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PostPosted: Thu Oct 27, 2005 11:50 pm
by flyalaz
Hey Chappy,

Have any pics of those wingtip bows?

Karl

By the way, Paul Grandall has a great setup for his plane. He is able to leave his engines, fuel, and control cables on the wings, and with a couple of cradles and jigs, do it all by himself in no time flat!

PostPosted: Fri Oct 28, 2005 8:54 pm
by Chappy
Karl,

The bows were made from the fibreglass bicycle flag poles that they sell at Wall-Mart, etc. to help people see kids on bikes. I think one pole was enough for two tips. The poles are about 1/4 inch and pretty tough, and cheap. I've never broken one, but when they get 10 years old or so they seem to start splitting from the stress. The one in the picture is beginning to fail, and has tape on it so I won't run the splinters into my hands.

I mounted it with small cable clamps (an Adel type clamp) against the outside surface of the outboard R9L (inside the tip).

I put them on with the express purpose of keeping the tips off the ground when assembling the plane. And yes, they do add a tiny bit of weight and drag.

Chappy

PS. Ain't Mylar pretty!

PostPosted: Fri Oct 28, 2005 10:50 pm
by flyalaz
Hi Chappy,

Neat arrangement. I guess gliders use something like that as well. When I get to my wings, I might give it a try!
I notice in the pic that the tape location appears to be at the spot where it would touch the ground? If that is true, abrasion might be causing it to split. Maybe if a little nylon was machined to fit, it might last even longer and save you the trouble of making holes in the covering. Just a thought.

Karl

PostPosted: Sat Oct 29, 2005 12:21 am
by Chappy
Naw, Karl, they just get tired of being bent too much over the years. Only a couple have done this over the last 26 years, and there was no damage to them from abrasion, etc. It only takes a few minutes to cut new ones and just stick'm in (the tension from bending them is all that hold them in), but I keep forgetting to pick up a new flag pole at the store to cut up.

Chap

PostPosted: Mon Oct 31, 2005 12:22 am
by Chappy
The bows, as fitted to my Lazair wings, are 1/4" rod, 33 1/2" long.

Chappy

PostPosted: Mon Oct 31, 2005 11:33 am
by yankeflyer
George that's great-looking work.

A couple of questions that I have are, what grade of titanium and do you or anyone else know the actual weight comparison between aluminum and titanium?

I've read a lot or at least all I could find on titanium on the Internet and there's a lot of information a lot of different grades and in weight and measures I think the answer to my question above is probably there but I'm not sure how to convert their numbers to pounds and ounces.

Also I haven't come across a series l assembly manual or construction manual. I have downloaded a series ll - will that be good enough to use in my work on my plane?

One more question, theTedlar on the tail has some wrinkles -- can heat be reapplied remove the wrinkles?

Miles

PostPosted: Mon Oct 31, 2005 6:50 pm
by Guest
The grade I used was 6AL-4V and the weight is about 48% more than 7075-T6 aluminum in the exact same part , but for 8 small brackets, that's not very much at all. I get my Titanium from titaniumjoe.com. He carries a ton of material and has just about any size and thickness you could want. I then had it waterjet cut to shape from a cad program and then had a machine shop use a 90 ton press to make the bends in the brackets. It took the press 3 strikes per bend to get it to the correct angle. So this stuff it really strong.

What series again do you have?

If the Tedlar is loose, the underneath tape is most likely letting go and needs to be replaced. If you can do this without destroying the tedlar, then yes, you probably can reshrink it after the repairs, but be careful that it's the tape and not the coverying that is shot.

George

PostPosted: Tue Nov 15, 2005 8:53 pm
by JPXman
back on the log theme:

did about .8 tonight here in edmonton on a cool, clear night. first flight of just buzzin around after all the work. i was still worried i had an issue with the fuel pump but the engines both ran strong. was a bit chilly, -14C at altitude according to navcanada!!! pull starting weather that cold is a pain in the ass, anybody know any tricks?

Tyler

PostPosted: Wed Nov 16, 2005 12:57 pm
by tommyb
if you have a primer give it 2 shots and try to crank the engines over by hand first (turn them about 6 times) than one more shot and pull away. this worked on my rotax but they are all different.
t

PostPosted: Sat Nov 19, 2005 8:34 pm
by tommyb
flew my 172 today 4 hours from NC to Indiana to look at a lazair. was very disapointed it was much worse condition thatn expected. after my short recess i then did 3+ home at 9500ft. I like to fly high :D