The way the super wing mast is talked about here it is the best thing since sliced bread...if that is the case, is there an engineer here who can calculate the laminate schedule to mimic the bend characteristics?

I am talking about in widely available carbon materials, not some mil spec pre-preg and bogging down in discussions of Autoclaves and such...that has been done ad nausea around here... and from what I can find searching the archives ....no one has ever just answered the most basic question...

Forget the building technique.......how about just the laminate schedule...how many layers of what type of material with what fiber orientation and the properties of an Epoxy resin that can be post cured, I can even give you the properties of the resin I prefer to use:

http://www.resinresearch.net/id3.html

Assume a vacuum bagged hand lay-up.

And no... I don't want to just go out and buy an aluminum one.

Not interested in "kicking the can around the parking lot"... can a qualified engineer give a straight answer to a straight question? I am sure it would be greatly appreciated by many.

If that is too much to ask, does anyone have the accurate specifics bend characteristics of super wing itself...specific enough to allow an engineer to calculate the proper laminate?

Regards,
Bob

Already been done, I have a long version on my Super Taipan...

Contact Gato,

I gave him the schedule two years ago, but can't be bothered digging it out.

Already done.

Bimare has built a mast section specifically designed for us. Their A class profile varies less than 1mm in any direction from the aluminum superwing section. It has been engineered and several different sections tested. Tooling is already done in metal and they are autoclaved, not simple vacuum bag. I know of several vacuum sections that did not hold up to the the long term use on an F16.

Jay and Pease have been working with us now for almost a year on the sail program fro these. Carbon is nice but without a matched sail plan it does no good.

If I'm reading into Matt's post....

He is basically saying, DON'T do it if you plan on doing vacuum bagging for the mast....AND he is also saying, if you don't have the sails cut to the mast, DON'T do IT!

Matt, if I'm wrong, please say so....





Mike

You can vacuum bag and probably be OK as long as you take into account the differences in the end product. Carbon is very unforgiving and fails rather catastrophically. There is a big difference often between real world laminates and engineered calculations or lab samples that needs to be addressed. More refined manufacturing techniques can help eliminate these. The builder/buyer just needs to be cautious.
On the question of sail, you are spot on. If the sail does not match the mast carbon or not, you will be slow. The same goes for aluminum. This is why I am opposed to those nice tuning guides where they tell you the tension and rake and setting for each condition. You need to set your mast setting to match your sail. Each sail will vary slightly. Different makers can vary significantly and we are F boats so this is allowed. Different masts or mast from different batches also have shown huge differences in their properties. Different crew weight combos or sailing style will pay in as well. What works for 1 boat will not necessarily be right for the boat right next to them.

Perhaps I didn't make my question clear ......The question wasn't has it been commercially done...but what is the laminate schedule for someone who wants to recreate a one- off for themselves.

I actually want to make one up for a F14 Project...but since the F16 class revolves around this mast section this is the logical place to ask...

It will be shorter than an F 16 mast at 25', and as such will experience lower loads. No sails have been designed or fabricated. However since there are at least a few sail makers that are familiar with the superwing and its properties it seemed like a logical step to start with a known/accepted/successful mast section/bend. To just build something with arbitrary bend characteristics and hope someone could design a well performing sail around it would be foolish. Coming from an extensive windsurfing background I know how hyper critical mast bend is to the performance of a sail…I want to get it right the first time.
Scarecrow, thank you for pointing me in the right direction…I will ask Gato if he has your lamination schedule handy.

To the naysayers...If I avoided every building project that had been attempted by someone else, and was unsuccessful, I would never have built anything. My whole life has been spent building things that others say “you can’t do that”, “can’t be done”, “that will never work”, “we tried that already, it didn’t work”…both in the marine industry and the residential/commercial building industry. I am sure many of you can relate and have a similar story…

Thank you again to Scarecrow and Matt for you constructive, informed response.

I wasn't trying to be a naysayer....


I was trying to make the point that having a custom built carbon mast wasn't going to gain you any advantages like a lot of people think.....AND....it would be too much work to get it up to spec for F16 at this point in time. That is until some groundwork has been laid.


If that was said in the OP, I wouldn't have posted my comments....



This is an F16 forum...






I say go for it!

for your simple "I want just to build it approach":
1 Make a plain test piece of a 25%/50%/25% (0°/+-45°/90° direction).
2 Measure the tension stiffness of it at compare it to the tension stiffness of a aluminium plate.
3 Use the stiffness ratio to scale the skin thickness (e.g. if the CFRP is twice as stiff you need half the thickness
4 build the mast with same outer shape and the found skin thickness

The mast will have the same bending stiffness, but not the same weight, strength and so on. Other layer set-up will give lighter masts and varying the skin thickness over the mast length would just be another parameter.
It will not be "first time right" if this is the first mast you build and by the way, a shorter mast need to have a lower second moment of inertia to have the same bending curve. If all these expressions are greek to you, better buy a mast. It will be cheaper (you forget to mention this specific point of nay saying :))
Seriously, I can't give you more detailed numbers, as I don't know the skin thickness of the super wing mast and which sort of carbon and resin you want to use.


Cheers,

Klaus

Klaus…thank you for your response. I must not have communicated my wishes effectively…It’s not quite “I just want to build it” it’s “I just want to build it after I have a competent engineer provide a laminate schedule” I don’t want to go into the mast building business…I just want to build one mast…the protocol you suggest, while it would eventually get me to where I want to go…if I live long enough…LOL , is to put it nicely the long way around. And even if I got the proper stiffness it wouldn’t tell me if the laminate could endure the loads placed on it till it was put to use on the water…I don’t want to re-invent the wheel when it has already been invented. If I was to get this involved in prototyping and testing I agree that buying one would be a “give away” in comparison. I am not at all put off by your expressions…I understand your reasoning and have conducted such testing for hull laminating schedule for a 86’ military patrol boat prototype…after the laminate was calculated by a marine engineer…as a verification, not as a starting point.

