My cousin (actually my wife’s cousin) has expressed an interest in a CNC machine to cut wood and I think I am going to build and ship an almost-entirely-assembled LowRider.
One way that the machine can collapse into a relatively small crate is if there are two detachable wooden rails along the two sides, one for the conduit rail and the other for the wheels. These can have the belt holders pre-attached. The most convenient packing, is if the Y rails are not much longer than the X gantry, and when detached they can lay parallel in a pretty tight space.
Also, it works better for me if plywood is at most 48" in length, so I am probably looking at a Y rail length of just under 48" and an X “table” dimension of at most 48". Then the crate can be about 48" long and the other dimensions can be roughly 12" x 12".
If the crate has four long, narrow sides, each 48" x 12" perhaps they can lay flat and the Y rails can attach to them. With pre-drilled holes and maybe threaded inserts, the crate panels can hold the Y rails the proper distance and square, and it can be a (somewhat large) table-top machine and not have to screw into your dining room table for example.
Depending how it’s built, I’m thinking it might be really fast to pack or unpack. It could perhaps have hinges to unfold instead of fully detaching, but I haven’t decided on that part yet. If it’s painless to pack and unpack, I might even build a crate for my own machine even if I’m not shipping it anywhere!
Does anyone know anything about crates? I’m sure there is plenty of information about best practices on the interwebs.
Also I haven’t begun thinking about packing within the crate, which is probably going to be the most important part. Big blocks of urethane foam on all sides or something?
The unpacked result is not a torsion box and would be relatively ‘floppy’ unless placed on a solid (and hopefully flat) surface.
If the box and Y rails are 48" and the short dimension is 12" then it works out to pretty closely match the rail length when unpacked, but this is not necessary. If the box is slightly smaller, say 11" x 10" then when unpacked it will be shorter in the Y dimension than the rails and that’s okay since the working area is a bit shorter anyway, so the rails can overhang a bit. In other words, these dimensions happen to match in the diagram but this is not essential. They need not match.
Are you looking for one-time protection while the machine is being shipped, or a more permanent “ongoing stowage and open/unpack for operation” use case?
I’ve dealt with a fair number of touring cases, both factory-made and built by a scene shop. These are protective cases designed for portability and re-use, often for years at a time loading in and out of performance venues as often as daily. Not quite the same as shipping cases, but a fair amount of overlap in the mission. Often these cases served as transport for the enclosed items, and also the “running location” (e.g. wardrobe cabinet or prop table) once things were set up at the venue. This minimized the need to handle items when loading in/out of a performance venue.
Most of the ones I dealt with had “one by” (e.g. 3/4" x 4") frames with sheet goods (most often 1/4" or 1/2" plywood, although 3/4" ply might be used for bottoms or for heavier equipment that needed more robust protection) for the sides, tops, and bottoms. This made the sides robust enough to be permanently attached (glued and nailed/stapled were most common), hinged, or screwed/bolted together with threaded inserts. Large locking castors were common, as were strap hinges that allowed tops or doors to swing 270 degrees and self-store along the back or side so a case could be parked next to a wall once opened. Loose-pin hinges could allow faces of the crate to be completely removed if that was beneficial.
I could see your proposed crate allowing for an operating length double the width if you used loose-pin hinges to join them in the crate shape, but spaced out the panels and had double the number of red braces for the operational setup. As long as there’s a mechanism to align the braces they’d carry the compression load from the belt with no issue, and the joints of the rails could be staggered from the joints of the supports to increase stability. Threaded inserts would hold it all together but still allow easy setup and take down.
I don’t know that it would be self-supporting, but could easily be set up on a floor or other existing table.
Originally I started with the problem of how to deliver a machine that’s easy to set up, but I think keeping and using the crate helps with this objective, so packing/unpacking indefinitely is a win/win. A bit of extra attention to repeated stowage, for instance hinges and latches with bolts and threaded inserts instead of nails/crowbar. (or is that only in movies?)
I had not considered a segmented Y rail, which I suppose would also mean two-piece conduit that meets in the center. Maybe an internal piece at the junction can help it function as a single piece.
It is always a dilemma to decide the right size, large enough to accommodate the intended use but not too greedy for “just in case” scenarios. In this case I am expecting it to serve for artwork but not for cabinets. A specific size hasn’t been requested but I’m thinking “poster size” should be about right. I’m willing to make a four-foot crate, so I don’t think I need to solve the extra-long Y axis problem this time.
I think for spoilboard, it could be segmented too and attached to the interior of the crate. It would need to be undersized to allow the crate to close properly. Depending on the job, it could be used with large gaps (“large” being perhaps 1.5 inches), or the spoilboard panels could be shifted to close the gaps.
Here’s an updated cartoon, where blue illustrates potential built-in spoilboard panels (front wall of crate hidden for illustration):
Maybe it would be possible for one panel to have full-width spoilboard, and two other panels to have top- or bottom-justified panels, and they could be assembled such that the spoilboard hardly has any gaps.
Here the grey boxes are the crate panels and the blue boxes are the spoilboard panels. By arranging somewhat out-of-order, three segments of the spoilboard could have little to no gap. A hinged, unrolling “sushi” design is not possible in this scenario, so I guess that’s a tradeoff.
There are a lot of options for tool-less closures, but these are often less desirable for shipping as they tend to either stick out and get caught on stuff (damaging themselves or what they hit) or require sides be thick enough that they can be recessed. I’d consider constructing the case with hinges, then screwing the final closure for initial shipping, and include some sort of catches or clasps that could be installed after it had arrived at its permanent home.
A sash lock is easy to operate but is likely to get damaged in transit as it sticks out pretty far and isn’t really designed to take a beating:
If going this route, I’d screw the case closed for the initial journey, and add a pair of them for ease of packing/unpacking once it is at it’s normal home.
Road cases often use butterfly latches like these:
These are designed to be installed in a recess, so the sides of the case need to be thicker. You can get just the latches, but then you’ve got the possibility of snagging again.
We also used coffin locks for some of the crates and sets we built:
These are installed completely inside the case so result in a flush surface, but need an access hole for the hex key to open/close them.
Lowest tech approach (after just screwing the box closed) would be a loose-pin hinge, operating kind of like a hasp.
The trick here is to figure out a way to keep the pin in place during the shipping phase, but have it be easily removable later on. We’d often use hairpin or brooch style cotter pins
as the removable pin as they could be attached to the case with a tether so as not to get lost.
This is a really nice concept, and a very cool project to think about.
I’m not up to speed with the ease of re-tensioning the belts (which I gather is simple) but none the less have been thinking that perhaps a version of an over-centre (toggle) latch could be incorporated for ease of repeatability. (printed to somehow match the stock fittings would be nice!
@ttraband Tom has pretty well summed up the hardware, but consider lift-off hinges as well - lots of knock-down display cases use variants, to work as hinges or to reassemble in a different configuration.
We didn’t use a lot of lift-off hinges on theater stuff as it just leads to more loose pieces you have to find a home for (and which can then get misplaced). Most of our lids just flipped open far enough to store along their own sides.
Hinges like this make that easy.
I’ve never dealt with these folks directly or ordered from them, but they seem to have a pretty comprehensive catalog of available hardware. The site may not have been updated recently.
