LockedUp RC
Results 1 to 8 of 8

Thread: Structo dump truck

  1. #1
    Join Date
    Aug 2019

    Default Structo dump truck

    I wanted to roll with the 1/14 scale Truckers and Construction workers, but tamiya semi or anything construction equpiment get expensive in a hurry. I had wanted to build some kind of a light dumptruck, this Structo hydraulic dump truck is what i ran across t an antique store. Not unreasonably priced, not in a condition that makes collectors hate me, wrap it up. This is mostly based off of the Tonka conversions of smallhaul and several others. (Steal All The Ideas!)

    For the donor, I picked up a 1/16 Redcat rock crawler. 4wd, solid axles, locked diffs and trans, and axle hexes were about the width i needed.

    Originally i wanted to convert my 1930s style nylint, but once i had axles it looked too narrow with the fenders, so I grabbed a 1960s Structo hydraulic dump truck tandem axle with the pow-r-r-r motor noise maker.

    My plan was to just go quick and dirty on this, use the original stamped frame and try not to get too crazy in hopes of making the indy show.

    Tires are just the modified stock hard rubber that's been under it since it left the factory.

    I ordered a set of tamiya semi springs, but what i got is too long. it's like 3 inch eye-eye. I can't figure a way to get my front axle under the fender and not have to chop off the front bumper to get spring shackles through it. it's pretty close to this truck.

    I'm painfully aware now that tamiya # 9808091, 9808092, 9808094 was the wrong type of spring. 4.75" long spring was way too big, but it's what amazon had. So i curled up the 'b' helper springs, and got the front end looking a little better. Once i got the front of the springs mounted, and played with shackle lengths on both ends.

    And mangled a hole in the chassis, got the trans mounted up to some brackets.

    And i still have some suspension travel when it's got a load of dirt on.

    Cab mounts i went really easy / lazy: I stuck a bolt through the bumper rivet holes and cab, threw a nut on those, the bolts slide into the original chassis rivet holes, then the stock tabs slide into the original slots.

  2. #2
    Join Date
    Aug 2019


    Bottom view

    Got the "interior" back in. Trans clearance wasn't quite as brutal as i expected it to end up.

    I know by the stunned silence you've all been wondering who would run such a modern, immaculate, classy, and well preserved vehicle in their fleet?

    I'm ready to hit the meet!


    Playing at the 2016 Toy Trucker and Contractor show RC room

    hit the general store for lunch

    shook a spring loose while driving around, had to hit the shop


    Learned some stuff about the truck at the meet.
    I picked up a Helion (4300 rpm) 370 motor to replace the stock 260. So i moved up from like a gutless inline 6 to a flathead v8. It took making the motor mount holes ugly ovals, and a little file work on the skid mounts, and taking a ridge off the side of the trans.
    Reference for later regearing Stock pinion is 14t, to 61t spur. not sure about 3 gears in trans. Axles are 14t pinion, 38t ring

    I also picked up a delrin cutting board to use as spacers for a t-case drop.

    Power and speed are up, and the driveshafts run a little smoother. I still need to redo the wheel adapter bushings, but it's getting better to drive.

    Little while later i got some light mounts, a trailer hitch made

    Then I ran across an rc demolition derby video on youtube that mentioned Traxxas 7378 rims/tires. Its 1/16 scale stock car racetruck steelies, they look like around 15" rims with fake tire sidewall. 12mm hex, 1 inch / 24 mm wide, use 1.9 tires, 2.5" tall tires. Yellow letter goodyear tire sidewall.. uses 24 / 26 mm tires from the buggy or rally cars.
    7377 is bare rims.

    Traxxas 7378 wheels, smoother running and not 1960s hard plastic. But not sure they're heavy duty looking enough. Plus i miss the white walls
    Black rims look bad, and should feel bad.

    Heres the new rims with some color on them. Argent, like rims should be if it's not a steelie or chrome.

