Has anyone tried or experimented with center articulating steering on a rock buggy? Instead of front/rear steering it actually steers via two hyd. rams in the center of the machine. Sounds confusing I know but our log skidders use that design so they can get around in the woods far better than if it was front steer or front/rear steer. Hopefully this pic. will help:

http://www.forestnet.com/archives/Feb_2000/pics/545_skidder_1.jpg

different angle:

http://www.forestnet.com/archives/Feb_2000/pics/545_skidder_4.jpg

Just thinking of different ideas.
:usa:

Thought about it, haven't tried it. But that tractor is so cool. I want one.:D

On second thought, maybe I will try it. That would solve the ujoint/birfield failures once and for all.

a friend and I were discussing that exact thing a few weeks ago..It'll make a dirt cheap dedicated wheeler. We are going to do 14 bolts front and rear welded because they are a dime a dozen The frame has to be STOUT! He's working on that now.

I'll just take that log skidder! Talk about a great recovery vehicle. Just drive right over little sluice and pick up any stuck/broke rigs along the way!

You'll have to deal with the center U-joint in the driveshaft, but that shouldn't be too hard. The challenging part is getting suspension to work with this set-up because of the compound angles.

Sweet idea though.

-John

i think the biggest hassel will be driving the axles. i have tought about this just because it would use dirt cheap axles. and it just so happens i have a couple of 2 1/2 ton rockwells that would work just fine. yall figure the drive line out and save me a bunch of head ache. i might just put one together. mike

I've thought about this for a long time, and even gone far as to make some models and some cad drawings of some supersecret chassis designs.

But I always come back to the same problem.

Imagine your on a side hill, and your climbing a rock with one tire, but you need to turn to go up that rock. You turn into the rock and now your rear is pointing down the side hill. Easy to get used to, but it might be more of a hinderence.

Thought about it, haven't tried it. But that tractor is so cool. I want one.

We have two and they go damn near anywhere you point 'em! Even thought about taking the blade and grapple boom off an old one, fabing up a bed for it, and using that for a toy. Only prob. is that top speed is about 25 mph. and the lowbed fees for moving it are pretty pricy! Nice part is factory lockers and a real cage! :D

You might want to take a look at those mid size off-road highway trucks. I worked with one a few years back (a moxy truck) that used a similar steering setup, but also rotated axially. This allowed them to attach the axles directly to the frame but still have plenty of articulation.

I have brought this up in the past.
I grew up chasing skidders and cats around the hill sides. working with my grandpa in the woods.

I like the way both of those pieces of equipment can make 90 degree turns just about anywhere:D

I thought of trying to make a smaller scale version but just how would you send power to the front and rear tires with out creating a huge weak link.

There would be turning radius/ center joint strength issues

My idea was to get a tecumsin air cooled motor off of a generator
attach it to a hydro pump to drive the steering rams and hydro motors to drive front and rear tires.

Sounds like it might work

Here's a link to ADT's (Articulating Dump Trucks)


http://www.moxytrucks.com/ADTs.html

Or how about this.

Your in the rocks, 3 or more tires in a hole. with regular steering you turn and try to climb out. with an articulated chassis, You DON'T turn, untill your free, and then when you turn your wheel base changes dramatically on both sides, one side grows, one shrinks. Could make for some very interesting stucks, and the chassis and susp/axles would need to be incredebly strong.

But I'm still working on a viable design!!!! :D :D :D

The changing of the wheel base can also actully help you inchworm yourway out of stuck situations.

in fourwheeler a year or two ago they had an article about a huge artic truck that this dude used in alaska. he would take tours on it and stuff. it didnt have any real suspension except for the giant hinge allowed some movement. im not really sure how the drive worked but it had a big diesel engine i think. it was utterly massive though

I need one of those skidders!!!!! that would be sooooo fun to drive!!!

Rocktoad: The changing of the wheel base can also actully help you inchworm yourway out of stuck situations.

