anyone attached pulleys to "scooter wheels" ?

to other types of wheels.

From looking at the catalog, you could cut aluminum spacers that would go between the ribs on the wheels and allow you to bolt a pulley to the side of the wheel. Depending on the thickness and shape of the webbing in the middle of the wheel that I can't see in the picture, it might be a fair chunk of work to get a flat surfae to bolt the pulley to and if the webbing is thin, the end result might not be too good.

Some of the wheels with metal hubs have holes already drilled for bolting pulleys or sprockets to them with simple round spacers.

A more conventional way to do this is to get wheels that bolt or pin to a shaft, mount the pulley to the shaft and support the shaft with bearings called pillow block bearings.

Surplus Center

has a bunch of different wheel types, pulleys, sprockets and bearings. All for a lot less than McMaster Carr or MSC.

Good Luck, Bob

to other types of wheels.

Thanks for the tip on SurplusCenter ! Those snowmobile bogie wheels look promising! Thanks again ... JCD

The original Budget Robotics Scooterbot used scooter wheels (hence the name "Scooter Bot"). They were actually 64mm polyurethane wheels for inline skates. That size more closely matches the typical 2 1/2" diameter wheel in use on small desktop bots.

I bought the wheels without the bearings, as the bearings weren't needed. In almost all the scooter wheels I've seen everything is sized in metric. That doesn't seem to be the case with the McMaster-Carr wheels, but those dimensions may be approximate anyway. In any case, these kinds of wheels are LOTS cheaper elsewhere. You'll often find the

100mm wheels at various surplus outfits. The 99 Cents Only dollar store was once selling them for $1/pair. I have one (unused) pair left you can have, if you pay the shipping. (Send me e-mail off the list, if you're interested.)

The biggest problem is truing the wheels. This means aligning the wheels to whatever hub you're using so that the wheel doesn't wobble (runout) when it rotates. I machined hub pieces that attached to a standard servo disc, but if you're good with basic shop tools, you can do the same with a fender washer and a drill press. When mounting the wheels I'd suggest a three-screw arrangement -- spaced 120 degrees apart. This will allow you to adjust the tightness of each screw, which will affect the truing of the wheel. You want to minimize wobble. Pretend you're working at Discount Tire.

While I attached a servo disc to mount to an R/C servo motor, the concept is the same whether you are attaching a sprocket. I'd avoid a gear, as that requires a precision most folks can't easily achieve with garage tools.

Depending on the diamter of your driver (disc, sprocket, whatever), you might also be able to mount directly to the body of the wheel. You can drill through the polyurethane if you need to. Don't worry: the air won't get out, leaving with with a flat tire. Modern science!

-- Gordon

pogo wrote:

to other types of wheels.

never had any trouble with it when I had one, it just

I have a couple of scooter wheels leftover from the ER1 expansion kit, so I will hold off on your offer for now, but I sincerely do appreciate it!

This is the real reason I have started on a "wheel quest". The lawnmower wheels I have been using tend to wobble - it seems like the two halves of the rubber part were slapped together not quite evenly - as it rotates one side rises above the other one and then back. It's not a big deal for now, but I do want to get it so it looks like a quality product one of these days. I ordered a pair of the solid rubber wheels from MSC that I plan to experiment with. I'm just trying to educate myself so I don't end up spending tons of $$ on parts that don't quite cut it for my purposes.

That's exactly the kind of feedback I need on attaching the pulleys! I figured either 3 or 5 screws seemed right.

Thanks again !

wheels I have been using tend to wobble - it seems like the

rotates one side rises above the other one and then

quality product one of these days. I ordered a pair of

trying to educate myself so I don't end up spending tons

If you want decent large-diameter wheels with little runout I suggest the kind they use for steering or support wheels in the newer-style wheelchairs. Try outfits like National Power Chair. Expensive yes, but high quality. You can save a bit if you can find the local wheelchair repair shop in your area. Even a used wheel is better than the cheapo injection molded lawn mower wheels.

Small wheels for electric scooters are also a good choice. You can find some on eBay for reasonably cheap, or mail order outfits sell them new for $25-35. These are airless mag or spoke type, and very well made. Diameters from about 6" to about 12".

-- Gordon

Industrial materials handling wheels can be had in many flavours

Perhaps you can turn the robot upside-down and start then wheels rolling, then apply a belt sander to the wheels.

Joe Dunfee

Acutally, I've thought about mounting them in my drill press and doing something similar. Might do it yet ! JCD

Try looking for electric bikes or scooters in disposal stores

sell or were selling motors and parts from electric bikes and scooters. complete rear wheel assembly approx Aus$32 = US$24 Shipping to US would be the cost probably around Aus$50 - 75 for sea mail Alex