My new rig: SLINKY
 

Well, having been to a few comps I've learned a few things:

1. Focus on the basics. Long, Low CG, Wide.

2. Clod's simplicity, low CG and lightweight are very hard to overcome advantages -vs- a shaft truck.

I also noticed that a rigs WB seems to be one of the main things that determines it's ability to climb verticle sections. So when I wanted to make a clod based rig, what WB to make it? The top rigs are about 16" WB But, I like the manoverability of 14-15" so I thought I'll just make mine have both.

Here's some build pics of slinky. Wheelbase will be radio adjustable from about 15" to 20"!

So right off the bat, I've violated #1 (keep it simple) what can I say, I like to try to be innovative.

Here's Slinky at 15":

http://img47.exs.cx/img47/4669/frame15.jpg

Here it is at 20"

http://img47.exs.cx/img47/936/frame20.jpg

Here's my upper link mount (copied from some I've seen) and my 1/4 scale servo mount:

http://img47.exs.cx/img47/2807/swerv..._linkmount.jpg


I hope to get it done for the Sept 11th crawlstock at Dirks. For sure Moab.

Re: My new rig: SLINKY
 

Looks sweet Ace!! I can't wait to see some action shots :D Did you build this just because you could, or because the shaft wasn't doing it for ya anymore?

Care to elaborate on the adj wheelbase setup and servo mounts? :)

Re: My new rig: SLINKY
 

I haven't given up on shaft trucks. But I've seen several things that are hard to overcome...

Vertical climbs:
The fronts spin on a clod. I thought this would hurt because of static -vs- dynamic friction. What I observe is a clod's fronts spin and wipe dust/dirt off treads and rock then it climbs. Also while the fronts spin the axle slides back and forth till it finds the smallest crack or area where the slope isn't quite as steep and the rig climbs it.

On a shaft, front and rear are locked. Thus, no cleaning and very little "searching" like a clod does. You either climb or tip over backwards. You can search with momentum bumps but were talking competion here and eventually the mo bumps knock you over backwards. 5 points please...

Low CG is also king of the clods. How do you get the motors (2nd heaviest part of a cralwer) lower than a clod. Also the battery, how can you get it as low as a clod? Just raises the motor/tranny that much more.
Only way is with saddle packs I suppose.

My other reason for doing a clod is runtime. My damn worm gear truck runs about 3 minutes in a comp. Most of the clod guys get an 3/4 hour! I like to run my truck w/o carrying 10 batteries with me.

Servo mount is just a piece of sheetmetal, bolts to the upper axle brace. I can take better pics later and post them.

Re: My new rig: SLINKY
 

could you show better pics of your servo mount im very very interested in that

Re: My new rig: SLINKY
 

HOLY SHIT ACE!!!!! 8O 8O That's pretty damn cool! I'm excited to see it run.

-PF

Re: My new rig: SLINKY
 

I didn't know worm gear drives were inneficienct.

I know why clods are so awesome; so I just was wondering if the shaftie wasn't doin it for ya anymore, I guess the answer is yes! I've always thought the front and rear ends mocing separately was way better, for the reason you just explained.

Get pics of the servo mounts when you can :)

Re: My new rig: SLINKY
 

Will post pics of the servo mount later, nothing to special.

I suppose I'll machine up another set of axles for a shafty. But 3 months of machinin wasn't in the cards till this winter.

I hope someday we have rules on wheelbase and width. Then I'll build a shaft to those specs. When it takes that much time to make the axles, only to find out it shoulda been 2" wider, it hurts!

One area Clods suck is the scrub radius when turning with all the wheelspacer/adaptors and offset wheels. El Capitan really turns nice and I feel it's cause the "scrub radius" is zero. Been looking for someone to make portals that correct this for a clod. Might have to be my winter project...

Re: My new rig: SLINKY
 

Thanks, I'm excited to see it run too!

LOL, it's you guys rigs that made me stay up at night dreamin this crap up. Sure hope it runs with (actually I'd be happier with whips ass, I owe you guys a couple) team UTAH. :lol:

Re: My new rig: SLINKY
 

Your adjustable wheelbase idea is crazy. I just hope that you can make the chassis stiff enough. Is it powered by air rams, servos,or what? I want to see how you mount the body :lol:

Re: My new rig: SLINKY
 

Body:

I'm gonna run another rail back to the rear. That way the front and rear body mounts are fixed. The WB will extend out the back.

As far as actuating the WB, I actually thought about air but settled on using a screw. Still working out the details but I think I've settled on using a regular servo to turn a 10-32 all thread lead screw.

I'm going to rig up the servo's resistor divorced to a lever that sees about 120deg for the 5" of travel. that way I'll have full proportional control on the WB. I plan on using a 4-channel airplane radio. Throttle=wb Rudder=rear steer, aileron=front steer and elevator=throttle.

I've flown planes forever and using the rear steer as the plane radio's rudder should be straightforward.

Thats the "plan" anyway :roll:

Re: My new rig: SLINKY
 

Ace; are you going to hope the tires just scrub when you're pushing the rear end back to lengthen the wheel base? Seems like it might be a bit much to demand from the whole system unless its pretty beefy... Or maybe you'll have to drive forward/back at the same time?

Re: My new rig: SLINKY
 

I'm hopin the axle will roll...

10-32 screw should give a heluva mechanical advantage.

If the servo won't turn it, a mag mayhem geared down 100:1 will!

Re: My new rig: SLINKY
 

Cool idea!


Now get your ass in gear and finish it! :flipoff:

Re: My new rig: SLINKY
 

For the servo, instead of adjusting it to go through 120*, just remove the block and bore out the center of the main gear, then it will just spin forever until you make it stop. Its what antweight battlebots do. Then setup either blocks or power disconnects for the extending rails. That's what I'd do anyhow. Or a drill motor.

Re: My new rig: SLINKY
 

Right, setting up stops would be a bigger pain than just making it proportional. Plus I can easily stop the slide anywhere, not just the ends. Besides having proportional WB is cooler than screwin with the channel all the time.

As Ron says:

http://img45.exs.cx/img45/5176/topAreaRedFade_02.gif

SET IT AND FORGET IT!

Re: My new rig: SLINKY
 

thats it i give up !

Re: My new rig: SLINKY
 

Wow, that's some crazy stuff you got going 8O

My frame looks simmilar to yours. Did you just heat and bend your frame or is it welded?

Re: My new rig: SLINKY
 

:lol: Stay up all night thinking of that one? I have his pasta machine... I have never had such a thought intensive machine.

The lathe came in :D Thanks for all the tooling!!! Now I just gotta get my work bench goin so I can start turning some stuff!

Re: My new rig: SLINKY
 

Glad you got the lathe. Hope you enjoy it!

Re: My new rig: SLINKY
 

More progress on Slinky, 'bout 3 beers worth.

Slinky is SLUNG, got the shocks mounted:
http://img18.exs.cx/img18/4508/long.jpg

Threw a body on top for short and long shots:
http://img18.exs.cx/img18/1007/short_w_body.jpg

http://img18.exs.cx/img18/7239/long_W_body.jpg

Here's my 1/4 scale servo mount. Have to see if it works yet!
http://img35.exs.cx/img35/8/servomount_bottom.jpg

This one's for SR5Dave, the reason I had to sell the lathe:

http://img35.exs.cx/img35/9869/my_sb9_2.jpg