Topic: MCT Glass - now named as the Opus GT

Well I did it. I have bagged one of the Glass MCT's due in at the end of the year.
But what a decision. Glass or carbon that is. But as i am no where near 200mph, I figure I have allot of learning to do on this first.
Price difference is about £220 wich will go along way to another one when i put this one in the side of thee mountain.

I like the speed but am not really chasing records, so I recon this will last me a good while before I out grow it (If I ever do), Well it beter or I will have atleast 2 people saying "I tould you so".

So who are the others going to? As I understand there is one left (May be more, it was the impression I got) Who is going to nab it? Kiwi Steve? Graham Deckit?

Will
(who is looking forward to receiving his shiny yellow plane)

Will:

You could have had my modded Opus V, RTF, for less!
Good for 180+, so great for cruising up to 180.
A Fumeistered wing too, probably stronger than an original, yet limited in speed not by its tail but by wingbend.
And a heavily carbon socked fuz, which won't bend or twist in flight.

But not as pretty!
Good luck with the MCT, you'll love the Opus experience

hobster sent me this

RC Groups - View Single Post - Opus MC3 & MCT Builds & Mod's

 

Will:

You could have had my modded Opus V, RTF, for less!
Good for 180+, so great for cruising up to 180.
A Fumeistered wing too, probably stronger than an original, yet limited in speed not by its tail but by wingbend.
And a heavily carbon socked fuz, which won't bend or twist in flight.

But not as pretty!
Good luck with the MCT, you'll love the Opus experience

I did consider your Graham. If advertised I am sure you will shift it quickly.

Will

You're underestimating your potential man! The only reason why you haven't gone over 150 is because you weren't there on the same day I was.

Despite the fact that I believe you are completely up to the carbon one with your flying as it is now, I can see the point in the glass one. It really does seem like a super model, and I like the idea that it may well be an absolute belter of a frontside sport model as well.

I'm looking forward to my nice shiny yellow model too  

Z

PS Just read your next post - get the carbon one!! Crikey mate - you've got advice from a speedy bugger like the Hobster - you gotta listen!

So that guys claiming that the boom bent enough to negate any elevator movement?

CM

hobster sent me this

RC Groups - View Single Post - Opus MC3 & MCT Builds & Mod's

 

that wasnt an MCT tho was it?

Looks like a V, was it even the DS?

My V DS is triple glass so surely the glass MCT is on a par atleast?

that wasnt an MCT tho was it?

Looks like a V, was it even the DS?

My V DS is triple glass so surely the glass MCT is on a par atleast?

hey pasty, how fast have you been with your v DS?

as fast as I drove home when I picked it up , its still in the corner without gear in it looking unloved.

shame on me.

Am I right in thinking that the MCT boom mould is a larger diameter boom than the V? In which case for the same layup, the boom should be a fair bit stiffer.

Still, get the carbon one!

Z

hobster sent me this

RC Groups - View Single Post - Opus MC3 & MCT Builds & Mod's

 

Hi Will, sorry didnt mean to deflate your excitement... you'll be pleased with either  .  The one in the pic was a T not a V but agree the cause of its demise is not certain, would have thought the extra diameter would make it stronger than the stock VDS fuz (if it hasnt had a super Deckit c-sock treatment   )

speedy Door Mat like the Hobster

   

LOL supposed to be "speedy b u g g e r" LOL

Will:
As bought from Abbo, my V's glass fuz appeared very strong & stiff compared with that of e.g. carbon Bird/Blade.
Didn't notice it bending during its 178 run, being more occupied with the wingbend. But used snapflap on that run to ensure sufficient elevator authority, having felt it was lacking during the previous run with the flaps taped-up. Given there's plenty of elevator control surface & decent leverage, figured boom bend was the culprit.

With the heavy carbon socking, it's rock solid.
Its next serious flight will be with flaps taped once more.
Though wingbend will surely act to limit its speed; if the dihedral doesn't act as a brake first, the nerve might run out.

So unless the glass wing is now a heavier lay-up (reducing wingbend) the fuz with its extra diameter will probably be more than up to the job.


Pasty:
Have you purchased yours new, recently?

I think its about a year old now 

[   I think its about a year old now  Whistle]

So, maturing nicely.

Any day now 

Will:
As bought from Abbo, my V's glass fuz appeared very strong & stiff compared with that of e.g. carbon Bird/Blade.
Didn't notice it bending during its 178 run, being more occupied with the wingbend. But used snapflap on that run to ensure sufficient elevator authority, having felt it was lacking during the previous run with the flaps taped-up. Given there's plenty of elevator control surface & decent leverage, figured boom bend was the culprit.

With the heavy carbon socking, it's rock solid.
Its next serious flight will be with flaps taped once more.
Though wingbend will surely act to limit its speed; if the dihedral doesn't act as a brake first, the nerve might run out.

So unless the glass wing is now a heavier lay-up (reducing wingbend) the fuz with its extra diameter will probably be more than up to the job.


