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Which propeller for my airboat?

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Old 09-17-2017, 03:01 PM
  #1
rva1945
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Default Which propeller for my airboat?

Hi there!

I just bought a Dualsky Eco 2212C 980KV brushless motor. I want to scratch build an airboat the size of the Aquacraft's Mini Alligator Tours model. I think I should use a propeller similar in diameter to the stock one, a 5.5x4.5 (right?)

Now, there is something like the matching between the motor and the propeller. At the shop where I bought the brushless motor they told me that it can handle a 9x4.7 to 10x5 propeller, according to the motor's specification, of course too large to fit in the cage, unless I build a larger boat. Will the boat flip in a turn with a propeller that size? Or is that motor-propeller matching intended for a larger airboat?

In case I follow the size costraint for the airboat, which is the size and pitch for a brushless motor like this one?

Thanks,
Robert
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Old 09-18-2017, 03:38 PM
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expresscraft
 
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Did you see our 35"x16" hull? its not a deck over just a hull. we made it taller so it would be better in open water. she can be cut down to look more scale. but most Important is this boat runs great on a nitro .60 2 stroke or a .80 four stroke. do not know what electric motor to suggest. We make these hulls for 70.00 .You need to scratch build the rest. But the foundation we provide works very well..
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Old 09-18-2017, 11:27 PM
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you have a small size outrunner with low kv,s so i would say try a 9 x 4 slow fly prop.
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Old 09-19-2017, 03:21 AM
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rva1945
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Thanks! It turns out I have one of those.
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Old 09-19-2017, 03:23 AM
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Now, you mean 9x4 cm or in.? 9in. seems too large for this airboat.
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Old 09-19-2017, 12:26 PM
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i did mean Inches. whats the biggest diameter you can fit ?
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Old 09-19-2017, 04:47 PM
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rva1945
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Well, I guess the Mini Alligator Tours has a rather small propeller, maybe 4in.
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Old 09-20-2017, 01:46 AM
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well you will need a very high kv motor to give some push with a 4 inch prop. its either modify the prop cage so you can fit a decent size prop in it or buy a high kv motor that will power the 4 inch prop well. do you need the prop cage ?
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Old 09-20-2017, 03:41 AM
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I will build the airboat from scratch so I will make the cage too.
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Old 09-20-2017, 11:50 AM
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Quote:
Originally Posted by rva1945 View Post
I will build the airboat from scratch so I will make the cage too.
As soon as they let me post links, I'll send you one or two to my scratch hovercraft in operation. Same idea, just two motors. I'm running 2204 2400kv's (stop me if I said this already) but that's what's required to get enough thrust from the 6040 props I installed on them. Despite my issues with building a reliable skirt that isn't going to tear off the underside of the deck or just get 1000 holes on it the first time I take it up and down the street, ruining the bag inflation. most of the construction techniques follow some of the flitetest techniques, but there's also a lot of stuff I had to build custom including the cage and ducts. Personally, without the skirt it actually hovers about an inch above the ground but once I get it a bit down the street it stats to knock off pieces of the styrofoam body.

Anyway, for your airboat, really, use the bigger prop. Like our friend said, you will not get the thrust you want out of a 5" prop at those slow speeds, and I know you want to get up on plane so..
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