The Arkansas Mud Hog

[Stonewall]

I got an idea in the middle of the night last week for a new amphib design. It may or may not work, and I may not even try to build it, but I thought I'd throw my idea out there to see what y'all think. My idea basically consists of a steel tub similar to that of the LTV Aerospace Kid vehicle, with tracks. The engine and drivetrain would probably be from a S-10 or other small V6 donor vehicle, using the origional rear axle and differental. Steering would consist of a pair of brake master cylinders mounted to either a set of levers or a steering wheel apparatus with one master cylinder for each brake on the hubs. Transmission would be a stock automatic. The tracks would most likely be snowmobile tracks, although I havn't completely worked out how the drive system would work. The tracks would also have a suspension similar to Howe & Howe Industries Ripsaw vehicle. It would probably be between 10 and 12 feet long and about 6 feet wide. Tell me what y'all think.

[jwiereng]

Hmm. External brakes. Methinks I would like them in the tub away from mud and water. Additionally there is more potential damage from snags to the exposed brakelines. I would be excited to independent suspension that enploys swing arms like the rear of a motorbike unlike the a-arms that Whipper's springers.

[Stonewall]

There are 2 ways that I could go about the brakes; I could modify the axle and put the drums on the inside of the tub with the hubs sticking out thru bearings, or I could put the whole rear axle on the outside of the machine with a seal just behind the yoke. I think that the latter would be best because it would allow me to access the differental much more easily for repairs. The stock drum brakes should hold up to the abuse, I believe that they have more braking surface area than disks therefore would be better in wet conditions. The brake lines would only have minimum exposure, they would be in the tub until they came out and hugged the axle up to the brakes. The motorcycle type swingarm would allow me to make the whole vehicle narrower and therefore more maneuverable. My biggest worry right now it how I'm going to keep the snowmobile tracks from running off the bogie wheels since they don't have center cleats to line them up.

[mudbug3]

This is a home built 6x6 using a car engine. There are also several other video,s of it to watch on YouTube as well. I dont know how amphibious it will be when you add the weight of all the componants that you,ve mentioned?

[Stonewall]

Flotation

I did some calcualtions on flotation. Fresh water weighs 62.5 pound per cubic foot. I plan on making the tub about 12' long, 3' deep and 6' wide.(not including how much the tracks will stick out.) If the lower 2' of the tub is 4' wide, and the top foot is 6' wide, the volume of the tub will be 168 cubic feet. This means that it will displace 10,500 pounds of water before it starts running in over the edge. So as long as I keep the weight under 10,000 pounds I should be alright.

[duckhunt81]

You mentioning H&H Tech got my attention.
I think they are using some sort of electronic controlled gyro thing to do all the steering. I think that technology whould change everything we (amphibs) know about steering capabilities, allowing more powerplant options. I do think whatever H&H is using is better suited for tracks.

[Stonewall]

I believe that the first one that they built, and made the youtube vid that got them noticed by Discovery, didn't have any gyros.

It looks to me like this is just a 427 with a 1 ton truck rear diff and brakes. I could be wrong tho.

[duckhunt81]

I was referring to some other their newer projects like the “Mini Rip” which is based off (I think) a Polaris 800 4 wheeler. They just adapted their track system to fit. The link below states that the technology used is “Computer Controlled fly-by-wire clutching, braking, and steering system”. Which I would guess this technology is a proprietary technology that H&H came up with. I have only seen a glimpse of it on one show last season, and it appeared to be some sort of a spinning thing. I would like to know more about it and see if it would be possible to use in an AATV. It did seem like a cool concept at least. It’s probably not a good idea on a home built project, but it would be cool if Argo or Max at least looked into this technology to see what different opportunities this could have in the AATV scene.

Ripsaw

[chris davison]

keep the brakes on the inside. Your bouyancy calks are ok but a steel hull and 3 feet tall, no speed reduction or torq increase for a vehicle that may weigh more than the donor car. I would suggest you mount a front wheel drive motor trans in the center and run chains 2x80 to front or rear to drive two axles that go out the 4 foot wide section at the highest point and drive tracks with them. These chains should have a 3 to 1 reduction like 18 teeth on the trans-axles and 54 teeth on the shafts going thru the hull. This would effectually decrease your speed by 66 percent and increase the torq by 66 percent.
Who would want to go 100mph using skidsteer?

