The Shapeoko 2 comes in one size: 500mm x 500mm. If you want a larger footprint, you’ll have to buy longer lengths of makerslide and make it happen yourself. In addition to larger makerslide, you’ll also need to get longer lengths of 20×20 rail, as the two Y axis makerslide rails are tied together by bolting to two lengths of 20×20 rail, one in the front, and one in the back. What isn’t immediately obvious is the rails that the Y axis makerslide connect to are not 500mm long, they’re 550mm. Now, if you’re sensible, you’d realize that this extra 25mm on each end is for the end plates to get a good grip on these rails. Alas, I wasn’t paying attention and ordered replacement 20×20 rails at 1000mm instead of 1050mm. This is a bit of a problem because I also ordered the standard 1000mm makerslide, which means that 1000mm on the X axis doesn’t account for the extra 50mm needed for the ends. Since the gantry is 1000mm long, it stands to reason that the Y axis rails need to be mounted outside of that envelope. Duh.
I always order more than I need, by about 10-20%. Murphy’s law for
ordering parts says that the relationship between how bad you need
something and how long you have to wait for it is inversely
proportional. If you got to have it now, it’s going to take all the
longer to get it shipped to you. Misumi is not exempt from this,
especially because I didn’t read the fine print that it would take 3
weeks just to get my rail cut, before it could be shipped. If I had
ordered a 4m segment, I could have had it within the week, but getting
it shipped to me would have been quite a bigger issue. That being
said, let’s be clear that the screw up was mine, not theirs, because
they clearly state it ships in 3 weeks. Let me also mention that
their pricing is pretty competitive, and they’re worth buying from
again. Just beware of what it means when you look at their shipping
Back to the original thought: it’s good I order extra. I figured I
could use the extra extrusion on a future project if I didn’t use it on this one, so I ordered seven 1000mm bars. Turns out I was short that 50mm on three of the lengths in the design of the frame so instead of waiting longer, I decided to make use of the other bars. I cut 4 of the 1000mm bars to be 550mm, and made a square frame with the 6 inner bars at 550mm, with the longitudinal 3 bars being 1000mm. This meant that I could match one dimension in 1000mm (the Y-axis) while making the X-axis have the extra length so I could fasten the Y-axis rail endpoints to it securely.
While we had a horizontal autofeed metal cutting bandsaw at the
hackerspace (which I probably really should have used, since it makes
really good square cuts) I decided to use my own 9″ bench top bandsaw
with a metal cutting blade. Since the blade was new and tensioned
right, it tended to cut straight. I still had to square up the ends a
bit with a file, as well as take down the burrs. But it had worked,
and soon I had the “window frame” done.
Although the plates allowed NEMA23 motors to be mounted, it meant I had to go get different bolts and nuts than what were provided for the NEMA17 size that normally comes with the Shapeoko 2. The new hardware collided with the rails, until I read and also heard from my compatriots at the hackerspace that you want to push your rails off to one side, this way it keeps you from having any mismatch in both side’s mount points. I had to make sure that the motor shafts were able to reach, which the pulley was able to with enough to grab the shaft.
Using my dremel tool and a grinding wheel, I ground down the shafts,
on the shaft in two places 90deg apart for both of the set screws on the pulley.
For the most part, it’s a piece of cake to assemble. Just tons of
parts. The two tough assemblies were the Z-axis motor mount and the squaring of everything. Holy cow, the z-axis needs 3 or more hands to be able to put everything together. They’ve fixed that issue with design of the X-Carve.
A good reminder: Loctite! Locktite! Locktite! While it seems trivial, I had an eccentric nut fall off during a cut because I didn’t locktite those. I had to readjust it, then loctite it. Use the blue type not the red type, because it’s likely you’ll need to remove or adjust things later.