counter-rotating props ?

[properchopper]

Just for fun, I re-powered my scale Coast Guard boat with some Titan brushed motors I had left over from the Twinstorm days. The stock wimpy motors turned some wimpy props [ picture]. I want to re-prop and I'd like to know if there's any advantage to install counter-rotating props, and if so, to rotate inward or outward ? The boat has a forward & reverse SC if that matters to the setup. There's a nice selection of eligible props right here, so any input would be well received !

[Jesse J]

Bonewar reports that cats turn better with props that rotate inward (clockwise on the left). I have found this to be true but have not tested other combinations. You may not have pronounced problems without a huge thrust cone like Bonewar and the twin cat brigade.

[Diegoboy]

The general rule in scale boating is:
Inward (as Jesse describes) for speed
Outward for stability

[properchopper]

Thanks for the info. Will go with inward. Since the hull is a semi-displacement design & won't be going that fast it may not make a whole lot of diff, but I'll give inward a try.

[Diegoboy]

Inward will lift the stern...

[properchopper]

Good stuff. Actually the boat's heavily ballasted to keep it from "bobbing" , it pretty much just plows through the water in a "semi-planing" attitude. Looks pretty cool underway; It's a scale model of the 47' Textron Coast Guard rescue/patrol craft & definitly excites my "scale" fascination

[Diegoboy]

I got SJFE into Scale boating!
My plan is slowly coming to light!!!

[785boats]

This may help you decide.

http://www.rcgroups.com/forums/showpost.php?p=8846499&postcount=15

Cheers.
Paul.

[ED66677]

counter rotating props, inward or outward, make a difference on surface piercing props but on fully submerged? not sure if there's any interrest?

[egneg]

I got SJFE into Scale boating!
My plan is slowly coming to light!!!

You don't know it yet but I am getting this delivered tomorrow. My winter project!

[Diegoboy]

I thought he already made a choice?

[Diegoboy]

You don't know it yet but I am getting this delivered tomorrow. My winter project!

Are you going to cut it off the stand and put a motor in it?

[egneg]

Are you going to cut it off the stand and put a motor in it?

That's a stand! ... I thought it was some kind of hydrofoil?

[Jesse J]

Where's the project if it is already built??

[egneg]

Where's the project if it is already built??

It isn't built - it comes as a kit from Dumas.

http://www.horizonhobby.com/Products/Default.aspx?ProdID=DUM1249