Hustler Automatic chain tensioner prototype

[laduece]

I'm a redneck engineer, and know there are ALOT of us on this site. I've come up with a auto chain tensioner prototype and just thought I'd put it out there for scrutiny !! They are also in general pics.



I bought this Hustler.

http://www.6x6world.com/gallery/hustler-6-wheelers/p17965-hustler-950.html

[thebuggyman1]

There has been a lot of talk about building better tensioners in the past, and I think your design has potential. Here are the issues I see.
It only tensions one way
centaur tensioner.jpg
If you look at this centaur tensioner, you will see it has the ability to tension no matter what direction the chain travels.
I don't like the spring you used, I think a rotary type spring would work better, or use a bar below it so the spring can have a straighter pull.
It is hard to tell from the picture, but is the bar you used stiff enough/strong enough to hold up? Or will it bend/twist under pressure? Maybe a hybrid of your design along with the ratchet mechanism of a MaxII tensioner????

[hydromike]

This looks like a good first step. My intial thought stems from where the original Hustler chain adjusters seemed to have issues. When you're in reverse, all of the chain slack goes to the bottom, and the top becomes tight. From the pictures, it looks like when the chain becomes tight, it'll hit the head of that bolt. The original Hustler adjusters often bent when all the force was "upward" on the chain roller; they often bent the unistrut, or the boxed section that the unistrut was welded to. I think that your adjusters will spin up enough so that the chain is tight before exerting that upward force on the roller, so maybe it won't be a problem afterall.

I'm on Mr. Taylor's side about the two-way tensioning. I realize that we do almost all of our driving in forward, but take a look at your chains when you're backing up a hill some time. I think you may want to make sure that you provide some slack take-up in that situation as well. I'd like to see a rotary spring, too. Overall, this is a good start. From a "room to work with" standpoint, you're limited with the original chain adjuster mount. It'd be nice to see a real tight spring for the top and maybe a bottom adjuster as well.

[2gnospam]

I am in the middle of this same effort. My setup uses two UHMW plastic "u channels". One on the top of the top chain and one on the bottom of the bottom chain. They are pulled together by a tension spring on each side. The upper u channel and lower you channel are support via 4 bar link to stationary plate on frame. Will assemble one and take a picture tonight. Although I have not driven this setup at this point, the design seems sound.

[Noel Woods]

A dynamic tensioner like in the Centaur is really the way to go. I've noted that the original Hustler design has the flaws mentioned above. A work around may be multiple spool style adjusters for each run of chain, one for the top adjustment and one for the bottom. That would add complexity but adjustment once installed would be easier.
Chain dynamics dictate what will work and what won't work, and because most amphibs are different from one another it would not be easy to make a universal design that functions on every machine.
I've made some custom adjusters for a machine that I'm putting together now. They are manual adjusters and work in tandem with what are more like conventional adjusters. They work pretty well so far and they are installed on a large and powerful machine.

[laduece]

I agree with alot of the comments, and wanted a rotary spring , just didn't have one (This was constucted mostly of stuff I had lying around). I'm new to this, and if it works at all I'm sure it will need modification before it can be called a funtional option. Only made one to try and won't know till i get rig put together.
As for the arm. It is a 3/4" Gearwrench. Hoping it can survive the force when reversed chain tension is applied. Spring is only there to apply light tension during forward operation to achieve next "click" for racheting head.
I've seen a few dual sided tensioners on this sight. My concern on those is the shock applied to the driveline components when reversing drives. But I don't know if that is a valid concern in this application.

[hydromike]

As for the arm. It is a 3/4" Gearwrench.

Now, that's bloody brilliant. I didn't realize that it had a rachet action. That eliminates a big part of my concern. I bet it'll take the force quite well, and I see exactly what you mean by the spring. It truly is an automatic chain adjuster, even if you just need to jam it down one notch (like the Max II adjusters).

Nice work....

[Noel Woods]

I missed the ratchet concept initially, now that its been discussed and I see the photo I think its a remarkably sharp idea. Redneck engineering has taught me many things over the course of my life and I think the concept here should work pretty well. Great idea Ladeuce!

[mudbug3]

I am in the middle of this same effort. My setup uses two UHMW plastic "u channels". One on the top of the top chain and one on the bottom of the bottom chain. They are pulled together by a tension spring on each side. The upper u channel and lower you channel are support via 4 bar link to stationary plate on frame. Will assemble one and take a picture tonight. Although I have not driven this setup at this point, the design seems sound.

This is the exact same idea that I had thought about myself and mentioned this idea to Noel Woods, but have yet to build it myself. I don't see why your chain tensioner won't work when driving in forward and reverse directions.

[kunzmm137]

It is a great concept, but I would have concerns about the gearwrench holding up very long. Think of the amount of force that will be suddenly acting against the wrench when you brake one side hard for a tight turn. That chain is going to suddenly be snapped tight with a ton of force. The original tensioners couldn't hold up, and unistrut is strong stuff. Test it out, but I think you will be breaking an expensive wrench after not too long.

[laduece]

Thanks for the complements and concerns.
IF this works at all, I'm sure there is more R&D to come. OR a total "Back to the drawing board" !! LOL
I also like the total floating two shoe type design mentioned. My concern with that type is the shock that will come with each directional force reversion. The slack being controlled by the tensioner will alternate with each force reversion be it brake or traction change causing signifigant shock to drive train components. I have seen someone on this site with a two roller, two arm floating tensioner. Anyone know how that worked out, or if it is still in use ?