    The t-case drop is pretty visable, but i'm not ready to make a custom frame. It's lower so the drivelines are smoother.

    It's still fun to play with your toys with someone else.

    Didn't get any great pics there, but it was kinda fun dragging around my 1970s tonka sandloader trailer.

    Structo hydraulic dumper and Tonka sandloader. I've still got too much lift.

    It's not a Tonka, THAT'S a Tonka truck.

    I was planning to use a figreli / actuonix actuator for the main lift ram.
    My bed is 5.20"w by 7"L by 2.5"h. Hinge is 1.5" fwd of the gate, ram attach 2.25" fwd of gate. Original 'hydraulic' ram is an oil damped spring 100mm open, 80 closed, 20mm travel. (Eww, metric) I'm open to suggestions of better ways to do it.
    L12- 30mm ranges mount hole lengths from 82 to 112mm
    So i'm thinking i need an L12r-30-210, or L12r-30-100. Not sure if the 100 or 210 ratio speed would fit this look better?
    Or there was talk of an L16-30 becoming available and only 14mm longer than the L12-30-. Not listed on their site.

    Scrapwood mock up, not just cardboard!

    Then realized i really ment 82-112 for the travel holes instead of 80-100 pictured, so i remade it, and in theory full lift can actually go just past vertical. That won't be the end of the world, it can be stopped where ever.

    My first operator didn't like the rig and wanted to run other equipment, so we hired this guy instead. So far he's really enjoying the chance co work, even if it's an old truck and isn't complaining about not having new stuff.

  3. #3
    Join Date
    Nov 2017
    pineapple under the sea


    the tamiya kits that were 300$ years ago now are 500$

    add the mandatory lesu parts and you are up to 1000.

  4. #4
    Join Date
    Aug 2019


    Yeah, that was a fairly large part of trying to make my own. Plus i liked steel with real weathering, running something very uncommon, and i enjoy the challenge of trying to make it work. Kits would be so much faster and easier though.

    Forgot to mention my first operator really didn't like the rig and wanted to run other equipment. He was taking night classes and all that. Little bit of a dramatic way to go.
    'I quit, and i'm going that way.'

    Let's actually do some work for once

    What's the absolute coolest trailer you can ever stick behind a dumptruck?

    Alright, nice!
    This 1950-1954 Doepke 'Unit 357 Crane' has been hanging out in my garage for a while, but I keep (lying to myself) saying I'm not going to start yet *another* project until something is "finished". I built a brass towbar and a sleeve to connect the stock short little Doepke towbar to my hitch. Slide the joggle bar through the hole, slide sleeve over both to lock the bars rigid. It at least tracks better than the video of TheStuffz crane behind his truck with a rope.
    Tire changes are hard at this scale...

    I really liked the hubcap over real rims idea. A rare earth magnet is stuck to the inside of cap, which holds it to the lug nut. The cap amazingly comes to the edge of my rim, with the fake sidewall left exposed.

    Version 1 of DUMPtruck! Not just a truck that looks like it should dump. I'm running a used Figreli L12-30-100-12S, and i'm feeding it off an old servo board with no feedback so it holds any position. I'm not sure if it's got enough torque.

    My driver got a magnetic implant, with a magnet between his back and seat, and another on back side of the seat. Now it doesn't matter as much that this has vinyl seats, doesn't have seatbelts, and rides like a dumptruck

    I learned that if you're towing a mobile crane, you need a way to secure the outriggers up. Also make sure your sandloader chute handle is over center so that doesn't drop.

    Also threw this together in a hurry for the meet. Nylint steel trailer.

    Woodsman trailer is full of scale 16 inch log rounds and splits, with a Polaris Sportsman 850 AWD strapped down. Drop the trailer, pull the straps, and the quad could be hooked up to the front. Add a rider and a chainsaw, you're ready to get more firewood. Quad might go real rc later

    Tamiya rally block tires, sp-476 or 50476 on the Traxxas steelies.

