Steve Innova

Qualified, schmolified. The engineer isn't building the wing, you are. You're not just testing the layup schedule with destructive testing, you're also testing your skill properly executing the engineer's plan. I'm testing my shoulder harness attach points using destructive testing. Sure it takes a lot more time to build a test article, set up a test stand, procure the 2000 lbs of sand weight etc... But I'll know it's safe.

I migyht offer them for free, but I've had a couple times where I've gone to the trouble & expense of crating something up for someone and then they back out when they find out how much shipping costs. Funny thing is though, when someone's already paid for it, they seem to be more likely to follow through with actually picking it up/shipping it. I also don't really want these wings to fly on someone's airplane. These are for destructive testing. If no one wants them for a couple hundred bucks, I'll set up a test rig and report the results.

I'll make an offer to anyone who is really set on blending their wings: I have in my possession two (2) wings and winglets. One has have some minor defects in the wing root area -- probably not enough to scrap them, but since I didn't build them I've already decided not to build new ones from scratch. For a reasonable price, I will sell you these mostly good wings & winglets, which you can then use for destructive testing of your particular blended wing design. There are several articles on how the Rutan Aircraft Company (or was it CSA?) destructively tested the wing/winglet for a long-ez. That should give you good baseline data. Or build one to plans, the other blended. Unless the design is validated with at least static load testing, I wouldn't fly under blended winglets. -- One more thing. Dust's blog (not so much a forum any more) has interesting pictures on how to shape the foam for a blended winglet, but if he is using no spar or other reinforcements to hold the winglet on, I would steer far clear of that design.

It's not just the structural issues of the attachment. That's relatively easy to test, assuming you're willing to build a test article and test it to destruction. But there are substantial aerodyanamic considerations too, depending on where you start the blend. Don't forget, the airfoil has twist to it. With each additional inch of wing you're removing, the characteristics of the airfoil change ever so slightly.

I hope not. But what calculations did you perform to ensure that the blended winglet + wing area, length etc... imparts the same center of lift characteristics to the aicraft? The Mk IV is swept wing design, placing the end of the wing behind the aircraft's center of lift and center of gravity... Changing the characteristics of the end of the wing adds or reduces lift behind the aircraft's CG. That'll change the stall characteristics. Move that center of lift too far forward, and you could end up with the center of lift too close too/ahead of the CG, giving you a nice deep stall. If you know how to calculate the lift distribution of your particular flavor of blended wing/winglet, I would be very interested in that information, as would many others. If not, I'd suggest copying, exactly, Jack Morrison's mod, since we know his didn't have adverse consequences.

What "theory"??? Why 9.5" ??? What analysis, calculations are you people doing when selecting the length or amount of the wing to cut off? I'm not at all convinced that it's as simple as just "shortened wing + blend = orginal wing length" Maybe it is, but maybe it isn't. I like the idea and will most likely go this route for drag reduction, but I'll be damned if I just pick some arbitrary wing length and start cutting. If you don't have the experience neccessary to analyze aorodynamics, find someone who does and inform the rest of us.

The extra weight probably came from differences in foam batches. Although the weight is nominally 2lbs/ft^3, but I think it varies significantly, maybe between 1.6-2.4 lbs.

Does the wing need to be plans length with the blend? What did Jack Morrison do? Did he cut off any portion of his wing to fit the blend, or did he just add the blend to the end of the wing? This point if pretty important.

It requires moisture to set. Mist the parts & glue joint lightly with water (use a spray bottle) and you'll have no problems.

I've thought of doing the same thing, but am leaning against it. Here's why: #1. More difficult, overall. I hate doing long layups, so much easier to split the job up. Spready spar cap tape over a curve is much more difficult than laying it out straight. #2. Harder to vacuum bag. I'm vacuum bagging the wings. It'll be very difficult to get the whole winglet / wing assembly into a single bag and avoid having the bag pull the winglet one way or another. #4. Possibly heavier. The spar tape is heavy, if it isn't needed, don't bother. #3. Why bother? The winglet doesn't see enough force on it to require a thick spar. The plans method of using BID layups seems to work fine. I'd rather not add weight.

Some expanded foams will damage AL parts that they are in contact with.

You can save at least $1000 over the course of the project, switching between AC spruce and Wicks to get best pricing. Also, during Oshkosh week at the end of July, Wicks always has 10% discount and/or free shipping. I always place a big order then.

Lynn Erickson, I had your gear (Bill Ortell's) and now own the 2nd generation Infinity Gear. The 2nd gen infinity gear guide tube is a 1 piece machined AL tube, whereas your steel chromoly stell tube was (if I recall) 3 peices. The steel guide tube, and two AL half-cylinders, bolted to the top of the chromoly tube.

I had them but sold them to Nico.

How about a link?

There's no need to rely on hearsay. The specs for TG are available.

I've been building for 5 yrs and I use almost all slow. Sometimes if I'll be making lots of small layups over a couple weeks, I'll mix in some fast hardener to speed things up. Slow is just so much more controllable. You never know how long something will take until you do it. It really sucks to get behind the epoxy curing, and have to re-do it.

That's a savings of around 5k, easily.

If you use MGS 285 epoxy, it's hazmat and costs extra shipping. Freight shipping is most economical. It's worth it to get about 10 qts of the slow hardener LG287 I think, all at once. Much cheaper than paying the hazmat charge with multiple shipments. Steve

To put a plug in... I have a project for sale. $1600 or best offer gets you a fueslage, mostly completed through Chapter 13, plus armrests and other components. http://www.canardzone.com/forum/showthread.php?t=5320 Because I already sold the plans, take $250 off. New price $1350.

I'm pretty sure that the plans hard-points and harness set up doesn't meet FAR requirements. Experimentals might be exempt from the FARS, but seat-belt rules are one of those areas where you would be wise to reference them.

Some people have thicker necks, and wider shoulders. If you're one of them, consider making the pilot seat to your comfort level, but keeping the passenger seats at 8.5". There are documents online that describe ideal aircraft harness separation levels. Or you could make your decision based on the FAR requirements, that's what I've done.

Spar damage = scrap the part. That'll give you most peace of mind. I've been investigating destructive testing of a new seat-back / shoulder harness set up. It's actually very expensive to get the neccessary amount of lead or iron weights and build a test rig. From a steel supply store, steel costs about $1/lb. If you need 2500 lbs, do the math. You might save money just building a new one, and you can re-use the aelerons and metal components. It can actually be a very fun experience, building a canard.

Run 24v and you'll save a bit of weight in wires. (Goes with the $100 / lbs rule of thumb)

For a flight critical item like the canard, I'd probably rather just re-build it if the damage was anything more than superficial. It'll take about 100 hrs or so, maybe more if you haven't worked with composites before. But you can probably re-use the elevators and all the metal parts from your current canard, which will save lots of time.