Limited travel on RMG winch setup

[tharmer]

I've got a bonehead question. I've built a control board per the ec12 build site. The winch has about 12" of travel (or rather the boom does before the collector tries to go through the pulleys). My boom needs in the neighborhood of 18" of sheet travel. What do I do?

The only possibilities I see are to move the main boom sheet attachment to something like 10 inches from the mast or to do some sort of sheet doubling as I did when I had the bang bang in there. I have not been able to find any info on ec12.info or with google.

Any suggestions? This has got to be a problem that has been solved a million times...I just can't find the solution.

-terry

[s vernon]

The obvious answer is to move the collector loop 19 inches or more aft of the pulley when the sails are full out. Is that not possible?

Or maybe I did not understand the situation.

Scott

[Rick West]

Terry,
The 12" is way outside normal. A block mounted to a bulkhead at around station 4 will give you more than enough sheet line length without the collector loop passing the jib fairlead on the way aft. Even if it does the jib sheet line goes to the trim server arm which is near station 30.

If you are using the internal one piece board and boom that was posted this winter you will have about the same.

What winch are you using? If a drum winch, what drum? Give us some more information of what you are working with because something appears to be not quite right.

...94

[tharmer]

Here's more information:

Zellanack control board
RMG 280D Winch
32ZS6, 32 to 12, 6-turn, Z spiral drum

End points set as per RMG manual

Here's a photo of how the control board sits in the boat.



The arrow shaft is 21 1/2" inches long. The mahogany socket that supports and locates the forward end of the arrow shaft at the bow is fairly close to the waterline so that the shaft does not have too much angle from the board to the socket.

[John Hulsberg]

Terry,

I suspect that the 280 D Winch, that you have, has only five turns, as supplied by Rob; and the drum that you are using needs six turns to control the drum to it’s specified 19 inches. You might have RMG replace the servo pot to make the winch into a 280 DL (6 turn); or use a 45ZS9 (4 turn, 17 inch) drum.

You might determine if the winch is giving you 4 turns with your radio transmitter; the short travel you describe is not fully explained by the winch and drum?


John Hulsberg
EC-12 # 2023
1 Edgewater Dr
Middletown, PA
Jhulsberg (at)Verizon.Net

[Ken S]

It appears you have an older Hickman hull....I have one also. From the picture you've supplied it looks like your arrow shaft is too short, making your bow block too far aft. I put an arrow shaft from the radio board right up into the bow...yes its got an up angle from the board to the bow but that really doesn't matter. The bow block hangs below the shaft so the shaft is out of play.

I'll try and post pics here of My setup...you'll see the bow block nut is just underneath the rounded portion of the bow. Which is right about station 4, thats where you'll need to put the bow block in order to get this to work.

So if you move your bow block forward you'll get the additional distance you need.

Okay I can't figure out how to post pics here I'll try sending them to you through email.

[tharmer]

Ken, I understand what you mean. I'll get a new arrow shaft tomorrow. Also, John, you're right. I fiddled with the transmitter (JR 10X) and the 280D for an hour or so and I think I've figured out the deal. First, I'll order the 45ZS9 drum. Second, I can get 16 1/4" if I don't put two turns on the small diameter part of the spiral. If I put two turns, I get 13". Third, I found out that if you fiddle a bit, you can get 5 1/8 turns from 100% throttle throw. No more when I set my TX to 140%. The speed was too fast (I think) so I reprogrammed the winch for a slower speed. Because I don't have two turns on the minimal spiral, I've programmed the winch to be less sensitive to the throttle stick when the line moves close to the minimal spiral. Add a bit of deceleration and some expo on the throttle stick on the TX and I think it will work. With this setup, at full sheet out, my boom is about 3/32" from the shroud. at full sheet in (trim in also) the boom is centered on the deck. With the new drum I'll have a bit more to play with.

Thanks for the help guys.

BTW Ken, how can you tell I have an early Hickman? Good eyes. Mine's a 2001. I've got Zelanack rigging and mast, a set of Black sails and a set of new Winjammin' sails. All this and I've only been sailing for a few <i>hours</i> with this guy. My first race is May 18th so I hope to have a bit more stick time by then.

Rick, your "Dummy" series is great. I feel right at home with the "dummy" stuff (being one myself). [;)]

-terry

[Rick West]

Terry, I would disagree with the 45mm. We know the 30 and the 32mm drums work and they give you better resolution in line travel at close haul.

When you get the block up to around station 3 also check to see there is no rubbing of the line on the rib frames below the deck. It should not but check.

Also see if you can shorten the lead from the collector to the block. The meaning is to have the collector knot, or tie to a swivel, right to the block at close haul but never touching.

Let us know when you work this out. You are nearly alone up there in WA now.

...94

[greerdr]

It is ok to have the boom on centerline with everything choked down, but we seldom sail the main in that "vang sheeted " position. Slow but pointing high.

R.C.Greer

[Ken S]

Terry....as far as I know Hickman's are the only hulls with the "flange" filled in back to about 4". The rounded "flange" up near the bow was a dead giveaway.

[tharmer]

Rick, the trick for me was to adjust the winch line travel by how much line is on the small part of the spiral drum. More winds on the small part = less overall travel.

[greerdr]

I think we start on the big part and end on the small part of the drum.Easy to mix up the rotation but try big rotations first.


R.C.Greer

[tharmer]

Yep. I've got it set now.

[Rick West]

I use just a turn on the axel. That seems to be enough for fine adjustment at close haul.

...94