[PSUBS-MAILIST] Group Help Request

[Joe Perkel]

How can a home builder maintain that contour 360 Deg out of "X" material?

Joe

Sent from my overpriced 
iPhone

On Oct 28, 2013, at 2:57 AM, Marc de Piolenc <piolenc at archivale.com> wrote:

> Quick clarification: a properly contoured Kort nozzle, MARRIED TO A MATCHING PROPELLER, will increase static and low-speed thrust. Of course it won't increase power, since that comes from your motor. If you just put a shroud around your existing prop, you will be disappointed, and a shroud that doesn't do the job is overpriced unless it's free! Key ingredients for success:
> 
> Prop matched to the shroud
> Shroud matched to the speed and thrust requirement of the vehicle
> Motor matched to the resulting prop
> 
> Marc
> 
> On 10/28/2013 8:33 AM, Jon Wallace wrote:
>> 
>> What is the cost of having a true Kort nozzle machined by a CNC? I think
>> a 30% improvement in thrust for $30 would be great but I suspect
>> machining a Kort is going to equate to many hundreds of dollars, if not
>> reaching beyond a thousand.  When I look at the Snoopy underwater videos
>> it is difficult to imagine a kort nozzle really making any difference in
>> the operational experience given that the motors are operating very
>> slowly and pushing Snoopy around at about 2 knots (estimated).  The
>> props are designed for power, but that's what we want underwater.  True,
>> a kort nozzle would increase that power but what is the return on the
>> cost?  In other words, on a road with a speed limit of 30mph and no
>> passing zones it doesn't matter whether you have a 1.6 liter or 5.4
>> liter engine under the hood does it?
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