    I felt like knocking together a little brass trailer. Kinda based on the old single axle car haulers. Good for baby excvators, skidsteers, shipping containers...

    Drop hitch to level it out

    By swapping out drop, level, or rise hitches it can go behind this, my vw van, and my vw truck

    Somehow the jackscrew gearmotor hasnt magically become the next variant of bed lift yet. Good thing it's dumpy looking, the bed really isn't that dumpy.

  5. #5
    Join Date
    Aug 2019


    I may have been complaining for a while that my "Tonka Sandloader" doesn't really work as a loader for my dump since they won't reach the bed on my lifted Structo, and it's really only useful to the truck as a trailer that's really hard to back up.
    They kinda work on the 'no tailgate' style dumptrucks, like the orange one i don't have rc converted. Plus you probably aren't going to move that much material with one, the bulldozer tracks these are based around only have 0.200" tall scooping paddles.

    So something bigger. I like OLD stuff that you can see doing stuff and things when its working.

    Careful mr bruder, this was built before safety warnings so there is no sticker to say there aren't safety stickers. "Don't stupid". "No dumb here". "The entire thing is a crush point". "This WILL kill you, and it will hurt the entire time". Yeah, maybe it's better the new stuff has less cool things to watch working, whatever.

    I tracked down a 1946 Doepkey #2001 Barber-Greene Bucket Loading Elevator. Little rough and needed some work, but not too bad for being 74 years old. The real question is how it'll do in crumb rubber?

    But seriously what is it?

    I know at the meets and shows we always have Excavators and Wheelloaders loading trucks, or maybe Bulldozers feeding Conveyors up to a Hopper that can load trucks...

    I think it's always interesting to look back at the older ways of doing something.

    It's quicker to load truck than using my Dragline. Now i've got to work out how to power and control it so everything is hidden or looks right
    1955 Nylint Michigan T-24 crane rc conversion
    Last edited by Frizzen; 04-23-2020 at 07:31 PM. Reason: Moar!!!

  6. #6
    Join Date
    Dec 2017


    This is very fun.

  7. #7
    Join Date
    Mar 2020


    Those are really cool rigs.

  8. #8
    Join Date
    Aug 2019


    Going on the popularity so far, I didn't think this other model was worth starting another thread about

    So on my Barber-Greene model 82-A tracked Bucket Elevator, first i made the missing things poorly out of brass, and got everything i could mostly straightened and back to smooth running.

    Since the stock crank had a 5 tooth cog, i ordered a set of replica 5 tooth 'small chain idlers' for the machine from a toy parts dude on ebay.
    After cleaning up the parts, i soldered a brass shaft into that gear, made flats on other end of shaft to take setscrews in motor coupler. Opened up a 3mm motor coupler to fit the new shaft and gearbox outputs.

    Current gearmotor labeled as
    Jf-310 12v dc, shenzehn jinlu motor co ltd

    Shorter motor i'm also considering
    20ga130d012 , dc 12v , 200rpm

    Since i only care about turning 1 channel on and off, and i don't mind single speed operation, i wired up a 1a (700mah running) "Mini Relay Wireless Switch 12V 433Mhz Remote Control Relay Switch, Secure 1-Channel Micro Receiver with Transmitter System in Latched Mode DC 3.7V 5V 6V 7V 9V 12V" --- ugh, with a name like that, you know it's some of the finest the finest Chinesieum from amazon.

    To run the motor & rx off the same power supply the wiring is a little different
    Red, Yellow to Deans +
    Black, New wire to Deans -
    Blue to Motor
    New wire to motor

    Motor runs off of Normal Open and Com relay pins
    Red A button turn on, Grey B button off

    Then made a motor mount that's basically "this is only temporary, unless it works"... If i can find the hardware, i've got plans to make it better.

    Which brings it to about here

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts