connecting Versaplanetary gearbox
 

Pardon the stupid question in advance. Almost-lone (and non-engineering) mentor trying to help kids figure stuff out, here... :)

We have some Vex versaplanetary gearboxes attached to a couple of bag motors to drive two mechanisms. They have 1/2" hex shaft outputs, and we wanted to connect them to a longer shaft that stretches across the body of the robot.

However, hex shaft couplers are totally out of stock at Vex (as is everything else). Is there some other way to connect the shafts, or someplace else to order a shaft coupler?

Feeling really dumb, here. Thanks for any help.

Re: connecting Versaplanetary gearbox
 

In a pinch I've used VEX hex spacers as a shaft coupler. You can use shaft collars or a bit of glue to hold it in place. http://www.vexrobotics.com/acetalspacers-vexpro.html

Re: connecting Versaplanetary gearbox
 

That's exactly what we're doing, now (plus a layer of duct tape), and we're afraid it won't hold, but maybe it will. How much of a load could it take? This is for a pivot arm that doesn't have too much of a load on it.

Thanks for the feedback!

Re: connecting Versaplanetary gearbox
 

I suggest ordering a few colson live hubs from Vexpro and putting some setscrews in. http://www.vexrobotics.com/vexpro/mo...sonhubs-g.html

We have one hex to hex coupler we are not using.
http://www.vexrobotics.com/vexpro/ha.../217-4008.html

Also one of the colson live hubs.

We went a different direction.

PM me your address and I will put both in the mail in the morning.

Re: connecting Versaplanetary gearbox
 

You could use one of these -

https://www.andymark.com/Hub-p/am-0096a.htm

Re: connecting Versaplanetary gearbox
 

Thanks for your kind offer! I recall that we have a couple of the AndyMark hubs that Chris Fultz suggests, so I will have someone check that first thing tomorrow. If we don't have anything that works, you'll be hearing from me.

I appreciate all the feedback. I was just thinking that we were probably missing something obvious.

Re: connecting Versaplanetary gearbox
 

We have had good luck with cutting off a 1/4-20 bolt and screwing them together and using a shaft collar to keep them from spinning off.

Re: connecting Versaplanetary gearbox
 

BSV,
Duct tape does not a fastener make.

Re: connecting Versaplanetary gearbox
 

As part of our climber mechanism, we just cut the adapter off of a 1/2" hex deep wall socket. It seems to work fine. I'm sure you could find one at any hardware or automotive store.

Re: connecting Versaplanetary gearbox
 

Clever.

Re: connecting Versaplanetary gearbox
 

Other option is to use the 1/2 round output on the Versaplanatary, turn~ half an inch of the Hex shaft to .500 round on a lathe, and use standard and common round coupler.

Re: connecting Versaplanetary gearbox
 

If you or someone you know has access to a 1/2" hex broach, you could make your own out of a piece of 3/4 or 1" aluminum bar and a couple of setscrews. You could also make one without the hex by drilling and boring (for concentricity) a piece of 3/4 bar. Setscrews could lock it in place and transfer torque.

Re: connecting Versaplanetary gearbox
 

But, but, but.... the MythBusters use it for everything!

Haha, no kidding. That was only temporary.

Re: connecting Versaplanetary gearbox
 

Oh, this is a nice idea, too. Backup plan if the hex hubs don't turn up. We'll find out this evening.

We unfortunately do not have any lathe capabilities (yet. I am hoping to change this if we can ever attract any real mentors into the fold.)

Re: connecting Versaplanetary gearbox
 

Last year my team extended the versaplanetary output shafts by threading another piece of thunderhex shaft onto the end and using a hex collar over the seam to keep it all together. Worked great and held up the whole season on both sides of our elevator.

Re: connecting Versaplanetary gearbox
 

We don't have easy lathe access either, so we just cut it off with a chop saw equipped for steel.

Re: connecting Versaplanetary gearbox
 

How big was this hex collar? If it is the size I'm thinking of (the ones from Vex), I am very surprised that worked. I definitely don't think it would last this season with robot-on-robot defense and banging over defenses. I suppose if you had a longer shaft collar it might work, but at a certain point you blur the line between collar and coupler.

Re: connecting Versaplanetary gearbox
 

You could get the hex coupler from The Robot Space:

http://www.therobotspace.com/Product...e=vex-217-4008

Re: connecting Versaplanetary gearbox
 

Or West Coast Products:

http://www.wcproducts.net/217-4008

Re: connecting Versaplanetary gearbox
 

Try taking a 2-3" long hex spacer and band saw a cut down the the length around 1/2": Use a hose clamp to tighten.

Re: connecting Versaplanetary gearbox
 

Try mcmaster.... http://www.mcmaster.com/#9063t33/=11an9gg
the link is to 1/8" wall they also sell 1/4" wall. 222 has not ordered any of this stock so I cannot comment on if it will work or not, but it's worth a shot.