DIY top down furler for 40 footer

[Bikerwookie]

I have heard on good authority that early torsion ropes were just braid on braid soaked in resin.

 

[PTB]

Ta da! Prototype v1 of my top down furler. In the end I made my own from some precut bits of 50mm tube off ebay and a 125mm pulley wheel, and a pair of deep groove 47mm x 25mm bearings. The trickiest bit is using basic hand tools though I'd do it much better on a version 2, and would cheat and get someone to machine and weld a few bits. The cage is some old car repair resin/cloth I had spare moulded over my wife's butty box. I Haven't actually fitted the sail yet but it seems to rotate okay using an old 14mm halyard as the antitorsion rope, though the plan is to put some heat shrink on it.

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What a great project.! Keep us all posted, thats really good pbo stuff. Any particular reason for ditching the Ronstan RF79 as a starting point? Cheers Phil

 

[2copplane]

What a great project.! Keep us all posted, thats really good pbo stuff. Any particular reason for ditching the Ronstan RF79 as a starting point? Cheers Phil

I ditched the ronstan idea as the lead time was about 4 weeks, though I may make a v2 using the rf79 as a base.

Anyway it works! First deployment was a bit of a shambles as the sail was furled really badly, it didnt help as I was sailing dead down wind. Silly I know but was restricted by the channel. Sailing goose winged was a good stress test as the chute repeatedly collapsed then filled (with CRaCK!). Nothing broke except the cable ties that I used to squeeze the headboard, However it still furled okay.

Once on a broad reach then things were much much better, especially furling as by keeping some sheet tension I could achieve a really tight furl.

Antitorsion rope- i'd give the current rope 6/10 put perfectly serviceable. It took quite a few turns to get it furling, but I think that was the large headboard catching on the genoa/forestay.

Next test is to try sailing with it furled and using the genoa.

 

[grafozz]

anti torsion rope

Interesting - just wondering
-What size of sail? = 13.8m luff x 7m foot

-What type of sail? = Sobstad "gp ? " BADLY MADE ! ,cruising chute - all seams fraying !

-How long have you used this homemade anti torsion rope? =made last season

-How much superglue? = a small 20 g pot - used it all up

-How durable is superglue when it's exposed to UV?

jury,s still out .

I will post a photo of the rope later .

 

[PTB]

I ditched the ronstan idea as the lead time was about 4 weeks, though I may make a v2 using the rf79 as a base.

Anyway it works! First deployment was a bit of a shambles as the sail was furled really badly, it didnt help as I was sailing dead down wind. Silly I know but was restricted by the channel. Sailing goose winged was a good stress test as the chute repeatedly collapsed then filled (with CRaCK!). Nothing broke except the cable ties that I used to squeeze the headboard, However it still furled okay.

Once on a broad reach then things were much much better, especially furling as by keeping some sheet tension I could achieve a really tight furl.

Antitorsion rope- i'd give the current rope 6/10 put perfectly serviceable. It took quite a few turns to get it furling, but I think that was the large headboard catching on the genoa/forestay.

Next test is to try sailing with it furled and using the genoa.

To complete the story so far, what are you using as a top swivel? Did you make that as well?. P

 

[2copplane]

To complete the story so far, what are you using as a top swivel? Did you make that as well?. P

The top swivel is an rf78b ronstan that I picked up off eBay. Really a bit smaller than i wanted for but £15!
I went out today for a second trial, forecast was 30+ gusts but the wind was nearer 18knots, e.g as an indicator the other boat near to me had two reefs in. I decided to risk it in one of the lulls and it unfurled perfectly, though to reduce the apparent wind I headed off on a broad reach.
To improve sail shape i let the halyard out about 3 metres, and sailed beautifully, but the wind was building so thought it best to furl it away. In hindsight the easing of the halyard was a mistake as to furl you need a tight antitorsion rope, and hard as I tried i could not winch the halyard back in as the pressure on the sail was too much. Mistake number 2 was I had used a short scrap of old halyard as a temporary sheet so could not really let if fly loose. Mistake number 3 was not originally putting the mainsail up, as I could easily have used the lee of the main to reduce pressure on the chute. Anyway by sailing dead downwind I could get the sail to collapse, and each time I would winch the halyard up tighter. Once the torsion rope was tight the sail furled very nicely.

The best feature is how compact the sail is for stowing as Previously the chute had its own aft cabin to store it, but i should at last be able to fit the thing away in a locker.

Conclusion: the hardware is man enough for cruising use with a 15.4m luff chute. The antitorsion rope could be better but does work ok. It can be made for less than the cost of a snuffer. It does require an element of common sense to get the best out of it. It is just a bodged up prototype but I'll use it until it breaks then try my original design using the rf79 as a base.

Being able to hoist in the marina, sail as normal, and furl unfurl at will is blooming marvellous. I can see it being left up for days at time, just in case it is needed. If anyone fancies making one happy to give a few pointers, or I have a few more pictures I can post.



I'll be selling a nearly new navy blue snuffer if anyone is interested

 

[PTB]

Yep, post some more pics if you can ... P

 

[Daydream believer]

Thanks tawhiri hadn't thought of that! I've just bought a couple of metre lengths of glue heat shrink and standard stuff. The glue stuff seems pretty tough,so I may just put heat shrink round the entire braid on braid and leave it as the out core.However I'll have to make the same consideration for the heat shrink. I'm also quite pleased how well in transfers the torque, even though the sample is only 8mm finished diameter.

Next question is how to thread 17metres of 12mm braid on braid into the heat shrink, anyone done something like this before?

Buy a cheap cable puller which is a set of 1 metre carbon rods & thread that up the heat shrink.
failing that , if you have enough sail battens push a line through with those taped together get a line through & then drag the main line through

 

[2copplane]

Buy a cheap cable puller which is a set of 1 metre carbon rods & thread that up the heat shrink.
failing that , if you have enough sail battens push a line through with those taped together get a line through & then drag the main line through

Thanks I'll borrow a cable puller. Far simpler than my plan A to make a small bobbin, with thread inserted, then launch it down the tube by attaching to a water tap.