Topic: Large Scale Sail Winches (Read 38263 times)

Tom Eccles · « **on:** July 20, 2008, 08:03:26 pm »

Gentlemen,

I am searching for a powerful drum sail winch for an A class I am about to start building.

She will be approx 73" long X 14"beam and approx 9ft 6ins from keel to top of mast. She is a copy of our club yacht which runs with what I believe is an Americas Cup servo.

If anyone has any suggestions I will be most grateful.

Many thanks
Clegg

isisagoodun · « **Reply #1 on:** July 20, 2008, 08:29:13 pm »

I think the A class guys use the RMG380D from Australia. One of the UK agents is Ken Binks (Kbits). Try Googling 'RMG380 Sail Winch' for them.

Ralph

Stavros · « **Reply #2 on:** July 20, 2008, 08:35:57 pm »

This is what you need fro your A class ample power for your needs

http://www.howesmodels.co.uk/RadioControl/viewProduct.php?ProdID=1284

Stavros

JayDee · « **Reply #3 on:** July 21, 2008, 12:11:13 am »

Hello,

Only three turns on that winch drum, will not move a 30 inch long Main Boom very far !!.

The main winch on my schooner has up-to 7 turns and uses nearly all of them.
The RMG winches have about 4 times more torque than the Hitec, BUT they cost 4 times more £££s.

A Hitec HS 815 BB failed on my J Class Endeavour after 10 minutes of sailing in a light breeze, similar sail area
as an " A Class " and a more powerful unit.

John.

.

tigertiger · « **Reply #4 on:** July 21, 2008, 01:35:53 am »

Quote from: JayDee on July 21, 2008, 12:11:13 am

A Hitec HS 815 BB failed on my J Class Endeavour after 10 minutes of sailing in a light breeze, similar sail area
as an " A Class " and a more powerful unit.

John. .

Hi John
The HS815BB is a sail arm, not a sail drum winch. Or was this modified to run as a drum winch?

JayDee · « **Reply #5 on:** July 21, 2008, 11:18:53 am »

Hello Tiger,

You are quite correct, but it is such a powerfull servo that I thought it was up to the job.
The stated torque at 6 volts is 24Kg/cm, which is higher than any other servo I have found.

Just shows how high the forces involved are on a large yacht.
Smooth and graceful they may be, but the Wind is a Devil !!.

John. :-\ :-\ :-\

MikeK · « **Reply #6 on:** July 21, 2008, 01:28:20 pm »

Hi all, I fitted a pair of HS785HB winches to my 'A' boat. One to each sail via a 'Y' lead to the Rx. To get a bit more sheeting speed I put in an extra purchase in the system. I have found that the winches are perfectly capable of handling the loads in this setup

Mike

John C · « **Reply #7 on:** July 21, 2008, 04:05:05 pm »

I hope the 815 is ok as I have just bought one for my latest ongoing build (sail arm version), but I'm not a fast builder I can't churn them out as some guys seem to do cos I'm a newbie to working sail and some times it takes a fair bit of research (I don't belong to a club) before I'm happy to carry on (and then I still re-do stuff)

I did wonder if I might need two servos, but as my build is half the size of Jay Dee's @ 37"loa I'll keep my fingers crossed. by the way I already managed to terminate a 1/4 scale servo in my Y2K.

Looked like a hell of a lot of knitting on that A class!!!

John C

MikeK · « **Reply #8 on:** July 21, 2008, 05:16:58 pm »

Looks worse than it is ! Instead of the sheeting line being attached to the endless winch line, it passes through a pulley made fast at that point and up the deck to an anchor point, so the winch is heaving on a bight of sheet. There is only one extra line per winch from a 'normal' set up. Sounds as complicated as it looks now

Mike

John C · « **Reply #9 on:** July 21, 2008, 05:33:30 pm »

You're not wrong there!

John C

JayDee · « **Reply #10 on:** July 21, 2008, 05:59:41 pm »

Hello Mike,
Been looking at your winch setup, have you ever worked out just how much power you have available at the sails?.
This may come as a big surprise !.

If the system is running on 6 Volts.

Servo Torque is 13.2Kg/Cm

Drum Torque is 6.6Kg/Cm ( The Drum is 4Cm dia )
Sheet Torque is 3.3Kg ( Sheeting is 2 to 1 )

Minus Friction losses leaves 3Kg at the Sails.

If the system is running on 4.8 Volts.

Servo Torque is 11KG/Cm

Drum Torque is 5.5Kg
Sheet Torque is 2.75Kg

Minus Friction losses leaves 2KG at the sails

This low output to the Sails is only relieved by the presence of TWO winches.
Did you only have one winch at first ?, then fitted another one ???.
I think the sail area would have been too much for one winch to handle.
John.

ooby · « **Reply #11 on:** July 21, 2008, 10:59:42 pm »

Almost a side note, gentlemen, but RMG makes a 9 turn winch for their 380HD. "Smart Winch Drum 45ZS9, 45 to 15MM 9 turn Z Spiral".

ooby · « **Reply #12 on:** July 21, 2008, 11:02:18 pm »

Pardon me, that's a 9 turn drum, not winch.

tigertiger · « **Reply #13 on:** July 22, 2008, 03:22:46 am »

Quote from: ooby on July 21, 2008, 10:59:42 pm

Almost a side note, gentlemen, but RMG makes a 9 turn winch for their 380HD. "Smart Winch Drum 45ZS9, 45 to 15MM 9 turn Z Spiral".

