Hi,
Ive been running Grauper 2317.51 L anr R rotation props on one of my cat but I keep breaking blades so know its time to buy a pair of proper props .
What size props would be equivalent to these props?
I emailed Dasboata and he suggested Octura 450/3 L&R, 457 2 blades or prop shop 5518/3.
I dont know alot about props so could someone please give me some advise or point me in the right direction.
Thanks Peter

If you are currently running the CF Graupner props they have the same pitch of the octura x4 series of props. If everything is running well for you on the 51mm props the Octura x450 L/R will be almost identical (less 1mm diameter) to your current props. Jumping from a 50/51mm prop to 57mm props (octura x457s) is a huge jump. If your system can't handle the load of that big of a prop bad things can and will happen. I would say if the Graupner props are working well for you then the Octura x450s would be the best choice for you. Even though you are losing 1mm in diameter you should not see a decrease in performance. The CF props also flex under load, so the metal 450s even slightly smaller may actually perform better because they can maintain their shape under load. My vote is for the x450s hopefully this information helps.<div>
</div><div>By the way what is your setup?</div>

Thanks for the reply Diesel, its a medium MHZ Mystic cat 1160mm long running twin neu 1912 (counter rotating) HV Castle ESC and 2x 10s 5000mAh 30c thunderpower packs.
I think I will go for the Octura 450/3 and see how the boat goes from there.
I have ran 57mm props on the boat but I kept breaking the joint where the flex cable is loctited into the shaft.

sounds like you should have gone with a thicker flex shaft. I think the metal props will get you out of the hole faster, my metal props all seem to come on plane faster then any plastic prop i've tried. plus i think they sound better and make the boat look better, out of the water at least. seems like the x450's will be a winner, i know prop selection gets limited when you need l/r rotation.

No the cable itself isnt breaking, its were the the cable is joined to the shaft breaks. Mayby I should say the joint lets go. I will look into soldering the joint. im going to get the 450/3 as I think these would be a good starting point.