Topic: Hydrofoil - is it a viable proposition as a model. (Read 12204 times)

pugwash · « **on:** January 31, 2011, 12:53:08 pm »

Just sitting here daydreaming and wondering what I would build after I have finished the last warship I served on (haven't even started the last build yet)
and wondered if it was possible to build a hydrofoil and if so would if be possible to raise and lower the foils as in the real craft.
Any suggestions pro or con would be appreciated

Geoff

tigertiger · « **Reply #1 on:** January 31, 2011, 12:54:19 pm »

I think a commercially available model was done. I think the foils were fixed.

In fact I seem to recall seeing a couple of models on here in the past.

boatmadman · « **Reply #2 on:** January 31, 2011, 03:51:51 pm »

Here you go:

http://www.modelboatmayhem.co.uk/forum/index.php?topic=11904.0

Ian

pugwash · « **Reply #3 on:** January 31, 2011, 04:36:30 pm »

Ian Did you get it to run OK in the end without the torque roll and eventual capsize

Geoff

Umi_Ryuzuki · « **Reply #4 on:** January 31, 2011, 07:15:01 pm »

The Gunze Sangyo PT-50 is one of the best running models out there once it's trimmed.

As for retractable foils, they are very problematic.
Retracting isn't the real problem. The type of foils that retract are inverted "T" foils, and they are
inherently unstable. The real boats had computer controls that managed pitch, yawl and roll.
These were controlled either by movable trailing edges, or on later models, by bleeding air over
the wings to reduce lift. Controlling such a boat requires a gyro, and the most successful builder to
date, is Takahashi Yoichi, in Japan. (the foils do not retract, but are fixed)

Another issue with retractabl foils, is that the foils have to lower, , contact and seal the water intakes
from the lower end of the strut, to the Jet pumps inside the boat. However this is a minor problem
compared to actually getting enough thrust from your pump, and running stable on the inverted "T" foils.

Aimee

boatmadman · « **Reply #5 on:** January 31, 2011, 07:38:03 pm »

Geoff,

I have to admit that the foil went on the shelf, where it remains gathering dust.

Ian

grasshopper · « **Reply #6 on:** January 31, 2011, 07:45:14 pm »

Some years ago I built one of these
http://www.myhobbystore.co.uk/product/17064/lecrofoil-mm1021

my version was modified slightly using a cheap 540 motor on a 2:1 gearbox and the propshaft extended to pass through the rear foil - it was powered by 8 'c' size nicads (not sub c like most rc packs) and preformed very well. The foil design was good and copied but I increased the 'chord' of the foils to make them easier to make.

Worked really well as long as you didn't make sharp turns - plus DON'T let the club 'know-it-all' adjust the foils - the plan angles are perfect!

pugwash · « **Reply #7 on:** January 31, 2011, 07:48:14 pm »

Thankyou all for your comments and suggestions. Something to ponder about. Plenty of time yet to plan something.
Geoff

jules64 · « **Reply #8 on:** January 31, 2011, 10:26:03 pm »

Geoff

A design was published in Model Boats Jan 95 by Graham Goodchild.

I have never got round to making it but it looks interesting.

I can send you a copy of the article if interested.

Best wishes
Jules

pugwash · « **Reply #9 on:** January 31, 2011, 11:55:25 pm »

Jules I should have that edition stored away - will check and if I can't find it will send a PM.
Thanks
Geoff

Celestialsphere · « **Reply #10 on:** February 17, 2012, 06:11:13 am »

There is a couple of pix of a model by Takahashi Yoichi on this page:

http://www.interq.or.jp/sun/miki-k/rep2010/rep2010.htm

Cheers

Andrew

Melbourne, Australia

dougal99 · « **Reply #11 on:** February 17, 2012, 11:59:52 am »

Just come across this thread. A member of my club had a hydrofoil model, with fixed foils, which is stable and sails well. I believe it is a commercial model but have no idea of its pedigree. The pictures are from 2005 and I haven't seen it recently.

Martin (Admin) · « **Reply #12 on:** February 17, 2012, 12:50:05 pm »

That looks like my model!

boatmadman · « **Reply #13 on:** February 17, 2012, 02:05:01 pm »

Thats the one I have. Must get it going again.

dougal99 · « **Reply #14 on:** February 17, 2012, 02:22:51 pm »

Quote from: Martin - admin. on February 17, 2012, 12:50:05 pm

That looks like my model!

So you've got one too! Not yours this time Martin. Perhaps we could set up some formation Hydrofoil sailing

BarryM · « **Reply #15 on:** February 19, 2012, 09:45:20 pm »

By coincidence, the latest issue of 'Marine Engineers Review' has an article on the history of hydrofoils and they go back further than you might imagine.

A brief extract:-

"In fact it appears as though the very first 'hydrofoil' was invented by pure accident! In 1861, an Englishman by the name of Thomas Moy, decided to study the aerodynamics of wings by observing how they behaved in water where he could see the swirls and eddies they created which could not be seen in air. He experimented by attaching underwater wings to his boat on the Surrey Canal. To his surprise the boat rose out of the water and, unintentionally, he had invented the hydrofoil."

Serendipity in a stove-pipe hat, perhaps.

Barry M

boatmadman · « **Reply #16 on:** February 20, 2012, 10:18:12 am »

Here is a link to mine - no finished pics though, and no running pics.

http://www.modelboatmayhem.co.uk/forum/index.php?topic=11904.0

a3nige · « **Reply #17 on:** February 20, 2012, 10:51:27 am »

http://www.foils.org/modelrc.htm
http://www.cornwallmodelboats.co.uk/acatalog/mar2392.html
http://www.foils.org/gallery/models.htm
http://www.watercrafststore.com/9-Hydrofoil-Model.html
http://www.grahamktaylor.com/models/hydrofoils/rapier/rapier%20page.html

billa65t · « **Reply #18 on:** February 23, 2012, 06:28:13 pm »

One of our club members has a hydrofoil that he brings out every now and then it goes well Dont know haw old it is but he built it from a kit.

Here in Jersey we used to have a few of the real thing running between the Islands ,France and the Uk they used to cruise at about 27 knots.

[attachment deleted by admin]

Martin (Admin) · « **Reply #19 on:** February 24, 2012, 09:44:35 am »

Sorry Guys, I've accidentally deleted some photos, please can you repost them and I'll move back to the right place.

billa65t · « **Reply #20 on:** February 24, 2012, 07:52:51 pm »

Hydrofoil photos

rathikrishna · « **Reply #21 on:** February 27, 2012, 07:35:41 am »

Friends..one of the most affecting head ache is related to a Hydrofoil craft is torque roll..i eliminated simply this by two things..most of the torque related instability is because of the tip stall / tip lift of the hydrofoil it self..by decreasing the chord of the tip of the hydrofoil eliminates this problem to a great extent..second remedy is to fix with two counter rotating props..to me, proved one is turning inwards..each other..and its also easy to add a retractable foils ..with a mechanism of a CCM of a DVD player..

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Author Topic: Hydrofoil - is it a viable proposition as a model. (Read 12204 times)

pugwash

pugwash

Umi_Ryuzuki

pugwash

jules64

pugwash

Celestialsphere

billa65t

billa65t

rathikrishna