DonStegall

My Feedback: (1)

I now have my jig/fixture made and tested for cutting spar slots in 66-012 cores.

I can cut full depth 1/4" slots or 1/4" deep 1/8" slots. Theoretically I could cut 1/4" or 1/8" slots to different depths.

I'm making a full depth 1/4" spar wing for somebody for 428. I will post photos of the spar when I put it in the wing.

The 1/4" deep 1/8" slots on both sides are probably the easiest as they let you put in spruce spars top and bottom for only about 1/2 an ounce. And they add tremendously to the strength of the wing when capped with carbon fiber laminate.

So now I have spar slotting service available as well.

Note: the picture of the spruce spar is on the old foam I used to use and it is not the quality of foam I use now like the foam pictured with the 1/4" spar slot.

DonStegall

My Feedback: (1)

The Viper 500 wing is a great convenience being ready to fly. But it comes with a weight penalty. I had a visitor to the shop the other day and I mentioned that the wing weighed 18 ounces without the servo. He didn't believe me. So I pulled out a wing and put it on the scale. It actually weighed 19.5 ounces untouched.

I had mentioned that I was going to cut 8064 wings (same airfoil as the Viper 500), and I already had the templates printed out. I finished the templates early this morning and cut a core. It came out great. I did the leading edge for 3/16" balsa, but I also did this so that I can do Bill Vargas style carbon fiber leading edges. There will be just enough room for the CF. So I don't have to mess with two different kinds of cores.

Now if I can get the time to make fiberglass tips, lightweight Viper wings will be pretty easy.

GSJames

I just received my package of 424/Q-25 wings from Don Stegall. I received one sheeted wing for a Seeker (NACA 66-012) and two extra sets of unsheeted cores. The results look excellent. The foam is of good quality and is light weight. The cutting looks very good with lots of "hairs" and excellent feathered trailing edges showing that the heat setting was "right on". I recommend Don's products.

wrstew

My Feedback: (30)

Ain't it great? Don't have to go to the box store and try and score unblemished foam, transport it, make the templates and all that. The BigBrownTruck recently brought me three of Don's wings, great packaging and who could beat the price? This is a great service for those of us who don't have hot wire set ups, and for what he's charging, who needs em? Keep him busy, so's we all can take advantage of these talents! Now, for the balsa application.....

GSJames

Yep, I just went over to a friend's house and weighed the wing from an in-the-box Viper. It was 19.3 oz. And that's without servos, pushrods, etc. We weighed one of his old Dodger wings and WITH with the servo, linkage AND landing gear it weighed 16.5 oz

DonStegall

My Feedback: (1)

Thanks for the comments guys. I appreciate the kind words.

My web site is updated with information on the Quickie 500 Wing Cores and the Quickie 500 Sheeted Wings. I don't have the sheeted S8064 wings on there yet, but they are available in Light and Standard.

I got my wing skins in from National Balsa and they are really nice. Thanks Dave Norman for that suggestion.

DonStegall

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People wonder if I use the products I recommend.

I can tell you there has been a run on EZ-Vac systems from ACP. They raised the price by $5.

I had to put my GAST pump back into service making composite parts. Right now it's busy with a Katz Meow side and it's pulling 25".

So I got an EZ-Vac 2nd Day Air'd in and I immediately put it to use. I had a $4 dry vacuum gauge already rigged up with a connector and a T connector setup. I like the T so I can bleed on one side if needed. I don't know if the EZ-Vac can handle 2 parts at once. It's showing just under 5", but I think the gauge is probably not accurate. I will switch it out to a quality oil filled gauge tomorrow when I take the wing out.

I've got to bag an Extreme Wing with a full depth spar. I didn't want the trial run to be on an expensive wing, so I'm doing a Light+ wing first.

The nice thing about the EZ-Vac is that the vacuum is constant, and the unit is quiet. No surges like the others when the pump runs and cuts off. I think it is probably better for foam that the "big rigs" that surge and fall.

I guess I will know tomorrow. But Jim Katz has been using one for years, and I trust his judgement.

daven

My Feedback: (1)

Is 4" all you use for wings?

DonStegall

My Feedback: (1)

Dave,

Normally I use 8".

