Video! updated 7/17/05
This is a Kyosho Twinforce. I was impressed with the realistic solid axle design.
It was originally designed for speed with 2 motors. I have it powered by a Black & Decker cordless drill motor/transmission. The transmission uses 2 stacked planetary reduction gearsets for a very useable crawl ratio. The output shaft has been machined down to fit the chain gear and the original spur gear support bearing. A little JB-weld and it's crawl time!
I'll eventually build a tube/link chassis but I'm having pretty much fun as is. One arm on each end has been wristed, springs trimmed, relocated shocks, locked the diffs, and did some tire cutting. That's it!
Here you can see the lesson learned when you wrist your radius arms. The screws going in deeper wore a groove in the shaft until it snapped. oops
And the repair. 1/4" brake line and some gentle mig work and shorter screws.
The rear arms extended.
And some new steering including a custom arm. The caster has been rotated to zero, I think it steers on the rocks better this way. (who needs high speed stability on a krawler)
Extending the rear radius arms ended up being a bad idea. Anti-squat was terrible.
The upper link.
The new axle trusses with servo mounts.
Steering arm detail.
Playing with excessive flex.
Bead locks: That's a 3" SCH40 PVC pipe coupler I used as material for the inner bead rings, the inside diameter is perfect. The lock rings are plastic (inner) and aluminum (outer) 'cause that's what I had laying around. These now fit 40series.
Shots as it starts to look like something. You can see the monoshock/swaybar setup.
Obligatory flex shots.
Revo shafts and adapters.
The mono-shock setup was scrapped, too much antisquat. (again with the antisquat) (Antisquat: Rear of rig lifts and the axle is trying to drive under it. This raises the center of gravity and increases the potential for rollover.) So I decided since I don't ride in it, who needs suspension with vertical travel? So now the axles only twist with sway bars for chassis control.
This is the front differential. The spiders are removed and my "locker" goes in. This gives a little slop in the front driveline to aid steering in tight quarters. The rear was simply glued.
New links using #10 hardware and 3/8" aluminum bar stock. Overkill??