• If You Are Having Trouble Logging In with Your Old Username and Password, Please use this Forgot Your Password link to get re-established.
  • Hey! Be sure to login or register!

Micro AeroDynamics VG Installation

I’ll second the above - I carefully but easily installed Micros on my PA12-150 with excellent results using the templates. Time savings alone worth it.


Sent from my iPhone using SuperCub.Org
 
I'm cheaper then you, probably, and bought the complete kit. My time is not worth much, but worth enough to spend that extra money. The performance gain on the low end makes them a bargain at twice the price. One tip, if you used green Poly-Tone on the LE, the stencil adhesive can be tough to get off, put it on lightly, just enough to hold position, and take it back off soonest. My paint was cured 6 months, work installing was in my hangar (not direct sun), and stencil was on for a few hour. The glue transferred to the paint, was a bit+h to get off, without taking the paint with it. Micro was advised of this adverse reaction, with Forest Green p tone, news to them. Done other vg installs, also p tone, but different color, no problem.
 
Get the templates. They're worth the money. Search here, and you'll find good data on distance from leading edge.


I’m sure that’s good advice but my VG’s are already on the way (without the templates)

There is a PA-12 experimental at my field that has a set of Mirco’s or at least they look like Micro’s and it will be simple to make templates from it. My inquiry was to confirm the mounting distance from the leading edge to the front tip of the VG in order to confirm it is in fact a Micro installation. The owner of the 12 purchased it with the VG’s on it and there is no documentation as to their origin.

if anyone can provide me with that distance it would be much appreciated. I can manage the rest.


Thanks.......... Phil
 
Take a carpenter's square to the PA-12. Hold long edge against bottom of wing with short vertical against LE. Measure back to VG parallel to bottom line.

Gary
 
I’m sure that’s good advice but my VG’s are already on the way (without the templates)

There is a PA-12 experimental at my field that has a set of Mirco’s or at least they look like Micro’s and it will be simple to make templates from it. My inquiry was to confirm the mounting distance from the leading edge to the front tip of the VG in order to confirm it is in fact a Micro installation. The owner of the 12 purchased it with the VG’s on it and there is no documentation as to their origin.

if anyone can provide me with that distance it would be much appreciated. I can manage the rest.


Thanks.......... Phil

Micro Aire will appreciate you absolving them from any liability by using your own installation. Call them for the templates. If your time is worth anything it will be worth it having the templates. You can see I used templates on my installation. Others have said to use templates. This is the second time I said to use templates. You are banking on the PA-12 having a correct installation. How can you be sure?
 
My 2c is that it is more important for the VGs to be in the same position on each wing than in whatever distance is used from the leading edge. This will prevent one wing from dropping out from under you in a critical situation.

For example long ago when the Cal Center leading edges were all the rage a fellow didn't have time to install the second one before going on a trip out in the boonies. He found himself in a situation where one wing stalled resulting in he not coming down for breakfast anymore.
 
Geez, guys, it’s an experimental Cub. Lots of guys have bought VGs and experimented with the best location. Most of us choose to pay to use somebody else’s testing and template as a convenience but I know guys who move them around to see what they think works best. Phil asked the standard template distance from the LE. If I could remember it I’d tell him. In his shoes if I had access to a standard category Cub with VGs I’d measure and try to duplicate it.
 
I have stayed out of the pissin" contest about whether they work or not. Those that say they don't are not getting the most out of there machine. They work. As to where they are located, we have done quite a few in this area and IMHO they should be put on with the patterns or don't put them on. Do it right or don't do it at all: just not worth it. Why try to re-invent a wheel that works? The best improvement has been determined to be in a precise location because that's where they belong. Drag me through the mud if you like; "my skin don't leak"
 
Kinda hard to give a measurement of where to mount the VGs on the wing. There is a simple tool and the templates that locate the angles, distance from each other and back of the front of the wing. I don't know how you would tell someone that.
 
Kinda hard to give a measurement of where to mount the VGs on the wing. There is a simple tool and the templates that locate the angles, distance from each other and back of the front of the wing. I don't know how you would tell someone that.


If you put a square on the leading edge with the long side flat on the bottom of the wing I’m looking for the measurement where the square touches the leading edge to the front of the VG. Put a string on the point where the square touches the leading edge to the front tip of the VG and measure the string.

That is the only measure I am unsure of.
 
I’m a big fan of VG’s, had an engine failure in a Pacer and believe they made a difference on the outcome of the crash.
I’ve installed them on several airplanes from Bonanza to my starDuster. The StarDuster had them on it when I got it , wrecked. The bottom wings were smashed in so I had to rebuild them and reinstall the VG’s. This may help the op without the templates. I used the formula that has been posted and found my numbers put them a 1 1/2” further forward. I put a chalk line on the wing for both positions. Then looking from the tip to root blocked the wing increasing the angle of attack and found the further back placement took the VG’s out of the slip stream too early. I installed on the forward line and the plane stalls very gentle below 50mph. The original installer made notes in the paperwork he didn’t feel the did anything. So I’m not sure if it really helped but the stall #’s in the paperwork I’m stalling 3-4 MPH slower and very stable.
 