The gauge on the EZ-Vac is a $4 hardware dry unit. I don't think it is accurate. It's actually reading between 4.5" and 5". I took that picture early before it reached its max. I have a Weiss oil filled gauge than I'm going to swap out as soon as I take this wing out of the bag.

The bag looks very tight. Just as tight as when I use the big rig pulling 8" going down to 4" before it starts back up again.

The EZ-Vac is rated at 6".

That's why I tried iit on a "cheap" wing first.

I did the wing at 9pm and I give them 22-24 hours to cure. So I'll know by 9pm EST or so.

DonStegall

My Feedback: (1)

Dave,

Since the part is well on it's way to being cured, and I have a T with valves on it, I just shut off the valve for a minute and changed the gauge.

I turned the pump back on and opened the valve. The bag only creaked maybe once.

The good gauge from CST reads 7" which is right in there where it should be.

Good eyes on the first set of pics.

vicman

My Feedback: (10)

Have you seen the coke bottles that guy wears! He should've been able to see the gage from his house much less that fuzzy pic. LOL.[sm=49_49.gif]

I bet I know what Dave's next post will say

DonStegall

My Feedback: (1)

With my left eye messed up from my contact I went to bed early and didn't take the wing out. But I got up early and took the wing out of the bag. Eye is still hurting though.

The results using the EZ-Vac are fabulous. The wing is straight as it can be. Everything is fully pressed down. It is not overly compressed. I couldn't be happier with the result.

I believe the constant 6-7" is better for foam wings than the surge of a big pump using a vacuum switch. I have a T on mine and I might use it to do 2 at a time when my 60" x 30" piece of glass gets here. Or I may just buy another one. At only $95, why not have the redundancy?

About the wing I did. I used the new skins from National Balsa. This was to be a Light Wing. The skins are very light. Even though this wing will be used for Quickie 25, it is going to be used on a Seeker. I decided to upgrade it to use the 1/8" x 1/4" spruce spars because I felt it would still be "light". I didn't try to go with the absolute minimum epoxy and even with the spars, the wing came out at 9.5 ounces. That is very good as my previous low for a wing even without the spars was 9.9 ounces. And the spars add 0.6 to 0.7 ounces.

I will give up one of my "secrets". I use porous release film between the shucks and the skins. It keeps any epoxy that comes through the skins from sticking to the shucks. I figured this out from my composite work. Good thing. On the balsa skins where they are joined, some epoxy came through. But the release film made it a non-issue. Release film has pinholes every 1/4" and it lets air and epoxy through, but it is very thin and very easily comes off. I get mine from CST.

The main place the epoxy came through was where the carbon fiber laminate is. I put a tiny amount extra of epoxy down where the laminate goes and it happened to be on a seam in the balsa skins. Some would say I don't need the extra epoxy, but it is basically just an almost dry brush down the strip where the CF lam goes. And if the epoxy came through the skin there it shows that I'm getting a good bond

daven

My Feedback: (1)

Vic knows I had lasik done in January, although my corrected vision prior was better than I see uncorrected now. Was hoping I wouldn't need perscription glasses to fly, but with glasses they can correct to better than 20/20 which really helps with those light boards

DonStegall

My Feedback: (1)

This is not a 424 wing. It is an Extreme Wing. It has a full depth spar capped with carbon fiber. The gap is filled prior to skinning the wing.

DonStegall

My Feedback: (1)

The Extreme Wing is done. It is a little heavy at 13 ounces. The spar added a little over an ounce. But it is unlike anything I have built. It has no flex whatsoever. I used a bigger carbon fiber leading edge and I was doing fine on the epoxy until I got to that stage. I think once the leading edge is fully shaped down, it will lose a little weight.

Scorpion Racing

Looks good Don, did you use a full depth 1/4" or 1/8" spar on this one for the 13oz weight? And also, did you lay the full depth spar in an end grain fashion? I may try a few of these ideas later this summer for 424 & 428 wings.

I know you gave a tip on using peel ply between the shucks and the wood skins to keep them from getting stuck, I have found cheap old parchment paper from the grocery works very good too; at a much better price.

Keep up the good work Don.

