Large Hulls

[Richard HallettParticipant @richardhallett59375]

   Has anyone any experience of electric power in chine hulls getting them on the plane. Say 48″  –  60″ .

What motor and power recommedations please

 

[Richard HallettParticipant @richardhallett59375]

Electric Power

[Paul TParticipant @pault84577]

Hi Richard

 

I have the same problem, since the banning of IC units I have tried many different electric motors but havent managed to get the right result.

 

Paul

[neil hpParticipant @neilhp]

I don’t know much about them but the Mayhem site has a good following, and that is Brushless motors with their own ESC’s

And these seam to do what you want.

They get the big Speedline Severns up onto the plane, but are heavy on battery power

[Richard HallettParticipant @richardhallett59375]

Gentlemen

Many thanks for your replies. So…a suck it and see situation emerges. What if we thought of the original power situation of the full size article. Take a PT boat. Chine Hull…Petrol Power, latterly Diesel but limited to essentially a low revving engine for the size of the craft, therefore a large three bladed prop to absorb the power and in the PT Boat…three engines originally!! 

 

In our model then, why not a large engine, moveing away from model engines and use…say …a motor from a cars windsreen wiper or maybe a golf trolley motor . Probably the batteries would then become an issue and one would probably require a fork lift truck battery!!!!!

 

However, maybe enough nicads may be enough for a decent run.. Any ideas/suggestions (clean please)

 

Richard

[Paul TParticipant @pault84577]

I am about to install a Ripmax IC electric starter motor into the barrel back, I will be fitting 1:2 gearing to increase the revs and pushing the power through a 3 bladed 60mm prop.

It would kill nicads in seconds so I am fitting a pair of lead gel batteries that should give about 20mins run time but the motor should get the boat up and onto the plane.

 

Paul

[ashley needhamParticipant @ashleyneedham69188]

Not that I am biased but the MFA 800/850 motors are very powerful and cheap. At 2 inches in diameter they are very torquy. The MFA 48″ Fantome goes quite well on 2x 800`s, lasts for an hour with mixed running on a 12v 7Ahr gel batt. The recommended props are 50mm “x”, but I have had fitted some 50mm 3-blade brass props (of max pitch) and the performance is on par with the plastic ones.n The point being that the brass ones look much better and would go ok on a pt boat. I can imagine 2x 850 motors would get a reasonable sized boat flying, for £50.  and 20A draw. Depends how fast you want to go. I have discovered, now I have a big boat, that speed is verry illusory. I was dissapointed at first with the apparent performance, but when it gets next to much smaller, and apparently much faster speed boats/rtr types, the Fantome is usually quicker. Its the size, `coz its so big it doesnt seem to be travelling so fast. I dont suppose a whopping 60 inch boat would have to speed along with only it tail in the water to be quick….does that all make sense? Ashley

[Paul TParticipant @pault84577]

Hi Ashley

 

To get the barrel back upto scale speed I only need to atchieve 10mph but that takes some power.

I agree that it is daft to have model boats that are not racing types blasting along at high speeds that would scale up to over 200mph.

 

Paul

[Bob Abell 2Participant @bobabell2]

Hello Chaps

 

We had a long departed club member, who built one of those giant lifeboats!  At first, it was quite novel to see this boat charging about the lake at top speed making an enormous wake that used to wash over the landing stage and the members feet!

 

After a short time the novelty wore thin and he was confined to certain restaints and left the club broken hearted!………………Bye!

 

So!……………..You ain`t coming round `ere matey boy!………………(only kidding, looking forward to seeing it one day)

 

We also had another long departed member, who appeared one night with a giant high speed something or other. It was fitted with a hush hush special brushless motor and he battered it round the lake at a crazy speed, in enormous almost out of sight circles, with scant regards for the wildlife, turning was a matter of slithering round as best he could and having red tunnel vision, he didn`t see this poor little paddle steamer, chugging along…………….and smashed it too smithereens!

 

We didn`t see him again!………………..Bye!

 

So the lust for speed does have it`s drawbacks?

 

Just an amusing story from the archives………………….Bob

[Richard HallettParticipant @richardhallett59375]

Gentlemen

 

Again, I thank you for your valuable advice. It’s been 30 years since I last “messed” with boats and a matter 29 years too long, however, technology has moved on at warp speed and I haven’t so I do find that your help has saved me endless potential frustration.

 

My last experince of getting chine hulls running correctly, clearly showed that if the hull does NOT acheive the plane…it a looks silly pushing its way though the water. We are not trying to acheive great speed but get over the initial “lift” whereupon it looks right.

 

Bob, I take on board (no pun intended) what you say but I worry about a visit to your club as the death rate appears rather high! Wonder how coffins plane?

 

Again,  I thank you all

 

Richard

[JC Uknz 1Participant @jcuknz1]

I would suggest that you look at windscreen wiper motors and other such things from a car wrecker ….. that is what one member of ours puts in his boats, same motor different hulls I believe.  They go well above scale speed.

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