Around a year ago, when the ShapeOko 3 was first being announced I
started getting the idea that it would be really awesome to just buy the
rails and build my own machine. It just sounded like the kind of
challenge that I was looking for. Unfortunately, it quickly became
apparent that the ShapeOko 3's rails weren't going to be available by
themselves. This realization of course didn't deter me too much, I
simply started looking at ways that I could mimic the performance of the
ShapeOko 3's non-general-purpose linear motion rail.
as I'm writing this there are two very simple paths to get rails for the
build I was initially envisioning. The first is by getting a Shapeoko 3
xxl expansion pack. Although, at $700, it's a bit on the pricey side.
The second option is to get some MegaRail 80 shipped over from the UK.
Unfortunately, neither of these options were available when I started
procuring materials for this build.
Around September 2015 I
decided that I'd thought about the build long enough, and if I was going
to build something I should probably start doing it. With that decision
made, I went about procuring all of the raw materials needed for the
build. For the rails I settled on using some 1/4" thick extruded
aluminum rectangle that measured 4" x 2" x 36". I really felt like I was
gambling with this choice, but I got lucky and the extrusions ended up
usable for the project. Now, there are several options for rail that I
One of course, was Open Build’s OpenRail. The
second option would be to use hardened steel rail which is available
from numerous vendors. Finally, the third option that I considered was
hard coat anodized aluminum rail.
I sort of ruled out
OpenRail because I felt that Delrin V-wheels might not be able to
support the weight of this machine, and even if they could they'd end up
being the weak link for this build. I had almost come to grips with the
fact that I was going to have to spend a ton of money for steel rail.
Then kind of out of the blue I discovered a guy on eBay selling hard
coat aluminum V-rail. It was so much cheaper that I had to take a look
and figure out if I could run steel V-wheels on it. It was kind of hard
to find any solid proof that the rail would even work.
three things swayed me to try the hard coat rail. First, was obviously
the price compared to harden steel rail. The second was that I had found
some hardened steel rail that matched the hard coat aluminum rail's
dimensions. This means that if the hard coat rail doesn't hold up but
the machine ends up working great I at least have a relatively simple
option available to fix a bad decision. The third thing that persuaded
me to go with hard coat rail was a post by Bart Dring in which he
answered a question about hard coat maker slide.
From reading this,
I'm reasonably confident that the rail will last long enough to prove
the machine a success or failure and save a bit of money right now
anyways. However, I do believe there is a strong likelihood that the
hard coat rail will eventually wear out. Although, it sounds like
keeping the rail clear of debris will potentially aid in maintaining the
rail for a longer period.
After spending most of a month sourcing and purchasing components for the build, I figured that I would be able to get the whole thing built by the end of November 2015. Boy was I wrong! Turns out that when you don't have the experience or the equipment for such a project, things take a lot longer than you think they might. Then add in the uncontrollable factors of life and work, and I find myself nearing the middle of April with less done than I thought I'd have at the end of October last year.
Early on, I identified that the linear motion rails would need to be built first. Mostly because they are the foundation that the rest of the machine is built around. So, with that, let's talk about the rails.
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3X 1/4" thick 6063 extruded aluminum rectangle...