Bumper yaw string

Yes Thanks Bumper! I too bought a MKIV and am quite happy. Although I think Bumper might be unhappy with me, as I immediately modified it. I had problems with the previous MK II or whatever it might have been, snagging the canopy cleaner microfiber cloth I use, so I ever so carefully rounded the front point and beveled the edge of the plastic. I know what your going to say Bumper, I've completely ruined the aerodynamics of the thing. But I have to say it has stayed on now for at least 4 years with an avg of 200 hrs/yr But alas its now worn out as the yarn is completely unraveled and I had to tie it on the end (yes I am a cheap glider pilot). I was by the way the first one to ask and receive a white one! Do they come with a lifetime warranty

CH Ventus B

On Thursday, December 3, 2015 at 12:51:49 PM UTC, wrote:
Yes Thanks Bumper! I too bought a MKIV and am quite happy. Although I think Bumper might be unhappy with me, as I immediately modified it. I had problems with the previous MK II or whatever it might have been, snagging the canopy cleaner microfiber cloth I use, so I ever so carefully rounded the front point and beveled the edge of the plastic. I know what your going to say Bumper, I've completely ruined the aerodynamics of the thing. But I have to say it has stayed on now for at least 4 years with an avg of 200 hrs/yr But alas its now worn out as the yarn is completely unraveled and I had to tie it on the end (yes I am a cheap glider pilot). I was by the way the first one to ask and receive a white one! Do they come with a lifetime warranty

CH Ventus B

Ahh yes - the perennial issue of whether to tie a knot at the end of the yarn in the Mark IV. I tied a knot right at the end of my last one as it started to unravel a little but it changed the aerodynamics so that the terminal couple of centimeters or so waggled annoyingly. Then I tied a knot about a centimeter from the end and allowed the end to fray to create a little drag and that worked OK. My current one is still as delivered, hasn't unraveled yet and is performing well.

The MKIV "high tech" yaw string length is about 7 to 8 inches (18 cm - varies a little due to the assembly process). I tie a simple overhand knot about 9 mm from the end of each yarn to prevent unraveling. In some fields of endeavor, 7 or 8 inches might be considered too long, so the MKIV instructions suggest cutting the yarn to your preferred length. AND to tie a knot in the end (please), or it will come unraveled in short order . . . it's just the nature of things and part of the cosmic reality.

All that said, a recent customer in France, with a DG-80X (you know who you are :c), ordered a MKIV custom made with a 40 cm yarn. With the canopy stretching almost to the nose on the DG, he wanted the MKIV base mounted in the distance while having the yarn where he could see it! He is currently the record holder with the longest yaw string in the entire world. Hopefully this won't become a "mine's longer than yours" trend.

bumper

On Thursday, December 3, 2015 at 5:31:33 PM UTC, bumper wrote:
The MKIV "high tech" yaw string length is about 7 to 8 inches (18 cm - varies a little due to the assembly process). I tie a simple overhand knot about 9 mm from the end of each yarn to prevent unraveling. In some fields of endeavor, 7 or 8 inches might be considered too long, so the MKIV instructions suggest cutting the yarn to your preferred length. AND to tie a knot in the end (please), or it will come unraveled in short order . . . it's just the nature of things and part of the cosmic reality.

All that said, a recent customer in France, with a DG-80X (you know who you are :c), ordered a MKIV custom made with a 40 cm yarn. With the canopy stretching almost to the nose on the DG, he wanted the MKIV base mounted in the distance while having the yarn where he could see it! He is currently the record holder with the longest yaw string in the entire world. Hopefully this won't become a "mine's longer than yours" trend.

bumper

Aha - I cut them a little shorter and didn't think about there being an original knot

Bumper, a couple of questions:

How about dipping the end of the yarn in glue rather than tieing a knot?

At replacement time, how is the base removed without damage to the
canopy or residue left on the canopy?

On 12/3/2015 10:31 AM, bumper wrote:
The MKIV "high tech" yaw string length is about 7 to 8 inches (18 cm - varies a little due to the assembly process). I tie a simple overhand knot about 9 mm from the end of each yarn to prevent unraveling. In some fields of endeavor, 7 or 8 inches might be considered too long, so the MKIV instructions suggest cutting the yarn to your preferred length. AND to tie a knot in the end (please), or it will come unraveled in short order . . . it's just the nature of things and part of the cosmic reality.

All that said, a recent customer in France, with a DG-80X (you know who you are :c), ordered a MKIV custom made with a 40 cm yarn. With the canopy stretching almost to the nose on the DG, he wanted the MKIV base mounted in the distance while having the yarn where he could see it! He is currently the record holder with the longest yaw string in the entire world. Hopefully this won't become a "mine's longer than yours" trend.

bumper

--
Dan, 5J

On Thursday, December 3, 2015 at 10:15:22 AM UTC-8, Dan Marotta wrote:
Bumper, a couple of questions:



How about dipping the end of the yarn in glue rather than tieing a
knot?



At replacement time, how is the base removed without damage to the
canopy or residue left on the canopy?


Dan (and all),

The MKIV base removes cleanly, leaving no adhesive residue, even after years of UV exposure. In '98 I did an exposure test with multiple strips, exposed 24-7 in the California sun, a strip removed every month or so. No problems as all.

To remove, start peeling off the top plastic layer, if need be, carefully grasp it with pliers and pull gently straight up. If this leaves the adhesive layer behind, and it commonly does, it will roll off with finger or thumb pressure as does that gooey glue stuff sometimes used on mailers.

A simple overhand knot (make a loop in the yarn, pass the end of the yarn through it, and pull up snug as you adjust the position of the knot - then tighten hard, does the job nicely.

If I were to use some sort of glue on the yarn end, as I do to secure the yarn within the base laminate "sandwich", it would need to be a soft glue material to avoid damage. Not just from the glue itself bonking the canopy, but from any abrasive dust or dirt that may be on either suface.

Silicone may be soft enough but its lack of weather resistance and tendency to attract and hold abrasive dirt rules it out. Having a treated yarn end would not allow the user to easily adjust the yarn length to their preference. A knot is not so bad!