want positraction?

[Sparky]

actually, its not posi. its a selectable locker.

imagine having both axleshafts, not connected, with say, half an inch gap between them.
these axleshafts are spined on the ends. you have a sliding collar, with spines on the inside, that bridges the gap between the axles. but it can slide. so slide one way, locks them together. slide it back, one wheel drive.

http://i14.photobucket.com/albums/a318/sparky96181/bikes/lockeddiff.jpg

this is how transmissions work, so you might could source parts from that.
in a car, this would be called a selectable locker, meaning its not positrack, it is fully locked when engaged, and fully unlocked when open.

you could even get fancy with it and use a cable- actuated "fork" to shift from locked to unlocked. but i would just reach down and do it whenever i felt i needed the extra traction.

[SirJoey]

That's a good idea, Sparky. I've seen this method used in other machine applications,
with a lockable, spring-loaded sleeve, but never considered using it as a "posi" in an HPV.
The sleeve could be easily pinned in either position with a clevis pin, too. Good thinking!


http://img185.imageshack.us/img185/9206/signaturehalloweenvr0.jpg

[greenevegiebeast]

that would be good for a of road hpv, like a hpv fourrunner.

[macka]

In jeeps they make a Y shaped arm that pivots, and it is actualted by a vacuum solenoid, but a lot of guys deep six the POC vacuum unit for a lawn tractor throttle cable to lock in the front end of the 4WD system. They also leave it unlocked for 2 low for pulling applications.

[Sparky]

yup- the jeep application was where i got the idea. if anyone wants more info on that setup, search for jeep YJ front axle disconnect.

[TheKid]

I had a similar design for a reverse gear for my quad, but didn't get around to implementing it. I installed a tube to hold a jackshaft on the hauler, and will attempt to implement the reverse gear on that.

[macka]

yup- the jeep application was where i got the idea. if anyone wants more info on that setup, search for jeep YJ front axle disconnect.

also can be found on madxj dot com

[xPosTech]

You could build a low cost version by grinding (not gonna mention machining) and filing hex ends on the axles and grinding the square drive end off of a deep 6 point impact socket for the slider.

Take your time on the fit of the axle ends because they will wear/fail before the hardened impact socket, although it will get de-tempered somewhat from grinding and welding on the shift mechanism. Re-tempering is fairly easy, though.

Case hardening the axle ends would help for wear. Gargle for easy instructions.

Welding hex stock to the axle ends would work, too.

Or thread the axle ends for the long hex connectors used to connect all-thread, then weld up after the connectors were threaded on the axles.

Thanks for the heads up, Sparky.

Ted

[Sparky]

the socket idea is good. you could then use a bolt head (or nut) welded to the axleshaft.

perhaps a pipe with setscrews and a keyed axleshaft. should work. perhaps multiple keyways/setscrews and a very snug fitting pipe.