A printable drivetrain for a Willys MB Jeep. It's fully printable, no donor car needed. The axles fit between frame and suspension leaves and the drive shaft is on the right side, giving it a very realistic appearance.
It has, however, a few limitations:
-Designed for a N20 gear motor (not only slow, but also very low power). Forget jumps and hill climbs with this motor.
-The turn radius is really big, like the original thing.
-It has no differentials, it's permanent all wheel drive
-Rims need to be glued to the axles, might have unbalanced wheels
That said, it gives a working car, and replacing the current gearbox with a bigger motor is on my to-do list. As you can see the frame mounting is not perfectly designed, as I plan to change the ossum frame to a U-profile frame - for weight and stability.
Prints fine in ABS, and should go with PETG, too. PLA it too brittle most likely.
I printed all parts in ABS, except for the suspension that I printed in PETG. All parts are oriented the best way to print. The hollow housings need a lot of support but no cleaning post-printing on the inside - which can be a pain with these small details.
A list of all needed parts:
- 1 servo: SG90 9g
- 1 motor: N20 gear motor
- 14 bearings: MR84 (8mm outer diameter, 3mm width, 4mm inner diameter)
7 for the front axle
2 for the gearbox
5 for the rear axle
- 33 screws: M2x10 (normal head, not 'flat head/counter sunk')
12 for the suspension
8 for the front axle
4 for the gearbox
8 for the rear axle
1 for the servo horn/steering
- 33 nuts: M2
- 6 pins: 2x10 (2mm diameter, 10mm length)
3 for the front axle
2 for the gearbox
1 for the rear axle
- copper/steel: 1.5x15 (1.5mm diameter, 15mm length (source: cable))
(steering, bend it)
-4x steel wire: 0.8x10 (0.8mm diameter, 10mm length (source: garden wire))
(clamp the axles to the suspension leaves)
Body, chassis and more: By ossum (look at remix source)
Body tub: By Anarchy3D 'Body (Ultra Realistic Ossum Jeep Remix)', the gearbox fits there
Rims and tyres: Originally by bre4, I used my own mod here (look at remix source)
Front bumper: my mod
Rear bumper: By Intashu (look at remix source)
Bending of a copper or steel wire for steering: I should add a proper picture, but I'll do it with ASCII for now:
The topmost ends go though the holes in the steering blocks, the horizontal part should be below the hinges to avoid collisions with the suspension, and somewhere in the middle is a loop that is just wide enough to allow a M2 screw to fit in between.
The servo horn will have a M2 screw secured with a nut.
Upon moving the servo this screw moves in a circular path, resulting in up- and down-movement in said loop, and horizontal moving to the left and right, steering the wheels.
There's no servo saver, but at the current vehicle speed a servo with plastic gears is just fine.
Mount the leaves to the brackets, and glue the brackets to the frame, at the place the original brackets would go. You should see the original mounting holes on both sides of the brackets partly. When dried remove the leaves again to mount them to the axle.
Put the axle upside-down, with the flat sides on top, and put a suspension leaf on one side, with the ends hanging down. Then take a wire, bend it to a U-shape, as wide as the leaf. Put it on the leaf, bend the two ends around the axle in a U-shape coming up to the leaf on the other side of the axle. Then twist(*) the ends above the leaf gently with pliers and you're done. Repeat it on the other side, and on the other axle and then mount it back to the brackets on the frame again.
(*): Don't twist too hard, as twisted wire can create very strong forces. And you don't want a tight fit, as some play is necessary to allow different compression on every side.