High RPM on a 3/16 "flexshaft

[Chris Harris]

chris, when you run 1527 in saw can you use motor with 5mm shaft? trying to trade my 2230 for a 1527 to run straightaway. dont want failures right off the bat !!

I would not run a 5mm shaft for the 1527 in any case especially for
SAW. It just seems to be too long of a rotor for a 5mm shaft
I have seen them break and it is really ugly, usually taking out the ESC
in the process.

Chris

[gsbuickman]

prefer 3/16 flex & I generally run pro-boat shafts. I try and stay around 37k for sport boating. Like Fluid I have run 42k w/o issue. I did see a 3/16 AQ shaft fracture just behind the collet, after the prop smacked something submerged at the pond.

I am wondering about the 3/16 flex on my vintage 31" shovelnose hydro. Currently it's got a k&b .30 pushing an Octura 1460 prop.
http://www.offshoreelectrics.com/search.php

I thought it would be cool to keep it vintage with a cordite 700 class motor. I have an Astroflight 60v/50A ESC to push it with.
I am thinking of 6s power for 54,000kv. If not I could go 4s for 36000 to be safe. The thing I am wondering is how many amps that prop will pull at 1.4 x 2.36" = 3.304" ?....

Well according to the speed calculator, on 4s this prop is suppose to turn 112 mph. I'll stick to the 56.4 mph estimate on 2s.