back/head stay length and mast rake

[fixxxer0]

when i bought my C&C 30 last year i had the standing rigging replaced (i noticed a couple cracked swages and the rigging was at least 12 years old and raced on).

i cant exactly remember much how it sailed before the rigging was replaced ( i think it was pretty balanced) but since then i have noticed i have some slight lee helm, where i would rather have slight weather helm.

now i know all about lee/weather helm and sail balance with the main and jib and the trim of both. my concern is the mast seems to be straight as an arrow with no rake. from what i have found, C&C recommends ~8" aft rake (which in my case would remove the lee helm hopefully and add slight weather helm).

here comes my question! i have a roller furling (has a north sail sticker on the unit)and a turn buckle on the backstay. with this ~40' from the deck mast straight up, how much would i have to slacken the forestay and tension the backstay to get ~6-8" rake? i dont think i have much play with the stay lengths, the turnbuckles can only take up a couple inches i think.

will the stays have to be shortened/lengthened? i dont even know how i would slacken the headstay with the roller furling on it...


any suggestions?

[GeorgeB]

The short answer is you should have had your rigger do both a static and a dynamic rig tune before you handed him the check. First things first. Are you sure that your rig doesn’t have the proper rake? Suspend a plumb bob from the top of the mast using your main halyard. The string should be eight inches aft of the mast at the boom (you will need to remove the main sail). You will also need to remove your jib off the furler and remove the lower reel assembly (you should be able to down load the instructions from North). Next, ease the lower forward shrouds if you have them. Then ease the headstay while taking in the slack on the Back stay. Do this until you have achieved the desired rake. You should have enough turns on your turnbuckles to do this (it doesn’t take that much). Then tighten down so you have the proper tension (I have my own Loos Gauge). Re-tension the lower shrouds and putting in any desired pre-bend. Double check to see that the mast is still in column by checking to see if the plumb bob is centered over the (centered) boom). You can also do this by measuring from the mast head to each of the lower shroud chain plates. The should be symmetrical (port to starboard). Put the sails back on and go sailing. With the boat at the desired heel, check for slack in the leeward shrouds. Tighten. Do the same on the opposite tack. Back at the dock, re-check your work with the Loos Gauge, making any corrections if necessary. Re-install with new cotter pins. Go sailing. Have fun.

[SEMIJim]

Originally Posted by fixxxer0

with this ~40' from the deck mast straight up, how much would i have to slacken the forestay and tension the backstay to get ~6-8" rake?

Rake isn't usually expressed in inches, because that value is dependent on rig dimensions. Probably what C&C refers to is the distance between the back of the mast and the mainsheet when the boat is level and the mainsheet is hanging straight down.

But that's not even Step #1 of rig tuning. Before you do that you have to get the mast in column. You can't just go wrenching on the forestay. There's a step-wise process to rig tuning.

Suggest you read this: Adjusting Your Rig and follow it to the letter.

I'll tell you this: Once you get it right it will have been worth the trouble. I did it season-before-last, improving on it last season, and the helm is just terrific. From air the light side of moderate up to pretty stiff: On many tacks we can just let go of the tiller and it just sits there gently vibrating for a while, and eventually the boat begins to start slowly rounding up

Originally Posted by fixxxer0

will the stays have to be shortened/lengthened? i dont even know how i would slacken the headstay with the roller furling on it...

Got no clue on that one. Don't have roller furling.

Jim

[fixxxer0]

Originally Posted by GeorgeB

The short answer is you should have had your rigger do both a static and a dynamic rig tune before you handed him the check. .

I agree... especially since on my bill was "rig tune". I already left him a message (he knows me by name) and will speak to him about it, but if its not terribly maybe I will tune myself. In fairness, the static tune was done since the mast is centered and in column. Honesty, I don't think I knew enough about rig tuning and lee/weather helm last year to have said anything. Plus i bought the boat mid-season and was rehabing the engine so I did little sailing, and was my first boat with a wheel so still getting used to it.

Originally Posted by GeorgeB

Then ease the headstay while taking in the slack on the Back stay. Do this until you have achieved the desired rake. You should have enough turns on your turnbuckles to do this (it doesn’t take that much). .

this was my main concern and reason for asking the question... when you say "it doesn't take much"... can you give me an idea how much? is it something like 1 inch? more? less?




And SEMIjim: "On many tacks we can just let go of the tiller and it just sits there gently vibrating for a while, and eventually the boat begins to start slowly rounding up"

Mine is exact opposite. I let go of the wheel and after a while eventually the boat starts to fall off a little bit at a time.


Thanks for the replies

[GeorgeB]

It sounds to me that probably, your rig already has some rake already in it as it isn’t immediately “heading down” when you take your hand off the wheel (tiller?). Another hallmark of a mast raked forward or straight up is difficulty tacking. Think good thoughts and do the plumb bob test and report back. “Mast in column” means that the mast is straight and not curved or bowed and is a symptom of the lower and upper shrouds not being in balance with each other. A mast can be in column and still raked. To check for in column, lie on your deck and sight up the mast. You should see a straight line. Bows and curves will be readily apparent.

[knothead]

The furler with the North sticker is a Harken. It's made with an integral turnbuckle. To adjust it, you need to loosen the left hand locking nut and star washer under the drum and the locking collar which is inside the torque tube on top of the drum. The unit is adjusted by holding the stud and rotating the actual drum. It should not really be used to tension the rig, only to adjust it. So your backstay should be loose and you should have a halyard led forward to slacken the furler during this process.
The t-bolt on the bottom of the unit has some marks on the flat side which should not be visible. If you can see them, you have opened the turnbuckle too much.
The stud and that t-bolt should have been started equally and you might want to check that that was done.

The rigger should have measured the pin to pin before he started to disassemble the furler to replace the wire. If he did this, he should have simply reset that measurement before the furler was reinstalled and you should have exactly the same rake as you had before the rerig.

[fixxxer0]

Originally Posted by knothead

The furler with the North sticker is a Harken. It's made with an integral turnbuckle. .

Hrm... it doesnt look like any of the harkens ive seen in the last 15 years or so...

Its mostly stainless with what looks like circular SS tubes on the top and bottom of the drum. Obviously a picture would be the easiest but I dont have one at the moment.

Any idea where I can find some documentation on this, if in fact it is a Harken?

[captbillc]

i have harkin roller furling on the headsail. the PO had a forward rake in the mast. i could not back it off far enough & the headstay needed to be replaced anyway, so i got a longer one with a swaged eye on the top & cut it so it would be 2" longer. i put a stayloc stud on the bottom to screw into the harken drum. it worked out fine. i have a wheel on the backstay to adjust tension. the harken manual gave me the step by step instructions to get the job done.