how many watts is the 880kv Turnigy T600

can anybody please confirm the watts for this motor? I cannot find the info anywhere, I am using the motor in a fast scale electric boat, and need the info to calculate which prop to use, thanks

http://www.hobbyking.com/hobbycity/store/uh_viewItem.asp?idproduct=11143

Edited by pmdevlin - 08/Jul/2011 at 6:16am

thanks trumpy, I will elablorate! I am running a 6.5kg scale electric boat, way over scale speed, and am testing with a variety of props, data recording with eagle tree. I also have a reduction gearbox, and can easily change the ratio. Started with 2.5:1, but boat was too slow at max speed 12mph (previous motor was an align, and delivered 23mph on same ratio, but kv was 1260). I changed to this lower kv motor to achieve more grunt, as its a big (42") and heavy boat. I then tried 1.25:1 ratio (ignoring the different amp draw readings for now) speed now up to 22mph. Tested this week with 1:1 ratio and I have achieved my required speed of 25mph, but at the cost of very high amp draw (98 max and 2037 max watts). So its now a play off, I really want 25mph, and 20 mins runtime at fast speed, but I think I am over the tolerance of the motor, so will have to down prop to reduce amps and watts. If I go from a 55mm prop, to a 50mm the watts drop to 1944. If I want a lower ampdraw (on 1:1 ratio all amps are 90 to 100 depending on the prop) then I will have to change the ratio back to something more forgiving. I am using 2 x 3 cell 5000mah 35c lipos for 22v, hope that helps!

I am with you on this one Troels
Pmd you are doing a great job of evaluating what the boat can or cant do , but at putting over 2Kw into the driveline and just reaching the 25 mph figure I would be thinking its a draggy hull too , I am no great boat expert either , but all that power has gotta be going somewhere

I am fairly confident in saying though , that you are pretty much using that motor to the best of its abilities . Have you got any means of measuring rpm as well?
you might find its not reaching full potential there by being overpropped and that might account also for high amp draw ?
This might sound silly but trying a prop with a lower pitch might help a little , as the motor can more efficiently reach higher RPM's and possibly the desired speed with a lower amp draw ?
I often think of boat drivelines as like driving with the handbrake on if they are over-propped

The Huntsman 28 is a flying boat, in contrast with a displacement boat, like a tug:



With this kind of hulls, you must reach a lift-speed and after that you have not speed limitations, apart the hull's strength.

A diameter's propeller of 50 mm in direct drive seems to me too larger, it's what I use with low speed workboats. When I overpower them, I can heard the typical cavitation's noise.

So, as Troels and Trumpy do, I recommend to reduce the diameter's propeller, not for the reasons they give (hull's speed), but because it's the only way to reduce the pitch.

The boat propellers have not various pitches for a given diameter, as airplane propellers, the pitch depends on the diameter in a given range, 1.4 diameter for two-blade carbon propellers, 1.2 diameter for two-blade nylon propellers, and 1 diameter for three-blade nylon propellers.

Originally posted by trumpy We must be shopping at different Places for props Jean-P LOL Here I can get an Octura 40mm in Part No   Diam.       Pitch calculation    Shaft size     1240     40mm 1.57" 1.2 x 1.57 = 1.884   .187 1440     40mm 1.57" 1.4 x 1.57 = 2.198 .187 1540     40mm 1.57" 1.5 x 1.57 = 2.355 .187 1640     40mm 1.57" 1.6 x 1.57 = 2.512 .187 1740     40mm 1.57" 1.7 x 1.57 = 2.669 .187 1740/3 40mm 1.57" 1.7 x 1.57 = 2.669 .187

I spoke from propellers having an affordable price, in order to experiment!

A bronze-beryllium Octura propeller (the one available with different pitches) costs between EUR 30.00 and 56.00 here in Europe. They are intended for high performance racers.

By comparison, a nylon or carbon propeller costs about EUR 3.00.