You're right. I do it all the time in rocky country to get around and over boulders. The down side is that if you slide sideways into a tree and get it between the wheels and against the machine you're pretty screwed! I've had to climb under the machine and fall many a tree to get unstuck. Rocks aren't such a big deal as you can crawl up on 'em and use your steering to get you lined back up.

You might want to take a look at those mid size off-road highway trucks. I worked with one a few years back (a moxy truck) that used a similar steering setup, but also rotated axially. This allowed them to attach the axles directly to the frame but still have plenty of articulation.

Same as the Skidder. Axles are mounted solid to the frame and the center allows the front/rear to rotate independent of each other. For instance, I can back off the side of the trail to get a log and the rear will be twisted as much as 45 deg. while the cab is still level.

Imagine your on a side hill, and your climbing a rock with one tire, but you need to turn to go up that rock. You turn into the rock and now your rear is pointing down the side hill. Easy to get used to, but it might be more of a hinderence.

See above. The front and rear of the machine twist independtly of each other.

As far as the drive train goes it's engine, tranny, X-case all in the front 1/2 of the machine. The front drive line is a continuous tube (no slip needed). The rear drive line goes from the X-case to a huge U-joint at the center (articulating) point of the machine then another drive line to the rear axle. Since the axle is mounted to the frame, no slip/travel is needed in the drive line.

Hope this clears some things up. If not, :flipoff2: :flipoff2: :flipoff2: :D

Originally posted by Rocktoad
I thought of trying to make a smaller scale version but just how would you send power to the front and rear tires with out creating a huge weak link.

There would be turning radius/ center joint strength issues

My idea was to get a tecumsin air cooled motor off of a generator
attach it to a hydro pump to drive the steering rams and hydro motors to drive front and rear tires.

Sounds like it might work

I like this idea but I would use 2.5 ton rockwells and electric motors. The electric motors could tie directly into the roackwells and have a short little "driveshaft" that consisted mostly of a slip joint to take up the slack of the suspension movement. The only problem would be you would only have 1 gear, unless you could find a very short remote shifted gear box. Altho with an electric motor that has tons of tourque at 0 rpm and can spin to 24 thousand rpm I don't think you would need many gears.

Originally posted by toymaniac


I like this idea but I would use 2.5 ton rockwells and electric motors. The electric motors could tie directly into the roackwells and have a short little "driveshaft" that consisted mostly of a slip joint to take up the slack of the suspension movement. The only problem would be you would only have 1 gear, unless you could find a very short remote shifted gear box. Altho with an electric motor that has tons of tourque at 0 rpm and can spin to 24 thousand rpm I don't think you would need many gears.

yesssssssss dis has been on my mind too!

Originally posted by toymaniac


I like this idea but I would use 2.5 ton rockwells and electric motors. The electric motors could tie directly into the roackwells and have a short little "driveshaft" that consisted mostly of a slip joint to take up the slack of the suspension movement. The only problem would be you would only have 1 gear, unless you could find a very short remote shifted gear box. Altho with an electric motor that has tons of tourque at 0 rpm and can spin to 24 thousand rpm I don't think you would need many gears.

And don't forget the batteries. Lots and lots of batteries.

Of course, with a big enough diesel generator, you could make a system like on a locomotive... Hmmm.

Originally posted by Jakesteramalamajama


And don't forget the batteries. Lots and lots of batteries.

Of course, with a big enough diesel generator, you could make a system like on a locomotive... Hmmm.

You dont need lots of them for ARCA type of events etc. Your tow rig has a generator in it!

For trail rides. you pull a jeep trailer with a generator on it. While playing on little sluice etc. you take it off. While watching everyone else you crank up the generator.. while wheelers are sleeping on overnight events you crank up the generator to torture the folk who keep slamming u for being different.

Ain't PAYBACKSSS great!!!!!!! :trooper: :usa:

I think the way to go about this is to have the steering and the drive all hydraulic. No driveshafts, tie-rods, drag links, or u-joints at all, hell you wouldn't even need brakes, brake lines, or M/C since your drive is controlled by hydraulics...just like a boat.

