In my application I need six GT2/GT3 aluminum timing pulleys with tapered bushings. The three smaller ones must come from stock (cost issues) the bigger ones must be made to order. I will use Gates PowerGrip GT3 540 3MGT 9; GT3 600 3MGT 15 and GT3 850 5MGT 25 timing belts. I need quality suppliers for the synchronous sprockets. Here is where I went so far:

SDP/SI doesn't have what I want.

I have a quotation request on CMT (www.cmtco.com). Their Concentric Maxi Torque bushing system is fantastic. It allows the biggest shafts on small sprockets I have ever seen. They have the smaller sprockets on stock.

I have a quotation request on Walther Flender (www.walther-flender.de). I had to provide detailed drawings for all the sprockets. No stock whatsoever. All sprockets made to order.

The month of August is terrible. Vacations time everywhere and my dead lines are approaching. Can anyone be so kind to point me alternative suppliers. I'm afraid CMT might not have delivery times compatible with my project.

Thanks in advance for all your cooperation.

Regards

Looking at my catalogue from common drives, such as T, AT, HTD and L, I saw you moved somewhat in the direction of the unobtainables. Google learned that GT is a proprieetary design of Gates ...sold through Gates approved dealers...., then Google "GT2 Gates Europe" gave this:
http://www.gates.com/Europe/brochure.cfm?brochure=2207&location_id=3628
They are in Spain. Hope this helps.

Gates is a belt supplier. Pulleys generally come from third party quality suppliers. When space saving and backlash is an issue there is no mach for Gates GT3 belt design. My project is a robot loading application. It includes a circular storage drum (600mm diam) that must index 20 radial positions (72Nm - 12,5rpm). The motor is a Siemens 1FK7022 (0,6Nm - 6000rpm) geared down with a 3 stage belt drive (ratio 120:1). GT3 belt design allows me to use 3mm pitch on the first two stages and 5mm on the last one, it's a neat and compact design. In the event of a power failure the mechanical motor brake induces a braking torque of 132Nm on the storage drum. All the standards you mentioned come up with a bigger and more expensive coupling. An anti-backlash worm gear for these torque values would not be cost effective.

Comparative performance ratings in Watts (source: manufacturers own catalogues)

Atlanta HTD 3M timing belt (width = 9mm; 28 teeth small pulley) @ 1000rpm => 146W
Gates PowerGrip GT3 3M timing belt (width = 9mm; 28 teeth small pulley) @ 1000rpm => 387W

Atlanta HTD 5M timing belt (width = 9mm; 28 teeth small pulley) @ 1000rpm => 483W
Gates PowerGrip GT3 5M timing belt (width = 9mm; 28 teeth small pulley) @ 1000rpm => 787W

The numbers speak for themselves...

I am not critisizing your choice nor your power calculations. It's only that you now have a good design.. on paper. If the pulleys have to be made on order, because of non-catalogue number of teeth or being non-stock you have a problem. Small numbers are last served and expensive. A design should also be based (and if needed compromised) on availability of the needed parts. Good luck.

Thanks fkaCarel for your input. Didn't take as criticism. Just opening to everyone the reason of my choice, that's what this forum is all about. Half of the pulleys (Number of teeth >= 136) would have to be made to order whatever the standard. SDP/SI offers a GT2 5M aluminum pulley (28 grooves, 9mm width) for $13,70 USD (I just would like to dodge set screws and Fairloc collars).

A couple of years ago I was going to use some CMT pulleys. As I recall, they quoted a lead time of at least a couple of weeks. I've had samples - they are beautifully made.

Maybe these guys have something: http://www.talonbearing.com/power_transmission_products.htm#roller_chain

CMT quoted yesterday the 6 standard pulleys to $3,200 USD. They don't have anything in stock. Everything is made to order.

I converted the project to Gates HTD and ordered today all the 6 pulleys, taper bushes and Gates belts to AIRE Bearings - UK for less than $350 USD. They took 2 hours to answer my e-mail quotation request. I call this a service guys...

[QUOTE=interflexo;195286]CMT quoted yesterday the 6 standard pulleys to $3,200 USD. They don't have anything in stock. Everything is made to order.

3200 BUCKS! did you specify gold for the material or did they just ass-ume
thats what you wanted.

The material would be aluminum with clear anodized finishing. They have big series in production. If someone orders 6 different pulleys (1 un. each) you have to pay for the job preparation. The lead time would be 4 to 6 weeks. At the phone they said it would be expensive but there is expensive and EXPENSIVE! I assume they deliver top quality work.

On the Aire Bearings order regarding the big pulleys we are talking about:

One 367mm Diam, 144 teeth, HTD 8M, 30mm width with taper bore
Two 216mm Diam, 136 teeth, HTD 5M, 15mm width with taper bore

3 smaller ones
6 taper bushes
3 Gates HTD belts
1 shaft Drivelock 70 bush

Lead time 1 to 2 days. Everything in stock...