why are FE boats not using 4 or 5 blade prop?

[fuse01]

i was just watch the miss geico ( real ones) and they have sick 6 blades props.

so the question is why are we not using 4 or 5 blades? what are the limitations ?

[Ub Hauled]

I have a 5 blade prop and tried it... it turns out it would not hook... I believe that there is too much aeration.

[Fluid]

Small diameter multi-bladed props don't work well on most models. Two or three bladed props are the fastest. Some things just do not scale down well.



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[epsonjackson]

it would have been great if it could scale down well, 5-6 props would have been better

[egneg]

The only one I know that has had any luck with them is graill. He used a pair of prop shop 8015/5's cut down to 65mm on the Platinum Princess. This is a 96" cat and the amp draw went up and run time went down. He said he would try them again after he got the turbines put in.

Chuck

[Boaterguy]

It would be neat to try, maybe i'll get one for my rigger, just for looks and fun, would a 35mm/5 be about = to a x447?
Edit: I just went on propshop and I couldn't find any 5 blade, where should I look?

[Punisher 67]

Small diameter multi-bladed props don't work well on most models. Two or three bladed props are the fastest. Some things just do not scale down well.
.

I once tried a 5 blade prop on my 57" Apache , I was an absolute turd.....in-fact it ultimately bent the 3/16 shaft from cavitation

[jevmax]

Two primary reasons. Load and drag.

[jcald2000]

And we turn our props a lot more rpm so the wake from preceding blade is disturbing the flow around the trailing blade. You won't see any 30,000 rpm shaft speeds on the big boats. At least not when I was racing them 20 years ago. LOL

[Boaterguy]

Oh, so pretty much lots of aeration?

[bigwaveohs]

Imagine the fun to S&B a 5-blade prop!

[Gary]

All you have to do is buy an Eagle Tree set up to test all the mods you make on your boats. Its the best part of boating in my opinion. This way any prop change will show the MPH and RPM so you can work from there. You just cant guess from "eye ball" readings.

[Punisher 67]

Imagine the fun to S&B a 5-blade prop!

Yes I lived through that , It was a challange .

[Boaterguy]

Yes I lived through that , It was a challange .

How is it done?

[egneg]

To modify a 5 blade and then S/B it is a real challenge. I did the work for graill's props.

[Boaterguy]

Where'd he/you get them?

[graill]

The only one I know that has had any luck with them is graill. He used a pair of prop shop 8015/5's cut down to 65mm on the Platinum Princess. This is a 96" cat and the amp draw went up and run time went down. He said he would try them again after he got the turbines put in.

Chuck

True the big dog churned something fierce until you get the thing running then they bite in, out of 12 runs using the 5 blade only 3 had a really great top end over 90, the rest were churn runs regardless of the depth and angles. 5 blades look great for display but in practice, exhibition runs are all your going to get as the 5 blader will decide when they want to finally bite in.

That said Chuck did a great job on them and they do work, just do not look to set any records with them. great for cruising.


Note: Picked them up at Das boata after some wheeling and dealing. Real Prop shop props are getting hard to find nowadays, i sucked up alot of them a few years back to have on hand.

[graill]

i was just watch the miss geico ( real ones) and they have sick 6 blades props.

so the question is why are we not using 4 or 5 blades? what are the limitations ?

Like a few folks have already pointed out scaling down the big stuff doesnt always work, that and the "Theory" (damn the theory!!)prevents the cool stuff from being miniaturized and working well, most often props.

What is the theory? look it up, a couple of race folks provided some great info on it a year back or so, it is some great reading.

[Boaterguy]

I just want to get one for cruising on my rigger, i'll find a cheap one and do 12 hrs of work on it, after that, I don't want to work more on it
Edit : You guys got me wanting a nice 5 blade!!! the smallest I can find is 120mm!!!

[dasboata]

I have some 55mm 5 blades email me if interested

[egneg]

I just want to get one for cruising on my rigger, i'll find a cheap one and do 12 hrs of work on it, after that, I don't want to work more on it
Edit : You guys got me wanting a nice 5 blade!!! the smallest I can find is 120mm!!!

I think you would be better off with a V series prop.

[Boaterguy]

I have a good prop, I just want this for cruising and looks

[egneg]

IDK ... the V series looks pretty darn good as far as a scale prop goes.

[fuse01]

yeah 5 blades.. looks darn cool ... especially for demo purpose ...

can i get 1 too? wish to put it on my geico and maybe power it on a small motor to cruise around the pond and enjoy the scale look

[Boaterguy]

I didn't get it, You can email him, he said 75$ shipped, S + B + P

[Punisher 67]

How is it done?

Really no different than a 3 blade just more blades to balance on a 5 blade

[iamandrew]

I dont mean to annoy everyone in this post, but having seen the 200kmph boats, they are all using 5 blade props

[Punisher 67]

I dont mean to annoy everyone in this post, but having seen the 200kmph boats, they are all using 5 blade props

True enough but as mentioned already scaling propelers down doesn't always guarantee they will work as good as there full sized counterparts

[tdjhutch]

its the size of the water molecule that stops props from scaling down & being effective