HTD 5m steel pulley.

Here are some , buy you may need to shop around to find a drive with fewer teeth.

I think you will find that most come as a MPB (Minimum Plane Bore) and that you will have to machine the bore to the size wanted.
A key is a bit trickier but eChuck did it by drilling a hole off center to accomodate the key before boring the shaft hole, he then made a radius on the key to fit the offset hole radius.

Dave

MB-1-E
Electric - Bridgestone MB-1 Mountain Bike
Icon Photo of lighning striking Eiffel Tower Jun 3, 1902, taken by MG Loppe'

Check out echuck5's post below the first one and Chuck describes it better than I did.

It depends on the size shaft you are putting this on, but mine (and Chucks) is a 5/8" dia. keyed motor shaft.
Since a key for my shaft is 3/16" square, a 3/16" dia. hole can be drilled 5/16" from the center of the sprocket (the distance of the radius of the shaft.) 5/8" shaft has a 5/16" radius.

Once you have this 3/16" hole, then you bore the 5/8" dia. hole for the shaft. It will cut half way through the 3/16" hole that you just drilled leaving a half moon key slot.
Next you would take the key itself and round over the top of the key so it's half moon shaped and fits right into the half moon shape of the key slot in the sprocket.

I can't seem to get my pics dark enough, but you should be able to get the idea from this.

Dave

MB-1-E
Electric - Bridgestone MB-1 Mountain Bike
Icon Photo of lighning striking Eiffel Tower Jun 3, 1902, taken by MG Loppe'

What size (how many teeth) are you looking for.
5mm sprockets were used on a number of scooters and might be available as a replacement part.
The original Zappy used a 5m-15 sprocket with 13 teeth.

Here's the result in a little better detail ...

Hope this helps.

Dave

MB-1-E
Electric - Bridgestone MB-1 Mountain Bike
Icon Photo of lighning striking Eiffel Tower Jun 3, 1902, taken by MG Loppe'

Thanks Dave for posting the diagram.

I can't. Last version of autocad I owned was 98 lite 2d. Switched to turbocad which won't make a jpeg image. First time I found something that turbocad would'nt do that autocad does. Current version of turbocad I have is version 8, probably four years old, I'll see if the latest release will do this jpeg stuff, turbocad otherwise works great.

chuck

Actually I have to export from AutoCAD as a BMP (bitmap) image then translate it to a jpeg via Infranview (a very handy [free] image tool.
There's probably a better way but this is the way I do it.

I never tried Turbo-CAD but maybe I will one day.
I hate the way AutoCAD treats it's customers, they are always trying to make stuff obsolete and non-interchangable so you have to upgrade to keep in business. I'd boycott them if I could, but they got me by the shorthairs, I draft for a living and it's pretty much the industry standard (and boy do they know it). I may just see about compatability of some of these others, it they aren't too different, I could handle and appreciate the change.

Dave

MB-1-E
Electric - Bridgestone MB-1 Mountain Bike
Icon Photo of lighning striking Eiffel Tower Jun 3, 1902, taken by MG Loppe'

Dave,

Way off topic, but.

My Dad is the engineer. In the early days of Auto-Cad, I remember having to type in coordinates, then came the digitizer, wow, I could draw it faster now than by hand.

I think my Dad switched to Turbo-Cad in the early 90's. Auto Desk had programs just as good for Turbo as for Auto-Cad. Borland suite had Coral Draw, it, truly, was the best software I found for converting files. It worked great with Turbo-Cad. That is what I am looking for, just a simple intermedary software that works with images of all kinds.

ps,
Paid $50 for my last version of Turbo-Cad at an office supply store.

chuck

Hi Edirtbiker,

I don't really know how the anodizing will effect them but I do know that the ones that I got from Gates and SDP are already anodized and are a very tough alloy I drilled one and it curled out and chipped pieces rather than smearing them like some softer aluminum that I've drilled.

If your belt is not slipping, they should wear quite well. As you also probably know, the larger the diameter of the grooved pulley the more teeth you will have in contact with the belt at any given time.

It sounds like you have access to some machine tools, you can purchase the pulley material in extruded stock and just cut it off at the width you want and make multiple pulleys ahead of time. I believe you can get flanges as well if you need them.

I'm pretty sure you can find the steel ones from Gates, although I don't like dealing with Gates at all. I think they tend to look at the sale of a couple of pulleys as an inconvience for them.
Very unlike other parts suppliers that I've delt with.

Good luck and keep us posted.

Dave

MB-1-E
Electric - Bridgestone MB-1 Mountain Bike
Icon Photo of lighning striking Eiffel Tower Jun 3, 1902, taken by MG Loppe'

`
I'm not sure, but I beleive Chas has.

Peace Out,
Gman

Now that we have clarified our beliefs, your invited to join us as we begin building on them to define our Community Mission Statement

I have 3 bikes which use internally geared hubs and work very well. One 4-speed, One 7-speed and one 3-speed hub, all made by Nexus. The 3-speed is a very heavy trike and has been driven over 750 miles with no problems from the 3-speed hub. I have a 7-speed to replace it but haven't had a chance to make the change. The other is a bike the "Merida" which was manufactured with the Nexus 4-speed, so there are lots of these bikes in use. The last is another Merida which has a 7-speed. This is the bike my brother-in-law uses to ride to work and back almost everyday. He lost his licenses so I let him use this bike till he can get one again in 2008. This bike has been going strong for 3 years. The 7-speed gives the Merida a 29 MPH top speed.

I like the ability to shift gears when you need to climb a hill or just get up to speed quickly. I live in a very hilly area and the gears were required for me to pull up some of the steeper one.

One point about shifting. You can shift from low to high (up-shift) while under power but you must let off the throttle for just an instant to down-shift. My brakes have disable switches so if I tap the brake lever when I down-shift that is enough to let the hub shift.

Gears the way to go,
Chas S.
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