Come to think of it...with an auto all you'd have is a gas pedal on the floorboard. That be hella funny to explain to people when they ask wtf?? You could just say its so you don't get confused on which pedal to use :D

That would allow full articulation on a hinged frame without any binding. And for spare parts....axels and hydraulic lines and your set :flipoff2:

Originally posted by 2hiToy
I think the way to go about this is to have the steering and the drive all hydraulic. No driveshafts, tie-rods, drag links, or u-joints at all, hell you wouldn't even need brakes, brake lines, or M/C since your drive is controlled by hydraulics...just like a boat.

Come to think of it...with an auto all you'd have is a gas pedal on the floorboard. That be hella funny to explain to people when they ask wtf?? You could just say its so you don't get confused on which pedal to use :D

That would allow full articulation on a hinged frame without any binding. And for spare parts....axels and hydraulic lines and your set :flipoff2:

This is exactly what I have been thinking.

This is exactly what I have been thinking.

Me too - but I have no way to make it.

Go for it Rocktoad...this would be WAY too cool, and truly the next step.

Excellent idea....just got to execute now! Good luck.

Ps - Man, what a cool idea.

We've had teh hyd discussion before. The biggest concern I see is what happens when a hose blows on the trail? Just what we need for the eco-nazi's to kill anohter trail on us.
And before anyone starts about other fluids that leak on the ground from axles, trannys, etc, there is a hell of a lot more fluid in a hydraulic system than in all the compartments on a "normal" rig combined.
Plus the fact that what happens when the hose goes and it is the one you don't have? And, where are you gonna keep the clean oil, your looking at about 15 gallons of it, and where are you gonna put the contaminated dirt that the oil gets on when the hose blows?

As for the articulated steering, it would work, the d-shafts go through the center hinge point and the u-joints are on either side of the hiinge. I'll see if I can get a close up of one from work tomorrow.

Originally posted by JeepinIan
We've had teh hyd discussion before. The biggest concern I see is what happens when a hose blows on the trail? Just what we need for the eco-nazi's to kill anohter trail on us.
And before anyone starts about other fluids that leak on the ground from axles, trannys, etc, there is a hell of a lot more fluid in a hydraulic system than in all the compartments on a "normal" rig combined.
Plus the fact that what happens when the hose goes and it is the one you don't have? And, where are you gonna keep the clean oil, your looking at about 15 gallons of it, and where are you gonna put the contaminated dirt that the oil gets on when the hose blows?

If it's setup properly you shouldn't have a problem with hoses blowing.

Bypass valves maintenance and good sound engineering should prevent problems.

I don't see too many hoses blow on tractors.

Originally posted by Rocktoad


If it's setup properly you shouldn't have a problem with hoses blowing.

Bypass valves maintenance and good sound engineering should prevent problems.

I don't see too many hoses blow on tractors.

I work for the Cat dealer down here and it's not so much a question of how many hoses I see blow, but WHEN it will blow. All the engineering in the world doesn't stop failures from happening. The problem is what happens when it happens.
I've been on sites after a hose blows and the dirt has to be put in a sealed container, tested for the contaminates before it is moved from the site and the site has to be inspected by DERM. All of this is a real PITA when you are talking anything that spills over 5 gallons.
And if you don't call DERM and they find out about the spill, you go to jail and get a hefty fine.

I dont have the means to build it but I've been thinking about the hyraulic system too. I know some of you guys are familiar with Gradall's and similar machines for moving equipment on construction sites. They are all hydraulic, some are 4 wheel steer and they can turn the tires nearly 90 degrees. You can walk the $ wheel steer versions almost totally sideways and I've run a few that can switch between front, rear, crab walk and complimentary (like a monster truck. They are nice and wide and plenty beefy too. I cant wait to find a wrecked one for sale.

) Engine

B) Power shift transmission

C) Front axle differential

D) Independent front
suspension

E) Interaxle diff. integrated
into the transmission

F) Articulation hinge

G) Sloping rear frame

H) Parking brake

I) Rear axle differential

J) Rear axle housing

K) Gear- driven, free- swinging
tandem housing

L) Disc brakes

The post above is from moxytrucks.com.

