Mast Rotation Inducer

Can you guys give me some ideas on how to rig a positive mast rotation system or a mast rotation inducer? This system will make sure the mast stays roated in light air and choppy conditions. Make sense?

There's a thingey you can put on the front of the mast. Probably get it at Murray's.

http://www.apsltd.com/c-70-boommastbailsstrapstangs.aspx There is one that is more square in shape and a lot of guys used it on the H17.

Yeah, but I am worried about the jib track/sheet and spin stuff in front of the mast.

Very simply thinking, it is a line from the current mast rotator arm to small cleats on the main beam. I was just wondering if someone had come up with a slick solution. You could put a small turning block on each side of the main beam port/starboard) and run it back to a cleat on the other side....

I used this on my H-17 with a small double block for purchase and a cleat on the boom. Had a big ball to pull to adjust rotation. Use a bungee to corner casing in light air.

Doug

I think it would only be necessary for a distance type event. I rigged some up on the 18HT a few years ago for the RTI. I think we used them, but can't remember.

Anything in light air with your foot on the boom or mast rotator to hold it in the correct place seems like a long distance race.

Tom,

Yeah I got a few idea's for you.

You can fit a bungee to the mast rotator arm and have both its ends tied off to the spi pole some distance in front of the mast.

Another option is to tie one end of the bungee of to the boom and then go in front on the mast one time and tie the other end off to the same place on the boom.

In either case you need to kick the boom over in light airs but then it stays there.

I never rig these as I always use my jib cleats and two small line to pull the mast rotation arm over in light airs. When sailing two up it is a task I delegate to my crew (often myself incidently) as they will be on the leeward hull anyway.

The underlying principle if the same for either setup. See picture.

Basically the overall line length for the loop is longer when the mast and boom are aligned with eachother. This stretches the bungee cord. When the mast and boom are perpendicular to each other then the total length of the bungee is the shortest. When using a thick bungee cord the axial force in the loop is sufficient to pull the mast to side it is set. Working against the rotation limiter, so you can still adjust your mast rotation the normal way.

Numerous variation of this principle are possible. Using cleats etc. Where two pieces of line are fic to the mast and the run in front of the mast back to the boom and two individual cleats.

I'm not going to describe them all, so what are you looking for exactly. Something that is really simple and works or something that work really well but has you riveting eyestraps to your mast etc ?

Wouter

Wouters last option works well. We had one on both my Hurricane 59's but with rope and a cleat under the boom. Just push the mast spanner and cleat the rope onto the boom. Job done.

That's how Robbie Daniel has his set up.

I had a Boyer Mk 4 that worked as shown in the attached figure. I remember I always forgot to uncleat it before jibing.

That is why mine was attached to the boom. It was like a self tacker. It didn't matter witch tack or gybe you were on.

Doug

Thanks. That sounds like the ticket. Something that will allow a gybe or tack and something that is removeable for the days you do not need it. I may just tie a rolling hitch of some sort on the boom, make the bungy the right length and voila. A removable, simple solution for the days you need it.

I liked the setup because it was so adjustable on the water. You could trim the mast rotation to changing wind conditions and pop the cleat to go downwind. I had bungee system looped to a line between the bow tangs that helped rotate the mast to about 110% for going downwind. Simple, yet efficient, as I needed all the help I could get with the H-17 downwind.

Doug

On the Taipans they add another component that may also be of interest to you.

Basically it is the bungee setup but now the bungee near the boom runs through a small block and the small block is attached to a line that runs through an eyestrap and cleats of to a cleat some distance to the rear of the eyestrap.

This allows the crew to engage and disengage the setp while sailing.

I don't know how well the bungee works but if it is insufficient then this Taipan cleated setup can also be implemented with a simple line for a bungee and really secure the mast. However, It will no longer rotate on its own so you'll have to uncleat and recleat it everytime you gybe or tack.

Wouter

Ohh yeah, Geoff's picture is the setup.

Note however that it is not needed to put an eyestrap onto the mast. The system will work just as well without it (and with a continous loop)

Wouter

Doug, i would like to understand the rotation inducer you used on your H17 but the photo is, well, i just can't visualize it. I wonder if you could draw a diagram?
Will

Will:

Really simple system once you get all the parts made up. I loved it.

Doug