The XPB Stage 1 underway.

[bexrbetter]

Previously you (like Morgan and others) had your longerons attached to verticals and diagonals with riveted gussets.

 

I have exactly the same system of gusset retention as the Morgan and Others.

 

How many Effin times do i have to say it?

 

 

[Nobody]

I have exactly the same system of gusset retention as the Morgan and Others.How many Effin times do i have to say it?

Almost. The Morgan and others don't have the weld. They therefore don't have the residual stress and toe microcrack in the primary member that your detail will have. Even if the weld does not carry load the primary member will be affected.

 

 

[Litespeed]

Bex,

 

I can see why you are seeking other ways to make it easier for us, and that is commended.

 

I would have thought though that when given the cost of getting a welded truss and then using gussets and rivets and meeting all the engineering needs- is is getting complex and expensive relatively.

 

Why not do similar to what you had planned earlier- a riveted truss.

 

Look at the absolute best practice and have the gussets on both inside and outside if needed and all precisely bent and drilled to match holed tubed.

 

Customer just quick assembles with cleco's, aligns and rivets.

 

 

[bexrbetter]

Almost. The Morgan and others don't have the weld. They therefore don't have the residual stress and toe microcrack in the primary member that your detail will have. Even if the weld does not carry load the primary member will be affected.

No, because the way you are, continually, stating it, is as if it matters, it does not matter.

 

In the worst case impossible scenerio, which is impossible, if the longeron broke in two at that point, which is impossible, it wouldn't cause an issue at all such is the redundancy.

 

But please post it again, and again ......

 

... or run the numbers.

 

 

[bexrbetter]

I would have thought though that when given the cost of getting a welded truss and then using gussets and rivets and meeting all the engineering needs- is is getting complex and expensive relatively.

No it's not, period.

 

I'm the one who just paid for it, I know exactly how much it's costing.

 

Why not do similar to what you had planned earlier- a riveted truss.

Look at the absolute best practice and have the gussets on both inside and outside if needed and all precisely bent and drilled to match holed tubed.

There is no change here, it is still a riveted truss.

 

I'm experimenting with ways to speed up the build and accuracy, the foundation isn't changing.

 

Amusing no one ever considers the damage riveting does to the primary structures but the moment you mention aluminium welding ......

 

 

[rgmwa]

In the worst case impossible scenerio, which is impossible, if the longeron broke in two at that point, which is impossible, it wouldn't cause an issue at all such is the redundancy.

It would create an issue because the structure didn't perform as designed or intended, and that's an issue irrespective of any uncertain level of redundancy in the system that might save the day in the event of an `impossible scenario' happening.

 

Nobody is criticising what you are trying to achieve, which could be a great result for the kit aircraft business if you are successful, but introducing welding without a careful analysis of what that may do to an inherently fatigue-prone structure should not be dismissed as not worth considering. It would also be a foolhardy designer who didn't consider the `damage' caused by rivet holes in primary structures and not take that into account in the design where necessary.

 

rgmwa

 

 

[bexrbetter]

It would also be a foolhardy designer who didn't consider the `damage' caused by rivet holes in primary structures and not take that into account in the design where necessary.introducing welding without a careful analysis of what

For sure, but never see rivet damage mentioned or discussed, yet I can show you countless threads all over the net about aluminium welding arguments. The motocross world went beserk when Honda introduced the aluminium framed 1998 CR125, consider for a moment the pounding motorcross offers yet they are all running just fine 20 years later, and in the meantime a number of steel frames have famously broken. Mild steel is used even in works bikes BTW, not 4130 because it cracks in very short time, oh the irony.

 

And yes I am aware that Honda process their frames accordingly, just making a point that the aluminium fatigue hysteria is nothing new and these responses were expected, hence the acronym in post #575.

 

It will be analysed, although not much point if the reaction is so negative that people don't take to it based in lore rather than facts, market rules sadly, and lore in aviation is way up there.

 

 

[bexrbetter]

they would be cheaply priced so you would sell lots of them for a handsome profit.

From your excessively long winded post it is quite obvious you have a purpose here way beyond aluminium structures, I don't think you missed an aspect of my business/build that you didn't sneak in some nasty 'read between the lines' overtone. Repeating remnants of private conversations in public is, though harmless enough in this case, somewhat telling of a person's deeper character.

 

But anyway ...

 

If I sell a kit for $10,000, what's the absolute maximum profit I can make? Yup, $10,000, but only if all the labour, factory space, machines, consumables, and of course materials were free.

