windshield and canopy bow forming

[n502pd]

Ok, this may be for scratch builders, but any one with a good idea or two will certianly be appreciated. On SNX-DO2, there is the references to bow diameters, one with the inside diameter, and the other for the outside diameter. I see that and plan to follow the specs there. My real question is(are) the method(s) used to actually form the correct diameter of the bow. the windshield bow is 1/2 6061 t6 ROD, while the canopy bows are 1/2 x .058 6061 t6 TUBE./ How does one bend the curve diameter so as to meet spec accurately? I can only think of a slip-roll device for forming hoops, but dont really want to purchashe one from HF. The rod would be probably easier to make without kinks, but I worry about the tube having kinks in it and not being a smoothe 'semi-hoop', if you will. Any suggestions? Pictures do speak for them selves sometimes. Thanks in advance! :?:

[rizzz]

Like many other scratch builders I made this super sophisticated bending device:


I then drew the bows in AutoCad as per the plans and printed them full size on our large plotter at work:


After that it's just a matter of trial and error until the bows match the drawings.


Make sure you draw a center line on the bow & drawing so you put it on the drawing in the same spot every time.

[Bryan Cotton]

When I bent up my hummelbird bows did the same as rizzz.

[Gripdana]

I did the same but I filled the tube with sand and used corks to plug the ends.

[n502pd]

ALL RIGHT! Thats what I am talkin' about!! Great picture, and directions for its use! AND, I knew about the sand, but had totally forgotten about it...'old timers desease' I guess! thanks very much! Ordered the material tonight! and I will attempt to remember to post a pix or two on the outcome! Much appreciated! :D

I am sorry to say thet the CFO and I are due in Floridia to assist my sister with a move to N Carolina at the same time at ASA/Crossville. Maybe next year. :(

[DCASonex]

End of tube takes a 7/16" -14 tap very nicely to hold in the sand. Use dry sand and and vibrate or bounce the tube a bit to compact it before plugging. Otherwise my rig for bending Sonex bow looked similar. No problems.

David A. Sonex 1327

[n502pd]

Thanks for all the great responses! The material should be in this week, and maybe I can get to bending soon after (grand daughters birthday this weekend!), and I will post the results. :D

[N111YX]

Another hint with this task...don't shape your aft bow per the plans. It may be close but chances it will not match your turtledeck curves.

The trick is to get a piece of paper large enough to trace the bow with a pencil, sort of like what a kid would do with a penny. Then, you'll have the full-scale exact shape to work with.

[n502pd]

Thanks Kip! that is exactly what I pickled up on another reply to my help request. I did that today and the windshield bow came out just fine. I am having some problems with fitting it as per plans, but should be able to work it out shortly. I will show progress when I have time to upload pix! :D

[n502pd]

Alrighty!! Done with the bows! I have put pix of the sequence, as everyone has given me, onto my kitlog site:
http://www.mykitlog.com/josephnelsen

Take a quick look. They came out great and I am pleased with the bows. I did as Kip suggested and formed the rear bow to the traced curvature of the turtle deck, and not the plans. That seemed like it will fit fine, when I actually cut it down durring canopy fitment at a later date. I will proceed with windshield instal, and then maybe if the WX gods are pleased, I may actually get the wings installed and alligned sometime in November. I have pressing issues in S Florida and N Carolina with family for a goodly part of October. Thats why Nov is getting the nod.

Thanks again to this site, and all its members for the assistance! :D :D