Here are some annotated pictures of my UniStrut Frame…
1st, the mostly finished product: (Note the lack of bricks/weights, chain tensioners, casters, etc, theres still some work to get it tip top)
Aside from some additional full length (10’) cross members, this design is identical to @bdillahu 's original design as far as the cut UniStrut is concerned.
Note: due to the measly selection at my local home center stores, I could only find 1/2" hole L-Brackets, and exclusively used 3/8" bolts and ‘strut-nuts’ (specially shaped to grip the overturned channels). This actually worked really well as the 1/8" all around wobble allowed enough give to set everything in the correct position more easily than a tight fit of a 3/8" hole on L-brackets would have. It’s counterintuitive but definitely helped along the way.
Starting at the back of the left side (as facing the machine) is a simple L-bracket, long side up:
Moving to the front of the bottom strut, you’ll see that 2x L-Brackets are set with one Long side up on the floor strut, one short side out on the vertical strut:
Returning to the back of the frame, we see the 2x L-bracket ‘T’, This longitudinal connection uses a 2" long 3/8" bolt, washers on both sides and a standard nut. The ‘T’ connection greatly assists in getting the frame square and level while assembling, which is a little tricky without them as everything wants to wobble and twist. Once the ‘T’ connections are in place on the horizontal members you can easily slide the vertical elements around with one element of the ‘T’ connection loose, and the other tightened and aligned:
Next is the connection of the rear vertical strut forming the pointy end of the triangle, along with the front facing horizontal support:
Note how the horizontal strut is both set back (on the long L-bracket, in a ‘T’) and the rear strut is made to rest on the front horizontal strut:
Once you’re this far along, you’ll have a frame thats standing up and sturdy enough to really dial in your connections, make sure its all level, and there’s no twist and tighten it up to give it some strength:
Next is the assembly to hold the Motor mounts. Another ‘T’ connection on the 7" top bars, and the only non-standard connection, 3 large washers used to span the gap. Make sure these washers are big enough (1.5") to securely grip the channel slides, or they will bend/slide into the channel when tightened up.:
The top most full height cross member is heavy enough to conk you on the head if you’re not careful, and it likes to slide until its tight, so you’ve been warned…
This is where we move onto the MaslowCNC motor mounts these bolts are 1/4" wide and might be 2.5" long, I can’t recall, but were knocking around the garage. They’re applied with generous washers:
And thats about it.
I opted to keep the ‘work piece crossbar’ plain metal for now, and still have some alignment work to do to set up a spoilboard. The frame does NOT need a sheet of plywood in place to maintain its stiffness and I’m thinking that a 1.25" rigid foamboard as a spoilboard might leave me with just enough of a lip (3/8") to balance many different thickness of stock without much further modification.
Once I get the machine dialed in and running I have parts for joining 2 struts lengthwise, and will be investigating the maximum width a stock maslow can be made w/o additional chain.
Also, it appears that I can use the motor’s own screw mounts to install the chain rollers, it’ll be a close fit but I’m pretty sure they’ll work well and keep the chain well attached without interfering with the outrunning chain.
anyway, good fun building this, I cant wait to get the last bits in place and see what she can do!
cheers,
other than that, it’s not a hard limit, it’s the sled sticking.
