The Prod

[jray]

A question for those running retractable prods. Has anyone noticed any tendency for the prod to rotate during operation? My plan at this moment is to attach the spinnaker tack on the outside of the prod, basically lashing a block and running the tack line on deck. This won't work well if the block is right side up one time and upside down another. My hope is the blocks and lines used for extending and retracting will keep it from spinning. Thoughts?

[jray]

Got it figured out, the prod can rotate slightly during retracting and deployment but always finishes the same when totally extend. Tack block is lashed on and everything is working. (On the trailer, in the yard)

[Kevin]

Awesome! My deploy line is rigged on the top of the prod so that seems to keep it in one position most of the time. My tack line is run inside the pole and comes out a fairlead bushing on the end so a little rotation wouldn't effect me much.

Go Critical Twist.

k.

[Chad]

Ran across this pic of a different boat's bow tube, and thought it might be inspiring to someone...

Cool prod.jpg

(from SA's "ctutmark"s web album of his european boatshow visit)

[Kevin]

That does look pretty kick ass. Notice the lashing for the forestay as well, that actually might be a code zero setup as there is a in deck furler just behind it.

I like the color too .

K.

[TexLex]

Ok, i am planning on doing an external prod, but i am plannin on running my tack line through the pole and want to find an end fitting like the one in the pic, but I am having a hard time finding out where to buy it or how to make it. Any ideas?

Chris

[Kevin]

I made mine using a SS lined through deck bushing and a disk of black g-10. You could easily make a "plate" about 4mm thick to do that job too. My plate was trimmed and fitted inside the prod so the loads are compression mostly on the top portion to the prod itself. The hole was big enough for the fairlead that I could get inside to put a fillet in there between the prod and the disk and it's flush to the front edge of the prod.

To make a carbon plate you can follow the non-patented chad method. Start with 2 blocks of would that are nice and flat. Apply poly packing tape to each. Start with on block on a sturdy bench. Layout absorber cloth, peel ply, layers of scrap carbon, and e-glass cloth. Note that e-glass is stronger in compression than carbon so plan you layup of scraps accordingly. Vary orientation as desired, lots of 45/90/45/0 will make it pretty strong in all directions. Trim things so they stack up nicely. 32ish oz = 1/16" as I recall from chats with Chad who will correct me on any of this I have wrong I'm sure. top with more peel ply, absorber, top block and a bunch of weight to squeeze everything together. This is poor man's vacuum bagging. For my gnav slider I made several thin plates and then doubled them up with additional material between the 2 and on both sides to build it up to a finished plate thickness. It ended up working pretty good. I also needed the thin stuff for other parts of the project. If you have g-10, that's a lot faster .

If the prod is up on the deck, is it articulating? If yes, then there is need for something at the aft end of the prod and the length of your tack could be effected by the articulation. I would think it would need be best to have a swivel bracket for the prod at the bow instead of going through the prod like ttb and shazza did. I'm thinking that mini 650 fitting idea here. I thought Chad posted a picture of someone who had made something like that.

Kevin.

Kevin.

[Chad]

Chris,
If you are talking about the end fitting on the prod, then just use a circle of delrin. I found a hole saw with an ID that closely matched my prod's OD, then cut a rabbet around the perimeter to recess it into the prod end:

IMGP1963.JPG

Blog link, with lots of safety caveats: http://i550knotracing.blogspot.com/2010 ... -shop.html

For a mini-style prod, take a look at Jason's boat in China on FB. He made a fitting similar to the gucci one on the SA thread you started.


I'm not sure, but I think it wouldn't work well to do an internal, through the pole tack line if you do a TTB style prod. I think you want the tackline to have a fairlead near the pole's pivot point, and then use an external, lashed on block at the end. With a TTB style pole, if you run the tackline through the butt of the pole it will change length as the pole articulates.

[TexLex]

Thanks. I found the through hull fittings/ferrules I need.

Re: the boat pictured above, that is exactly what I want to build, but this is the first I've seen of this boat. (Not sure how I could've missed it.) Can you provide me a link?

Thanks guys! Couldnt do it without you all!

[Chad]

http://www.facebook.com/groups/122920237740920/photos/
Scroll down near the bottom...

[TexLex]

GOT IT! THANKS! Does anyone know the material the fitting is made of? I have just "friended" Jason and I will inquire of him as well.

[Chad]

looks like glass, or ply covered in glass. If he doesn't come through, I know a guy that draw a sketch or two for ya...

[Marino]

Don't know if anyone can answer this question.
Does it make a difference if the prod is tapered or a straight pipe?
There is a local shop that makes the prod tapered.
Looking to purchase from him or C-tech.

[Chad]

Tapered is fine. Make sure the outer receiver tube is a sorta sloppy fit at full extension -i.e., don't use the taper's wedge effect to halt the prod going out- it'll get stuck.

[jray]

Getting a seal between the sleeve and a tapered prod might be a chore. Mine is not tapered and I've been using a piece of wheelbarrow tube to make the seal, just replace it each season.

[micah202]

Ok, i am planning on doing an external prod, but i am plannin on running my tack line through the pole and want to find an end fitting like the one in the pic, but I am having a hard time finding out where to buy it or how to make it. Any ideas?
Chris

.....if you're going to have a rotating external prod,,you might have some 'issues' with the internal tack line as the pole rotates.

........here's some detail pics of my external rotating pole,,with automatic in/out as the halyard is pulled/released........click on the pics for detail notes.....

..................... http://www.flickr.com/photos/59103003@N ... 076955693/

[Marino]

Thanks for the information, now back to work on the boat