Toothed pulley sources

[Beakster]

Hi,

Any idea where I would find a toothed pulley to bolt to my helm wheel which I can then drive from a motor?  Also what size should I be looking for?

The largest I've found is this 190mm one 
Belt Drive Driving Sprocket Kit for 2 Stroke 66cc 80CC Engine Motorized Bicycle https://a.co/d/5EGOh96

It looks to me as if the commerical autopilot kits are using a pulley that's about 300mm.

Thanks

[seandepagnier]

It is possible to 3d print one, however my printer maxed out at 280mm and was slightly eccentric. I used hdt5m type belt.

[Sully]

I'm also struggling to find the correct gear for a wheel drive.

Pulleys are not as available as I thought. Apart from those you found in AliExpress, I found these. I still have doubts if this would be optimal for our purpose, as long as:

1) They would attach directly to the wheel shaft, in contrast to the use of J anchor bolts to the wheel spokes in other mountings (like CPT autopilot, Raymarine, etc...).

2) Their diameter is much smaller than those other J bolts mountings (16 cm vs 30 cm?).

On the other hand, following Sean advice, 3D printing may be the best option. I found some designs online (e.g. https://www.thingiverse.com/thing:5492156, https://www.thingiverse.com/thing:3636189), but no one adapts 100% to what I need and I don't have a printer nor knowledge on design. 

There is a thread in this forum where Sean posted his designs: https://forum.openmarine.net/showthread.php?tid=4342 and https://drive.google.com/drive/folders/1...BwMoeFjrUV. So I will probably try this and see what happens.