VEX Robotics Relaunches VEXpro Product Line with over 120 New & Improved Products

Can you post the dimensions of the VersaHub? Definitely looks like something we'll be using in the near future.

[David Doerr]

Originally Posted by AdamHeard

I've thoroughly read all the product pages along with a few other team members, and for the items like the ballshifters, it is a bit confusing during the first read...

I agree. A close read reveals that the pneumatic and encoder hardware kits are included with the shifter. Those items should probably have "(included with the base kit)" or something similar added to the description.

I hope if you order the optional gear kit along with the 3-stage shifter you get both the 60:24 and 64:20 gear sets - because that's what I did and that's what I wanted...

[DampRobot]

JVN, can you comment on the material of the Ball Shifter casing? I assume it is some sort of plastic. I've had a lot of trouble with polycarb sideplates making motors overheat in drive gearboxes in the past. Have you tested for this? Also, any plan to sell aluminium versions of the casing (as side plates with spacers)?

[JVN]

Originally Posted by DampRobot

JVN, can you comment on the material of the Ball Shifter casing? I assume it is some sort of plastic. I've had a lot of trouble with polycarb sideplates making motors overheat in drive gearboxes in the past. Have you tested for this? Also, any plan to sell aluminium versions of the casing (as side plates with spacers)?

The Ball Shifter casing is Glass-Filled Nylon. I've never heard of motors overheating as you've described. We are not planning to sell an aluminum version, or a side-plate + spacer version -- though the design does lend itself to teams being able to make their own.

-John

[DampRobot]

Originally Posted by JVN

The Ball Shifter casing is Glass-Filled Nylon. I've never heard of motors overheating as you've described. We are not planning to sell an aluminum version, or a side-plate + spacer version -- though the design does lend itself to teams being able to make their own.

-John

Funny, we've often had problems with Fischer Prices overheating in the drive, and many teams use fans on their practice robots to keep their CIMs from overheating (even with aluminium side plates). A little surprising, but interesting nonetheless.

[scottandme]

Are the parts lists for the 2 and 3 stage ball shifters mixed up?

The 2 stage lists "Ball Shifter Long Output Shaft Assembly with 60t and 44t Ball Shifter Gears"

The 3 stage lists "Ball Shifter Short Output Shaft Assembly with 60t and 44t Ball Shifter Gears"

The images (and CAD) show the 2 stage with a shorter output shaft than the 3 stage, which I assume is correct.

Any ideas for using the 3-stage shifter for a WCD/direct driven center wheel? The lower housing hex standoffs look like they will interfere with putting a 16T #25 sprocket on the drive axle to power the front/rear wheels. Turning the gearbox sideways would work, but that eats up >2" of ground clearance, meaning at least 6" wheels would be required.

[MichaelBick]

Originally Posted by scottandme

Are the parts lists for the 2 and 3 stage ball shifters mixed up?

The 2 stage lists "Ball Shifter Long Output Shaft Assembly with 60t and 44t Ball Shifter Gears"

The 3 stage lists "Ball Shifter Short Output Shaft Assembly with 60t and 44t Ball Shifter Gears"

The images (and CAD) show the 2 stage with a shorter output shaft than the 3 stage, which I assume is correct.

Any ideas for using the 3-stage shifter for a WCD/direct driven center wheel? The lower housing hex standoffs look like they will interfere with putting a 16T #25 sprocket on the drive axle to power the front/rear wheels. Turning the gearbox sideways would work, but that eats up >2" of ground clearance, meaning at least 6" wheels would be required.

As far as I've seen, to get a reasonably speedy robot, you need to use 6" wheels anyways. The ball shifter ratios really aren't built for direct driving 4" wheels. That said, the 3rd stage is really versatile. There are a a lot more options that you can get by switching out the 2 default 3rd stage gears ratios for different gears.

[David Doerr]

Originally Posted by scottandme

Any ideas for using the 3-stage shifter for a WCD/direct driven center wheel? The lower housing hex standoffs look like they will interfere with putting a 16T #25 sprocket on the drive axle to power the front/rear wheels. Turning the gearbox sideways would work, but that eats up >2" of ground clearance, meaning at least 6" wheels would be required.

How about turning the gearbox upside-down so the CIMs are on the bottom?

[David Doerr]

Originally Posted by MICHAELABICK

As far as I've seen, to get a reasonably speedy robot, you need to use 6" wheels anyways. The ball shifter ratios really aren't built for direct driving 4" wheels.

What ratio would you want to have in order to drive 4" wheels?

[MichaelBick]

Originally Posted by David Doerr

What ratio would you want to have in order to drive 4" wheels?

IIRC a 30T vex gear and a custom 54T gear make a nice 15-16 FPS(assuming no friction).

[AlecMataloni]

For anyone interested, a friend of mine made a consolidated zip folder with STEP files for every available vexpro product that was just released.

He's hosting it on his google drive: https://docs.google.com/file/d/0Bx6d...FyZTdQSlE/edit

Beware: Google Drive has a download cap, so if someone were to mirror this, that would be appreciated.

[Joe G.]

Originally Posted by David Doerr

What ratio would you want to have in order to drive 4" wheels?

Or, the new VEXpro 34t and 50t will cover the right C-C distance, and provide a theoretical 16.17 fps in high gear.

[scottandme]

Originally Posted by David Doerr

How about turning the gearbox upside-down so the CIMs are on the bottom?

That's the orientation I was looking at.

With 5" wheels, the 60:24 3rd stage would give you speeds of 5.5 ft/s and 12.6 ft/s (probably ~4.5 and ~10.2 after accounting for 80% of theoretical). Current draw would be right under 40A at stall in low gear, which is ideal. Would have been near perfect for the 2012 game.

Playing with making aluminum plates to replace the housing, will be heavier but at least mounting will be easier.

[David Doerr]

Originally Posted by scottandme

That's the orientation I was looking at.

Now I see what you mean. None of the hex standoffs seem positioned optimally for driving the front/rear wheels on a WCD.

[dcarr]

Originally Posted by AlecMataloni

Beware: Google Drive has a download cap, so if someone were to mirror this, that would be appreciated.

http://www.team3309.org/VexPRO_CAD.zip