Remote control leach tension

[2copplane]

Most biggish boats have a a mainsail leach line that is all but impossible to adjust when sailing. One option is to have the line led down the luff, but even then then it would be an on deck activity to adjust, and expensive to retrofit. I've messed around with a hoop and tried using the boat hook to limited success.

Would it be feasible to construct a small (micro)low profile electric winch that would attach on the sail near the clew to control leach line with a remote control?

Looking on eBay low profile 12mm thick motors with a gearbox can be picked up for a few quid. I guess the remote options are Bluetooth, IR or RF? If bluetooth perhaps add even more uneccessary complexity with an iOS app so "Siri tighten my leach an inch please".

I've limited and long forgotten model and electronic skills and it might be a nice little project to rekindle them.

Any suggestions, preferably polite?

 

[Woodlouse]

A linear actuator in the boom would do it. You could have it at the inboard end to facilitate ease of fitting with a line that runs to the outboard end and through a turning block onto the sail. Since you'd have to wire anything up to the power I'd say that the easiest means of controlling it would be wires to a button in the cockpit.

That said, I've sailed on a lot of boats, some of them all electronic push button controls, others with a lot of hydraulics, but a powered leech line is a new one on me.

 

[JumbleDuck]

A linear actuator in the boom would do it. You could have it at the inboard end to facilitate ease of fitting with a line that runs to the outboard end and through a turning block onto the sail.

If you are running a line from the tack, along the boom to the clew and then up the sail, why not just run it down the mast and along the coachroof? Adding an entire electromechanical subsystem to avoid two blocks and a jammer sounds a bit over the top.

 

[Woodlouse]

If you are running a line from the tack, along the boom to the clew and then up the sail, why not just run it down the mast and along the coachroof? Adding an entire electromechanical subsystem to avoid two blocks and a jammer sounds a bit over the top.

Well there is that. I was just going along with the op's original wish.

To be honest for the amount of time one spends adjusting the leech line I'd have it running down the luff of the sail onto a cam cleat there and leave it at that.

 

[2copplane]

I should have mentioned I have an inmast mainsail which, having thought about it a minute, makes a leach line down the luff impractical. And while I would like an excuse to fit an linear actuator i cannot see how it could be attached to the boom and still allow the sail the furl/reef.

I agree a leach line tends not to be adjusted much, but mine currently is all but impossible under way and others must have the same challenge.

 

[jdc]

To adjust the tension with two reefs in, I have evolved a technique particularly suited to being alone on watch:

1. detach harness strop
2. stand on the top of the wire rail on the lee side
3. in one fluid movement stand upright and grab the reeefing line on the leech
4. lift one foot off the rail to gain that vital extra inch and reach the jammer.

what could possibly be simpler or safer?

How about a continuous loop of string like some jib furling gear, bathroom blinds or a chain hoists? A small drum with the leech-line around it, but instead of an electric drive have a bigger diameter pulley with aforesaid line around it. The difficulty will be setting the optimum friction.

 

[Daydream believer]

Forgive my ignorance - but why do you need to constantly adjust the leech line?
Would you not adjust it once & leave it set?

 

[jdc]

Forgive my ignorance - but why do you need to constantly adjust the leech line?
Would you not adjust it once & leave it set?

I usually need to adjust it only when reefing.

There are four jammer cleats, one above the clew, one above the first reef, one above 2nd and one above the third. The optimum tension is a bit different when reefed, and in any case the act of reefing tends to let off the jammer(s) below. Possibly this is deliberately so and a testimony to the sailmaker's art.

Also the tension should ideally be adjusted according to wind strength - in very strong winds one needs a bit more tension to stop flutter (which can destroy the sail) - again this is associated with reefing.

 

[charles_reed]

Most biggish boats have a a mainsail leach line that is all but impossible to adjust when sailing. One option is to have the line led down the luff, but even then then it would be an on deck activity to adjust, and expensive to retrofit. I've messed around with a hoop and tried using the boat hook to limited success.

Would it be feasible to construct a small (micro)low profile electric winch that would attach on the sail near the clew to control leach line with a remote control?

Looking on eBay low profile 12mm thick motors with a gearbox can be picked up for a few quid. I guess the remote options are Bluetooth, IR or RF? If bluetooth perhaps add even more uneccessary complexity with an iOS app so "Siri tighten my leach an inch please".

I've limited and long forgotten model and electronic skills and it might be a nice little project to rekindle them.

Any suggestions, preferably polite?

Talk with Paul Lees of Crusader - he solved the problem for me on my new main.
Might even be a possible retrofit.

Don't think particularly highly of your proposed solution, unless your main is >300m. Looks like a solution looking for a problem.
PS Though you like to reserve your reasons for rejecting any solutions, he has done it for an in-mast furler, but one has to query the cut and quality of any in-mast furler which needs a leach-line.

 

[savageseadog]

Our leech line goes up the luff of the main, round a small block at the head and down the leech. There is a large velcro patch which enables adjustment at the tack at the gooseneck.

 

[Daydream believer]

I usually need to adjust it only when reefing.

There are four jammer cleats, one above the clew, one above the first reef, one above 2nd and one above the third. The optimum tension is a bit different when reefed, and in any case the act of reefing tends to let off the jammer(s) below. Possibly this is deliberately so and a testimony to the sailmaker's art.

Also the tension should ideally be adjusted according to wind strength - in very strong winds one needs a bit more tension to stop flutter (which can destroy the sail) - again this is associated with reefing.

Must admit, My sails set without flutter in all 3 reefs without leech line tension at all.
However, could you not just put a small tackle on the line at the clew As you have an in mast furler the clew would be over the cabin when reefed so one assumes you can reach it. One would just take up the topping lift 300mm to ease tension on the leach then once tensioned let the topping lift off .If the tackle was a cascade system the blocks could be very small. Dinghies have quite powerfull kickers using these blocks
For full sail a knot in the line could be set for the correct length so you would not have to adjust it at full boom length. Only once you started to reef would you need to tighten

 

[William_H]

Interesting problem peculiar to an in mast reefing/furling system. To be honest I have never seen one but obviously with no horizontal battens I imagine l;each flutter is a real problem. Leach flutter is a function of the weight of the trailing edge of the sail and the tension on the trailing edge which can dampen the flutter. I have an old dinghy jib where there is no hem leach line or anything so no weight just a heat sealed cut cloth trailing edge. One way to beat flutter.
If an adjustable leach line is your only option then it becomes tricky. I have seen the leach line go around a pulley at the top and down the luff but not much good on an in mast furler. So adjustment must be from the bottom. I would have thought one adjustment might suit most conditions but apparently not.
I would be avbit horrified at the idea of a linear actuator attached to the sail clew. Weight being one reason and the need for power wiring another.
I would think that a leach line turned at the clew to a point about half way along the foot might serve as being reachable from the cabin top. The cleat would have to be small enough to to be able to be furled with the sail. Sorry no help at all really good luck olewill

 

[Pagetslady]

Why not put a length of 3mm bungy into the end of the leach line then it would keep the tension on all the time.
Mike.