If you put a square on the leading edge with the long side flat on the bottom of the wing I’m looking for the measurement where the square touches the leading edge to the front of the VG. Put a string on the point where the square touches the leading edge to the front tip of the VG and measure the string.

That is the only measure I am unsure of.

With a square you get all you need for info off the other plane. Up the vertical leg and back to the wing are the distances you are looking for off the inch marks on the square. Just make sure the up and back is measured with another ruler that's parallel with the bottom leg under the wing.

However I understand Micro and CC support sites and they deserve your business to keep it safe per their STC. I've done four sets for my planes and have prints but won't offer up the info like others here out of respect for their business. Maybe you figured that out by now? But measure away and figure it out on your own.

Gary
 
Charles White, back when he ran Micro, made me a dealer for the exp crowd at one point, after I called him and bitched about them only being (at that time) offered for certified planes, with the attendant certification/paperwork costs rolled into the price. He saw the logic of expanding his customer base, though at a lower price, and presto, I got them "cheap" and was a dealer for them. I sold about 30+ sets of them.

We had the same issue, once we knew where to put them, how to describe to others where that point was. Assuming the forward lift strut was in always the same place relative to the LE, I used a soft tape measure, like a seamstress uses, butted into the lift strut bracket, and laid it around the LE to the forward edge of the VG line. Using a framing square, on the not exactly flat bottom surface of the RANS S-7 wing, was problematic, the strut bracket soft tape method was easy to describe over the phone, with not much room for error. Whether or not a fraction of an inch placement makes any difference in how well they work, I doubt it, but with the results I got on my initial S-7 install (very favorable) I wanted to duplicate that as much as possible. BTW, I have never painted mine, they look pretty cool when they catch the sun just right and stand out from the wing, I like that for some reason.
 
Maybe he should explore why different mfgrs place VGs in different places. Maybe one size doesn't fit all. I never recognized much benefit from adding VGs on my -12. The benefit was undeniable on the Cessna. Both pireps generally go against VG rhetoric for those types. When considering VGs on the Wildcat I asked a couple of experts familiar with slats and was told to buy the template from Backcountry since they already had the ideal slat-VG relationship figured out. Their VGs are bigger, too. Maybe that's better than the exp VGs I can get for a fraction of the price. Too late now. I may go a different route next time.

If you keep your certified Cub's Micro templates and find yourself with an exp Cub and want to add VGs do you buy new templates? If you're doing two exp planes side by side do you buy two templates?
 
From the very unscientific method of looking at the 3M site and picking the one that looks like what I used? 4910 looks like what I have. They say the tape is acrylic foam but mine is as clear as water. it's pliable enough to allow a little give but if I keep pushing against the bond it will ultimately release. I think this is a better VG adhesive than the unforgiving Loctite activated glue or the Super Glue most of use when that pops loose.

I taped a few feet of VHB to my counter sticky side up. I applied my VGs as crowded together as i could and then cut them free using an Xacto knife on a cutting board. Putting them on the wing was easy and there was no hurry. Pull the backing, set in place lightly, adjust if necessary, and then push them down tight. The tape conforms to irregularities like LE screw heads under the fabric, tape edges, etc. I avoided the domes of the screw heads themselves but around the screw edges is no problem.
 
Last edited:
IF I ever had to remove one of the Micro's, short of using a cold chisel and a hammer, I'd try judicious amounts of heat. That Micro supplied glue is almost too good, I like the sticky tape concept. I sure don't worry about losing any though!
 
The RANS S-7 has what I believe is properly referred to as "plain" flaps. Not to be confused with plane flaps. They hinge at the trailing edge in such a way that is simple, light, and easy to manufacture. They are effective also, and the thing lands plenty slow, but it has occurred to a few of us that just possibly, VG's on the upper surface of the wing's trailing edge, about 2 " or so from where the flap is hinged, may help keep the airflow attached to the upper surface of the flap when it's deployed. This assumes the ones already in place on the wings LE are too far away to directly energize the flap surface. Similar to what they do on the hor stab/elevator.

I am sick of reading about the double slotted P flaps advantages you Cub guys can bolt on by simply writing out a check, (and I don't want to take on the task of engineering something similar for the S-7, that's beyond my ability most likely and I'm too busy anyway) and I'd have a set of those tomorrow if I had a Cub. BUT, I can ably layout and install VG's, using double sided carpet tape for experimental purposes. What you think, been done before, a waste of time? I don't want my plane to be laughed at! BTW, I landed three new 8K plus sites the other day, it does alright as is, but a bit more drag and/or more lift at certain flap settings would not be a bad thing.
 
