Prop for ASP 52

[Pilot Ben 28]

 

Has anyone got an idea for a prop for an APS 52. This is for a shoulder wing model(Ripmax Expression) http://www.modelflying.co.uk/reviews/product.asp?p=1421 and it would preferably have a bit of speed.

Thanks,

B

 

[Martin 0]

 

I assume you mean an ASP 0.52 2-stroke - they also do a 0.52 4-stroke, which is a very different beast.

 

Something like a 12x6 or 12x7 is probably good if by "a bit of speed" you mean you want a higher top speed. You could even go down further in diameter, to an 11x7 or 11x8. If you're more interested in acceleration at lower speeds, you could try something with a larger diameter but lower pitch. Be aware that any change in prop will require re-tuning the engine (needle setting(s) and Tx idle position), and that low-diameter, high-pitch props will tend to rev higher and produce more noise.

 

Are you going to bench-run the engine first, or just stick it on the plane and fly it?

 

I have a number of different APC props around this general size. I can't remember the exact ones I have, but you can borrow them some day at the field to try out if you want, once the plane is ready for action. You should probably make sure you're happy that the engine is run in to your satisfaction before you start fiddling with different props, though.

 

There are some prop suggestions and corresponding measured max RPM in this review:

http://www.justengines.co.uk/acatalog/c ... 2__S_.html

 

[Bravedan 106]

AND...........as Martin says, factor in that speed is not all you are aiming for, you need to meet the Club's noise level requirement..............some prop combinations on that engine will DEFINITELY fail you.

[Peter Royall 47]

 

I use an 11 X 7 prop on the 52's that I use, but rarely go full throttle because a) its not necessary and b) a lot of db can be generated because of prop tip speed.

A 12 X 6 is ok, but will take time to slow down when u want to be at tickover for landing.

Hope that helps?

Oily

 

[Martin 0]

 

FWIW, I've just checked the IC props in my box, and this is what I have:

 

• APC 11x6

• APC 12x4

APC 12x7

APC 13x4

APC 13x6

APC 13x7

 

11x6 and 12x4 are probably a bit light for a 52 (the 12x4 might be OK, but you want speed so I'd go for a higher pitch than that). They were the ones I used on 46 size engines.

 

There is also an APC 12x6 which looks suspiciously like an electric prop, even though I'm sure I bought it as an IC one (I don't know why I would have bought 12x6 electric, and it's not in a bag with shaft adapters like their electrics normally are). I have a 12x6 on the OS 55 AX on my WOT 4 and I'm sure this was bought as a spare.

 

I also have a Master Airscrew 11x6 free to anyone who wants it!

 

Anyway, these props live in the box I normally bring to the field, so just ask me when I'm there if you want to try them out. I also have a tacho in the toolbox I normally bring.