08-17-2004, 10:09 AM | #1 |
Rock Crawler Join Date: Apr 2004 Location: Longmont, CO
Posts: 901
| 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": Here it is at 20" Here's my upper link mount (copied from some I've seen) and my 1/4 scale servo mount: I hope to get it done for the Sept 11th crawlstock at Dirks. For sure Moab. |
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08-17-2004, 10:45 AM | #2 |
I wanna be Dave Join Date: Jan 2004 Location: Flagstaff, AZ
Posts: 2,399
| Re: My new rig: SLINKY
Looks sweet Ace!! I can't wait to see some action shots 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? |
08-17-2004, 11:43 AM | #3 |
Rock Crawler Join Date: Apr 2004 Location: Longmont, CO
Posts: 901
| 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. |
08-17-2004, 11:59 AM | #4 |
Quarry Creeper Join Date: Jan 2004 Location: Long Island NY.
Posts: 397
| Re: My new rig: SLINKY
could you show better pics of your servo mount im very very interested in that
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08-17-2004, 12:13 PM | #5 |
Say hello to my dactylion Join Date: Jun 2004 Location: On the Boat to Whore Island
Posts: 4,470
| Re: My new rig: SLINKY HOLY SHIT ACE!!!!! 8O 8O That's pretty damn cool! I'm excited to see it run. -PF |
08-17-2004, 12:51 PM | #6 | |
I wanna be Dave Join Date: Jan 2004 Location: Flagstaff, AZ
Posts: 2,399
| Re: My new rig: SLINKY Quote:
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 | |
08-17-2004, 01:21 PM | #7 |
Rock Crawler Join Date: Apr 2004 Location: Longmont, CO
Posts: 901
| 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... |
08-17-2004, 01:24 PM | #8 | |
Rock Crawler Join Date: Apr 2004 Location: Longmont, CO
Posts: 901
| Re: My new rig: SLINKY Quote:
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. | |
08-17-2004, 01:25 PM | #9 |
I wanna be Dave Join Date: Jun 2004 Location: Centennial, CO
Posts: 2,129
| 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 |
08-17-2004, 01:32 PM | #10 |
Rock Crawler Join Date: Apr 2004 Location: Longmont, CO
Posts: 901
| 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 |
08-17-2004, 03:21 PM | #11 |
I wanna be Dave Join Date: Jan 2004 Location: Flagstaff, AZ
Posts: 2,399
| 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?
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08-17-2004, 03:32 PM | #12 |
Rock Crawler Join Date: Apr 2004 Location: Longmont, CO
Posts: 901
| 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! |
08-17-2004, 07:33 PM | #13 |
06 Super National Champ Join Date: Jun 2004 Location: Stark Industries Bar and Grill
Posts: 11,361
| Re: My new rig: SLINKY
Cool idea! Now get your ass in gear and finish it! |
08-17-2004, 10:29 PM | #14 |
I wanna be Dave Join Date: Jun 2004 Location: Centennial, CO
Posts: 2,129
| 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.
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08-18-2004, 08:14 AM | #15 | |
Rock Crawler Join Date: Apr 2004 Location: Longmont, CO
Posts: 901
| Re: My new rig: SLINKY Quote:
As Ron says: SET IT AND FORGET IT! | |
08-18-2004, 09:37 AM | #16 |
Rock Stacker Join Date: Mar 2004 Location: wasatch front
Posts: 61
| Re: My new rig: SLINKY
thats it i give up !
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08-18-2004, 09:38 AM | #17 |
RCC Addict Join Date: Apr 2004 Location: Cincinnati Ohio
Posts: 1,673
| 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? |
08-18-2004, 09:55 AM | #18 | ||
I wanna be Dave Join Date: Jan 2004 Location: Flagstaff, AZ
Posts: 2,399
| Re: My new rig: SLINKY Quote:
The lathe came in Thanks for all the tooling!!! Now I just gotta get my work bench goin so I can start turning some stuff! | ||
08-18-2004, 10:55 AM | #19 |
Rock Crawler Join Date: Apr 2004 Location: Longmont, CO
Posts: 901
| Re: My new rig: SLINKY
Glad you got the lathe. Hope you enjoy it!
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08-18-2004, 09:05 PM | #20 |
Rock Crawler Join Date: Apr 2004 Location: Longmont, CO
Posts: 901
| Re: My new rig: SLINKY
More progress on Slinky, 'bout 3 beers worth. Slinky is SLUNG, got the shocks mounted: Threw a body on top for short and long shots: Here's my 1/4 scale servo mount. Have to see if it works yet! This one's for SR5Dave, the reason I had to sell the lathe: |
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