Yes, that would be the issue. You would have to move the sheet exit point from the deck, back further. This gets complicated quickly.

Yes it would allow further movement out, but then does not allow the boom to be tighter in when close hauled. I think I would prefer to be on a broad reach and still be able to beat to windward more easily than to be on more of a dead run. Thanks for the suggestion - only practice on the water will give me the final adjustment.

Glad I could be of assistance.

Would moving the mainsheet attachment point on the boom closer to the mast give you more range of movement of the boom to full out?

I do this alot with the DF65 to adjust the boom because it is so simple to adjust the attachment on a DF65

Have now re-worked the tension system on the mainsheet, with thanks to RossM for guidance, albeit I have modified his thoughts a bit - first photo shows full tension, where the white elastic is at full stretch, and as it is not quite long enough, there is also an elastic 'connection' at the top end of the white elastic to absorb the extra stretch required - second shows no tension with sail fully out, . I have not got the full mainsheet run required - but it is probably close enough. Tested this many times now on dry land, and just need a real wind test to validfate this solution. Thanks for all the input.

That's not a laugh - it works, and does the job - just need a few more mast supports!!! I have a similar problem with twin foresails - except the forestay, round which one of the foresails goes has far more friction that a solid mast - but it all works - so that is what it is about, and trying to keep it looking vaguely realistic

If you want to have good laugh before starting, check my video on moving a STAYSAIL between 2 masts. (only the engineering mock-up)

Thanks RossM for your input -will try your loop line setup, and see if it hangs together. Will keep you updated.

can your pulley handle the LOOP LINE, MAINSHEET, and ELASTIC LINE volume?

This is going to be a BUSY pulley. can you put the tensioner on the back side of the loop? 2 idler pulleys side-by-side with the tensioner pulley between them, pulling away. the usual method. see also my KUBOTA picture. I think some elastic line might suit you for the tensioner spring

A simple LOOP KNOT in the LOOP LINE

expanded size for display. Tightened and half tightened

Then tie the mainsheet to that loop

repeat to tie the elastic to the mainsheet 4 inches or so down the line

anchor elastic other end to the SHEET SIDE of the loop

Main sheet is tied to the loop line

Elastic is tied to the mainsheet, about 4 inches down

Elastic begins to stretch as the mainsheet rounds the pulley

This keeps the tension on the mainsheet as it rounds the pulley

Travel is about 4 inches more as the mainsheet rounds the pulley

I think all you need is an 8 inch elastic in the right place

Hi RossM - just had another thought - a double pulley at the top? one with the mainsheet on it, the other with the elastic as per your diagram? Then the question is getting a strong enough connection between elastic and mainsheet without using a ring connection. I have some elastic that doubles its length when full stretched, and is strong from almost zero stretch, which I think will give me necessary tension.

It is a schematic diagram - so in reality I am thinking the ring connecting the sheet lines and the elastic would be tight on the pulley with the mainsheet fully out - and the elastic would have 'some' tension in it, but still be round the top pulley. Trying to get the joining ring to stay in place going round the top pulley will I think be another failure. My main problem is that top pulley to winch drum is 15", assuming I can get the pulley tight onto the newell post, and I really need 15 1/2" minimum - it may just mean the main does not go out fully, which in some ways might be useful to save a nasty full power uncontrolled jibe.

ELASTIC

I am thinking that the elastic will be too tight at full extension and too slack at retraction. SET THE ELASTIC ON THE OTHER SIDE OF THE LOOP

Can you bring the mainsheet AROUND the upper PULLEY to gain the extra length? That would mean that you would have to rout the MAINSHEET right along side the PULLEY LOOP line and attached to the elastic that tensions as it rounds the pulley.

Have the ELASTIC line tug on the MAINSHEET, JUST AS IT STARTS AROUND THE PULLEY, to keep it seated in the pulley. Is that what you were thinking in your diagram? So the elastic would only have to stretch the distance between LENGTH BETWEEN THE PULLEYS and LENGTH OF MAINSHEET. Approximately 5 inches. Shows ELASTIC at FINISH POINT

Hi RossM - main sheet loop has a run of 12", and I need a minimum of 16" for the mainsheet run - the calculation I have done is that I can get a pivot radius of 6" inside the hull and frames, which gives me a mainsheet run of 18", which is ample. Still have the problem though iof a heavy servo on one side of the boat, requiring balance on tother. See my latest drawing of suggested setupo - would it work?

I have now done some more strenuous brain exercising - I have come up with the attached, which I think will give me the elastic length required retainign tension on the mainsheet feed to the drum winch - does this make sense, and is it realistic before yet another internal rebuild? Thanks for all your guidance.

Just an idea . . .

Instead of running the sheet from the 'too short' MAIN SHEET LOOP, (because the loop is too short), run the required LEVER from the MAIN SHEET LOOP.

How much lever length-arc do you need to run the MAIN SHEET?

How much run do you have on the MAIN SHEET LOOP?

Thank you all for your input. Yes RossM, it is Three Daughters. BillH2, I do not have enough accessable length to do a continuous loop for the mainsail. The foresails are on a continuous loop, with a tensioner and work fine, as they have a shorter pull length. See photo - the foresails are on the aluminium angle frame, with the tensioner pulley at the stern. The white 'pipe' running down the centre is the latest attempt to get a direct feed to the stern/mainsail winch. The fine line above it is thin elastic, fine enough to allow it to run down the pipe with the sheet. The white winch surround is to try and stop the sheet snagging underneath the winch pulley. I have measured up, and need a 5 1/2 inch lever for the required sheet travel, and this fits between the frames - BUT would put the servo on one side of the boat, requiring the same weight on the other side to keep the balance, and she does not need any more weight!!. So it is probably some new tension design, but needs more playing. I am also now adding the topsail, so need the full strength of these heavy winches, as it is a big sail area.

I have a sailing yacht in my ‘to do’ file. Watching with interest.🤔

Is this the Bristol Pilot Cutter- THREE DAUGHTERS?

Is there a tensioner pulley? I have spent many years with continuous loops and tensioner pulleys. The tensioner pulley is in the centre, the spring is along side it (a Kubota). It doesn't slack or tangle

BillH2 is correct

Its better that you redesign the system so you have a continous loop running off the winch with sheets attached to the loop. The loop need to be tensioned with some sort of spring

Hi Luckyduck, I was asking the same question as RossM, while I was trying to translate your question correctly.

In addition to the images, I would like to know if possible: how much is the surface of the mainsail, how much does your boat weigh, do you have space for the lever bar in your hold, how many turns does the winch make, does the sheet wrap directly around the drum or have you created the system closed loop?

It sounds like a lot of torque. BUT before throwing the baby out with the bathwater can you post some pics of your layout?