Slipstream folding propellor

[blackbeard]

In view of the impressive ability of bronze folding propellors to eat expensive anodes, the above propellor, stainless steel and said not to need anodes, looks attractive. It also looks strong, which would be useful in Solent rubbish strewn waters (which also prompts me to ask how well a rope cutter would work in conjuction with a folding prop.)
Has anyone experience of the Slipstream, especially the 2 blade variety? any comments, pro or con?

 

[davidbains]

Have you considered a Kiwi prop with it's Delrin blades. Strong enough for New Zealanders!

 

[blackbeard]

[ QUOTE ]
Have you considered a Kiwi prop with it's Delrin blades. Strong enough for New Zealanders!

[/ QUOTE ]
yes, and I have seen some very favourable comments on this; but I only have the power from the mighty 1GM10 Yanmar, which isn't enough to drive a Kiwiprop. Also, rightly or wrongly, I would prefer a folding prop to a feathering one; go on, tell me I've got this wrong!

 

[Norman_E]

Re: Slipstream folding propeller

Some folding props seem to have difficulty in reverse, because centrifugal force is used to open them, but the propulsion force in reverse is trying to close the blades. Feathering props have blade stops in both directions and some makes can be set to different pitches forward and reverse, so as to give you the best trade off between initial thrust and economy in forward, and maximum thrust in reverse.
A great pity in my view that the Kiwiprop is made for such a limited range of engine sizes.

 

[DaveS]

The manual's on the boat so I can't confirm this directly, but I didn't think there was a lower power limit for the Kiwi - they just cut the blades a bit shorter to match the engine power.

A folder should give a slightly lower drag than a featherer while sailing (though the difference between them is insignificant compared to the reduction in drag with either substituted for a fixed). The downside is the risk of a folder either not opening or delaying opening when starting to motor.

The Kiwi also has awesome thrust in reverse even at minimum revs - which I suppose on consideration might overwhelm a very small engine. From an inadvertant practical experiment I can confirm that engaging reverse while operating a VP 2002 on one cylinder will definitely stall the engine! /forums/images/graemlins/blush.gif

 

[DavidMcMullan]

Kiwi's 3-blade brochure states range of 15-56hp.

 

[roycharles]

Just ordered a Slipstream prop at LIBS to replace the anode eating Volvo bronze folding prop (Volvo have agreed to a refund under warranty!). Looks to be a good piece of kit but I won't have it for another two weeks. I am told that they have sold quite a few in this country and no problems have come to light as yet.

 

[DaveS]

Ah, sorry for the bum steer. That's a shame. As someone mentioned on another thread, it's a pity they don't do a wider range (his motor was too powerful!)