Mike…Wasn’t trying to paint you as a naysayer...I just knew going into this that it is so hard to get a straight answer to a straight question...

I have no delusion of directly competing with a Bimare, Hall or any other viable commercial mast builder. My mast will be slightly heavier, slightly weaker but also way less expensive (if my time is not factored in) ….and I am alright with that. Just want to use my knowledge/experience with composites to build my own one-off carbon mast...to do that all I need it the laminate schedule...and profile shape...a sample..a left over cut off just long enough to make a template... say 3" … would be nice for reference...

I have come to the conclusion after writing all this that I have been asking the wrong question here….What I really need to know is where can I get the necessary information about a superwing and it’s properties to provide to an engineer to calculate a composite mast. My father-in law is a structural engineer at Kennedy space center, I am sure he can do this in his sleep if I can provide him with all the necessary information.

I see!!!!!!

" will not be "first time right" if this is the first mast you build"
Klaus I would have to disagree with you on that one point...If I am given a proper laminating schedule that is reproducible...I see no reason why I cannot use my over 4 decades of composite experience to build a quality, fully functional, carbon mast the first go around.

It all comes down to the engineering and execution, I see three possible outcomes......
1) Properly engineered laminate schedule + properly executed...= a properly functioning mast.
2) Poorly engineering (or seat of your pants engineering) + properly executed= failed mast.
3) Properly engineered laminate schedule + poorly executed = mast failure.

I miss
4) properly engineered laminate, but engineer don't know about the builders background + properly executed
or
5) properly engineered + properly executed, but builder doesn't know about design rationals

Ask Boeing 787 engineers about that...

And yes of course, I change my sentence:
...if this is the first mast or similar complex composite part you build.

I meant my approach seriously. In your first post, you said, you don't want to use mil-std composite. Hence you should make in any case test pieces to get the stiffness properties of the fibre you want to buy. Costs you one day, not your whole life. The laminate schedule is not optimsed, but it will work (it is an isotropic layout, same strength in any direction). You asked a simple question and I gave you a simple answer.

If you want a more complex answer, send me the cross section of the super wing mast and the material properties of the fibre and resin you want to use. I would charge you at least 3500 Euro for that job, not for the mast, just for the design (not because I am insane, but because it is my first mast and I need some lead time + testing). And than, you still have the risk 4).
Any commercial mast builder will be cheaper, because he has done already this job and changes only a few parameters in his calc. Apart from the fact that those products are already tested.
Or you ask your relatives or buy books about composits and engineering. (Again this is a serious proposal)

My 2cts as an engineer.

Cheers,

Klaus

Why don't you contact Ben Hall or Goran Marstrom? I'm sure they could help you.

Klaus
I appreciate your response, and your offer to do the calculations and testing. $3,500 does not sound unreasonable for the scope of work you propose...However my wife works in design engineering for United Space Alliance and is up to her eyeballs in every discipline of world class engineer you can imagine, several floors deep. After 32 years at the Kennedy Space Center, and her position in design engineering operations, she knows, and has worked with, the majority of them personally at one time or another. My search is now focused on the same information that I would need to supply to you if you were to do the calculations. Capable engineers are fortunately not a problem for me...I just need the specific information...and I may have found it from a source outside of this forum. I have no shortage of family, friends and my wife’s co-workers who are engineers that would be happy to do it as a favor...you can't compete with free...especially when it is coupled with some of the greatest engineering minds on the planet. Thank you again for your offer to help.

Regards,
Bob

Why are you bothering to ask to question here then? Im sure your engineering guru friends and family could come up with something better couldnt they?

Im only guessing here but wouldn't shortening the mast completely change the way it behaves. Maybe you'd be better off starting from scratch.

Aido...I asked here because many of the F16 designs revolve around this particular mast section, It did not seem unreasonable to assume that someone had developed a carbon lay-up to mimic it's bend characteristics, and that laminate schedule was common knowledge...obviously its not...at least to those participating here...the only foolish question is the one not asked.

Yes, shorting it will have an affect....mainly one of stiffness, but if you start out with a known quantity you are way ahead of the game....It is much easier to modify the section dimensions and/or fiber orientation than to start from scratch with a total unknown.

Maybe you could find a broken A cat mast that still has enough length for the F14? What do you need, about 25 feet? And what's an A cat mast, about 32-34?

It might be -too stiff- if cut down from 32 to 25 though.

Timbo
That could definetly looked into for a "plan B"...I think Darryl's A&O F14 has some type of modified A cat mast. Would be dependent on finding a broken one that is long enough and priced right...

I check with Darryl for more information about the route they took...what ever he did...it works very well.

WE used a "standard” A class carbon mast section with the addition of having a section from 300mm above the hound position to 800mm below the hound position having an insert laminate of 300gm/sqm of Kevlar (this is the area where most, if not all breakages occur during an extreme "pitch pole" due - in carbon masts - to the loads on the tension side of the impact, the Kevlar makes the masts almost “bullet” proof). As far as bend characteristics of the mast - I positioned the hounds to achieve the required bend rather than play with a great variety of lay-up variations and cut the sail "to suit the mast" rather than "the mast to suit the sail". To source the carbon mast from an established manufacturer is infinitely more cost effective than going through the process of making your own – believe me I have tried that route. The whole 25’ “bare” mast section weighed in at 8 KG, and it is a better section than the superwing (I should know as the Greg Goodsall “super wing” was made from my original calculations and drawings that I sent to him (at his request) back in the eighties when we looked like we may – at that time – split the cost of the dies to have them made commercially, I still have those original drawings as well as all our correspondence).