IFS Piece of @#$% !!! :D

I too have been pondering about doing this, anyone who works around heavy equipment knows the value of hydralics. The thing about it that makes it good is the transfer of power from one source to another nets very little loss in effecentcy (power source to point of consumption). aside from the enviromental impact if a hose were to blow, the only real problem to solve is proper cooling. My friend is a hydralic system designer for Catterpiller, he told me high oil volume is necessary for cooling purposes. I think the answer to this problem would be using a refridgerated cooling system in which the oil would pass through. this way you only need a small resivor. blow a line, and you only loose a quart or two. You would have to have a loss of pressure shut down safty for the pump of corse.

Originally posted by JeepinIan
We've had teh hyd discussion before. The biggest concern I see is what happens when a hose blows on the trail? Just what we need for the eco-nazi's to kill anohter trail on us.
And before anyone starts about other fluids that leak on the ground from axles, trannys, etc, there is a hell of a lot more fluid in a hydraulic system than in all the compartments on a "normal" rig combined.
Plus the fact that what happens when the hose goes and it is the one you don't have? And, where are you gonna keep the clean oil, your looking at about 15 gallons of it, and where are you gonna put the contaminated dirt that the oil gets on when the hose blows?

I'm not claiming to be any kind of hydraulic engineer or anything...but it seems feasable to be able to incorporate some sort of sleeve around all hydraulic lines that would be able to contain a failure of the primary line. Of course the sleeve would have to be able to withstand the hydraulic forces, but maybe have this outer sleeve clear so a failure in the line is more visible. Is anything like that possible or just not financially worth it???

ok... before we continue to assume hydorolic oil problems and whats needed to be done with spills etc. consider if their are any substitues out there? Caster oil. olive oil, Hemp oil. etc. Is there any echo-friendly oils that sytem could be designed to use?

just a thought?

Originally posted by 2hiToy


I'm not claiming to be any kind of hydraulic engineer or anything...but it seems feasable to be able to incorporate some sort of sleeve around all hydraulic lines that would be able to contain a failure of the primary line. Of course the sleeve would have to be able to withstand the hydraulic forces, but maybe have this outer sleeve clear so a failure in the line is more visible. Is anything like that possible or just not financially worth it???

Anything can be done for the right amount of money. What you are asking to be done is to put a hydraulic hose in a hydraulic hose.

Originally posted by coachgeo3
ok... before we continue to assume hydorolic oil problems and whats needed to be done with spills etc. consider if their are any substitues out there? Caster oil. olive oil, Hemp oil. etc. Is there any echo-friendly oils that sytem could be designed to use?

just a thought?

THere are bio-friendly oils thast can be used. There are even ons that won't hurt you if you breathe them. Cost is a factor, but the main concern is the contaminants from wear in the oils.
Clean oil itself, w/ no additives or use is not considered a hazardous material. That's according to the feaderal DERM and also the local DERM here.
PS, we have very strict policies down here as we are so near the water table.

Ya, with hydrolics, you're guaranteed to break a hose at some point but it's not really a big deal and isn't very common. Run bio oil (it's actually veg. oil that's refined into hyd. oil) which is as eco friendly as you can get and bring a roll of trash bags. When you break a hose, shovel up what you can and kick dirt over the rest. If you really douche a rock, spray it w/ simple green and wipe off.

We ran bio oil back in Utah in the snow cats (hydro drive)I ran and in turn, had to help clean up spills when they happened. It was easy, even on rocks. Plus it turns bright orange when it hits snow and smells like french fries! Way cool... :D :D

There you go!

One problem solved!

Can u use bio oil as power steering fluid? Might be good stuff for the guys running Rams for steering etc.

Center pivoting truck I saw last year-

http://users.superford.org/ylobronc/mudmore/pivot.jpg
http://users.superford.org/ylobronc/mudmore/pivot2.jpg