Outer Limits 4x4 Board

Hi all, soon I will be starting my yr 12 design and technology major project and I'm after some ideas. The course has a strong design aspect, so the more research the better ( to a point lol) and I can make a project using any materials ect. I have a year to build it and I have all the resources and machines needed for just about anything... Full computerised cnc lathes and milling machines, benders, welders ect.
Here's the kicker it needs to have a genuine need..
I was thinking if building a 4x4 rock crawler go kart aimed at paraplegics and amputies, so it would all be hand controlled.
4x4 with perhaps twin tide on lawnmower motors say 6hp?, one for front and one for back. 4 wheel steer, big articulation and a good gearing setup, but make it single seat, and COMPACT. So I mean like go kart size with say ATV wheels?
Am I being stupid? Can it be done? Haha Thankyou for all your help.

We had that same sort of project at school as well, although only for 6 months, and the teachers said absolutely no go karts. The reason being was that the majority of them weren't being completed in the 6 month time, even a basic design. And the ones that were completed, a lot of hours were spent on them at home as well. I don't know how much time you get a week to work on it and how good your work ethic is, but we had 5x 70 minute lessons a week and when you exclude the time its going to take for you to get started and pack up each lesson, you'll end up loosing about 20 minutes. I'm assuming your starting this at the beginning of next year? If so, put as much time over the holidays into designing and planning everything so that when the first lesson comes next year, you can start measuring up and cutting steel.

I'm not trying to talk you out of it, but it is a fairly large project to do even a basic go kart, because you're going to have to do all the reporting and all that as part of your course as well I'm assuming? So plan everything in good detail and just hope that you don't get any setbacks throughout the term.

Thanks mate, I understand what your saying. Well I will have a fair few lessons throughout the week plus I have a whole day on Wednesday's. I will be the only one in my class in the metal workshop in these lessons so I won't have to wait for machines ect.
I start next school term and I have a full year till it has to be completed. I also have welders benders ect at home so I can work on parts here as well.
I was planning on building a new Meyers manxter or sililar, but dont have the funds right now. I am very mechanicaly minded and am up for a chanlenge just would like some ideas and a bit of guidence particularly on the drivetrain side of things... Thanks

Ok then, as long as you can stay on track. Set yourself some milestone goals as well, this might help to keep you on track. Google hand controlled vehicle systems, you might get some inspiration from that. Otherwise, depending on your budget, space, skill, time and overall motivation constraints, there's a build up thread of a small 4wd buggy with a 3cyl motor by Rhett (http://www.outerlimits4x4.com/viewtopic ... 6&t=215005" onclick="window.open(this.href);return false;) that you might be able to get some ideas from regarding small and simple set ups.

I have changed the plans, done some more research, looked at some builds and worked out what i want.
I found a sick build on pirate, using Suzuki diffs, and Honda running gear.
Im planning on sierra diffs, auto box and transfer.
I want to run the motor and gearbox transfer behind the seat, and in the rear of the car.
In theory I should just need to make new driveshafts, and different length cables? That should be all that's needed?
I'm trying to make it compact so the smaller and lighter the better, so I am open to anyones thoughts and suggestions thanks.

Check the rotation of the Honda engine a lot of them run backwards so won't work with a normal transmission diff combo.

Keeping it all one brand will save a lot of hassles.

That's my 2 cents worth.

If you use motorcycle parts you will be able to build it much cheaper. If you look for some of the early nissan IRS diffs then you can even run either IFS, IRS or you can place the diff and stubbs in a frame that you build yourself and have a high center diff housing for clearance. They are very light and easily souced. Just an R180 should be OK. Then if you make it light enough you can also use motorcycle suspension components. Just use motorcycle forks as your shocks on each corner. Very easy to run them in pairs and a huge range of sizes. You can use a motorcycle engine to power the buggy. They already have a gearbox and are nice and compact. You can even run a short, strong chain from the engine to a drive shaft so you can easily change gearing to suit what you want. If you get an engine from a quad or something then you'll also have reverse. Or you can build an adaptor to run either a starter motor or winch motor for a reverse gear and they are mostly either semi auto or fully auto gearboxes as well so would suit your idea. If you start running car engines and the like then you're going to add a lot of weight very quickly. It is all part of your engineering to decide on a balance between strength and weight. A lot of people deliberately build in weak points so that they know where it will break first if something happens and make that part be a cheap and easily available part.

