Grand Daddyish build

[TNThomas]

My big concern with the 6x6 is being able to turn. If you had rear differentials it would be ok. But with straight axles it may want to just push and go straight. John Deere and other companies who built 6x6 vehicles have found this out the hard way. They don’t want to turn. Even a regular kart with a solid rear axle has some problems with turning. Another thing, moving the passenger up so high will be a very violent ride for them. Like trying to ride the top of a flag pole in a hurricane. I encourage you to rethink. Just something to think about.

Yea, good advice on the John Deere example, thanks. I was wondering the same thing, and having you bring that up reminds me that it could be a major flaw. I always find myself trying to go a little "too big" on some of my plans, and its probably best to just keep this as simple as possible. I'll do something similar to the last frame example (the smaller one), and stick with thinking of the rear as more of a mini-bed, and less of an additional seating modification. Realistically, my little kids will be too scared being that close to the 670cc engine (super loud), and once they are comfortable sitting up/back there, they would be better off with their own little buggy tuned for them, so I might as well save the additional work, and put that towards their own little go-carts in the future.

 

[madprofessor]

Have you considered articulating the frame as far rearward as possible? I think F.A. did that on some lunar rover build or such. Seems like it would greatly enhance the kart's ability to force a turn.
EDIT: Hah! Just saw where F.A. posted that lunar rover right here on this section yesterday. Look it over.

 

[TNThomas]

Have you considered articulating the frame as far rearward as possible? I think F.A. did that on some lunar rover build or such. Seems like it would greatly enhance the kart's ability to force a turn.
EDIT: Hah! Just saw where F.A. posted that lunar rover right here on this section yesterday. Look it over.

Can you expand on the "articulating" part a bit? Are you talking about the pivot poitn for the rear (where it attaches to the frame?), turning, or other. Thanks for the brain power.

 

[madprofessor]

Can you expand on the "articulating" part a bit?

What I imagined in the past was like the trailer hookup platter on a semi truck, but with 2 opposing platters. Made wide enough, there would be no danger of rolling either part without the other. A wide crossway hinge under the bottom platter would make a swingarm hinge for suspension, and keep it straight lengthwise at all times. The top platter would turn for the articulation in an effort to follow the front wheels that would then sort of act like the way a front wheel drive car does, dragging the rear along with it. But the rear would be pushing it instead.

 

[Denny]

Yea, good advice on the John Deere example, thanks. I was wondering the same thing, and having you bring that up reminds me that it could be a major flaw. I always find myself trying to go a little "too big" on some of my plans, and its probably best to just keep this as simple as possible. I'll do something similar to the last frame example (the smaller one), and stick with thinking of the rear as more of a mini-bed, and less of an additional seating modification. Realistically, my little kids will be too scared being that close to the 670cc engine (super loud), and once they are comfortable sitting up/back there, they would be better off with their own little buggy tuned for them, so I might as well save the additional work, and put that towards their own little go-carts in the future.

That is a very smart thing you just said. You could lengthen the frame and seat them behind you though.

 

[Denny]

What I imagined in the past was like the trailer hookup platter on a semi truck, but with 2 opposing platters. Made wide enough, there would be no danger of rolling either part without the other. A wide crossway hinge under the bottom platter would make a swingarm hinge for suspension, and keep it straight lengthwise at all times. The top platter would turn for the articulation in an effort to follow the front wheels that would then sort of act like the way a front wheel drive car does, dragging the rear along with it. But the rear would be pushing it instead.

To do something like that he would need to go to hydraulic steering with rams on each side of the pivot point. Then add in all the extra parts like pump, steering valve, lines, rams, a hydraulic tank and filter would add thousands to the build. And after you did all that you would be stuck with a seriously unstable high speed vehicle. That is seriously twitchy. Have you ever driven an articulating loader. Bad idea!

 

[TNThomas]

Ditching the extra seat idea for now. Too much thinking, not enough building. Bed is 2 feet long, and just over 34" wide. Black is the rear shocks, they are 26" ish tall/long. Opened the box for the 670 as well.

 

[TNThomas]

Boom! Less think, more build.

 

[TNThomas]

I built a support in the front and back top end of the cage for hauling long stuff without using the bed or roof. Built for lumber primarily.

 

[Functional Artist]

To do something like that he would need to go to hydraulic steering with rams on each side of the pivot point. Then add in all the extra parts like pump, steering valve, lines, rams, a hydraulic tank and filter would add thousands to the build. And after you did all that you would be stuck with a seriously unstable high speed vehicle. That is seriously twitchy. Have you ever driven an articulating loader. Bad idea!

Yup, I agree, articulating steering is a lot more complicated (hydraulic or mechanical)
...& NOT for a vehicle that produces, any kind of speed

If you think about it, most articulated vehicles are "creepers"
...like on work sites & such
...but, I've never seen one out "on the road"

 

[TNThomas]

Whew! Im back, pretty much done with the house remodel, so my focus is going back to the buggy. Measuring for the rear axle. Ill be going with a 54" x 1" solid steel. Axle. Ill keep the bearings as close as possible to the rear wheels to reduce the chance of bending.

 

[TNThomas]

Mocking up the steering, rack and pinion, and steering wheel.

 

[TNThomas]

Ok, I got the 1" dia × 54" long axle in, and not going to lie, I think im going to bend it if I run just 1 axle. Too late to go 1-1/4", and I couldn't find what I want in that dia anyways. Im going back to the original plan of dual rear live axles, 6 total wheels. The engine (predator 670 v-twin) should easily handle it. Ill do a similar setup as the image below from a different forum. Same engine, same Comet 780 drive, same comet driven, and similar, but ill use a longer jackshaft. From that jackshaft ill run a second sprocket and chain to the second rear axle. Exact same tires, axle, hubs, sprocket, and gear ratio between the two axles. This will roughly split the force/wear between each axle setup. And both will rotate at the same rate.
And with two setups, there will be roughlt half the stress flexing each of them. Im sure steering will be mediocre, but I plan on riding primarily on forest trails, sand, and snow, so not tons of super sharp turns. Rear axle tires, and hubs weight 62lbs.

 

[TNThomas]

Rear most axle will be right under the rear seat (from a CJ-7).

 

[Denny]

Just make sure you build the rear swing arm as wide as the axle from hub to hub.

 

[TNThomas]

Waiting on axle components, so working on steering. Partially welded up bracket that will hold the steering wheel. Bearing in the middle, and knuckle at the end. Tabs are for extra support.

 

[Denny]

You better build in some heavy duty roll over protection for the rear seat passengers. I got a feeling it’s going to want to sling them out being that high up.

 

[TNThomas]

You better build in some heavy duty roll over protection for the rear seat passengers. I got a feeling it’s going to want to sling them out being that high up.

Im probably just going to leave it as is. If anybody is back there ill be taking it easy driving. But the rear seat is the last of my worries right now. We are suppose to have another snowy winter this year, and I need this baby ready in case the city gets shut down

 

[TNThomas]

Got some work in on knuckles/steering bracket. Last 2 tires came in. She is probably going to want to fight me a bit, but I'll primarily be driving in sand/snow/mud, so im not too concerned.

 

[Denny]

Looks good! I just hope you can get it to steer.