Sorry for the lack of updates, Been crook as last couple of weeks,
Well most of the bottom is sheathed with plywood now the exciting task of sanding before fiberglassing and fairing. Watch this space Lol.

An Early photo of PT1011, Will add more as progress is made
Be kind I am a novice Lol

I was running a 1/24 S-Boot 3 props/ 3 MFA
850's came down to 1 prop 1 brushless just as good.

Ah, I didn't realise you were going to use a gas engine. Hope you've got a gearbox that's up to the job. Sorry, I'm unable to advise on the props.

G.

I am planning to use a 29cc 2T gas engine, Am thinking may I should go for 45mm props, Thoughts please. Thanks for your input Gordon

A 1.5m Brave Borderer is going to need a powerful motor if it's to drive two props through a gearbox. Is there no way you could use two motors, then you could space the shafts as far apart as you like?

G.

Thanks' Doug,
I remember reading somewhere that the space between props should be 1.5-2 times the diameter of the propellers, which calls for a minimum of 82.5.
Thank you for the reply

Hi Chris,
Don't see your problem🙈
If you put two 55mm props tip to tip the distance between their centres will be 55mm.😉
So you will have 78.6-55=23.6mm between the prop blades when the shafts are fitted to the gearbox.

BTW: Our Brave Borderer guru is a great builder and 'good bloke' from Canada.
User name 'Rowen'.
Check out his Brave Borderer Build Blog at link below.
Cheers, Doug😎

https://model-boats.com/blogs/40884?sort=ASC