Could be good to knowđź‘Ť
Started my build today by making the propeller shaft, is a 20mm solid stainless steel axle, will probably drill a hole through it later to save some weight (it is not cut in right lenght yet)
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I would suggest going smaller with the drive shaft. Everything will need to be bigger, seals, bearings etc. It will add a lot of extra weight. Weight is now a major consideration for me when Im building. It has a nasty habit of sneaking up on you.
I second this. There is no reason to have a shaft larger than 10mm. Even with a prop that requires a larger shaft, it makes more sense to use a bushing instead.
Thanks for respond, might be a bit stuck in the Heavy duty world (last project was a big offroad car)
Will check my local hardware store for bearings and seals today.
They will be cheaper too. Most of our bearing suppliers here go down to 6900 size (10x22x6) for both bearings and seals. Common size makes things easy.
Propeller shaft finished, is now 15mm and has 2 normal bearings and 1 thrust bearing to take up the push load from the propeller and a seal in both ends.
The pull force is applied on a normal bearing through a c-clip but don’t t plan to do any reversing so it should be fine 
Bought a used ple40 gearbox today but it has 1:8 in gearratio, i think it will be okay but i guess i can use a more “aggressive” (bigger or more pitch) propeller to compensate for the lower RPM(compared to a 1:5 gearbox) ?
The assembly is a bit long right now but it is a easy task to short it.
Didn’t know what gearbox i would find so thought it was good to have a long narrow part before the propeller so it can “breath”
Did a test in a lake today with a AEG screwdriver with 1500rpm maximum so probably 1200rpm under the water.
And it pulled hard! Hard to say how much but i guess 5-10kg
Yes, did the same at the Time ! This let you imagine when it is spinning at 3000rpm in water …
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Damn you have access to a nice CNC!!! I wish I could find something that near me.
Yes it is a wonderful machine (Okuma MCR B2) has most stuff but no continous 5axis head and only tiltable in 1degree intervalls.
I’d watch the heat of the ESC being in such close proximity to the batteries.
my plan was just to have it on top of the batteries but i think i have space to put some kind of plate in between or maybe having it lying on the side in front of the batteries.