Probably not enough air flowing there to do much. Venting the flap LE ala Rev 3 would work better.

Maybe you could get Carbon Concepts to build you some slats? :)
 
Last edited:
One thing at a time, and preferably easy on and off, for experimental purposes. Still not quite ready to invest in slats, time and labor wise, and any speed hit. Which also means less range and duration, least we forget! Besides, any enhanced flap action may only compliment any future slat install.
 
That's been done, by S-7 guru Joel Milloway, with good effect, no decrease in cruise near as he can tell, and more effective flapping. But he also made them wider span, and went deeper chord on the ailerons also. In other words, he had to fabricate 4 new control surfaces, including the ribs for them, then cover and finish them. Something to keep in mind if I wreck mine and need to re-build it, but way more of a mod then I want to mess with as a minor add on. I also know some (Hal Stockman) have extended the chord by attaching brake formed aluminum trailing edges, right over the fabric, to the flaps and ailerons, again with good effect. Both methods add a bit of weight though, and Joel was the one who wants me to try the VG's as an alternative. So at least I'll have someone to blame if they don't work! I'm calling Micro today to see about pricing for a few, as a multiple time buyer of complete kits I'm hoping for a fair deal from them on a dozen or so of the same size I have on the wings.

I am in no screaming need of doing anything at all, the plane flies great as is, lands real slow with good control, etc., etc. I'm just being greedy, like we all are when it comes to STOL, I want just a little more. :roll:Last weekend pic, two different sites 8 K+, the new ultralight Airstreaks at 3.5 psi handle the sharp rocks just fine.
 

Attachments

  • IMG_20191102_115248155.jpg
    IMG_20191102_115248155.jpg
    88.8 KB · Views: 171
....and Joel was the one who wants me to try the VG's as an alternative. So at least I'll have someone to blame if they don't work! I'm calling Micro today to see about pricing for a few, as a multiple time buyer of complete kits I'm hoping for a fair deal from them on a dozen or so of the same size I have on the wings.

I am in no screaming need of doing anything at all, the plane flies great as is, lands real slow with good control, etc., etc. I'm just being greedy, like we all are when it comes to STOL, I want just a little more.
courierguy, Notice what is happening to the streamlines over the trailing edge starting at about 1:07. See how the one closest to the upper surface has moved away from the wing. This indicates that the boundary layer flow has moved some distance above the wing at high angles of attack when you are looking for your VGs to help the flaps. This means that VGs will likely have no effect at all for your experiment. Do not be disappointed if nothing happens. If you can prove me wrong good, I will have learned something.


Here is another using yarn demonstrating the same result.

 
The RANS S-7 has what I believe is properly referred to as "plain" flaps. Not to be confused with plane flaps. They hinge at the trailing edge in such a way that is simple, light, and easy to manufacture. They are effective also, and the thing lands plenty slow, but it has occurred to a few of us that just possibly, VG's on the upper surface of the wing's trailing edge, about 2 " or so from where the flap is hinged, may help keep the airflow attached to the upper surface of the flap when it's deployed. This assumes the ones already in place on the wings LE are too far away to directly energize the flap surface. Similar to what they do on the hor stab/elevator.

I am sick of reading about the double slotted P flaps advantages you Cub guys can bolt on by simply writing out a check, (and I don't want to take on the task of engineering something similar for the S-7, that's beyond my ability most likely and I'm too busy anyway) and I'd have a set of those tomorrow if I had a Cub. BUT, I can ably layout and install VG's, using double sided carpet tape for experimental purposes. What you think, been done before, a waste of time? I don't want my plane to be laughed at! BTW, I landed three new 8K plus sites the other day, it does alright as is, but a bit more drag and/or more lift at certain flap settings would not be a bad thing.

I think your idea is valid. If I had an experimental I would try it in a heartbeat. I can’t see a down side to giving it a go.
 
I'm tapping out, before I start. Anne at Micro got me lined out, turns out there is a reason why you don't see this done.....my vortices are perfectly fine as is, even way back there, extra aft VG's would just mess things up. Then she got technical, something about the wing stalling from the back first, and halfway through that explanation I told her I was going to hang up, we were done! I'm smart enough to usually know when I have a stupid idea and just move on, this one qualifies. Chuck White still checks in daily, MR. VG, but at 92 the ladies answer the phone, as his hearing is like mine, I asked her to tell him I said hi. She claimed she would be happy to take my money, but was knowledgeable and honest enough to dissuade me. No pain,no gain. I'll spend the money on more mo gas.
 
Gotta love it when a vendor recommends that you not buy their product. Seems to me that's the ultimate in honesty.
 
Cessna caravan has vg’s on thé flap itselve. We did some expérimentas on somme planes with sloted flaps, Had Good résults. In thé end thé Vgs on thé leasing Edge give thé best All around résult.
 
Back
Top