shown in red in the photo below). To help you maintain your builder’s sanity, I highly recommend filing the holes on these pieces so that you can push the threaded rod through these pieces (not loosely push, but not have to screw it in either). The constructed triangular end pieces are shown in the photo below:

Once the ends are constructed, they will be joined together using pieces of threaded rod of various lengths. Again, the ability to push the threaded rod through the holes rather than having to screw the rod into the plastic will save you time (and sanity) in the long run. When I built this, I put all the pieces on the connecting bars first, then joined the two bars together, which I recommend over pushing rod through 2 sets of vertex pieces. The Mendel-Parts kit was about 10 M8 nuts and 10 M8 washers short (gah!) so I hopped in the car and headed off to the hardware store (hardware run!). The assembled Mendel frame is shown in the photo below:

Additionally, the Mendel needs to be inspected to ensure that various widths meet appropriate distances. My tape measure tragically only does feet and inches, so I searched for an english/metric tape measure while I was in the hardware store. Turns out that such a tape measure is… surprisingly difficult to find. Most tape measures feature 8ths of an inch on one side and 16ths on the other. Seriously toolmakers, let’s do english and metric. I assure you, the American education system has advanced to the point that most people can count to 8 AND 16, and identify different lengths of line as meaning 1/2, 1/4, 1/8, and 1/16. My newly acquired English/Metric tape measure is shown in the picture below:

Next up was installing the X-axis into the newly built frame. This part was somewhat tricky, especially inserting the the threaded Z stage rods into the Z leadscrew bases. When you install this, and the Y stage, MAKE SURE YOU DON’T PUT THEM IN BACKWARDS. The metal on the X stage should be on the same side as the Z leadscrew base containing the opto endstop. Also, make sure you use 16mm screws to secure the M8 bearings in the leadscrew bases. Using 20mm screws will result in the screws colliding with the Z-stage pulleys (hidden on the bottom of the machine). The installed X axis is shown in the picture below:

The completed Z stage:

Next we install the Y stage:

And, finally, we wrap the print bed in kapton tape, attaching it to the Y stage. Add in your Mendel electronics and you’re done!

Be sure to check out additional build photos in our flickr photostream.

Construction is done! So can we start printing yet? Almost. Next time we will test the completed system, fix minor errors, and calibrate the system. Stay tuned!