Newbie asks: departure angle vs. breakover angle
- Thread starter moroza
- Start date
Thanks! The 'Bud' of 'Budbuilt' is an engineer, and has put a fair bit of development into this crossmember. IMO it's probably stronger than the vehicle frame, which is made of somewhat thin materials. Many people have smashed rocks and stuff with these crossmembers without problems. 1/4" plate IIRC, and the bends add strength while keeping a low profile.
It is a LOT heavier than the stock rock-magnet crossmember. So from a weight perspective, the stock crossmember wins. And from a materials cost perspective, the stocker wins too. And it came with the truck, so the stocker is free (to you). But there's no way I would ever take the Budbuilt one off my truck. More clearance is one thing, it's also shaped in such a way as to avoid hanging up the truck. After putting that piece on, I never hung up the truck by the crossmember again.
Just a happy customer, no affiliation, yada yada. IMO just get one, they're awesome.
As for tires, 33x10.5x15 was the best size from a cost and fitment perspective. I fit mine on without lifting the vehicle. Just moved the axle forwards a bit, and modified all the steering links and also the torque-link. No need for suspension lift, or fender clearancing, or significantly reduced turning radius (tire rubbing frame when turned) etc.
Never really wanted to do an expo build on my pickup, just wanted to 'wheel the snot out of it. And gain enough driving experience and stuff with a low priced, low weight chassis (1550kg) so that when I finally do an expo build I will be better equipped to not get stuck. Or at least be able to get myself un-stuck in my 2500kg Landcruiser.
If you don't already have the chassis, I'd shop around for an extra cab with the 112" wb and put a regular cab onto it. Or since you're cutting out the rear of the cab, you could probably keep the extra-cab and work with that.
Good luck with your buildup! And post up some pictures when you work on it. Sounds like one heck of an interesting project.
moroza
New member
I've already got an '81 longbed. I'd like to hear more details about the axle relocation you did; I'll likely be doing something similar for engine swap purposes. Did you use the factory "extra hole" in the front leafs? Shortening the trac bar seems easy, but what'd you do for the drag link (assuming stock steering)?
moroza
New member
Alrighty, I've taken the answers to my original question seriously (and also gotten more nervous about stretching a frame that's not so strong to begin with), and redesigned my whole rig for a stock wheelbase and angled rear. Here's the .skp file for anyone who uses the (free) program Google SketchUp. Here're some more details:
Current plans are 3 inches of polyurethane or polyisocyanurate rigid boards all around, maybe more in the roof. Structural materials are mostly riveted aluminum, with some wood thrown in a few spots. For planning, I have it nominally as 2x1" beams, but actual pieces will depend on what I can find. It'd be great to come across a stash of broken aluminum ladders, and chop them up for beams.
The "stove" refers to either the smallest Ammocan stove, or something very similar of my own construction. I plan to use propane only for cooking, and diesel only for moving the vehicle.
Window shapes and positions are approximate; actual details will depend on what windows I salvage from something else. Really, that statement applies to everything in the design.
Walls materials and their thicknesses, inside to out:
3.2mm plywood (1/8) inside, except around stove, where it's cementboard and alu skinning
50.8mm alu and wood studs, insulation between them
25.4mm more insulation
0.6mm (0.019") alu skin on outside
floor:
15.9mm plywood (5/8)
50.8mm studs and insulation
25.4mm more insulation
0.6mm alu skin on outside (bottom)
roof:
3.2mm plywood (1/8) inside, except maybe around the stove
38.1mm insulation
50.8mm studs and more insulation
12.7mm (1/2) plywood
0.6mm or thicker alu skin on outside (top)
I couldn't find a 1st gen cab model, so I took a 3rd gen and fudged it to similar dimensions. The collection of stuff in front of the truck is a cutaway of the wall/floor joint, illustrating my positioning of the structural beams to avoid thermal bridging.
Er... how do I upload a .skp file? Here are screenshots in the meantime:
Current plans are 3 inches of polyurethane or polyisocyanurate rigid boards all around, maybe more in the roof. Structural materials are mostly riveted aluminum, with some wood thrown in a few spots. For planning, I have it nominally as 2x1" beams, but actual pieces will depend on what I can find. It'd be great to come across a stash of broken aluminum ladders, and chop them up for beams.
The "stove" refers to either the smallest Ammocan stove, or something very similar of my own construction. I plan to use propane only for cooking, and diesel only for moving the vehicle.
Window shapes and positions are approximate; actual details will depend on what windows I salvage from something else. Really, that statement applies to everything in the design.
Walls materials and their thicknesses, inside to out:
3.2mm plywood (1/8) inside, except around stove, where it's cementboard and alu skinning
50.8mm alu and wood studs, insulation between them
25.4mm more insulation
0.6mm (0.019") alu skin on outside
floor:
15.9mm plywood (5/8)
50.8mm studs and insulation
25.4mm more insulation
0.6mm alu skin on outside (bottom)
roof:
3.2mm plywood (1/8) inside, except maybe around the stove
38.1mm insulation
50.8mm studs and more insulation
12.7mm (1/2) plywood
0.6mm or thicker alu skin on outside (top)
I couldn't find a 1st gen cab model, so I took a 3rd gen and fudged it to similar dimensions. The collection of stuff in front of the truck is a cutaway of the wall/floor joint, illustrating my positioning of the structural beams to avoid thermal bridging.
Er... how do I upload a .skp file? Here are screenshots in the meantime:
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