Homemade Amphibious Tracked Vehicle

[pinestumps]

Hey, I think I know. I'm guessing your drive sprocket is on one of the ends, right? Going one way, the track under the vehicle runs tense. Going the other way, the track will slacken. One or the other swims better. If you can, get a go pro , a case, and a stick and look at what the track is actually doing down there.

Thanks for your insight. In between summer travels I have been reading too many DoD funded reports from the 60s and 70s on improving water propulsion via tracks (relating to the LVTs of Vietnam I presume). The reason I see reverse going slightly faster than forward is due to the idler/sprocket placement in relation to the bow/stern pitch of the vehicle once torque runs through the driveline (there is a considerable torque reaction once the tracks are moving). I also did some further testing and without the bow fenders, at the highest speed the engine could take (about 8mph land, talk about inefficiency in the water!) I would actually go backwards instead of forwards. I think this is because there are 50% more grousers on the return side of the track than the thrust side. As with any project, more time and forethought could have developed a better vehicle with proper bow fenders, side skirting and maybe even a return chute to redirect track return current 180°. It was fun to learn about track machines and the compromises of amphibians during the build and I am glad others enjoyed it as well.

Ohh also website is up with plans/kitset available next week for those with money burning a hole in their pocket.

https://decentmfg.com/

The plans cover a revised vehicle with no walking beam, beefier axle plates, a lowered hull which provides stability in low payload conditions in the water, and a heightened/tailfinned upper hull for more freeboard. It's no Argo or Muddox, but to some it might be a fun & useful winter project.

[pinestumps]

Hey, I think I know. I'm guessing your drive sprocket is on one of the ends, right? Going one way, the track under the vehicle runs tense. Going the other way, the track will slacken. One or the other swims better. If you can, get a go pro , a case, and a stick and look at what the track is actually doing down there.

Oh I see what you are getting at, something like this?

Makes sense that the track would droop with nothing to stop it. I will try to video it next spring when I take it to less murkier waters lol.

[pinestumps]

80hr teardown, belting got torn off the idler from log ingestion and the brake pads wore down. Kinda disappointing but probably due to the 80% sand/silt I run this thing in. I figured it is the pad or the rotor when it comes to wear. Axle seal looks good.

Track grousers looks good, couple of dings from point loading on rocks. 1/8" of wear on the forward drive of the poly teeth and destruction of bleeder screw (as expected lol). Still a longggg way to go for that 500hr mark

[pinestumps]

Back at it

[pinestumps]

Finally kits/plans are ready to go... AT-15 “Drunk Frog” – Decent Manufacturing
Took a lotta time (more than I expected as usual) but I had to get them right!

[john swenson]

it is a cool machine stumps.. it looks as if it turns easy also. got to expect some wear and tear. love the shots of the tracks. j.b.

[JoeMeg]

I've seen some VERY creative designs and builds on this site over the years. This one is upper tier. Very nice!

[pinestumps]

Any others run into nasty submerged objects with their machines?

[pinestumps]

winterizing

[Rock Doctor]

Cool build, I love it.

RD

[pinestumps]

Little winter performance update.

In the 2' of fresh powder we had, the winter tracks allowed me to climb 10° grades with little difficulty. Anything over resulted in loss of traction, no vehicle bellying though. Really didn't get as much run-time as I wanted this season, but it was nice to test it in the snow.

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[tbone9]

That’s as awesome machine you’ve got there. That’s really good to be in that deep of powder and not belly out. Did you notice a big difference in floatation by putting on the extra belting on the outside?

[pinestumps]

That’s as awesome machine you’ve got there. That’s really good to be in that deep of powder and not belly out. Did you notice a big difference in flotation by putting on the extra belting on the outside?

Flotation was no issue with the track extensions, I still had about 7" of ground clearance with 2 people onboard. One thing I didn't think about was the uneven loading of the track and the subsequent sideways 'twisting' of the track in the soft snow. My super duper angle iron extensions sank 2-3" in the snow while the summer tracks sank a full 6", no bite where I needed it . On snow cats asymmetric track I notice they run a grouser all the away across to eliminate the twisting, but with the season over I'll take it as a learning experience!

[tbone9]

I often wondered about that every time I see those track extensions hanging way out there.

[pinestumps]

From this winter in michigan

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