[Stonewall]

I think that I understand what you're saying, but couldn't I achieve the same reduction by using a smaller drive sprocket for the tracks? That way I could avoid chains altogether(I really don't like chains) If I were to go the chain route, could I still use the s-10 drivetrain and move the axle foreward with sprockets on it?

[Stonewall]

I think that my drivetrain will probably be a chevy 305 v8 motor and a turbo 350 trans, with a low gear drag racing rear end from a buddy. Will probably shorten the axle to about 1' long on each side of the diff, then bolt a shaft onto the brake/hub setup to drive the track sprocket. The truck that this axle is currently in will top around 70mph with ~30" tires, so I think if I use a 20" track drive I should get around 40 mph. Thanks for y'alls help and keep the suggestions coming!

[chris davison]

What are the diff ratios availiable for it? How small compared to the doner car tire is the track sprocket?
If you could get like 5:38 gears and that sprocket was half the tire diameter that would work. An automatic trans would be the best with the engine as close to center mounted in the hull as you can get it. That may only be a universal joint between the trans and the diff.

[Stonewall]

5:38 sound rite, but I'll have to ask the guy that has it. I am hoping to top out at ~ 40mph with this vehicle and if the truck with this axle tops around 70 with 30" tires, I think a 20" drive sprocket would be just rite. Having the engine in the middle severly cramps my rider area plan, I had hoped to have it mostly foreward with things like the radiator and fuel tank at the rear to counterbalance, Do you think it will be too frontheavy?

[chris davison]

you seem to be able to handle the math figure out lengths weights what will fit where draw several plans and then use the one that gives you the most of what you want. One of the most important things to remember is have a picture of what you want or what you want to use it for or capable of and designe towards that. Plan to build in stages like 5 or 10 Example stage 1= lower frame designe buy build weld complete. Then start stage 2.

[6X6]

You mentioning H&H Tech got my attention.
I think they are using some sort of electronic controlled gyro thing to do all the steering. I think that technology whould change everything we (amphibs) know about steering capabilities, allowing more powerplant options. I do think whatever H&H is using is better suited for tracks.

I was referring to some other their newer projects like the “Mini Rip” which is based off (I think) a Polaris 800 4 wheeler. They just adapted their track system to fit. The link below states that the technology used is “Computer Controlled fly-by-wire clutching, braking, and steering system”. Which I would guess this technology is a proprietary technology that H&H came up with. I have only seen a glimpse of it on one show last season, and it appeared to be some sort of a spinning thing. I would like to know more about it and see if it would be possible to use in an AATV. It did seem like a cool concept at least. It’s probably not a good idea on a home built project, but it would be cool if Argo or Max at least looked into this technology to see what different opportunities this could have in the AATV scene.

Ripsaw

From what I have seen, Howe and Howe appear to have a clutch setup similar to an electric PTO clutch, although they will have it setup progressively instead of on/off, and a double setup to either engage or brake. Quite honestly the toughest part would be the servo motors and controllers for those, and setup properly would be quite durable. I may be way off but the couple glimpses I've seen I don't think there's any "Magical Secret" just good testing/development. You should be able to make a mechanical setup if the clutch is set inboard, and you could then lock the diff and still steer. You'll need a solid stationary clutch face, opposite, a clutch face that rotates with the drive input, and the movable clutch between the two solid to the output shaft. Alternatively would be a clutch and separate brake, brake outboard of the clutch which is essentially a simplified T-20 (although the clutch and brake switch based on forward or reverse) or a Baker hill Tranny, which may be easiest to use as a base for a design.
BTW A gyro would be used to make corrections to any unwanted course changes, and correct so that wanted course changes actually happen. Not sure if they use them or not, but they wouldn't actually DO the steering.