Rutland 503 spec - RPM?

[gotwind2]

Has anyone here had any experience of the Rutland 503?

I need to know the cut in rpm and max rpm of this tiny 20" (500mm)diameter prop please, or maybe there is a formula to find out the rpm from the data on their site?

I know it needs a real gust to get anything out of it, but I can get hold of just the 6 bladed injection moulded prop for £27 ($50) and I can hopefully make an alternator to suit.

Manufacturers website

http://www.marlec.co.uk/products/prods/rut503.htm#

It costs a ridiculous £260 ($500)new - for about 20 watts of power :/

Cheers

Ben.

[TomW]

Ben;



I need to know the cut in rpm and max rpm of this tiny 20" (500mm)diameter prop please

Props do not determine "cut in RPM", the alternator is what determines what RPM is needed to reach charging voltage or "cut in".

Just thought that was important to point out the subtle difference...

Good luck.

Cheers.

TomW

[bob golding]

hi not wanting to be negative here. i dont know the answers you are seeking but, in my expererance of these things, i did have one and sold it on pretty sharpist, i woulndt bother. you would get much more out of a set of pvc pipe blades and get about 25 quid change as well. if you can find some 6 inch yellow gas pipe they would make a good pipe type prop and being polyelthylene rather than pvc they wont suffer from fagtigue cracking like pvc. or if you are after a small turbine to play with i still have the plans for the japanese kids windmill type rotor somewhere. sorry i didnt answer your question, i dont know. about 400 rmp at a guess. they are very frienly so might be worth just dropping them an email or phone them. contact me off list if you want the plans for the japanese design.

cheers

bob golding

[CG]

I think I could find something better than those blades to spend 27 quid on. PVC guttering for one thing. http://www.fieldlines.com/story/2005/10/17/1228/6385

[dconn]

Hi,

I've wiped out about 4 Rutland 913 and a couple of their Furlmatic 910-3s - just from too much wind (tops of hills for wireless Internet).  They seem very prone to self destruction.

Derek