Pushing the MBK Rokkaku Kite
by Craig Ensey
(Lebanon, Oregon, USA)
First flight of the MBK Rokkaku
Recently, I got the kite bug and again and I had to build something new. This time I wanted success so I set out to build an MBK Rokkaku kite that was 100% stock. Building from the plans without mods is a new concept for me since it's in my nature to change working designs for no real reason. The intended results are often worse than I expected!
After rounding up my frame, sail, and some odds & ends, my project was at a whopping $3.23 (USD) with a lot of sail material to spare.
In fact, The sail is cut from 9 foot by 12 foot sheet of .7 mil painter's drop-cloth which I purchased at the dollar store. Since it is a large sheet, I will be able to cut several sails from it.
The spars are 1/4 inch poplar dowel from Home Depot. The bowlines and toggles were made from cotton twine and wooden beads from my wife's jewelry supplies.
When I cut the sail, I chose to cut two layers out at once rather than folding it over as per the plans. The two layers were taped together with electricians tape so you can see the outline from a distance. Total construction time was about 3 hours over two evenings. It was also a very easy build. I highly recommend this for a first time builder!
Although I had doubts about the durability of the drop cloth, it has been through several rough landings and one encounter with a tree that tore a small hole in it.
Flying the MBK Rok kite for the first time was a different experience since most of my kites are heavy wind fliers. It was flying very well in a light breeze with some mild gusts. The Rok is much better suited for Willamette Valley weather than my Rhombus Box Kite or my Peter Lynn Box Kite which would not have flown in such a mild breeze.
The first flight was on a cloudy day with some "spitting" rain that turned into a classic Oregonian hydro-assault moments after I launched the kite. Yes... I know I'm not supposed to fly in bad weather where I could get struck by lightning, but I'll take any air time I can get!
I found a few hours after Church the next day and I went to the park with my 3 year old for some quality time with him and some time to fly the kite. That outing was sunny, but the wind was very inconsistent and gusty (again) so I didn't get a long flight. I also had issues with the spine poking through it's pocket on the top corner of the sail as you can see in my pics. Nevertheless, I still got some great pics of it in flight!
Today, I decided to go out again for some flying in a fresh breeze. I should have listened to that small, logical voice in my head that said "You're going to implode your kite if you try to fly in a wind this strong." Of course, I didn't listen seeing as how this light wind kite had been modded into a heavy weather kite.
Like many anxious kite fliers, I beefed it up and put 5/16" spars all around for some extra strength. This worked for about 20 seconds, just long enough to get out of ground effect. It was no surprise when the kite imploded and came down to me with a broken spine.
After all these trials which resulted in more mods to the frame, I think I will go back to making a "bone stock Rok" with no mods whatsoever. It flew best when it still had 1/4 inch spars, but there was still a lot of flexing in the bowed spars so I may still use 1/4" instead of 3/16".
Some questions: Does the extra weight from thicker spars really hinder the kite's performance? Also, where do I set the tow point? I was unclear on that in the plans page.
This is a work in progress so I will do another report when when I get a good long flight with the MBK Rok. Maybe I'll get my Rhombus Box, Peter Lynn Box, Pearson Roller, and my Rokkaku all up at the same time. That would be pretty cool, but difficult since they all fly in different wind ranges.
I hope this isn't too long, Craig E.
E-book special of the month (25% off)...
e-book takes you step-by-step through making a 120cm (4 ft) tall
Parafoil kite. This 4-cell kite performs best in gentle to moderate
wind speeds. That's 12 to 28kph or 8 to 18mph. Even in light
winds, this kite will hang in the air, although at low line angles.
In fresh winds, it pulls firmly for it's size, so small kids
should only fly it while supervised!
Every kite design in
the MBK Soft Series satisfies the following points...
- Materials are
plastic sheet, tape and line – and nothing more!
- Tools are a ruler,
scissors and a marker pen - and nothing more!
- All cuts are
along straight lines.
For the greatest chance
of success, I make recommendations regarding the materials. For
example, the type/weight of plastic, type/width of tape and line
type/strength. Close enough should nearly always be good enough,
since the design is well-tested and should be tolerant of small
differences from my original.
Get the e-book for making the MBK Parafoil kite. After making your first one in plastic and seeing how it performs, you can try soft Tyvek or rip-stop nylon for your next build.
The e-book is a PDF file - which means printable instructions to refer to while you make the kite. It also means convenient off-line access if that suits you better.
May 10, 17 06:00 AM
This previously published page is a mixture of informative data and historical background. Also there is also a video of one of my own tetrahedral designs in flight!