My MacGyver Build Now With DIG!

[K_B]

I figured I'd post a little update on my own build. It has evolved quite a bit over the last year or so and even more so over the last couple months.

GD-600 gearbox
Alloy knuckles
small brushless outrunner
Mamba-25 (now a Mamba Max)
lipoly batteries
maxx-shafts
Axial beadlocks
etc, etc, etc







But when things start to click, I can't leave well enough alone. So I jumped on the Dig bandwagon in an attempt to totally over-complicate this thing. And since I ALWAYS try to use stuff I have at hand, that further complicates things (hence the McGyver title) and usually makes for an ugly first attempt

I always thought that the RC4WD tranny was an ideal tranny for the Goliath due to it's size. And since they released the Disconnect version, I figured, what the hell.

The first thing I had to do was make a new skidplate. I recycled some leftover cutting board remnants (ugly, eh?):


Chassis plates installed:


I had to install the framerails on the outside of the tranny plates to clear the tranny and keep the main part of the chassis as close to the stock dimensions as possible so I don't screw up my link geometry.


I kept hearing that micro servos are no good for this tranny so I tried to install a full size servo:


It was just too big and wouldn't clear the upper links, so I went with a micro servo anyway, and I had one laying around anyway.


Because the disconnect mechanism added some substantial length to the rear output shaft I went ahead and made some new custom rear links to stretch my wheelbase from 12" to 12.5" and kept the rear driveshaft angles in check. You can also see the plexiglass battery tray up front, which, once again, was just scrap I had on hand. All in all, it worked, but damn it is ugly:


I realized almost immediately that the cutting board material I used has a slope in it (because it was a cutting board with the little drainage thing around the edge) and that put everything outta whack. But it was good practice.

I went to the store, picked up a FLAT cutting board and went to town on it. The final result was this. Still a little ugly, but at least everything is straight. Note the black motor mount which is actually a huge round servo horn that I modified :





I took it out this weekend and my overall impression right now is that DIG is over-rated . In certain situations, I could get the thing to turn on a dime with the dig engaged, but most of the time, it just dragged the rear end along. But I think with some more fooling (more weight on the rear tires or something) I can get it to work.

[90xj]

Looks good kb, I think you'll love having a tranny instead of the pti's spur/pinion arrangement.

[drc323]

Looks good kb, Did you counter sink the screws at the bottom?

[K_B]

Yup. Countersunk the screws, got my new shocks mounted up and reposistioned them further out towards the end of the chassis and regained a half inch in ground clearance so now I'm sitting exactly where I want at just under 3 inches. I also used 3" springs all the way around to have about a half inch of downtravel. Should help with sharp breakovers.

I do like this new tranny. I just slapped in a 10-tooth pinion (was running a 14T) and boy, what a difference. I actually have decent throttle control Honestly though, the hodge-podge GD-600 thing was working quite well. I've never had any real problems with it, but whenever something works, I can't leave enough alone.

I also painted up a bug body that I've had sitting for over a year. F-d that up too.

[K_B]

So after my truck took the expressway (multiple times) off the hill last weekend and the Fodge lost it's back half, I finally got around to painting this bugger up (HA!):



And here's another shot with the body off to show off those fancy shocks! That leak! I installed the rears upside down because these lack a pivot ball in the shock cap which I don't need if they're connected to the cable clamps on the lower links. Have yet to futz with the front ones as you can see.



Although I like how narrow the chassis is, I was informed that by laying it down on it's side, I not only lower the CG by 3/4" (which I figured), but I will actually gain 1/4" in ground clearance. I didn't think that the CG was that bad, especially since my motor weighs almost nothing, but I did some living room couch crawling and something seems off. It seems to be a combination of too stiff of a spring in front and weight distribution.

Between the cutting board material and the new, heavier tranny, I've discovered that I've added almost a pound to the weight of this thing. Good for traction, but the weight doesn't seem to be in the right places