1:10 10x10 "HEMTT" (actually M1074 PLS w/ M1076 trailer)

[dremu]

As I said, my styrene fab skills aren't fantastic, but in 1:10 the bits can be big enough for me to manage. In parallel with building the truck, there's also a conex ("shipping container", "ISO", etc). As drawn in CAD:



And then start to assemble:



Starts out as just 3mm styrene sheet from my local plastic shop, then 3D printed hinges, latches, and twist locks for the corners.



The latches actually work, if you're careful with them. The yellow splotch is a hinge for the handle; it's a piece of 3D print filament pushed through (1.75mm diameter), then melted on the end with a soldering iron to mushroom it in place.



Rather than actually corrugate the sides, I faked them with printed inserts glued into place. Rustoleum hides many sins.



Add some stickers, et voila.

This in turn fits onto a "flatrack":



to end up like this



As with the conex, the flat rack starts out life as styrene sheet, then has stuff added:



Most of the "stuff" is 3D printed, like the red A-frame on the left, but the tool box is left over from the body kit, and the tie downs on the sides are Fleabay Chinesium. They're so cheap that it's just not worth my time to try and print them, plus even the chintzy aluminum is stronger than printed plastic that small. The corners have snaps for the twistlocks on the conex:







They're so small I couldn't figure a way to actually make the lock twist, and in the end the thing weighs enough (just the conex empty is like six pounds!) that gravity holds it down just fine.

Like the 1:1, the back has rollers to facilitate loading and unloading. These are printed, and roll on a length of spring steel (aka a straightened paperclip. I've discovered that paperclips are amazingly useful in this hobby!)



The white blocks are added as I did some testing in the real world. My CAD design was nice and all, but keeping the flatrack aligned both fore-to-aft and left-to-right, while being able to load and unload it, turned out to be more of a challenge than I'd thought.

At the rear of the truck is a mechanism to not only roll the flatrack, but guide its frame rails on the angled rollers to keep it centered.





See highlight on the 1:1; not the same visually, but same idea functionally.

[dremu]

While I like build RC stuff that's accurate to the 1:1, I'm not remotely a rivet counter. I also want mechanical functionality, so I'm willing to to tweak things as I see fit, either for my own taste or to allow the thing to *work* like the 1:1, even if doesn't exactly LOOK like the 1:1.

One case in point is the suspension. The axles came with links and I could make them fit; I couldn't find a way to make leafs fit nor did I have any on hand. Another is the lift mechanism. I hate hydraulics in 1:1, so there's no way I'd do them in scale. That meant using linear actuators, though fortunately they can be easily controlled by an Arduino (see above wrt the RX and Arduinos.)

Here's a 1:1 moving a flatrack. The mechanism is actually compound. It has two sets of actuators, one to lift the main a-frame and another on the hook to bend backwards.



Learning to model that in CAD was, well, let's just say I tore out a substantial amount of my limited supply of hair

After many iterations, the design ended up like this at rest



Extending just the top, hook actuators looks like this



and then extending the bottom lifts the whole thing



Took me forever, but got all the sizing and angles worked out and it moves like this



That middle piece, the lift A-frame, was nightmarish to print, talk about a learning curve. It's too big to print at once even in my big printer, so it had to be split in two and then glued and bolted together.



and rendered for printing



For those not familiar with 3D printing, however, you don't magically get a nice clean piece straight out of the printer. What you get has supports and, unless you have the temperature and speed settings just right and the planets are in alignment, little melted bits and will require tons of sanding and filing and drilling to make perfect (or even good.)



That's an early iteration of the bottom half of the lift A-frame. After removing the supports and said sanding and such, the final version looks like this: