Many thanks to all who have replied.
Our first messenger uses a body of .25x.75 inch spruce approximately 16" long. Along the top side(.25" side) a piece of aluminum tube (model airplane fuel line) just large enough for 1/8" diameter rod to slide is duct taped. Tubing is taped underneath to constitute the release mechanism. I use the front stop arm as the front hanging point.
I do not use a folding sail, instead I have a semi-permanent 1/4" wooden dowel three feet long hung underneath the wooden support toward the forward end of the messenger. The dowel sticks out 1.5' off each side. The sail is made with a large pocket that slips over this dowel, two short dowels are attached using small pockets at diagonals like the "genki sail" shown on your web site however there are no vertical supports. The sail is held in position by lines attached to the lower outside corners and then to the release. When released the sail flaps about the upper horizonal 1/4" dowel. Flaping definitely slows the return of the messenger. By adjusting the length of the release lines the sail's angle of attack can be changed.
We have only tested two angles so far the first was with the sail perpendicular to the body of the messenger the second with the sail 45 deg. to the body toward the rear of the messenger. We also attached various weights to the messenger to measure its lifting ability. When I have some hard numbers I'll forward them to you.
Anthony's Reply :- This is great. Note that the sail angle would also depend on the angle of the kite line. I myself am more interested in near vertical lines which would mean that the messenger itself has to support the load. In fact I will be continuing my studys on and off into the future.
The diagrams were very clear. I experimented with a few variations on messengers and came to the same conclusion: A kite was the ideal sail. I fly Conyne deltas and they stay very high. I had to build a messenger that I could change the attack angle on so the sails would even show to the wind. It still needed a gale wild to pull up my load (disposable camera). I couldn't figure out how to mount the Diamonds. Your double spine is a great idea.
So...diagrams and detailed instructions in hand I will try out your ideas. Maybe I can get something together before spring. Of course I'll have to modify the plans for no good reason. I'm thinking of two small Diamond kites hinged together. That will create a horizontal hinge and get rid of flapping once they flop back. We'll see.
I'll let you know if I have any success! Thanks again for the ideas.
My friend was the first to built your messenger, and he was quite happy with it. So I decided to build mine, in order to carry small radio-controlled sailplanes.
Even if a sailplane doesn't act as a "dead load" _ it provides drag and little lift as much, because the radio-controlled release hook is situated in the nose, and it present a certain angle to the wind and is like a part of the sail !!_ I have made a bigger messenger (size x1.5).
I have not yet tried to lauch a sailplane (the weather is so bad in france those time...), but only dead load, up to 200g, without any probleme. The kite was a Cody (about 2m). I will writte you latter the result of those experiments.
Sorry, this are no "outdoor photographs", and my room is quite busy those time. But believe me, it is not only a messenger in armchair, it also flew in the storm and carried heavy payload !!
This was the original outline...
___ / \ | | \ | \ | \ | | | / | |I bent the loop even more so, so that it crosses over, and inserted it into plastic tubing for attachment to the messenger body, in a simular way to the normal coat hanger wire.
___ / \ | | \ | `---|-. | \ | | |This pin did not bend very easily and required the use a vice to hold while this was done. It isn't perfect, but is better than the use of coathangers. In any case the 3mm round wire does not seem rust, or wear and is very shiny and smooth. If fact it slides extremely well!
UPDATE: Ten years on and they are still as good as new!Anthony
I am glad to tell you that it work pretty well ! The wind was low with some moderate gust. Nothing to break the thing. In fact, when the wind die down, the messenger get down very slowly. So i think it is well calibrate for medium wind, just what i wanted.
So now that i know that it work, i will continue on making a parachute for my doggie, but i intended to keep it light. I don't mind if it come down fast as long as it can get up !
So, thanks again. You can say that there is a clone of your mesenger flying in Quebec city, Canada, on the Plaine d'Abraham today, on a snow covered field. It look good and it put a very big grin on my face. In fact, it made my day ! I am looking forward for next summer when there will be somebody else on the field, just to listen to their comments and grin ever more !!!
Anthony's Reply :- Hmm pretty good. I gather the sail is a type of plastic?
In that case you didn't need to fold it over around the edges. Also I can now using a fishing clip to clip the two top edges of the line slot together once it is on the kite like. This stops the double spine bending so much as can be seen on yours.
I myself have bever used epoxy, so don't have esperience with it. however I am using a 'hot glue gun' for some things in my kite design. A little hot glue before putting plastic tubing on means it will definately not come off again :-)
In addition, Anthony's design does not require any sail retraction mechanism.
So I have replaced the sail on my ferry with a new version based on Anthony's plans. Preliminary tests have been very satisfactory: it rises beautifully and promptly returns after releasing the payload. I still have to make some minor improvements to the self-adjusting hinge and to build a larger sail ... but I am confident that this is finally a ferry which really works well.
I decided to change the sail hinge to a heavier hinge that worked out very well. For a sail hinge, I purchased 2 small 3/4x34" brass cabinet hinges, I epoxied the 2 hinges together, then drilled a whole through the center so the new double hinge could slide over my brass messenger body. I added a couple of small "D" rings to my messenger body to clip static lines, etc.. to. I finished my parabear, chute, and pack this morning, the 1 meter diamond was ready for the test, and the winds on Pismo Beach were perfect.
The only problem I had was naming my little red bear; as I was leaving to go test fly, the phone rang; it was my mother telling me that my favorite uncle from Oregon had tragically died the night before, pursuing a hobby that he loved!!!! My parabear was instantly named "Reggie" in his memory.
Reggie took his first flight up the line to the waiting foam cylinder about 30' below my 4' box kite, the push rod was released as "Reggie" started to drop away, his elastic static line pulled the pin in his chute pack, and the rest of the ride is now history times aprox. 30. The hinged kite folded, and came immediately back to me, like a well trained dog.
The best part was all of the tourists walking around on the beach and boardwalk, lining up to watch the parachuting bear!!!!!!
1.) How long is the long carbon fiber tube? Based on approximations in relation to the line stop, coat hanger wire, and size of the sail area in your other pictures, I used a length of 46 cm.
I would be suprised if it was exact. A Ferry (or messenger) is a personal thing, everyone does it slightly differently. I have seem some with some very fancy braking mechnisims (on return) for example!
Generally it should be about the same length as the spine of your sail! It does NOT have to be exact.
I have added this and quite a lot of other updates to the messenger plan in response to your email.
2.) With a 7' Rok, I use 150lb line. In most winds, the line vibrates (sings). The ferry will return to me if I only have a 20-50 yards of line out, but will not return when I have 200 yards out. Do you know of any relationships with the length of the long carbon fiber tube, the angle of the sails, the line strength, the curvature of the line, or the size of the line supports, to how the ferry returns?
P.S. I used a different method to connect the sails to the main tube (sail hinge) - with a piece of plastic tubing and 2 plastic "T's" inserted (through which the spines run). This design allows for the sail to be 'rotated' to the correct angle in respect to the flying line and wind conditions. A line was added accross the bottom of the sails ('gap' line) and a 'leech' line was added from the gap line to the load support with a slip knot to allow tensioning.
No sorry I don't have information about that. For one thing legal height limit here in Australia is 90 meters (300 feet) and generally I drop from a height of about 40 to 50 meters.
I have found that sail flap was very detremental to the return performance of the messenger. This in my own messenger was found to be cause by the clear plastic tubing building the sail hinge to flex far too much. So much that when the sails fold back the sail spine twists more vertical to the ground than remaining perpenducular to the messenger body. This created a lot of sail flag and in many cases a lot of side ways push by the wind, slowing the return and creating a lot of fritction between the sail and the kite line itself.
When I had to replace the sail hinge I use a junk piece of ridge plastic tubing I had handy, instead of clear vinal, this solved a lot of problems and kept the sail perpendicular to the messenger body, both on ascent and decent and removing this sail flap and side ways push on the decent.
Your rotation method is very ingenious, but as I mentioned above I have found this rotation to be the cause of more problems than it was solving. I still use a diamond sail to generate lift, but now I use a stiff platic tube to lock the sail hinge perpenducular to the messenger body.
I used a vinyl tube for the hinge assembly (haven't got a rigid tube yet) and agree with your comment about it flexing too much. I will have to find a rigid tube.
I also made a chute and pack. I have noticed that it only likes a certain way of packing it or it gets stuck, much to the disapproval of the children.
However, overall it was a great hit at a recent fly. I have to see if anyone got pictures of it.
Thanks for the plans!!
Have a look at my line ferry page (now offline) there's details of your messenger and a triangular sailed messenger also.
Currently, I am using the wire 'handles" from a small binder clip for attachment of the messenger to the line. I simply squeeze them into the inside of the plastic tubing where the fit into small holes after hanging the wire over the line.
I am working on using small plastic wheels that the hardware store sells a replacemnt parts for shower stall doors. The plan is to use an aluminum bolt and nut as the wheel axle. That way I can put the roller wheel on the messenger after placing the ferry on the line. I'll let you know how it works!
Happy flying, George Malina, Aurora, IL (35 miles west of Chicago)
Visit his web site at http://www.kitekam.com, and especially visit his messenger page
The messenger was able to climb almost vertically in light breeze.
Thanks so much for your plans and advice.
Anyway, hope you enjoy the photographs.
Anthony's Reply :- Looks great! Watch out for those trees!
Are you still actively flying? - If so send me a snail mail address and i will send you a copy of my instructions. I think you would get a kick out of some of the things i have gone through. We have tracked the same learning curve. Everytime i change something I create a new problem i need to fix!
Thanks for giving me a great platform to start from
-- Anthony Thyssen.