 

You think I'm doing this for profit? No experienced businessman here would go on those numbers, including me.

 

For other reasons, I need to manufacturer a successful product for the next 5 years to see a return, a crap kit aircraft ain't going to sell in numbers for 5 years, regardless of price. There will be enough information out there after the first 5 to make or break the project. - about 295 short of my 5 year target, probably not good for business then to push out crap and/or bad service.

 

The onus for safety and airworthiness and structural integrity falls on the customer, not the kit producer, as you're aware, and if you're not planning on flying it yourself there might not be quite the same incentive to make sure it's perfectly sound.

The onus falls entirely on me, not only for continued sales, but because that's who I am, because I care, and I rebuke your nasty little overtone otherwise. Many times I find myself explaining to my sidekick why we have to do it in a certain way because "it's an aircraft, and there's only one chance".

 

You have never worked beside me, not a clue about my work and quality standards, so your little spiel is moot anyway.

 

but the kits people sell don't have to pass any form of testing in regard of whether they will assemble into a safe flyable aircraft.

Well it's lucky then that Vans and Sonex, Zenith, etc, are decent people then, like me.

 

and the additional riveted gusset does not constitute much of a splice.

Stupid, ignorant statement, you have no idea what size the gusset or rivet schedule is, just like when you loudmouthed about my wings also while having no idea what materials were involved. You could have asked and made determinations from there, offered opine, but that's not your agenda here is it.

 

Actually they are not the same as a Morgan I mentioned above, indeed they are in fact larger and heavier material because when we FEA'ed the Morgan, their gussets were only 'just' good enough, and that wasn't good enough for me. In fact the Morgan was used in FEA as a comparitive for a number of areas and generally has seen an increase in strength in mine just about everywhere, with little to no increases in weight.

 

My qualified Aeronautical Structural Engineer thought the Morgan as quite a strong plane and would comfortably stand 8g, verifying what Gary Morgan has previously mentioned. The same guy designed the landing legs on the China Moon landing module, kind of out qualifies you, considerably.

 

A while back you said you didn't have any formal engineering qualification.

That's why I have 2 Aeronautical Engineers, one structural, running the numbers and FEA for me, as I have already mentioned.

 

And actually I have 2 engineering qualifications, but not specifically the relevant Mech Eng or Aeronautical.

 

You have no qualifications at all, but here you are anyway.

 

Some might consider one model of the 601 to be a good example of that,

Did the 601 have any welds, or anything to do with this at all? No, just trying to put dramatic "death plane!" images into people's head for points scoring. BTW, it was designed by Aeronautical Engineers who have also given people millions of hours of joyful, safe flying.

 

I've largely refrained from commenting on your build because on the two or three occasions where I did your response seemed to be less than appreciative. And your reaction to the considered input provided by several here who are very knowledgeable and experienced builders has been quite dismissive, to the extent where it's noticeable that most have not bothered to contribute any further.

Oh boo hoo hoo . And I thought it was me with the ego issues

 

Your first response was 3 months in, 13 pages, post #244 bagging out my wings with no information at all to support your statements. What's the problem, I didn't bow down to your awesome, but completely wrong comments? BTW, You made a horrendous engineering comment in that post showing your lack of training, was just easier to patronise you and send you on your way though rather than deal with another 98000 worded post of yours.

 

So the only 2 times you have commented, then and now, is some sort of points scoring doom and gloom posts, no "likes", jokes or encouragement posts or discussion involvement along the way for the previous 240 posts, so when you jump in trying to look superior why would I give you the time of day.

 

BTW, I have made quite a number of changes based on other's viewpoints.

 

With "knowledgeable and experienced" builders, well it's very simple, I'm building my plane, not theirs. And I'll build it my way, not theirs. I read every word of Gary Morgan's here and other manufacturers at HBA, along with clever individual builds with intense interest and take in everything they say and do, and note they rarely present themselves as "knowledgeable and experienced", usually just present the way they have done it factually without forcing their opinions.

 

Kit building is a hideously expensive, time consuming thing that keeps many away, I'm trying to change that and apparently nobody has succeeded so far, certainly not the "knowledgeable and experienced" ones.

 

Or maybe that should read; the "frustrated" ones.

 

'Test pilots' rarely have any significant or relevant engineering knowledge themselves,

.. people who assemble a kit, rarely have any significant or relevant engineering knowledge themselves,

Do you know who I have engaged to be my "Test Pilot"? No, you don't, but he's apparently a "rare" one.

