DIY VG's

[n85ae]

Random thought:

Looking at the $80-250+ for a package of plastic VG's, and the thought occurred
to me. This is pretty expensive (relatively speaking), for something that seems
pretty easy to replicate for cheap.

I'm wondering if there is any reason VG's have to be T-Shaped, seems like you
could simply cut them out of .025 aluminum angle. One side of which was the
attach surface, with something like 3M double sided adhesive tape, and the
other side being the blade in the airstream.

Whether a T, or an L as long as you had say 20mm or so of attach footprint
that seems like it should work just fine.

You could easily fashion half left, and half right side pieces so the flat
footprint half of the L ended up on the upwind facing side.

Regards,
Jeff Hays

[Esser]

Personally, for the time it would take to fabricate all those pieces, I would gladly pay the $250

[WWhunter]

My question, do you have that much spare time to make at least 100, buy the adhesive, shape the bottoms so they fit, etc. and save money?
They can be bought for $50-$100 per 100 VG's. The one's for $100 come with the tape already included.

I will agree that it can be done the way you discribe. The metal VG's that were on my Champ were very thin. Also, the plastic one's are thin also and could be easily made with an injection molding machine. I personally wouldn't spend my time trying to make something that is relatively in-expensive as far and aircraft parts are concerned.

I have both types, one set I paid $50 and the other I paid $100 which included precut double-sided tape. The extra money spent for the precut adhesive was definitely worth the price.

[n85ae]

This is why a lot of builders are perpetual builders you know ... because
they're slow, and can't think outside the packing crate ... :)

Well actually I could whip out a lot of them very fast with my bandsaw, which is
why I was thinking about it. Just set the fence and repeatedly feed the L into it
lopping them off. Then nip off a 45 degree at the LE, and little quick trip around
table sander and they would be done. I bet I could do them all in less than a
1-2 hours max. Using 6061 they would not need anything but the adhesive
on the bottom (which with most commercial ones you have to do anyway)
Stolspeed for example you have to put the adhesive on every one.

I know I could make them fast enough, I was just trying to think of a good
reason why they have to be T-Shape, and for the life of me I can't

Jeff

[n85ae]

Oh yeah I almost forgot the critical part - "you don't have my wife". That's
part of the reason I need to think how to make them rather than spend $250
for a set all ready made ...

Jeff

[Slyfox]

I bought them and the wife helped me put them on. :confused:

[WWhunter]

Jeff, I totally agree that they can be made and it would have the cool "I made 'em myself' factor. I guess as I have gotten older I value my time more than I did when I was ounger and seemed to have all the time in the world.
One other aspect of the VG's I have purchased is that the bottom (mating surface) is curved for them to get a better contact on the wing. You may want to mesure your wing, make a template, and then shape your's to fit this curve. You'll have less issue with them coming off.
Just for anyone else wanting cheap VG's: google Black Max Airwave VG's. The owner's name is Keith and he is locted in Detroit Lakes, MN. He sells the cheapest VG's I know of. I think he raised his price a tiny bit but they are still cheap. $54.95 last I checked. I have the AirWave on the tail of the plane and have STOLSPEED on the wings.

[avidflyer]

I made some one time but never got around to using them. Basicly made a trapizoid and then bent both ends up 90 degrees. Got the design from someone else who used them on his ultralight and liked what they did for him. Made them out of thin aluminum cut in strips and then cut the ends at an angle to form a trapizoid. Really didn't take long to make them. I'm about 1350 miles from home so I can't get a picture. That would probably make my description much easier to understand. Jim Chuk

[n85ae]

How did the VG's on the tail work out for you? I might still break down and
buy the plastic ones.

Regards,
Jeff


Jeff, I totally agree that they can be made and it would have the cool "I made 'em myself' factor. I guess as I have gotten older I value my time more than I did when I was ounger and seemed to have all the time in the world.
One other aspect of the VG's I have purchased is that the bottom (mating surface) is curved for them to get a better contact on the wing. You may want to mesure your wing, make a template, and then shape your's to fit this curve. You'll have less issue with them coming off.
Just for anyone else wanting cheap VG's: google Black Max Airwave VG's. The owner's name is Keith and he is locted in Detroit Lakes, MN. He sells the cheapest VG's I know of. I think he raised his price a tiny bit but they are still cheap. $54.95 last I checked. I have the AirWave on the tail of the plane and have STOLSPEED on the wings.

[SkyPirate]

check with speedy metals,.bet they have or can get extruded "T" or "L" or any shape you want, or check with a window shop ..allot of the aluminum molding is a T that gets pressed into a rubber slot for commercial windows,..my only concern would be location ..the optimum location to put the VG's,..angle..etc

[WWhunter]

Actually had two aircraft with them on the tail. The difference I noticed was a little better authority of the elevator and rudder and slower speeds. It wasn't a lot but it is enough that helps for those real short strips that require minimal speed on landing. I fly out of my own strip in north central Mn and originally it was less than 1,000' with very tall trees on each end. Of course the way my strip is oriented i have a crosswind most of the time sogetting down and landed in the shortest/quickest time was neccessary.

In regards to Skypirates question, they are normally installed at 10-14% chord. I have read of guys placing them closer to the leading edge and getting good results but a simple google search will result in enough info to digest for many days!!

[SkyPirate]

thanks for the info WW :D

[t j]

There was a guy in Alaska some years ago that made vortex generators for his model 5 Kitfox from clear plastic 90 degreee angle used to protect sheet rock corners. Can't remember for sure but I think the only fabricating was to cut them to length and glue them on the wing. He reported good results.

[HighWing]

This is why a lot of builders are perpetual builders you know ... because
they're slow, and can't think outside the packing crate ... :)

Well actually I could whip out a lot of them very fast with my bandsaw, which is
why I was thinking about it. Just set the fence and repeatedly feed the L into it
lopping them off. Then nip off a 45 degree at the LE, and little quick trip around
table sander and they would be done. I bet I could do them all in less than a
1-2 hours max. Using 6061 they would not need anything but the adhesive
on the bottom (which with most commercial ones you have to do anyway)
Stolspeed for example you have to put the adhesive on every one.

I know I could make them fast enough, I was just trying to think of a good
reason why they have to be T-Shape, and for the life of me I can't

Jeff

I think I'm with Jeff on this one. If I ever have them, they will likely be made here. With the right tools many identical parts can be made very quickly. Regarding the T vs L. I think I would make 200 Ls and glue them back to back. Since they are attached to fabric, I wonder if they would flex the fabric losing some of their effectiveness.