Self Tensioning Spiral Drum on RMG 280DL

[John Hulsberg]

I’m putting together parts for my new EC, and am considering the use of the new self tensioning 45mm, 4 turn, tapered spiral Drum to eliminate the elastic and still have a spiral winch drum. Have others tried this setup yet on an EC-12? In your expert opinions or experience, will 4 turns or less of this larger drum yield the required 17 inches of travel? My “back or the napkin calculationsâ€

[John Hulsberg]

<font face="Arial Black"></font id="Arial Black"><font size="3"></font id="size3"><font color="black"></font id="black">More thoughts on the previous post...

I’ve been pouring over the RMG Site and found specifications of 430mm for the 45zs4 Tapered Spiral Drum. If the new 45mm, Self-tensioning (45zs4s) has the same 430mm (16 7/8â€

[John Hulsberg]

I remain hesitant to invest so much in a boat that depends on a piece of elastic for dependable sheet control. I’m intrigued with the use of the RMG Self Tensioning Drum (45zs4st). Lacking feedback, other than "go with what works", I emailed Rob Guyatt and received the following well thought out information which I'm posting in the group for the benefit of all that might also be building/refitting an EC-12. I guess that I'm going to order two drums, a Spiral Self Tensioning 45zs4st and also the less elegant spiral 32zs7, just in the likely case that the skippers that were kind enough to offer verbal advice are correct!

John Hulsberg
One Edgewater Dr
Middletown PA, 17057-1661
717.944.7241
Jhulsberg@Verizon.Net
AMYA # 1973
EC-12 # 2023
STAR # 95
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Hi John,
Thanks for your questions. Yes you are welcome to post my reply. I don't get on to the discussion forums as often as I should to keep up with things so thanks for bringing me into this thread.

Don't take much notice when you are told "xyz" is the ONLY way to go. There's always options. Some are a better fit than others but there's no such thing as perfection. The 32zs6 and the now obsolete 30zs7 were devised with the EC12 in mind. From most of the feedback I get, I understand that speed is not such an issue for most EC12 skippers. So the 32zs6 and 30zs7 were designed to give the required travel from more winch turns. But the 45zs4 certainly can be used for EC12. It will mean that sheeting is about 30% faster. Even though the drum is 45 mm diam when sheeted out, there's still plenty of grunt in the 280DL to handle the extra diam in an EC12. And for those that say it would be too fast, my stock reply is simply "it's only as fast as your thumb".

No serious drawbacks to using just 4 turns. Resolution is reduced to a total of about 600 increments rather than say 900 if using the 32zs6 for example. But 600 is still fine adjustment. The actual resolution depends on where on the drum the sheet is coming off. For example off the 45 mm diameter the resolution increment size is about 0.9 mm and at the 15 mm diam when at close hauled it's about 0.3 mm. That resolution at close hauled sounds pretty over the top and unnecessary but I understand that some skippers don't use a main sheet fairlead post to get the fairlead up close to the underside of the boom. If the fairlead is at the deck then that extra fine resolution comes in handy.

Cheers
Rob
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[Rick West]

John,
Rob is correct and always has the interest of his customers in mind.

There may be some that are using a continuous loop sheeting system on the EC12, which does not require bungee tension. However, such systems cannot use a spiral drum.

The use of bungee tension goes way back and likely to be near 100% used in the fleet. It is not a problem.

The 280DL is well suited for the EC12 and is now a 6 turn winch.

The 30z7 on the website was for the 280DL with 7 turns. Rob redesigned it to 6. Those of us that have the 30z7 in stock are using them. The adjustment is made on the full sheet out position during the programming.

The 6 turn 280DL is now suited for the 32z6 drum and the reason for the change in drum size was the lesser turn.

Rob is correct that the 45z4 will work for the EC12. However, the far majority like the resolution of the smaller drums. We would like a tension spring setup for the 32mm but it has not be worked out yet.

My suggestion, if it is just the drum that is holding you up, to order both the 45z4 and the 32z6. It is not that much money. Test it in the open hull and let us know what you get.

If I had one I would test it. The reason I don't is I did not like the numbers. I may ask Rob to send me on anyway. What the heck.

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