pic: 1726 NURC robot prototype

[Jon Jack]

Originally Posted by falconmaster

You are so right about the fan blades, We have had a very hard time finding boat props the size we need. they are either too small or too big. Do you have any ideas where to get them. We find that plane props work, buy you need higher rpms. Ye sthey are not efficient, but they are better than none. We also found that if you use large plane props and cut the tips off they work even better. Find the highest pitch you can. I like the muffin fan idea and it is possible to find ones with blades that are not that flexible. I was even thinking of doing a bollard test with every other blade cut out. Just to see what happens.

Thanks for posting your experience! Its right on. Please let us know where to get props. Do you think Seabotix might sell us just the props?

I did a search on Google for 'RC Boat Propellers' and I found this site. They have a variety of propellers in different sizes ranging from 30-60mm, which seems like the optimal size for this competition. They're also reasonably priced. I would start there.

If someone is interested, I also found a site that sells Kort Nozzels and Kort Nozzle Propeller combos. If you can't find an off the shelf kort nozzle, the least you could do is use some PVC tubing that'll fit closely around the outside of the propeller. A step up would be if you can find something that is tapered towards the prop so you can concentrate the water column increasing your bollard pull.

What are the rules in terms of what motors teams can use on their thrusters?