Re: [WheelWatcher] Attaching Wheelwatcher 1 to Parallax BOE-BOT

[Pete Skeggs <plskeggs@xxxxxxxxxxxxxxxx>]

Steven Paley wrote:

> Has anyone used the WW-01 with a Parallax BOE-BOT? The spacers don't fit if
> the servo's are mounted inside the BOE-BOT frame as recommended by Parallax.
> I could make my own spacers or mount the servos on the outside. I would be
> interested in any recommendations or experiences either way.
>  

Steve,

Please see the photo on our website for the WheelCommander differential 
drive controller -- it shows a BOE-BOT with WheelWatcher encoders on it:
http://www.nubotics.com/products/wc132/index.html
http://www.nubotics.com/graphics/wc132-boebot-600.jpg

It does not show it well, but yes, it works fine if you mount the servos 
on the outside rather than the inside of the frame. 

Note that the preprinted 32 stripe Codewheel Stickers that come with the 
WheelWatcher encoders do not fit well over the hub of the newly designed 
BOE-BOT wheels.  We actually designed the sticker to fit the original 
wheels that Parallax had designed for the BOE-BOT, but in the last year 
they switched to a different wheel design.

The solution to this is to either buy the original wheels, which are 
readily available from Acroname or other vendors:
http://www.acroname.com/robotics/parts/R158-BLACK-GREEN-WHEEL.html

or, you can try cutting or punching the center hole on the stickers to 
be at least .454" in diameter (they are precut to be .392"), being very 
careful to center the new larger hole with respect to the original 
center.  Interestingly, this is the same as removing almost exactly 
1/32" of material around the hole. 

To make this easier, you might be able to obtain a .5" hole punch at 
somewhere like Harbor Freight Tools, which would make the hole larger 
than needed but it should function as long as you center the stripe 
pattern really carefully over the Parallax wheel when you apply the 
sticker to the inside side of it.

Hope this helps.

Sincerely,
Pete Skeggs
Nubotics Tech Support