Vixen updates and tweaks

I’d like to share some updates and tweaks I’ve made to the Vixen over the past several months. I’m committed to continuous improvement in the flight performance, usability, and fit and finish of all my kites. Hopefully, this article will give you an insight into where we’ve come and where we’re going with the Vixen.

The Vixen was developed as much a design experiment as it is a kite. From the kite side, I was never all that concerned with it being a rock solid, pasted to the sky, platform. I like a kite with a bit of motion and action. A little movement is good, as it keeps the interest. Sweeping the window, or falling from the sky, not so much.

I’ve made quite a few small changes to the Vixen since teaching it back in March. A lot of the changes are construction details, and many of those are primarily cosmetic. Take out a pucker here or a stress line there. Some of the changes are structural, and most of those are simple tweaks that are easily done by the owner.

Center vee standoffs

I’ve gone to slightly longer, and much stiffer standoffs for the center vees. I use the same stick as the wing bows and spreaders, which is a .180 pultruded carbon. For a retrofit, I’m thinking that a .210 tube is the best choice. The .210 will fit inside the standoff fitting, but also act as a sleeve over the existing fiberglass standoffs. This will allow us to not worry about changing out the fitting. The preliminary measurements for the new standoff sleeves are 6 3/8″ at the rear, and 7 5/8″ in the front. You’ll need to cut the vinyl end caps off the old fiberglass standoff.

The stiffer, longer standoffs make the assembled frame dramatically more rigid. I’m wondering if the stiffer frame might negate the need for the anti-twist lines.

Tail spreader fittings

On my first prototypes, I used a fitting and stopper system to stiffen up the tail surfaces and induce some negative twist, which helps with stability and also backwards glide. (I do love me some backwards glide!) In the class kites and subsequent BMK kites, I did away with the tail fittings and added the twist to the wing instead. Recently, I’ve gone back to the system shown in the pictures below. (click to enlarge)

Front wing spreader

The mini-tee for the front wing is now dead center on the carbon spreader. It was previously a little off center to induce a positive wing twist, and manage what an airplane designer calls decalage. I’ve come to think this is best managed at the tail. You probably have all the bits you need for this already on your Vixen.

Spine extension

I’ve increased the length of the twin spines (longerons) by 3″. This opens the kite up a little. It was still looking a little cramped to me. It also moves the tail just a little further from the wing, which should give it greater leverage to correct tracking deviations. As part of this, I moved the rear bridle connection to behind the spar joint. Again, to increase the ability to self-correct. For a retrofit, I can supply a pair of 3″ carbon extensions, with ferrules. You will also need a link line that’s 3″ longer.


The center section of the bridle is extended about 12 inches, and the aft bridle connection points are moved back about 8 inches.

Vixen 2.0 “hard” changes

I’ve made a bunch of little changes to the latest incarnation, which I’m referring to as 2.0 Most of them are minor sail cuts to take out, or add shape to the tensioned fabric. The goal being a smoother finished surface and more refined look.

The most obvious change is the depth of the rear vee. It’s about 2 1/2″ deeper. Partly for aesthetics, but also to aid in tracking. This change could potentially be made to existing kites, but I don’t know that the cost wouldn’t outweigh the benefit.

Additional notes:
  • Try a light weight, high drag tail device, like a fuzzy tail, or perhaps a drogue. Please share your results with the group.
  • All of these mods are offered with no guarantee that it or they will solve every conceivable problem. There are a lot of variables. The upside is that it should make a positive difference in your experience with the Vixen. The changes are minimally invasive and mostly reversible. They aren’t going to make things worse and should make them better.
  • If you have comments or questions, please leave them below, or join us on the Blue Moon Kites group on Facebook.

Get the bits and bobs
  • If you own a Vixen made by me and would like to do the modifications yourself, all of the hardware updates mentioned above are available free of charge, including shipping.
  • If you have a BMK-made Vixen and would like for me to do the updates, your only cost will be that of sending your kite back to me. I will pay for return shipping. I highly recommend this option.
  • For workshop kites, parts are available at cost. Shipping is extra but should be cheap.
  • When ordering, please verify that your tail section fiberglass spreaders are 15 3/8″ or longer. Not critical if they are slightly shorter, we’ll just need to adjust the geometry “on the fly”. If they are longer, you’ll need to be able to cut them down.
  • Please contact me if you’d like a retrofit kit. I’ll work on modification instructions when I get a little spare time.
Make the updates
Let’s start with the tail section.

Click on the pictures to enlarge. Let me know if these don’t provide enough info. Don’t worry if I sent you a few extra pieces, it’s good to have spares.

Wing Spreader

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Spines extensions

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