1:10ish scratch forklift

[dremu]

(NB: if you don't see pictures, check out post 16 below )

Not exactly "Construction Equipment" but I didn't see a category for "Materials Handling"

Had more free time lately, so I figured I'd liven things up a bit here and do up some picture threads of my builds vs actually building. Might give ideas to the next guy, might stimulate discussion for good ideas to change up this build or for the next one.

Bit of background: I've been building things of many sizes for years, ranging from scale models to RC vehicles to a 1.5ton ride-on backhoe with working hydraulics. I hate hydraulic fluid.

One recent build was a 1:10 military cargo truck; see its build thread @ https://rctruckandconstruction.com/s...d.php?p=170548 . The trailer cargo and pallets were begging for a matching way to load and unload, so this came to be. Scale on this one is decidedly fungible for two reasons. First, it's not based on any specific 1:1 model. Second, the thing had to *work*, so some parts may be off out of necessity to fit the mechanical components required.

As always, the thing is first drawn up in CAD to ensure that the various pieces will all fit together, and to start planning which pieces can be fabbed and which are to be 3D printed.



and a view through X-ray goggles:



The drivetrain isn't really exciting; the front axle is left over from the green truck, driven by a continuous rotation (sail / winch) servo. There's no steering linkage; the rear tire is skinny and is turned directly by a regular servo.

It's also pretty simple electronically. Since the drive motor is a servo, it doesn't need an ESC; there's just a BEC for the lighting and most everything else runs off the RX.

The fun part -- and I say "fun" with some sarcasm, as it's bloody complicated and a headache to get all the pieces to interleave -- is the lift mechanism up front. I can't entirely take credit for this, got a lot of inspiration from someone else, I think a thread on the now-defunct scale4x4.org.

Anyway, there's a set of bearings riding inside aluminum C-channel, and that gets moved up and down by a set of linear actuators.



However, that alone doesn't give enough range to get the fork tines from the ground to high enough to clear the trailer bed. Therefore, there's a second set of bearings-channel inside, which is driven on a toothed belt.



Belt is on left side here; note brass tubes to give it more coverage around the gear's circumference. If it's just angled, you get like 60* around the gear and it slips; this way you get like 120* and it drives pretty well. Still has to remain tight, but there's tension clamps at the ends.

Another winch servo at the back has a gear which drives that belt (the blue one at the back here)



and lifts the center section up and down within the inner channels.

The front servo there is yet another winch servo that goes side-to-side. It has a pinion gear that drives a rack on the carriage to shift it side-to-side.



This has the carriage moved aside to see the rack gear (orange); obviously when glued together the carriage is actually centered on it.



Finally, that whole thing is hinged forward of the front axle to allow the tines to tilt up and down. This is driven by another shorter set of linear actuators.



The net result is as thus:



The body shell is mostly just styrene sheet; the quarter rounded corners are 3D printed. The ROPS, wheels and steering wheel are printed, but the dashboard and seat are sheet with square stock down the sides for strength. Big fan of Evergreen

Dashboard is various size washers painted and glued in place; again, greebling
not being my strong point. It's "representative", as I like to say, not "accurate"

Here's some videos taken from what I just discovered is a bad camera angle. Can't really see the front, though maybe that's a good thing as I'm not a particuarly good forklift operator. Using these little machines definitely gives you respect for the people who use the 1:1's.

https://youtu.be/QpjHqdb1sfc

https://youtu.be/2Ne4LAuIG-w

https://youtu.be/dkTAxT0vWmo