A SuperClod rises from the ashes

[killbucket]

The day the SuperClodbuster hit the shop, I bought one. Anybody remember how long ago that was?
I never even put the stock frame together, it's history. I had made an aluminum frame for it, and it weighed a freaking ton.
Add a 14.4 volt speed control, and impacts were noteworthy. Just glad I never ran over any children...who seemed to materialize from nowhere at the sound of the thing. And it ate batteries like candy.

So I decided to rebuild the dust-covered old girl, with an eye on a lightweight assembly.
The 7" tall tires are from a NewBright GMC Yukon (RIP), I made the rims from ABS pipe and CNC'd .125" ABS sheet.

The lower chassis is symmetrical, all four corners are identical. I've always wanted to do a cobweb frame, here it is.
Note the coat-hanger wire, and lack of a lower chassis lug. This is a work in progress.

There are only four Traxxas Revo 8-32 rod ends in the whole suspension. When the suspension is at full compression, the kingpins are dead vertical.
Theoretically, this would be when having the tire on top of a rock, when caster would interfere with control (theoretically!).

The axles rotate in the lower forks, similar to the stock layout. Suspension loads are managed through the axle tubes, and not the kingpin mounts.
Pulling three screws allows axle removal, without pulling the tires!

I rotated the axles 90deg.
Note that the kingpins are in the proper orientation.
This is actually very simple to do. I had the cases open to lock up the diffs (epoxy putty), so I pulled the screws and rotated the gearboxes.
I've always hated how the stock motor location interferes with steering and proper suspension geometry.
This puts the motor right over the axle centerline, and allows the quick-release axle mountings.
There will be a short link from the top gearcase screw to the wishbone top, to keep the wishbone from rotating.

What you're looking at is ABS, not aluminum. Wheelbase is 14.25", width at outside of rims is 15". Overall height completed will be 14.31".
http://www.air-sharp.com/clodwidowframe.dxf
The dxf file, so you can make your own frame like this. Crossmembers are up to you, I didn't include them in the file, to spur some creativity.
The frame will work with normal link rod suspension.

[SMUDGEBUG]

HOLY CRAP thats alot of clod are those wheels cast as well ?

[cartronicshn]

, are those axles facing downwards?

[killbucket]

Everything is plastic of one type or another.

The rims are cut from sections of 3" ABS drain pipe, and lathed into shape. The ABS is pebble-grained on one side, so it gives the rim backs a cast look. They are painted with Bulldog adhesion promoter, and Rustoleum Hammered silver for plastics.
The rims are anything but round (egg-shaped pipe at best), and I don't care. On a real truck they don't usually stay straight, so I think it's just fine. I'm sure it will be a mess at higher speeds.

The axles have been each rotated 90 degrees away from the truck center.
This does somewhat compromise the clearance, but the mondo tires make up for it. I had to trim off the little index nubs on the axle flanges, but otherwise it was a breeze.
I just added the wishbones to the dxf...

This isn't a race machine, or a competition crawler. It's serving as a test bed for making parts on the CNC (This thing existed only as a drawing this morning!).

[killbucket]

A better look at the front driver side parts. It would take a smack and a half to break this axle now.

A top view of the parts all mocked up, note the lack of tie rods.
Speaking of which, one carrier has the tie rod mount broken, so I'm going to CAD up a set of beefy arms to bond over the stockers. I'll make them a bit longer than stock, so they give a bit more leverage to the servo.

Still to come is a battery/servo mount. I'm going to lock the rear hubs straight. I've never built a 4WS truck, I've never liked the odd movement. A mount will go on the back anyway, so I can put the second battery pack there. The batteries will be mounted like bumpers/puller weights, horizontally across the axles.

The speed control will mount on one of the angled plates in the middle of the frame lower.

[tuner]

That is pretty cool. Is there any sway or movement in the suspention? or is it pretty solid?

[ADDICT]

wow... any weight in the rims? lol j/k looks like it could kill someone if you ran over them. Looks like a great build so far. Im likin the body.

[killbucket]

I'll probably put airsoft BB's inside the tires, which are actually very thin and light for their size.
Stepping on a scale with it, it adds exactly 7Lbs to my own weight as of now.

As far as slop, the only area is the upper a-arm mountings. I'll likely add bronze bushings to these to tighten them up.

The lower a-arms have forks that snugly encircle the axle tubes. At 1/4" thick, it will be a long time before they develop any appreciable slop.

Each end of the truck uses just two rod ends, and I went with the beefy Revo parts there.

Side-to side sway with this suspension is atrocious (this is the fifth or sixth version of this design I've assembled). I'll just be using this as a yard toy, so I won't be adding swaybars.

What is neat about this layout, is the "reverse-skateboard" steering effect at speed. Because the rod ends work together to create an angled roll center (like a skateboard steers), so when the body leans outward in a curve, the axle is forced to pivot slightly against the turn.
Result? Easy four-wheel drifts!

[killbucket]

Drew up the shock mounts, and the battery brackets.
Steering is going to be...different.
EDIT: .dxf updated, a-arms added, battery brackets, shock mounts, CAD of axle ends.

[rcktpwrd]

Now that is different!

It look pretty cool!

[killbucket]

Thanks!
The CAD file says it should be 14.31". In the mockup, it was 14.10"
I added bushings to the upper A-frame mounts.
It's 14.312" exactly now.

The shock mounts and battery brackets are on, now to address steering and the rear lock-out.

I'm making beefy tabs to lock the rear wheels straight, they will key into the kingpin mts' left-to-right stops. They will be bonded to the steering blocks permanently.

Steering will use custom arms, the stockers are all going to be trimmed off completely. The fronts wheels will link together with a thick tie rod, and the servo will link to one side only. I'm going to make my own servo-saver for this as well.

Pics to follow.

[Warn Off Road]

Nice! but man with that much work in it already, a 4 door body would set it off!

[killbucket]

GOOD POINT.

I've been looking at how people extend the Tamiya ABS bodies.
So much work results in cracked paint work, seen this too many times.
I have a "Top Secret" method for bonding stuff like this...but no time to make such goodies. An off-the shelf body might be OK.

I personally like the old ClodBod, having been around when the first ones hit the shelf with full Chevy badging.

[killbucket]

It can climb over the tools that helped make it!


My upper bushing mount setup. The bushing floats in both holes, once the hardware is in place, it's nice and solid. Note the lower suspension mount now in place, the black plastic chunk at the frame bottom.
Is my preference for cheap tools showing? Harbor Freight!

Fresh goodies out of the Shopbot. The dogbones will link from the top of the bumper mount/battery bracket (top left). One of my shock mounts looked a bit weak, so I whipped up four thicker ones. and finally, a cleaner looking set of bumpers.


Ugly chunks of plastic bonded on got me through a shake-down test.
I'm ashamed I made this decision, analyzing the carnage, even fuzzy math says this was wrong to do.
When the axles torqued in their mounts, all the force was concentrated on this one screw. With normal tires, it would have taken some time for this weakness to surface.

By the way, the tires work pretty good for yard bashing. The thick lugs make up for the slippery plastic, ex-medical waste they are probably made of. I can climb over stuff I used to go around.

This REALLY needs lathe motors now.

I'm designing a full-on crawler. I realize this project is hopelessly old-school...


Fresh-cut parts. Like having my own model comapany!
actually, I have my own airsoft gun company at www.air-sharp.com

[killbucket]

..before anybody wretches, that's a latex GLOVE in the background...

[killbucket]