Re: Using a turret? Whatre your ideas on elevator design?
 

Maybe a motor with an encoder. Can you fit an encoder on a window motor? or maybe on that new andymark planetary gear?

Re: Using a turret? Whatre your ideas on elevator design?
 

You can do it on the cheap very easily. Like this:

http://www.youtube.com/watch?v=rfFGw...C65188EFF4A22D

We used a globe motor and a large gear from the kit. For the large gear, we cut out a circle, bolted it to a lazy susan, and then stapled belting around the outside.

...it was absolutely, disastrously the wrong solution for Lunacy, but I think it could work quite well for Rebound Rumble.

Oh, and with lazy susan, belt, and gear in the kit, the net cost was somewhere around $4 for the plywood.

It's worth noting as well that the shooter was very wide because orbit balls were so frustratingly irregular -- methinks you could get away with a pitching machine-style pair of wheels with these balls. (Prototyping is yet to come for us on that score!)

Re: Using a turret? Whatre your ideas on elevator design?
 

A large pulley such as used on a swamp cooler (it's a southwest thing), and a V belt is how we did it in 2009. Worked great. We used ball bearings that fit in the pulley over the belt to support the turret.

here's a partial view of how it was built. I think it was still a prototype at this stage, but the same turret drive/support parts were used on the final version.

Re: Using a turret? Whatre your ideas on elevator design?
 

I had this idea, which our team is currently working on, where you make a half-circle of wireframe pipe that can fit the ball from under the 'bot to the top, then put at the center of the circle a wheel with prongs sticking out of it that move the balls around the loop (the prongs stick through the tube). Does that make sense?

Re: Using a turret? Whatre your ideas on elevator design?
 

If you can deal with the turret having a limited range of motion, your "sprocket" can be a wooden disk with chain bolted to the outer edge and driven by a smaller sprocket. You can either have the chain make a typical loop around the driving sprocket, or just have the chain in a circle around the disk and drive it as if it were a gear.

Re: Using a turret? Whatre your ideas on elevator design?
 

I heard a good one today from my students - take small sprockets of the right pitch, cut them in half or quarters, and attach them around the turret to simulate a large sprocket. No reason a large sprocket needs /every/ tooth. :]

Re: Using a turret? Whatre your ideas on elevator design?
 

In 2009, in the game lunacy one of the teams i watched used these things called Polycord. They are essentially plastic bands that are put around rollers at either end. These cords work extremely fast and efficiently. Look up the Team Cyber Blue from 2009, or 1114 from the 2006 competition.

Re: Using a turret? Whatre your ideas on elevator design?
 

If I am understanding correctly what it is that Alan is suggesting, you could also apply a torsion spring to the axis of the large wooden disk, wrap the chain around almost the entire disk and come up with other creative ideas to get close to 360 degrees of motion.

Re: Using a turret? Whatre your ideas on elevator design?
 

Otherwise know as a vortex lift, it takes up space. Poly-cord on a vertical conveyor belt is lighter and doesn't require and special bent material.

Re: Using a turret? Whatre your ideas on elevator design?
 

We didn't use any special bent material to make our "vortex", the sprinkler tube comes from Home Depot in helical coils.

Polycord is probably a good solution this year, since we don't need to store many balls.

Re: Using a turret? Whatre your ideas on elevator design?
 

High friction belts under tension does wonders for all kinds of movement.

Re: Using a turret? Whatre your ideas on elevator design?
 

1747 did that in 2009 with great success...

http://www.chiefdelphi.com/media/photos/32733

(the turret motor is in the back; a globe)

we used a large AL lazy suzan and cut and drilled washers to interface the chain to the turret. the chain was nylon. the only time it failed was when some programmers were using it to test the new classmate in 2010... the chain became derailed... easily fixable.

Re: Using a turret? Whatre your ideas on elevator design?
 

In 2005, Team 401 powered a turret by drilling holes on the top of a circular disc at a fixed distance apart. The distance between holes matched the pitch between the teeth of a sprocket (used normally to drive chain). The sprocket was set perpendicular to the disc and driven with a motor. It was kind of a poor man's gear and worked great. The best part is, you can make it with just a drill press, although a jig to help you make a consistent set of holes helped a lot. Just make sure you do your math correct and end up with an whole number of holes comprising your circle. Definitely measure three times, drill once.

Re: Using a turret? Whatre your ideas on elevator design?
 

or just limit it to a set amount of the circle...

Re: Using a turret? Whatre your ideas on elevator design?
 

Belts, yes belts ... we're on the same page. I've been searching through online catalogs, and there is an astounding number of different belts in the world.
For our vertical ball elevator, we would be looking for a seamless flat belt, about three inches wide and spanning a distance of about three balls. So the length of the belt would be a bit more than 4 feet, depending on the pulley diameters.
Can anyone lead me to a specific supply and catalog page for such a belt?
Thanks!