Everything can be printed in PLA.
Most pieces will be fine with 25% infill and 2 perimeters.
I would increase infill and perimeters on the rims, front axle, gearbox, bottom axle/gearbox cover to make them heavier and sturdier.
Body_front and rear are the biggest parts. They require a printbed of 180mmx270mmx122mm(Z)
They easily fit on a Creality Cr-10.
EDIT 2022-05-06:
I've made a 4split of the body which allows you to print it on a 20x20cm bed.
It will require more work attaching it together but at least allows you to make it on a smaller printer.
It can be combined with the bigger body pieces if you have a printersize inbetween.
Look for the Truck_V4_Halftrack_4Split_ files.
Completed this vehicle measures almost 58cm/23" long, 19cm/8" tall and 19cm/8" wide. Roughly 1:10 scale.
I used these as electronics:
540 / 80T brushed motor(RC4WD has nice ones on ebay).
Brushed Esc to work with motor(I bought a noname on ebay, search for ESC Brushed contrller and you find a lot of different ones)
Flysky FS-GT3C remote(Look on ebay)
Generic 3s 4000mAh lipo battery
Standard size servo for front axle(any works).
This build requires a lot of hardware, I've tried to count them but the number might be a bit off so buy a few extra.
All screws are hexagon socket caphead unless otherwise noted.
Front bumper requires 6x M3x16 countersunk screws.
Front shockmounts require 1x M4x40 and 4x M3x25
Front suspension needs 1x 70-80mm RC shock and 2 balljoints to this, it also needs two generic rodends and some threaded rod between those ~40mm long. Also needs 2x M3x16.
Front axle linkages needs 8 rod ends and threaded rod between these. 3 of the rods are ~42mm and one is ~60mm, this depends on your rodends a bit. They will need a total of 16x M3x16 and 3x M3 nuts.
Front wheels need 4x 4x13x5mm bearings.
Steering linkage requires 2 more rodends and threaded rod, length will depend on your steering arm and rodends, mine is 60mm.
Servo requires 2x m4x20 fasteners.
Steeringbar requires 1x M3x25 and 1x M3x16
Steeringhubs requires 4x M3x16, 2x M4x20, 2x M4 nuts and 4x 4x13x5mm bearings. Printing tyres or buying Tamiya truck tyres is optional.
Body attaches with another 3x M3x16.
Framehalves bolt together with 2x M4x20, 2x M4 nuts and 4x M3x16.
Towhook attaches with 2x M4x20 and 2x M4 nuts.
Each side of track needs 5x M3x16,7x M4x40(needs to be trimmed to length if you're picky), 4x 10x15x4mm bearings and .
The gearbox requires 2x M3x25 for motormounts, 3x 5mm diameter shafts that are 59mm long, 6x 5x16x5mm bearings, 5 M3 nuts, 5x M3x10, 6x M3x16 between frame and gearbox housing
I think that should be it, so a total of:
5x M3x10
52x M3x16
7x M3x25
8x M3 nuts
8x M4x20
15x M4x40
4x M4 Nuts
3x 5mm rod, 59mm long.
1x 70-80mm RC shock.
8x 10x15x4mm bearing(usually called 6700zz)
20x 4x13x5mm bearing(usually called 624zz)
6x 5x16x5mm bearing(usually called 625zz)
The track pieces will also require some lengths of 1.75mm filament as hinges.