Oshkosh 6x6 truck build

[wibblywobbly]

I decided to do something other than build another tank (I haven't got room for any more - should really sell a couple), so took a look at the trucks. I used to have a rock crawler, and also had a 4x4 Dakar truck, but always hankered after a good rock crawling scale truck.

After much searching around on truck forums I came across this. It has it plus points, it also has its minus points but overall it was what I wanted for use as a base. A quick chat with Simon, and knowing some of the horror stories about customs charges and missing parcels, I decided to buy through him as he had a couple in stock. I still hanker after one of the high end trucks that he sells (there is a huge difference in quality, running gear etc), maybe I will raid the pension fund next year?



It all comes pre-assembled RTR, so I had to strip off all of the parts that I didn't want.

and shortened the chassis.

The wheels weren't what I wanted but the manufacturer seems to have used a non standard combo of wheels and tyres, which suit the truck, but means you can't buy truck style wheels for it, so off to Openscad it was and I test printed some front and rear one piece hubs and locking rings.

The printer then decides to have a 'I am going to loosen a wire that Rob won't find' moment. Two days of head scratching, forum searching and prodding around, and I got it going again. It printed the front hub but much better quality than the rears...and then died again. I have now ordered a complete set of plugs for the Ramps board which is where the dodgy connection is.

I have redesigned the hubs slightly, and once the new wiring is here I can print all six so that they don't look like they were carved with a badly worn spoon.

I am actually aiming for a 6x6 version of this...but it's going to take a lot of building in 1/10..the styrene sheets are huge.

Oshkosh.jpg (38.08 KiB) Viewed 19364 times

More updates when I can make some progress!

Rob

[AlwynTurner]

Hi Rob, these look closer to the truck wheels, don't knowif this helps
https://grabcad.com/library/1-9-x-108mm ... -crawler-1
Good luck with the build it looks really interesting!
ALwyn

[Bogeyman]

Very nice Rob, will be following the build as always.

John

[Ecam]

Am fascinated with what is able to be done with a printer. Will be following along with this one.

[PainlessWolf]

Good evening, sir,
You should get another one of those chassis and use your printer to build the Mercedes G4 body to go on it. I would definitely buy one of those. ;o)
Happy Holidays!
Painless

[971wright]

Hi Rob Nice looking truck ,at least you can sell the body on e-bay (take the spare off first) I'm saving pennies to buy the 8x8 from Simon will drop your name and see if there is a discount LOL.

regards pete

[wibblywobbly]

I already have a buyer for all of the bits that I have removed, so that is a bonus.

After replacing every one of the plugs on the printer pcb, which took hours of soldering and routing cables, and then checking the backs of the boards with a magnifying glass, I re-assembled everything and it was still shutting down if I tried to print when the printer was still warm, which meant waiting an hour between prints. Last night I noticed that one of the heatsinks is loose, I bent it across a shade and the printer works perfectly again now. Grrr! I will wait until I have completed all of the printing that I need to do, take the pcb out and resolder the legs, it should be as right as rain then.

Ok, I modified my wheel hubs, and got them all printed, they take 1.5 hours each, but they came out quite nicely. I drilled a sheet of 3mm alloy to slot over the body mounts, this has stiffened up the chassis totally, so no more flex. I am currently printing the framework for the cab, this will be surfaced with styrene as this will give a much better finish than 3D printed surfaces ever will.

[AlwynTurner]

Great looking model Rob, will continue to follow. Alwyn

[wibblywobbly]

Printed one side of the cab yesterday, went to print the other and the printer stopped again. Looks like its the voltage regulator that has blown on the Arduino board, a common fault apparently. I am now waiting to hear back from the company (in Italy) as it is still under warranty.It's either that or buy a new VR (28p) and solder it on, or buy a Chinese Arduino for a lot less than a genuine one would cost. It's a pain as I can't do the cab until I have printed the other side.

The rear is styrene so I might make a start on that instead.

[wibblywobbly]

Decided to order a new Arduino board and a Ramps board for the printer, meanwhile, I have spent some time checking what will fit and where on the cab and bed. The flat surfaces will be replaced with styrene, the holes in the cab side are where shaped 2mm styrene will sit.

Need to design a crane for the shelf on the back of the bed.

The size of the truck is 230mm x 600mm, so it's quite big.