help with props

[DANIEL MORGANParticipant @danielmorgan23794]

hi

im restoring a 44 inch waveney life boat

fiberglass hull 12v 7ah battery the boat is quite heavy

runnung 2 x 550 motors with 2.9-1 gearboxes can any one please suggest

what size props i need currently it has approx 30mm 3 blade props

(plastic) useless i need some to give me some ummph

thanks for your help

dan

[DANIEL MORGANParticipant @danielmorgan23794]

what size props

[ashley needhamParticipant @ashleyneedham69188]

Dan. 550 on 12v and geared down by almost 3:1, those props are turning quite slowly. This sort of combo I would expect to be turning 50mm plus props…

I have 550`s driving 5 blade 40mm props direct on 12V on my Manchester destroyer, goes very well.

Brass of course it the thing to have. The question has to be… what size props are supposed to be fitted?? A million watchers out there must have a Waveny of some description and will positively FLOOD your post with answers (dont have one myself).. Model slipway or someone must do a Waveny, could look up and see what size props are fitted and scale up to suit?

Ashley

[ashley needhamParticipant @ashleyneedham69188]

I have just had a very quick surf, and a figure of 35-45mm has come up.

Ideally you need to be able to borrow, or try some props before buying as its a bit expensive otherwise. Even a 30mm brass prop will perform better than a plastic one!

What size can you comfortably fit on the shafts?? I would go for largish given the gearing and all that.

Ashley

[DANIEL MORGANParticipant @danielmorgan23794]

thanks for your help i can go to 50mm if need thanks a lot also do you think i need the gear boxes

or would i be better direct drive new to all this props and ratio stuff

thanks alot for any info

[ashley needhamParticipant @ashleyneedham69188]

I would want to take advice on the gearing before doing away with it, from someone who has a Waveny first. In any event if it is fitted ok, seems not worth the effort to get rid of it and fiddle around going to direct drive.

It depends on the size of prop you need as to if you need gearing or not. 550`s will turn 40mm props easily direct, for instance, if this is the right size. OR have 4 blade 40mm props and gearing ??

Sorry no easy answer here. Need a Waveny man to post to correct my assumptions.

Ashley

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