Bill Vargas

My Feedback: (5)

I did a few of those as well,,, I laid in the .007 CF on the balsa wing skins over the spar. A very strong foam balsa wing indeed! The other nice trick was to use some basswood under the wing skins for where the wing bolt hold down blocks go,,, instead of having to carve out the area for the regular conventional types of wing hold blocks(ply or dowels).

BV

DonStegall

My Feedback: (1)

This wing is definitely extreme.

The spar is a 1/4" balsa end-grain spar that was laid up with 0.014" carbon fiber laminate on top and bottom. Then it was glued into the core. Filler was added to bring it even with the core.

The skins have 0.7 ounce cloth over the entire inside surface. I used 0.007" x 1.5" x 48" carbon fiber laminate over the spar. Plus 1" laminate on top and bottom of the trailing edge. And the carbon fiber leading edge.

I wanted to make sure the skins would hold up to the spar and that the entire wing would be stiff. I think I can get it down to 12 ounces. But the customer has been waiting on this one for a couple of weeks and I want to get it out to him.

I had to develop the spar slot cutting jig and then I made several spars before I was satisfied. I tried bagging one, but the balsa is so flexible that it didn't come out straight. I used a press to make the final version.

There is no doubt in my mind that this wing is up to the most severe 428 flying.

Scorpion Racing

I plan on trying the BV carbon tow LE & spars for the next wing, looks like a strong and simple way to go. I like to use glass for my TE. I run a 3" wide strip (1.4 oz.) on the bottom TE skin, followed by a 2" strip, the foam core, 2" strip, 3" strip and the top sheeting and shuck. This gives 4 layers on the TE that you can sand down to for the finished TE. Comes out stiffer than any method I have tried yet, including the carbon and ply methods. The layers of cloth staggered also allow for a smooth transition for the sheeting and extra stiffness on the ailerons.

I may have you cut me some cores in a few weeks Don, can you do the 64-012? I used the Profili Pro for the wing design, and I think you use that too, right?

daven

My Feedback: (1)

Can you cut camber and wash-out into your cores?

DonStegall

My Feedback: (1)

Camber yes, at 48". The S8064 I'm cutting has camber. I've had a request for the 66-112.

To do wash out, I have to cut 24" sections.

DonStegall

My Feedback: (1)

Scott,

I use CompuFoil 2000 with all of the upgrades. I'm getting ready to go to CompuFoil 3D as Eric Sanders has taken good care of me.

I didn't mention it, but this wing also had 1.4 ounce x 2.5" fiberglass top and bottom on the trailing edge as well as a 3/4" x 1/64" plywood insert. I too think the fiberglass is probably better than the carbon laminate, but I advertise the laminate for the time being, so I put it in. I don't think the laminate hurts anything and I do think the ailerons are probably stiffer torsionally with it.

Since I use templates and not CNC, give me a little lead time for new airfoils. I was planning on doing the 65-012.

Getting the carbon fiber leading edge correct is a challenge. I cut some cores for a 1/8" leading edge and very little of the carbon was left after sanding the leading edge to shape. This core was cut for a 3/16" leading edge and I had to use more 50K tow. I need to work out a better way of wetting it out. Too much epoxy went into the leading edge. Over an ounce.

vicman

My Feedback: (10)

Scott/Don, do you guys alternate the bias of the glass when you do these multiple layers of glass on the TE?

Scorpion Racing

I probably should have, but I didn't! My main reason for doing it was I was getting a pinch where the foam ended and the balsa skins went out to nothing. I tried ply and carbon strips, but it was still a weak, flexable TE. I decided to use some glass under the skins to help tie the TE balsa in, and it ended up being the toughest TE I have. It is not really a new idea, most composite wings use a couple of extra layers of glass in the tip to stiffen it up, so I just borrowed the idea. I think the balsa skins on top of it add a bunch to the TE stiffness as well.

I will try the glass on the bias on the next ones though!

DonStegall

My Feedback: (1)

Vic,

Usually I'm just putting down one layer of glass on top and one layer on bottom.

Since the goal is torsional rigidity of the trailing edge and fore/aft rigidity of the ailerons/trailing edge, I don't do any on the bias. It also helps prevent warping to have the glass running the full width of the wing.