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Catalina/Capri 25/250 Sailor's Forums

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How would you shape this (sheave box flanges) ?

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OJ
Master Marine Consultant

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USA
4382 Posts

Initially Posted - 03/26/2012 : 10:08:42

Preparing to install an internal outhaul. Below is the box I am using to bring the ss wire inside the boom.

How would you shape the flanges to match the curvature of the top of the boom?

http://www.ronstan.com/marine/product.asp?ProdNo=RF452

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"There is nothing, absolutely nothing half so much worth doing as simply messing about in boats." Kenneth Grahame

Edited by - OJ on 04/17/2012 17:38:04

dlucier
Master Marine Consultant

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Virgin Islands (United Kingdom)
7583 Posts

Response Posted - 03/26/2012 : 11:33:32

I've done a few metal shaping projects and for this I might try putting the work in a vice then pounding it into shape. So as to not mar the work, I hold a small piece of wood over the area to be shaped when hammering. Since you need to match the boom curve, maybe you could replicate the curve using a piece of wood then clamp it and the sheave box in a vice together then hammer the flange into shape.

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delliottg
Former Mainsheet C250 Tech Editor

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USA
4479 Posts

Response Posted - 03/26/2012 : 14:41:14

You might also create a wooden pad from wood (Teak, Ipe, etc.) or UHMW plastic that's shaped to fit the mast and still presents a flat surface to the box flanges. You can use a [url="http://www.garrettwade.com/product.asp?pn=10K20.01&ch=10K20.02&EID=W6061011&SID=W6061011&utm_source=googlepla&utm_medium=cpc&gclid=COrat93Cha8CFWgaQgodZWgD4g"]profile gauge[/url] to get the shape of the mast transferred to the wood or plastic, cut it out with a bandsaw, jig saw, or whatever, and finish the profile with rasps or files.

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Sloop Smitten
Master Marine Consultant

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USA
1181 Posts

Response Posted - 03/28/2012 : 10:27:18

I would clamp one flange in a vise and put a crescent wrench around the pulley/holder and bend it to the angle needed. Then repeat it for the other side.

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Dave5041
Former Mainsheet Editor

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USA
3758 Posts

Response Posted - 03/28/2012 : 11:28:36

I would go with a pad on the internal boom surface with a glob of epoxy putty. Press it firmly in place to eliminate voids and flatten the surface with a piece of wet plastic before it sets.

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jerlim
Master Marine Consultant

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USA
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Response Posted - 03/28/2012 : 13:48:48

I'd love to see a photo of the final install!

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Prospector
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Canada
3159 Posts

Response Posted - 03/28/2012 : 14:06:30

OJ, I am a little fuzzy here - you are putting the flanges inside the boom with just the lip of the sheave exposed, right?

So you need the flanges bent back to fit the inside contour of the boom? Basically like this will be an exit block for te outhaul at the back of the boom?

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OJ
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4382 Posts

Response Posted - 03/28/2012 : 14:11:52

This is more challenging than it first appears. Bending the flanges without mishaping the box! As thin as the ss sheet metal appears - it's very rigid.

Thanks for all the ideas!

Will share the entire internal outhaul project.

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Prospector
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Canada
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Response Posted - 03/28/2012 : 14:13:53

Can you remove the sheave from teh box? If so, put a shim inside the box to hold its shape, then hold the box in a vise and bend the tabs.

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OJ
Master Marine Consultant

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USA
4382 Posts

Response Posted - 03/28/2012 : 14:28:19

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Prospector
 OJ, I am a little fuzzy here - you are putting the flanges inside the boom with just the lip of the sheave exposed, right?

So you need the flanges bent back to fit the inside contour of the boom? Basically like this will be an exit block for te outhaul at the back of the boom?
<hr height="1" noshade id="quote"></blockquote id="quote">Interesting thought Chris. Flanges will sit on top of boom. Stainless wire will connect to clew, run through box and connect to fiddle blocks inside boom. Line from fiddle blocks will exit boom near gooseneck, down mast and back to cockpit.

Can you tell I like complicated?

See Internal 5:1 in this link:

http://www.harken.com/rigtips/outhaul.php

Edited by - OJ on 03/28/2012 14:30:16

Prospector
Master Marine Consultant

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Canada
3159 Posts

Response Posted - 03/29/2012 : 06:32:30

OH - now I get it. I still think it would look cleaner inside the boom with just a couple rivets or screws sticking out. The nice thing on our booms is that you can remove the end plate to do this stuff.

Stainless does have great "memory" and it does not work easily. When I was doing metal spinning for a living, deforming stainless (any type/grade) was a fine balance between having a part explode and getting the right contours. Heating it only makes it more brittle, don't do that. I would be very tempted to bend it in 1/8" steps until you get a curve you can live with.

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Sloop Smitten
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USA
1181 Posts

Response Posted - 03/29/2012 : 11:53:56

OJ,
According to the web page you provided:
"The external tabs can be formed to fit the spar profile before fastening."
If bending the tabs ruins it I would return it and quote what the web page says.

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delliottg
Former Mainsheet C250 Tech Editor

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USA
4479 Posts

Response Posted - 03/29/2012 : 13:23:03

Oh, I see, my idea wouldn't work very well then. I like the shim idea, if you can get the sheave off the axle & replace it with the shim.

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britinusa
Web Editor

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USA
5404 Posts

Response Posted - 03/29/2012 : 16:10:58

How are you going to get it in place?

Paul

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OJ
Master Marine Consultant

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4382 Posts

Response Posted - 03/29/2012 : 17:10:54

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Sloop Smitten
 If bending the tabs ruins it I would return it and quote what the web page says.<hr height="1" noshade id="quote"></blockquote id="quote">

Joe! Funny!

Yes, the people at Ronstan in Portsmith, RI had zero advice about this task - borderline apathetic

.

A friend a has large vice and (as suggested above) will place round bar stock under the flange and strike it with a hammer (with a piece of oak in between.)

Edited by - OJ on 03/29/2012 17:29:15

OJ
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Response Posted - 03/29/2012 : 17:14:25

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by britinusa
 How are you going to get it in place?

Paul
<hr height="1" noshade id="quote"></blockquote id="quote">Hi Paul! Will drill a small series of holes in the bolt rope slot just in front of the aft boom cap casting . . . then square up with a file.

Will post pix in the near future.

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OJ
Master Marine Consultant

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Response Posted - 04/17/2012 : 17:19:24

Results - as suggested above - placed sheave box in a vice with a rod under the flange. Used brass bar stock (brass being soft) and hammer to round the flanges.

Thanks for the suggestions!

Edited by - OJ on 04/17/2012 17:36:10

dlucier
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Virgin Islands (United Kingdom)
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Response Posted - 04/17/2012 : 20:11:43

Nice job...Looks great!

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JimGo
Admiral

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962 Posts

Response Posted - 04/18/2012 : 09:26:23

Very professional looking! Great job!

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PCP777
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Response Posted - 04/18/2012 : 11:56:06

Looks awesome, I have an internal out haul ran to the cabin top, let me see how it was done.

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OJ
Master Marine Consultant

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USA
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Response Posted - 04/18/2012 : 17:00:57

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by PCP777
 Looks awesome, I have an internal out haul ran to the cabin top, let me see how it was done.
<hr height="1" noshade id="quote"></blockquote id="quote">Peter, I have a question for you first! Any pix of where your internal outhaul exits the forward part of the boom? I have an exit block for the line - I'm just not sure about placement . . .

Edited by - OJ on 04/18/2012 17:01:48

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