 

"People who assemble a kit rarely have any significant or relevant engineering knowledge", well what a stupid and irrelevant thing to say. Vans, Sonex, Zenith, whoever, kits are assembled everyday by "People" without the need for significant or relevant engineering knowledge.

 

.....

 

For others genuinely interested, for the final design I have already engaged and will go through the process of having a highly respected Aeronautical Engineer and Test Pilot, also an Aeronautical Engineer (rare apparently) optimising the final aircraft. If they say drop the welds, it will be so, not because some pretend wannabe engineer in a forum says so, but that is a little time off yet, still experimenting at the moment.

 

This step is a necessity for confidence in a "Chinese" aircraft, and would improve confidence in any new aircraft for that matter.

 

.

 

PS, if you think this build is controversial, just wait for number 2 where I will ignore all the "experts", lores and traditions ... bahaha!

 

.

 

 

[bexrbetter]

Acronym time;

 

TAMNBWDPC.

 

 

[SDQDI]

To all my new buddies who down prawn cocktails?

 

 

[Head in the clouds]

.... but that's not your agenda here is it. ....

Um ... I don't have any agenda here at all, except, as I said, that I'll comment about matters "which if not corrected could possibly have fatal consequences".

 

Why would I have a harmful agenda as your post above seems to suggest? If you recall, about three years ago I spent about an hour just about every day, for months, writing you long emails to answer your questions, which gave you the majority of your initial knowledge of aeronautics. I then spent a few days helping you by inspecting and writing a review of an aircraft structure that you intended to buy and manufacture. You also used my 'credentials', based on my fairly long history of designing and building sport aircraft to give your 'company' added credibility when it was seeking investment. I never have claimed to have any engineering qualification, however at the time you chose to present my previous experience as sufficient competence.

 

I have always sincerely hoped you might make a go of it, this sport could certainly do with a much less expensive kit and engine. All I've ever done is offer you the benefit of the experience I've gained through previously making most of the same mistakes you're making now.

 

There's little point asking you for information about specifics, because you always say the same thing, "there'll be an announcement soon", but 'soon' rarely seems to eventuate.

 

If you re-read my post about your wing carry-through (BTW, there were three of my posts on that page, not one), it was very considered and provided you with full justification for my concerns, complete with simple calcs based on what appeared evident. By showing the calcs process it allowed you to insert your own data if you wished and come out with the 'real numbers' rather than my assessed ones, but you didn't do it. At least, if you did, you didn't post the real sizing and result - and in post #254, you declined to say what the actual sizing was, so what's the point in asking?

 

If I was so wrong I wonder why you promptly abandoned that carry-through and substituted a different one. I know you said the first was just a 'test piece', or words to that effect, but if that was really the case why bother to go to all the expense of laser-cutting hundreds of lightening holes in it?

 

BTW, you say you have these aeronautical engineers working/consulting on your project - have you asked them what they think about the welded aly truss? I just called and asked one of Australia's most experienced aero-engineers who has many designs under his belt and his words were, "Welded? Steel, yes, not aluminium, not in the primary structure". He never was a man of many words ...

 

I don't know why you decided to mouth off at me like that, I didn't suggest the welded concept, and it's not my fault if you think up and set your heart on ideas that might not be best practice, so don't shoot the messenger, as they say.

 

Anyway, despite your unwarranted venom, I still wish you well and I'm sure if you stick to more conventional aircraft structural practices it'll meet less buyer resistance than if you include a bunch of 'unknowns'.

 

 

[Deskpilot]

Gentlemen, may I suggest you take your private vendetta into the world of private messages. Most of us here want to see how Bex completes HIS design and how it flies on completion. Personally, I am a 'belts and braces man' but have know knowledge as to how the belt is affected by the braces, if so at all.

 

 

[hihosland]

Arguing on the internet is like playing chess with a pigeon....even if you win the pigeon will still crap all over the board and strut around like they won.

 

 

[bexrbetter]

Arguing on the internet is like playing chess with a pigeon....even if you win the pigeon will still crap all over the board and strut around like they won.

Sadly anything you promote in this day and age needs to have Social Media taken very seriously, it's power to damage can not be ignored, and you would be stupid to ignore it.

 

The welded frames are off the table, not because it can't be engineered correctly, but because it's just too controversial and damaging to my goals at this point in time. That's how it is with the Internet now and I accept that.

