MOC-WIP Flatbed Truck w/ Piggy-back Forklift

[Countdown]

Hi all,

First large-scale MOC-WIP, this is the first iteration of my design exercise.

This project started a while ago with my fascination with 3 section booms; how they worked and their capacities etc... With some research around the interwebs and after a couple of trial builds found out that most of them are gravity "retracted" using strings. I tried to find an another way to make a 3 section boom using a "loop" of chain links ( Brickshelf ). With that not-so-easy project, one of the by-product I found out that a 3 section boom has tension extending and retracting. On the same day I saw one of those flatbed with a piggy back forklift. There you go, here's the result.

note: i cheated on this pic, forklift is held up by a liftarm at the back; more explanation further down.

Flatbed is inspired by the 8264-B but supersized. Geometry for the tilting platform was a real pain, a lot of trials and errors.

Flatbed:

Length : 69 studs

Width : 27 studs

Platform : 45L x 27W

1 PF-XL (drive)

2 PF-M (platform + steering)

Picture of the coupling system

Forklift:

Length : 26studs (+11 Forks)

Width : 23studs

Height : 27->43

Forks reach : -2 -> 32

3 PF-M

1 PF-XL

Basically it's the 3 section lifting geometry of the 8416, modified to use lego chains to achieve "self-lifting" on the back of the flatbed. It works in theory, and in practice, it needs a little help. But there's way too much flexing and tolerances in the boom to work really nicely.

Conclusion:

Not very pretty, but the principles work,

Upcoming design upgrades:

Flatbed:

1- double LAs and motors to tilt the platform

2- gearing down of the direction

3- widening of the "tracks" for the coupling system

4- truck cab

5- adding winch on platform

Forklift:

1- reducing weight

2- change PF-M to XL on lifting mechanism

3- double the chainlinks

4- reducing flex in boom mechanism

5- moving the tilting LAs 2 studs back

6- improve steering mechanism

Other Pics: Brickshelf Folder

-Nick

[DLuders]

Your TECHNIC flatbed and foklift are a good set. I know that it must have been awkward to design the chainlink lifting mechanism. I've always wondered whether one could use mimic the large links used for forklifts and for Genie-brand manlifts in the USA. I like the fact that Linear Actuators have been used on both of your MOCs.