Hi Ooby,

two simple non-tech questions.

How much? and
Where from?

Regards
Mark

ooby · « **Reply #14 on:** July 22, 2008, 04:29:24 am »

February 11, 2008, the RMG 380HD with "standard drum" was $240. USD. The additional Spiral drop down drum was another $17.25.
Mine was purchased from Midwest Model Yachting, LLC, Plainfield, Indiana, USA.

RMG Sailwinch, is located at 66 Radford Rd., Angaston 5353, South Australia. Phone: 61 (0) 8 8564 2444, Fax: 61 (0) 8 8564 3474, E-mail: rob@rmgsw.com, Internet: www.rmgsw.com

Rob was great to work with and most eager to answer questions. It also didn't matter to him if I purchased it directly from his factory, or here in the states.

tigertiger · « **Reply #15 on:** July 22, 2008, 04:50:07 am »

Thanks for answering.

Now tech qs

How big is it (roughly)? Much bigger than regualr servo?
What is the purpose of the spiral drop down drum?

MikeK · « **Reply #16 on:** July 22, 2008, 08:56:22 am »

Quote from: JayDee on July 21, 2008, 05:59:41 pm

Hello Mike,

This low output to the Sails is only relieved by the presence of TWO winches.
Did you only have one winch at first ?, then fitted another one ???.
I think the sail area would have been too much for one winch to handle.
John.

Hello John, thanks for the info on the winch outputs. When I built the yacht I never envisaged it as being competitive with modern designs. Consequently I concentrated on keeping the costs down and originally had a single old Whirlwind mounted running on 6V. In anything above a light breeze I fully expected to see smoke rising from the poor thing so, before that happened, I changed to this setup but on the usual sheeting system. This was so slow it was frustrating so I put the extra sheave into the system to speed it up, as yet I have not sailed in anything too blowy so don't know how it will stand up to that - based on your figures, I may yet see plumes of smoke rising

regards

Mike

ooby · « **Reply #17 on:** July 22, 2008, 03:25:46 pm »

Quote from: tigertiger on July 22, 2008, 04:50:07 am

Thanks for answering.

Now tech qs

How big is it (roughly)? Much bigger than regualr servo?
What is the purpose of the spiral drop down drum?

The RMG 380HD is approximately 3 3/8"L x 2 1/2"W x 2 3/8" H, with about 1/2in of the 2 3/8 below the mounting plate.
The purpose of the spiral drop down drum is to render the most accurate positioning of the booms when close-hauled, a function it performs most well. For this picture, I leaned the spiral drum against the standard one.
The particular set-up was purchased as one of two options for my AMYA J-Class, 1934 Endeavour, 4,000 sq in sail area.

ooby · « **Reply #18 on:** July 22, 2008, 03:42:53 pm »

RMG also makes a smaller drum winch, their #280. Here's an old one mounted in my AMYA EC-12, LOA 5ft, 23 lbs and 1,200 sq in sail area.

Tom Eccles · « **Reply #19 on:** July 22, 2008, 08:00:54 pm »

WOW!

Thank you all for your replies, particularly isisagoodun and ooby, two guys I have not had previous contact with.

The RMG winch seems to be the way to go. I have checked out the kbits website and sure enough they have these beasts on their books at only £134.00

I have been considering using the big Hi-Tech winch as a rudder servo in view of the forces involved. Before I do does anyone have any other ideas?

Bye the bye, Jaydee is a fellow member of our club here in Sunny? Southport. I can confirm that he builds beautiful boats and anyone who knows John will agree that he is very generous in sharing the huge knowledge he has in this field ( I can say that because, following the winch burn out on his J class John became a member of my "we ground boats" club)

Thank you all again

Clegg

JayDee · « **Reply #20 on:** July 22, 2008, 09:03:07 pm »

Grrrrr !!!

John,

tigertiger · « **Reply #21 on:** July 23, 2008, 02:16:35 am »

Yes thanks Ooby.

This was a winch servo I had not heard of before. And I learned about the spiral drum as well.

Clegg
Do you have a weblink for Kbits, or if not, other details.

ooby · « **Reply #22 on:** July 23, 2008, 05:52:52 am »

Clegg and Tiger, you are most welcome.

My salute to John! :)

MikeK · « **Reply #23 on:** July 23, 2008, 08:30:34 am »

There you go Tiger http://www.kbits.co.uk/

The PDF price list is all I have ever seen on his site

Mike

ooby · « **Reply #24 on:** July 23, 2008, 11:19:00 am »

Quote from: ooby on July 23, 2008, 05:52:52 am

Clegg and Tiger, you are most welcome.

My salute to John! :)

Instead of relying on a "happy face" to imply that I mean "salute to John" in the best sense, a quasi-military sign of respect, I'll say what I mean. John, your schooner is absolutely superlative! When I think "schooner", I automatically think of yours. It's pure majesty! Many thanks for posting pictures. "Salute!"

Joe

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Author Topic: Large Scale Sail Winches (Read 38263 times)

Tom Eccles

isisagoodun

Stavros

John C

John C

ooby

ooby

ooby

ooby

ooby

Tom Eccles

ooby

ooby