 

Gentlemen, may I suggest you take your private vendetta

Meh, zero cares given, I got a plane to build, ignore function activated.

 

It doesn't matter what these "Experts" say about myself or my goal, the end result is that nothing they have said or done in their time in the sport has changed a single thing about the cost and accessibility to owning a plane.

 

.

 

 

[peter]

Bex, Thankyou for keeping us updated on your progress. I have no knowledge of aeronautical engineering, I have no knowledge of manufacturing processes, my mechanical knowledge is at best basic. I built my Onex from a kit including assembling the aerovee by simply following the manual. I loved the building process and my little plane brings me joy every time the wheels leave the ground.

 

I genuinely hope your project is successful and applaud you putting it all out here on the net for basic punters like me to observe the process, learn a little and enjoy.

 

Thankyou, Peter

 

 

[bexrbetter]

Thanks Peter, many manufacturers won't go near the net for good reason, but I don't mind.

 

I have been madly working about 18 hours a day over the last week, i ain't kidding either, it's now 6am here and I'm about to go to bed for a few hours and go to the factory at 10.

 

I have made big changes, not to the overall concept, but to the module'isation and simplification of the frame and will be screwing it together this week. Example before every vertical and angle frame brace was an individual requiring not only the individual length to be cut, but also and individual angle cut at each end, now there is 18 identical vertical braces with 90 degree cuts and 9 with one end 90 cut and the same angle on the other end, albeit individual lengths.

 

This will make simpler, faster and more accurate frame building.

 

Anyway, sleep time.

 

 

[flyerme]

Thanks Peter, many manufacturers won't go near the net for good reason, but I don't mind.I have been madly working about 18 hours a day over the last week, i ain't kidding either, it's now 6am here and I'm about to go to bed for a few hours and go to the factory at 10.

 

I have made big changes, not to the overall concept, but to the module'isation and simplification of the frame and will be screwing it together this week. Example before every vertical and angle frame brace was an individual requiring not only the individual length to be cut, but also and individual angle cut at each end, now there is 18 identical vertical braces with 90 degree cuts and 9 with one end 90 cut and the same angle on the other end, albeit individual lengths.

 

This will make simpler, faster and more accurate frame building.

 

Anyway, sleep time.

Hope you found time fir an awesome Xmas Bex? Have a great new year mate

 

 

[bexrbetter]

Hope you found time fir an awesome Xmas Bex? Have a great new year mate

No Mate, Xmas is a completely non issue in China and to boot, my Missus wasn't even here, 2nd time in my life I have woken up to an empty house on Xmas morn so I just worked all day. Planning to be in Oz soon for a Feb or March Xmas with my family.

 

I Had a few drinks and pizza on Friday evening with a handful of foreigners here, then back to home and work ....

 

My Missus is floating around, literally, with Daughter, in Palau in the middle of the Pacific ocean. she went for a flight yesterday ..

 

 

 

 

 

 

 

[Pilot Pete]

All the best for the new year and can't wait to see what you get up to in the coming months.

 

All the best and be safe.... Pete

 

 

[scotsman]

Any chance of some pics of the latest design and build Bex?

 

 

[bexrbetter]

Any chance of some pics of the latest design and build Bex?

Just as soon as I have finished photoshopping the welded bits out.

 

Should be done by tomorrow.

 

 

[planedriver]

Wishing you all the very best for the effort you are putting into your project.

 

Kind regards

 

Planey

 

 

[bexrbetter]

So a few weeks ago I was looking at the sides of my project and was thinking that every vertical and angle brace was of a different length and had a different angle cut on each end, along with each individual gusset to carry it to the longerons, I quite like the design but a bit of a headache to consistently reproduce and maybe for others to build with consistency.

 

Note I am not intrinsically changing the design, just making the frame simpler, faster and more accurate to build.

 

That's what actually led to the welded sides, simplifying ease of fitment etc - we all know how that worked out

 

But I had also been considering another idea, and that was a simplified box shear web running the length of the fuse with appropriate further additions, something like this, I call it "The Submarine" .....

 

 

 

.. and of course I'm actually making it, should be done tomorrow ...

 

 

 

 

[geoffreywh]

interesting

 

 

[bexrbetter]

interesting

Someone will complain about it.

 

Actually today I decided to split them in half as it was awkward moving the whole side around with the kink in the middle. So much easier to work with 2 smaller and flat pieces.

 

Extremely easy to build up ...