Scratch-Built RC Excavator Is A Model Making Tour De Force

Some projects just take your breath away with their level of attention to detail. This scratch-built RC-controlled model excavator is not only breathtaking in its detail, but also amazing for the materials and tools used to create it.

We’ve got to be honest, we’ve been keeping an eye on the progress [Vang Hà] has been making on this build for a few weeks now. The first video below is a full tour of the finished project, which is painstakingly faithful to the original, a Caterpiller 390F tracked excavator. As impressive as that is, though, you’ve got to check out the build process that starts with fabricating the tracks in the second video below. The raw material for most of the model is plain gray PVC pipe, which is sliced and diced into flat sheets, cut into tiny pieces using a jury-rigged table saw, and heat formed to create curved pieces. Check out the full playlist for a bounty of fabrication delights, like tiny hinges and working latches.

We can’t possibly heap enough praise onto [Vang Hà] for his craftsmanship, but that’s not all we love about this one. There are tons of helpful tips here, and plenty of food for thought for more practical builds. We’re thinking about that full set of working hydraulic cylinders that operates the boom, the dipper, and the bucket, as well as the servo-operated hydraulic control valves. All of it is made from scratch, of course, and mostly from PVC. Keep that in mind for a project where electric motors or linear actuators just won’t fill the bill.

If this construction technique seems familiar to you, it could because we featured a toolbox made out of similarly processed PVC pipes back in June.

Thanks to [Ai4fun] for the tip.

20 thoughts on “Scratch-Built RC Excavator Is A Model Making Tour De Force

    1. And I watched the videos…. And I learned a lot! I would have never thought to use cheap plastic pipe for building parts like that. Thank you. Another possible ‘tool/technique’ in the tool box so to speak!!! Obvious of course … after you see it done :) .

  1. Man…. I’m not even into building this kind of stuff; I’m a programmer. (I do have the Hackaday in my RSS feeds since I found it a couple months ago.) But a programmer is essentially an engineer, anyway. I passed the article onto some coding friends with the statement: “This guy builds with the kind of detail that is exactly the way I want to code!” Seems 90% maintainable (can replace the teeth on the bucket, for example), the hydraulic system is crazy awesome. I watched ALL nine build videos, most of the time asking “what’s he building now? Is … is that HINGES?”

    1. CA (super glue to most people) comes in thin, medium, and thick viscosity. Works really well with balsa and some plastics. Assume that is what he is using too. I use it mostly with building my balsa airplanes (R/C), but also with 3D printed parts. No coming apart, so make sure placement is where you want it. No moving it afterword… Thin just ‘wicks’ right in and sets ‘immediately’. So careful when you use it. Good stuff! I use medium a lot too for when I need run a bead on one piece and then carefully set in place to bond. A ‘bit’ more forgiving on the initial placement.

  2. Excellent!

    I never thought of using PCV as a modeling plastic, but it’s likely cheaper than polystyren. It sounds nice, too, like polypropolyne.
    Good article, too. I would much rather see these articles, rather than some corporate story.
    (Got a little line-leak)

  3. How on earth are his fingers not just totally stuck together and covered with glue residue & random dirt & schmutz from things getting stuck? Cool technique but in my wildest dreams I could never have this kind of dexterity and neatness.

  4. I’m sorry but I’ve learnt nothing from the videos (well, apart from the PVC-plate-from-pipe trick). The only “lesson” here is that apparently this guy can fabricate freehand with sub-micron, sub-arcsecond precision, and you can’t.

    I’d expect him to use at least jigs for each step — but he apparently can hold a piece on one hand, a crappy drill on the other and put the hole in wherever he wants. The parts then screw together with no hint of panel misalignment whatsoever. He dabs superglue on stuff like there’s no tomorrow, but no ugly white residue is ever seen. And he obviously gets the superglued parts aligned every time!

    Yeah, it’s awesome to watch, but so are those guys that claim to build an underground pool with only a stick for a shovel. In those obviously there’s more going on than what is shown on camera. Maybe here also?

    1. Where do you get the “sub-micron” claim from? This is indeed quite a detailed build, but he produces almost as long videos of much less complex parts, like a PVC hydraulic press, where it’s very clear that every part was actualy made, as he claimed. Not only that, but there are other videos of the excavator video which go very in depth. Bit weird that you’re casting aspersions that link him to other people from the developing world who go to far less effort to explain how each of their processes work.

      1. “Sub-micron, sub-arcsecond” was obviously sarcastic. The guy just seems unbelievably good, that’s all. I’ve watched the video where he makes the tracked wheels and I had the same feeling: lots of small pieces drilled and glued “by eye” — and a track coming out incredibly straight at the end, like out of a machine.

        I’m not here to gratuitously damage anyone’s reputation — it’s just a simple matter of “extraordinary claims require extraordinary evidence”. If and when he posts some videos detailing the whole process in a believable way, I’ll happily change my mind. Until then, any evidence seems scant so I guess all are entitled to their own opinion.

        And hey, FWIW if the guy used jigs I’d be even happier with him as that would make a lot of engineering sense. Then other people could readily learn something and emulate him — I feel if most people just tried to copy what he is doing in the videos right now, they’d be disappointed.

        P.S. You’re right in that the comparison with the “wild constructors” was probably a bit too much, but bringing “developing world” into this? I did not do that.

  5. The clip of the one track moving by itself, reminds me of that old movie where the detached hand crawls across the floor, lol. Creepy.

    Insanely cool project though. Takes a lot of patience and determination to build something like that.

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