1/16 Scale FrankenDiff

[ddmckee54]

I'm going to be doing several Bruder conversions in the near future, since I'm retiring next week. I don't have the skill to scratch build, and I like the idea of using the Bruder stuff as a starting point. Bruder at 1/16 scale really doesn't look right when you use 1/14 scale running gear, plus the cost of the running gear is more than I'm willing to spend.

Soooo... my wandering mind latched onto the idea of Frankensteining a reasonable looking truck rear end out of other available low-cost bits. I probably got the idea from "mick thebass" on YouTube when he modified a couple of low-buck 1/12 scale WPL diffs and used them on his articulated Bruder dumper. He did some really neat stuff if you haven't checked him out. He hasn't updated his channel for a couple of years so I'm afraid he might not be with us anymore - which is too bad. The guy was a master at stuffing 10 pounds into a 5 pound sack.

I thought about using the Kong 1/12 scale diff, even got one to see if it'd work. It's a GREAT looking axle, smooth as silk, about the right size, and the price isn't too bad. But as far as I know they only make the rear axle version, they don't make a center axle version. I don't know about you guys, but the thought of building a truck that's SUPPOSED to have double drivers, and then having one axle sitting there doing nothing doesn't appeal to me.

So, back to the Frankendiff. I'm starting with your basic plastic diff for a WPL 1/12 scale car, it's guts are about the same size as the Kong axle. The actual axles will need to be shortened, but that'll be fairly simple machining to cut them to length, turn down the ends, thread them M4, and drill new holes for the drive pins. I'm just going leave it an open diff for now, no lockers.

Nope, the complicated part is the 3D modelling of the front and rear halves of the differential housing so that the WPL guts will fit into them. (While simultaneously learning Alibre, I use-ta-use Designspark3D.) The pinion housing is the most complicated part and I re-did that last night - I was NOT happy with the first attempt. I think I should be able to get the rear cover done tonight, it's pretty simple.

Then I'll 3D print a prototype and see what parts need to be fixed. I'll take some pictures when I've got some physical parts.

Eventually I'd like to cast the parts in ZA-12, both for durability and the extra weight. (But plastic will do for now.)