Jordan Series Drogue Cone Shape?

[YPSILANTI]

I live in South Africa and have not seen an actual JSD. I will shortly be making my own JSD. I have read all the information on the web and viewed the you tube clips. However, I am having difficulty on the curvature of the two ends of the actual cone. I do have the measurements from the diagrams. I used the diameter of 7 in x pie of 3.14 to determine the 15.7 circumference of the cone. I then took the radius, traced the circle with a compass to determine the opening of the cone. However, my shape is different to the images. Am I missing something simple? Is there an actual to scale cone shape template that I can obtain to use as my cut out of my cone. That will help enormously. Any advice will be appreciated.

[kmacdonald]

The circumference is (2) (pie) (R)=2 x 3.14 x 3.5 = 21.98"

Just call it 22"

But isn't the diameter supposed to be 5"?

Sailrite hs the dimensions. http://www.sailrite.com/PDF/Drogue-Instructions.pdf

[kmacdonald]

Has anyone ever thought of using larger cones but less of them to make construction faster and less expensive? Of course it would require stronger cone material and maybe straps.

[kmacdonald]

Originally Posted by YPSILANTI

I then took the radius, traced the circle with a compass to determine the opening of the cone. However, my shape is different to the images. Am I missing something simple?

You are thinking of and drawing it in the wrong plane.

[UNCIVILIZED]

Originally Posted by kmacdonald

Has anyone ever thought of using larger cones but less of them to make construction faster and less expensive? Of course it would require stronger cone material and maybe straps.

The recommended fabric weight for constructing cones is heavier than it used to be. There's some discussion on it in a couple of threads here on CF --> http://www.cruisersforum.com/forums/...-119799-5.html
And probably as well on SailRite's website. Possibly on the Drogue Device Database too? Victor Shane's Drag Device Data Base | Using Parachutes, Sea Anchors and Drogues to Cope with Heavy Weather – Over 130 Documented Case Histories

But the basic idea behind JSD's is to have the entire drogue assembly be long enough that no one part of it sees excessive strain at any point. And this is also the reason for the large number of cones typically used as I understand it. So that if you modify things like you're suggesting, you'd be stepping away from some of it's design principles. As to how well it'd work or not, you'd need to research that. Probably both via the data base, & via institutions like US Sailing, & maybe the USCG or RNLI. But I'm sure that there's some information out there on this.

Out of curiosity, how long is it taking you per cone in terms of manufacturing time? Laying out patterns, cutting, sewing, etc.

One other possibly relevent thought is that some boats, multi's especcially, carry several types of drogues. Each one best suited to a particular set of conditions. Since for example you sometimes simply want to slow down from say 12-15kts+ to 7kts or so. Which, a standard series drogue would slow you to perhaps 2kts in such conditions. So then you use another type of drogue for this. And instances of this are found in the DDDB.

[JPA Cate]

Ypsilanti,

The difference in the shapes is because of the seam allowance. If I were going to do it, I would slightly lengthen the cones, enough to hem the opening, for about the first 50 of them. Also, would use zig-zag stitch for this, for its flexibility.

You can also cut more than one cone at a time with a hot knife, and then pull them apart.

Sorry, I do not have a template at hand to photograph for you.

Ann

[newhaul]

The question I have is how many cones do I make for my 4800 ib 24

[kmacdonald]

Originally Posted by newhaul

The question I have is how many cones do I make for my 4800 ib 24

I would make 90. 1/2" polyester double braid will be fine. It's a lot more chafe resistant than nylon double braid.

[JPA Cate]

Interesting comment kmacdonald. Some people are going to dyneema line, not sure how you get the cones to stay in it, though, it's so slippery.

Ann

[newhaul]

Originally Posted by Ann T. Cate

Interesting comment kmacdonald. Some people are going to dyneema line, not sure how you get the cones to stay in it, though, it's so slippery.

Ann

I assume they are stitched to the line.

[Jim Cate]

Originally Posted by newhaul

I assume they are stitched to the line.

I'd just ask the guys at Ace sails, who are the commercial source for JSD. They will supply them with Dyneema line

Jim

[newhaul]

Originally Posted by kmacdonald

I would make 90. 1/2" polyester double braid will be fine. It's a lot more chafe resistant than nylon double braid.

Thanks for the response I was figuring on somewhere between 75 and 100 but also know if its to many it can.overload the vessel.
As far as the line I was thinking staying with nylon braid ( I can get 1/2 inch for under 200 bucks for a 500 ft roll) ( still have trucking contacts)

[UNCIVILIZED]

Originally Posted by Ann T. Cate

Interesting comment kmacdonald. Some people are going to dyneema line, not sure how you get the cones to stay in it, though, it's so slippery.

Ann

I'm fairly certain that there's a fair amount of commentary on spectra's use in JSD's on www.SetSail.com And wouldn't putting a couple of stopper knots into each tape after weaving it through the line hold them in place? Because as soon as a load of any substance comes onto the line, it's going to seriously tighten up. So much so that I'd think it nigh on impossible to get the cones loose until the tension was removed.

[mikereed100]

Hello YPSILANTI,

Here are the measurements for the template I made for our drogue. This template allows for a 1/4" hem in the leading edge, which is important. Our first JSD was made from a Sailrite kit and many of the cones disintegrated after only a few hours deployment. I would use at least 4oz cloth with at least a 1/4" hem (more would not hurt).

When we rebuilt our drogue we used the old line, which is nylon double braid since we already had it. If I were building from scratch I would use Dyneema. Our drogue is 150 cones, your Voyage 50 would use a similar, if not larger amount. The finished drogue is very heavy and bulky, much heavier still when wet. Dyneema avoids both these issues and you do not need the stretch of nylon. You tie a figure 8 in each of the cone straps so pulling out of the dyneema would not be an issue.

[kmacdonald]

You can buy the cones here: 100 SERIES DROGUE CONES SEA ANCHOR, DESIGNER DON JORDAN | eBay
He will sell them in increments of 10. I purchased some from him and was very happy with them. I have no financial interest and am only a satisfied customer.