Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[benjaml1]

Hull type: Wide beam ( Orion moldings "Fifie") Open working boat 1/6 scale
Engine: Stuart Turner "Sun" 3/4" x3/4" single acting twin. Max RPM guestimation 2000rpm
Displacement: Approx 50 pounds

Any recommendations on propeller size/pitch ? I want a scale presence on the water...

Ta in advance... 

[kno3]

I don't know, but did you try asking the people at Propshop?

[benjaml1]

I don't know, but did you try asking the people at Propshop?

Thank you for that, I am going to but thought I would ask the experienced forum first.... 

[kno3]

Looks like the experienced forum is either on vacation or clueless 

[benjaml1]

Looks like the experienced forum is either on vacation or clueless  

116 views & one reply...

Naaa.... This is a tough one. I can work out the pitch as the boat is a displacement hull with a lot of drag requiring a higher slip in the calculation. Diameter ? Well I could go for scale of 1/6th but just wondering what everyone else was using really... 3 blade, 4 blade etc...

Thank you kno3....  

[kno3]

If it's a slow revving engine, then use a prop with 4 blades. I'd go first with what looks good to you, evaluate the performance and then change the prop if needed.

[benjaml1]

Thanks for that... 

[steamboatmodel]

I remember someone saying one inch of prop for every 1/4" of cylinder dia. I normally ether fit a prop to the scale of the boat or the largest one that will fit.
Regards,
Gerald.

[benjaml1]

I remember someone saying one inch of prop for every 1/4" of cylinder dia. I normally ether fit a prop to the scale of the boat or the largest one that will fit.
Regards,
Gerald.

That would make sense, thanks for that Gerald... 

[BarryM]

Benj,

I have an old MB article on sizing of steam plant props that may help. PM me with your email address and I will forward it.

Barry M

[benjaml1]

Thanks Barry, PM on the way... 

[SteamboatPhil]

On mine I used a 4" dia x 10pitch 2 bladed, but then I was running a high speed flash plant. My second had a 3" dia x 6" pitch 3 bladed which pushed a 5ft long boat along at more than a brisk walking place. The prop was similar to the Stuarts props they did years ago. Sadly I can't remember where I got it from (it was more than a couple of years ago  ) You could try something around that size to start off with, and as kno3 has suggested try a couple of others (try with a few cheap plastic ones--that always helps the budget  )

[benjaml1]

Good advice on the plastic ones, never thought of that...