The ‘Green Meanie’ Wheel Loader
Built by Robin Schoolar in September 2020
In the construction business these machines are known as ‘Wheel Loaders’.
Mine is essentially freelance, necessarily so in order to incorporate all the weird and wacky ideas I wanted to try… but I have shamelessly borrowed random features that I found appealing from motley real machines.
I liked the rugged simplicity of this type of earthmover, but even though the model is significantly larger that I originally hoped, now that all features I wanted have been shoehorned in, it has far too much complexity in far too little space. Something is bound to break before end of day, and repair is typically impractical until it’s back home.
Outline statistics
- Structure and mechanism is all Meccano in original colours (I don’t have time for repainting) — except the black non-Meccano washers under every bolt and every nut
- Lots of gearing, all standard Meccano apart from final drive gears with enlarged centre holes and two 13-tooth ‘compatible’ pinions
- Five heretical universal joints for central articulation
- All gears are fixed to standard Meccano Axles using standard Meccano Hex Socket Grub Screws, with no flats on axles, no Loctite
- Four 7” diameter solid rubber tyres (on loan from a wonderfully obliging Meccano friend), mounted on 100% Meccano hubs
- Heavy duty axles are 100% Meccano parts (lots of cylindrical cores!)
- Four rams operated by triple sheave cords, all double-acting
- Cord is 250lb braided fishing line (but looks uncannily like green Meccano cord!)
- Four lift motors, two drive motors, one steering motor, two auxiliary motors
- 6 radio control channels in use (40Mhz, all electronic speed controls — no servos)
- Aerial mounting with built in strain relief (100% Meccano!)
- 6 limit switches all in Meccano parts, 8 non-Meccano limit switches
- Brakelights, Reversing lights, Indicators, animated by homebrew electronics
- Several rats’ nests of wiring and too many connectors
- 12V 9Ah lead acid battery
- Running weight: 20kg / 44lb
- Two decades in dreaming, two years in building, twelve months (still counting) trying to improve reliability
There is an article on this model in the June 2020 issue of the Runnymede Meccano Guild Magazine.