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The XPB Stage 1 underway.


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Bit by bit ....

 

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If the rivets look strange it's because they have been dipped in grey paint. If they don't look strange, ignore this or get to an optometrist.

 

 

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.. and just for kicks because I was bored today, thought I'd whip up a left wing, some guy told me one on each side would better balance the plane apparently ...

 

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.. and just for kicks because I was bored today, thought I'd whip up a left wing, some guy told me one on each side would better balance the plane apparently ...[ATTACH=full]50870[/ATTACH]

Not always, apparently

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Not always, apparently[ATTACH=full]50871[/ATTACH]

Bex has got it wrong. Apparently you dont need the right wing, only the left

You should have started with the left wing Bex

 

 

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There's something more important than wings that is concerning me greatly with this new design. That concern is related to the number of rivets being used in the construction. The number is obviously excessive.

 

Excessive numbers of rivets results in longer build time, leading to reduced levels of morale on the part of the builder-owner, as he sees 2,000 more rivets needing to be popped.

 

More importantly, excessive numbers of rivets results in an excessive weight penalty, leading to vastly reduced performance levels.

 

Most important of all, excessive use of rivets results in higher build cost and a reduced profit level for the manufacturer.

 

As a result, I see the need for a reduction in rivet numbers, in the order of 50%. This will immediately translate to a bottom-line profit improvement level of 16.463%.

 

Furthermore, a 50% reduction in the number of rivets required in the build, will result in a 32.346% reduction in build time, and 26.432% improvement in the aircrafts overall performance - thus leading to much happier builder-owners.

 

No need to thank me, I'm happy to play my little part in assisting with your companys performance, and its products efficiency. Signed, OT - former Ford bean counter. 003_cheezy_grin.gif.c5a94fc2937f61b556d8146a1bc97ef8.gif

 

 

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There's something more important than wings that is concerning me greatly with this new design. .. Signed, OT - former Ford bean counter.

That was a riveting post.

 

 

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If this wing flies, you will be surprised how even a small amount of non-moving tip trailing edge will dampen aileron response.

 

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That is if that end bit of trailing edge is not going to move.

 

My second aircraft had a wingtip similar to the Sapphire, with (admittedly) a small aileron.

 

Roll response was not startling.

 

Later, the trailing edge was cut off and joined to the aileron, giving much better roll control.

 

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I was initially going to go with just a left wing, but was convinced to add a right one as well...

 

 

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Geoffrey - Not sure if you were joking or not, but adhesives are all the go, in todays world ...Tougher and stronger glue

That article is from 2007. There's plenty of people, me included, who have experimented and still no real result for the average person.

 

Lotus cars are probably the closest to what a home guy could do, albeit you would still need an oven.

 

 

Oddly enough, the very best results I have had are with "No More Nails" on aluminium, I have an aluminum structure that's bonded with it an less rivets, 3 years old now and can't see any change. It could save you using many nails on your aluminium builds.

 

 

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I understand Sikaflex make some great adhesives, and they're used to secure body panels to bus chassis' (especially roof assemblies), very effectively. The specification requirements involve sustaining structural strength in a bus rollover.

 

Not sure how or if you'd be able to get certification for aviation use, though.

 

Bus and Coach 01a005sa01

 

 

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you will be surprised how even a small amount of non-moving tip trailing edge will dampen aileron response.

Later, the trailing edge was cut off and joined to the aileron, giving much better roll control.

Thanks for that, despite what some think i do appreciate it.

 

My ailerons are 1.5 meters long x 200+ width, so we'll see how we go first, but I have heard/read about your proffering previously and will bear the solution in mind.

 

If this wing flies, you will be surprised how even a small amount of non-moving tip trailing edge will dampen aileron response.