maybe just go rear drive with atv tyres alot simpler.

from memory subaru also have the R180 diffs and for reverse you can modify a zook transfer to have reverse read through this thread (im not sure where it is exactly but i know there is a writeup for doing the mods) http://forum.difflock.com/viewtopic.php ... highlight=" onclick="window.open(this.href);return false;
and also have a look at this build up for more ideas http://www.offroadfabnet.com/forums/sho ... php?t=1672" onclick="window.open(this.href);return false; and this site will give you even more ideas (or confuse the sh!t out of you even further http://www.minibuggy.net/forum/" onclick="window.open(this.href);return false;

have fun

Okay, I'm starting to get the point that bike stuff is the thing to use lol. I actually have an old 4x4 Yamaha (big bear I think?) quad in the shed atm.
I was thinking about a hw gearbox turned 90 degrees and use driveshafts from the where the cv's bolt up.
But now I think o could perhaps use a similar setup with the quad gbox I have? I will have a look tomorrow and see...

flyinwall wrote:..have fun...

I did........

http://www.offroadfabnet.com/forums/sho ... .php?t=876" onclick="window.open(this.href);return false;


outstanding thread for every fabricator wanna-be to get inspiration from

Gosh that cage in that thread looks horrible, no notching by the looks and just filled continuously with weld.... I wouldn't like to be in that thing...

buggy man wrote:Gosh that cage in that thread looks horrible, no notching by the looks and just filled continuously with weld.... I wouldn't like to be in that thing...

Ah come on. Live a little.......

buggy man wrote:Okay, I'm starting to get the point that bike stuff is the thing to use lol. I actually have an old 4x4 Yamaha (big bear I think?) quad in the shed atm.
I was thinking about a hw gearbox turned 90 degrees and use driveshafts from the where the cv's bolt up.
But now I think o could perhaps use a similar setup with the quad gbox I have? I will have a look tomorrow and see...

just use it for the running gear like in the thread i posted before

A transaxle buggy will work much better with air shox will be far better than bike gear and bike forks, for a crawler. a off road go cart bike gear would be the choice.

Thanks for all the links and input guys!
Well I have decided on a 'transaxle buggy'
I have a Subaru liberty 2.2lt engine and fwd gearbox here, but it will probably be a bit big.. I am thinking Suzuki swift engine, some Suzuki diffs, 14" air shocks, and some form of link suspension.
For the frame shape I hope to place the ngine behind the seat and make the frame fairly narrow.
I will keep you posted with any progress. I need to start a build thread lol for the hilux and now buggy...

I'd love to see a mini-crawler built with front and rear steer portals like on the front of this

ok since you have chose the path you want to go i urge you to check out this thread

http://www.pirate4x4.com/forum/showthread.php?t=633445" onclick="window.open(this.href);return false;

i think you will enjoy it

flyinwall wrote:ok since you have chose the path you want to go i urge you to check out this thread

http://www.pirate4x4.com/forum/showthread.php?t=633445" onclick="window.open(this.href);return false;

i think you will enjoy it

Awesome bit of kit that one!

Yea I have seen that build, god its a nice buggy, hopefully mine will be of similar size, but the more I keep looking the more I want to go bigger tyres which = bigger drivetrain which = more power haha i think you all get the point .

since you are doing it for school i think you should try and keep it smaller and simple just like the kid buggy and you will be very surprised how far you will go in it with 31" tyres and zook diffs

Ok totally out of left field and probably more work than anticipated but what about an outboard motor with a CVT style transmission ? Two stroke could be an advantage IE no sump or oil levels to worry about..........


Just a thought.

are they a cvt trans or just a dog clutch?

Have you thought about using something from an old Honda Odyssey off road buggy?

No gears or clutch to worry about it sorts it all out itself, throttle and brakes on the steering wheel.

Turn the motor 90 degrees and that gets the power to the front and back all in a small package.

The ratios in the diffs will bring the gearing down for crawling rather than speed.

They came in 250cc and 350cc 2 strokes so if you want it should have enough power light and come in a small pakage with everything you need and the 350 model had reverse.

It might give you a good starting point

prob get a fwd car to steal the engine/box out of cheaper than odyssey bits