Jib Track

[scorpion_1925]

when it comes to fitting my jib track, how do I work out what angle it needs to be at, is 45° a good guess or does someone know better?

[Clive Everest]

It should be perpendicular to the fore stay so that neither the foot or the leach tighten as it moves.
Much shallower than 45'.

[pratn0]

don't forget that the block on the on the car also pivots. which will take out some errors out on the angle side.  iv seen cars flat to the deck and cars vertical mounted and both worked fine.

i would focus more on getting a constant curve from one side to the other.  you don't want the middle to be tighter (further away from the f/stay pin) than the outer edges. as this would tighten everything mid tack and could be a sticking point if already on max trim.

[scorpion_1925]

Thank you

I have a nice carbon backing strip from Jamie I was just looking at it trying to decide on the best angle to mount it at.

Shamefully I hadn't thought about the pulley adjusting the angle naturally to correct any error.

[JP233]

Some useful info on this. But you may have to trawl though most of it:

http://www.uk-cherub.org/forum/index.php/topic,11.0.html

[Clive Everest]

Some of the 14s had W shaped tracks flat on the deck and did not have any problems.
They were intended to allow a bit of jib overlap. We do this with roach.
If the tips of the track are slightly closer to the fore-stay than the section slightly more inboard the jib fill move out to the stop reliably and also back itself a bit during tacks.

We made our track much wider than most Cherubs. We had barber haulers to tighten the sheeting angle but virtually never used them. I would recommend making the track as wide as possible.

[JimC]

Yes, as noted on the other thread Fizzy's jib track is at least W shaped, I recall it as a very exotic bit of metal bending. I don't suppose any of you have seen it! Tim Dean had skills and facilities beyond what was available to most of us though. I've had a quick root through my stuff and can't find any useful photos I'm afraid.

[JP233]

I got some pictures of fizzy from an old crew at Southampton uni. Gantry looks cool, she even has a compass! Some interesting bits of rope I couldn't work out what they were, but the glimpses I have of the jib track isn't that W shape. Could be perspective/darkness, but it looks alarmist straight with smiles at the end.

Martyn, when I did shinys track backing, I already had ears so only had to place the track on top.
Even so, I made sure the middle of the backing was lower than the ends because when I put pins in the track to shorten it, you also pull more tension on to the leach. Vice Versa, pull pins out, jib further outboard, less leach tension.
All the buzz words for light and heavy wind jib setup.

Weather it actually makes a difference. God knows! But it makes me feel better.

[JP233]

Some belated photos of fizzy.

Apologies for the blurry ness, knowing her, she was probably drunk.

[Neil C.]

That gantry is made of titanium. Exceedingly light and strong. It would break the bank to make for most people, but iirc Tim was doing some titanium work on racing yacht masts at the time and made it from some off-cuts!