Well at least I've stepped up from "will never fly" to "if"! 006_laugh.gif.0f7b82c13a0ec29502c5fb56c616f069.gif

 

I understand Sikaflex make some great adhesives,

Oh there's some great adhesives out there that would make superb additions (note I did not say primary) to homebuilt aircraft construction, but as with most ideas I have been through the discussions with the Luddites and, just give up. Sadly they are fast to jump in with "you'll die in a screaming ball of fire" nonsense

 

My second plane will be as I Efing well please though, using a battery of "won't work" ideas intentionally to P them off, only because I'm a spiteful bar stand 003_cheezy_grin.gif.c5a94fc2937f61b556d8146a1bc97ef8.gif

 

 

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Sanda Veenstra used that combination ("No More Nails" on aluminium) to lasting effect on many of his creations. Never heard of any failing in that way. Don

Hi Don,

 

I don't wish to be argumentative but I worked on and off with Sander while he was building the SV6, 7, 8, Bandit, Farmate, Thermite etc and the two seaters ... Tardis etc and he did experiment with 'Liquid Nails' in the early times, which is essentially a contact adhesive. However he found it to be disastrous because it's not intended to be used as a mastic, consequently I'm confident that he never used it on any aircraft. If you were to use it that way (as a mastic) it suffers from entrapment of the solvent and forms large voids when it does eventually dry out and becomes extremely brittle. That is why contact adhesives need to be coated on both surfaces and allowed to 'dry' before closing the joint.

 

Most of the SV wing-rib to spar, and spar to wing-skin attachments were performed using Sikaflex marine adhesive which is a polyurethane product and which IS designed to be used as a mastic, and should not be allowed to skin prior to closing the joint.

 

Some of the later bonded joints on SV machines were done with Plexus methacrylate structural adhesives, and not long before his demise I introduced him to the Permabond 'T' range of 2 part acrylic structural adhesives which were developed for, among other things, Boeing's bonded aluminium wing spars ...

 

 

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HITC, I yield to your more intimate knowledge of Sanda's building techniques. My source of information is a friend who owned a Thermite for a while. I have never owned or closely studied a Veenstra a/c. Don

 

 

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I like the use of "Glue" ( could be anything that is appropriate) and pop rivets. There must be some sort of microscopic "fretting" and or creep (nobody I know) on Alu to Alu pop riveted surfaces that "glue" would eliminate and improve rigidity and longevity.

 

The Plexus methacrylate structural adhesives mentioned seem to be for plastics... However I have used some exotic "sitkaflex" types on Alu to Alu joints and even after several years in the open air the stuff was sticky as all hell and had not gone brittle. I'm sure a little research would turn up a type of compound that would suit a skin to spar or stringer joint

 

 

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Re-building an Eastwood Tyro some years ago I used Araldite 134 on the major joints fixing the long fuselage member to the down tube and the horizontal seat carrier. I thought that it would take a huge force to dislodge the joints. They were plated with 3mm 6061 T6 and rivetted with very large 3/16 pop rivets. This method would certainly prevent the joints from "working".

 

 

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The Evektor Sportstar is bonded & riveted. Makes for a solid airframe with no working of rivets. My Sportstar has done almost 2000 hours as a school aircraft without any rivets working loose. You also get less drumming, so a quieter airframe.

 

I am told that it can make repairs difficult though. Sportstar 24-3978, the first demonstrator Sportstar in Aus was hail damaged in Canberra. Repairs were quoted as being crazy expensive, reskinning becomes very difficult. Hence it was sold off & continues to fly nicknamed "Dimples".

 

 

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Went in today, lasered and started setting up the wing ends.

 

Drove me crazy for a while finding the correct assembly process, get it wrong and you end up with warped sheets, but eventually I found the right procedure.

 

The trailing edges as you can see appear to have a reverse taper, but the trailing edge is actually parallel to the spar (both being perpendicular to the plane). They also have a twist within themselves so the very end has a slight negative angle, as you can see, all as an aim to prevent wing tip stall.

 

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It's surprising how different the colour's of the sheets appear in the pictures only due to the sheet orientation being different. All looks pretty much the same to the naked eye.

 

 

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