$40 Robot Caster

[Parth]

Hi all! I was just wondering if the $40 robot needed some type of caster or if it works just fine on its 2 wheels. Thanks in advance!

[pomprocker]

it would not be $40 if it needed a castor 

[paulstreats]

Also, i suppose its up to you. If you want to improve on the $40 robot then add a castor and tell us all what you used

[Parth]

Will do! If I ever find the time and the materials needed, I will definately test out the caster idea. I'll post my results! Thanks paulstreats, you've been a big help with all of my other questions too!

[bens]

Not to spam, but Pololu makes a line of fairly inexpensive ball casters designed specifically to serve as a third point of contact for small robots:

http://www.pololu.com/catalog/category/45

I have no idea if these would work with the robot you are building.


- Ben

[pomprocker]

it's been suggested by some experts to use a drawer handle as so:

http://members.cox.net/rbirac2/Ebot/casters.htm

[Parth]

Alright, thanks for the replies! I'll try out the Polulu idea, but first I have to get some money to build the darn thing Once I build it, I will post my results (if it needed a caster).

[Pratheek]

The robot doesn't use any castor wheel. But it uses a LED as a third wheel.
The LED is soldered to the sensor module.



You can see the LED clearly in the above picture.

[Parth]

Yeah I saw that pic with the LED and that's what gave me the idea of having a caster

[jman571]

I just went to my local Home Depot, and they have a good selection of "shopping cart wheel" style casters in various sizes. They range anywhere from about 4cm in height to massive wheelbarrow size ones. They have 4 pre-drilled holes in the corners so you can attach it to something. It didn't take too long to find the correct bolt size and I was soon good to go. It works well, although it did need a good spray of WD-40 onto the ball-bearings to allow it to rotate smoother.This didn't cost me more than $2 CAD.

Although you can't find the products on their website, when I went there was tons of them sitting in different bins.

Note: I live in Toronto, Canada. I also found identical casters at a local Canadian Tire. Lowe's might have them too, but I can't confirm that.

[Admin]

they have a good selection of "shopping cart wheel" style casters in various sizes.

The problem with these casters is that they are really heavy - they are rated for hundreds of pounds, yet your robot weighs less than one pound typically

Look around for lightweight plastic types.

[izua]

get these
cheap, small, inexpensive, translucent :> you really can't ask for more. and you get three!

i bought some and they're pretty cool.

[Admin]

Oh, I don't recommend ball casters because of clearance.

If the ball is 1" diameter, your clearance will be about ~.3". Less clearance for smaller balls . . .

But for flat floors, they work great . . .

[Centaur]

1/2 ping pong ball works well

[bens]

If the ball is 1" diameter, your clearance will be about ~.3". Less clearance for smaller balls . . .

This 1" ball caster can actually give you the full 0.5" clearance because of the the way caster's housing is designed, and it has the benefit of being both light (all plastic) and low friction (due to the three delrin dowel pins).  In general, the various size ball casters we offer aren't for heavier duty applications but rather for increased or decreased clearance.  They're definitely not intended for outdoors applications or robots that will encounter rough/rugged terrain.

- Ben