The ‘Green Meanie’ Wheel Loader

On 10 August 2025 Emanuel wrote:

Hi Robin. I am very much impressed by your Green Meanie Wheel Loader. Is it built with a special kind of Meccano parts? In my eyes the parts of the mover differ from the parts of all other models (being of a higher engineering level). Can such parts be bought? Where?

On 11 August 2025 Robin Schoolar wrote:

I’m always happy to answer a question as excellent as Emanuel’s … all the more so when he also says such nice things about my model.

The overwhelming majority of parts in Green Meanie are standard Meccano parts, as one of my objectives was to see how far I could take the model while keeping within the Meccano system.

The most obvious non-Meccano items are the tyres, which incidentally I was happy to change once I obtained the better looking tyres which can be seen in the video lasting 2m53. These are solid rubber Dunlop Trakgrip tyres, a little over 17cm diameter. They are over 40 years old, and these days are quite difficult to find.

The radio control system with its lead acid battery isn’t Meccano (but I made sure the aerial and its resilient mounting are all Meccano parts). Radio control systems with six or more channels are readily obtained from many manufacturers. The electronic speed controllers interfacing radio control to motors are Marine Viper 10 from MTroniks, which I would recommend very highly (NB I have no commercial connection for any items I recommend).

The lighting system is all my own creation, so not Meccano — but the translucent red and amber cylinders the lighting shines through ARE genuine Meccano parts (part A545) from Junior outfits. These parts in translucent colours are not common, but can be obtained if you hunt with enough determination.

Less obviously non-Meccano (because they are inside) are all nine motors. I don’t know of any source for identical motors, but the important ones are broadly equivalent to decent quality ‘can motors’ with ferrite magnets 35–40mm diameter. e.g. RS-550.

The non-Meccano cord which makes the four rams work is extra strong. Bought via Amazon with brand Ashconfish, at 0.8mm diameter, I am very impressed that it seems to live up to the claimed load of about 100kg. The rams would work with Meccano cord, but it would break almost immediately under the loads with this model operating.

All 94 gears in the model are genuine Meccano, apart from four which transmit the final drive to the wheels. These started off as genuine 2½” gears made by Meccano (part 27c) in yellow plastic, but I removed the central brass bush and the plastic toothed disc then bored out to 3/8” diameter. These run on large diameter axles which are entirely Meccano, notably the Elektrikit Core for Cylindrical Coil (part 528). The shafts on which the gears run are all standard Meccano Axle Rods, and I did not file flats on them. However I did find that Meccano grub screws 69a had to be the type with hexagon socket (https://www.meccanoindex.co.uk/Misc/setsearch2.php? Oover=2&Opart1=69&Opart2=a&Col=zn&Mat=ps&id=1754866178) so that I could tighten sufficiently to prevent gears slipping on their axles under load.

The final non-Meccano content is one or two thousand small washers, which I use under every bolt and nut to protect painted parts.

Everything else in the model really is genuine Meccano, all in original colours — I don’t repaint parts, primarily because obtaining a good enough paint finish would take too much time which I don’t have.

Some photos of Green Meanie show non-Meccano universal joints for the centre articulation of the model, but comparatively recently I found a way replace these with built up joints made entirely from Meccano, which do the job at least as well.

The other vital ingredients are persistence (much of it was built many times over, as I replaced designs which didn’t work with something better) and time (over two years construction before it worked at all; then improvements so it breaks down less frequently which have taken a further three years … more work on that still needed). Prior experience with Meccano probably helped a lot — I’ve been actively building with Meccano for over six decades.

I will not be writing building instructions for it. Not only would that take too long, but I would guess that anyone skilled enough to follow such instructions is most likely able to build a better model than mine without instructions.

If you’d like to know more about Green Meanie, there’s a lot more detail and information, including many large high quality colour photos in my eight page article in this magazine: https://www.constructorquarterly.com/pmwiki.php? n=CQ.147

The magazine is expensive … but the Editor takes huge pride in the highest standard photography and printing, which can’t come cheap, especially given the magazine’s comparatively few subscribers.

Have fun with Meccano, and remember that the best fun is solving finding your own way to solve problems you encounter.