Pasty:
Have you purchased yours new, recently?

couldn,t resist this ace graham and sooooooo entertaining   

graham (dsman)178mph opus v on Vimeo

[.....couldn,t resist this .....]

Notice the intelligent technique, trying out ALL the different lines in circuit.
  :banghead

We have a day, Wednesday. 

We have a day, Wednesday. 

Wednesday???

Four new Opi should be turning up at my place George 

Z

Four new Opi should be turning up at my place George 

Z

oooo Narce! 4 ?

oooo Narce! 4 ?

Ye Why have 1 if you can have 4?

Ok so here's some interesting info on the Opus GT. I reckon this will be a brilliant sports and DS model. Bear in mind that the glass Opus V has actually won the odd F3F competition in the hands of Espen Torpe of Norway, so this model works frontside as well!

We decided to bring in a glass version of the T tail, with the idea being to create the "if you could only have one model" model. The Opus GT uses the VDS wing which is proven to 180mph in DS, and a glass/ carbon version of the MCT fuselage so that you have the stability and tracking of the T tail fuselage. This fuse is still mega-strong with the entire wingseat area still in the same lay-up as the MCT. But the key difference to the MCT is the weight. This creates a model which will be an awesome frontside blaster, is F3F capable, is Great Orme big day capable, but also 10-15mph light day capable, and 180mph DS capable. Pretty good all-rounder I reckon!

Here's a comparism of the MCT and GT weights:

MCT wing - 1215g     GT wing - 900g
MCT fuse -   325g      GT fuse - 300g
MCT tail    - 90g         GT tail    - 62g

This reduction in the weight of the tails, with the moment ratio around the CG, means that the GT will take 73g less nose weight to balance than the MCT, as the bare fuselages still balance at the same point.

The total weight saving between the two is 440g. An MCT builds up to around 2.5kg (5.5lb) which means that the GT should build up to slightly less than 2.1kg (4lb 9oz) i.e. almost 20% lighter than an MCT.

I think this one will turn out to be a great model!

Zim

I STILL cling steadfastly to my theory that there is something terribly wrong with glider makers, in that their heavier versions are carbon, and their lighter versions are glass layup .

Point 1: Carbon fibre is stronger than glass fibre, weight-for-weight (generally; I'm not going to get into shear and compressive and all that science, I'm just generalising).

Point 2: With a glass lay-up, you need to use enough fibre (and resin) to give sufficient strength.

Point 3: If you use carbon, you can use it's inherent strength to sustantially reduce the total amount of fibre (and resin) in your lay-up (to get the same strength as above).

Point 4:  For the same strength of final product, your glass lay-up will therefore be heavier than your carbon lay-up.

To my knowledge, the above applies in composite products throughout other sports and uses.  A typical example is windsurfing: the higher the percentage of carbon in the fibre mix of a mast or boom or whatever, the lighter (and stronger) the item.  A 100% carbon mast weighs a mere fraction of a 100% glass mast of the same stiffness and strength (of course, it's way more expensive, but you pay for a huge performance gain).   

SO, why the h*ll is it the other way around with gliders ?  It's completely ars* about face .

Guess you're right, Woodstock.

Only thing is, the majority seeking a carbon MCT are looking for both strength & weight, principally for DS.
And the weight is better built-in as structure than carried as lead/brass ballast.

Given a choice, I'd have something like double the carbon in my MCT wing, with the balsa spar fully boxed (balsa is exposed on it aft side, to servo bays!) & thicker skinned at least to the D-box.

Horses for courses!

Yes, I forgot this was the DS forum, where weight normally is a bonus.

 But, Zim was talking about the new GT in glass, and how much lighter it was, and that's what got me going (again )....

But you made a good point
And there are (quite a few) carbon planes made to your spec.

I've two non-Opus carbon planes  (names you're familiar with) which are fun front side, but their carbon fuselages in particular are a tissue-thin joke.
Although to be fair, the familiar stress fractures probably originate mostly from landings rather than airborne activity; and any beefing up just adds to those landing loads! 

So local reinforcement done: tho' the fuselages of both would have been better off carbon-kevlar socked over their wingroots during build.

Chris I think you're only partially correct. Let me explain. It basically just depends on the discipline. You are paying for performance, NOT the material.

For example - the Opus - if you don't want a 250mph capable Opus, but one that is more of an all-rounder, then you are essentially looking for a lower performance Opus. Would you pay more for this lighter version, lower performance version than the high performance Opus MCT? Of course not! Glider manufacturers aren't being daft - any fabric weights less than 200gsm are massively less expensive in glass, whereas with carbon the price goes up exponentially as the fabric gets lighter. For example, 200gsm carbon cloth - no problem to get this around £30/m. Try 65gsm carbon cloth - well then you're looking at £75+/m! So to make a model which isn't quite as strong, and is substantially lighter - given that it is clearly not worth more to the buyer due to the lower top end performance - you use glass fabrics as this gives you the ability to price the lighter model lower - in DS it's this way round.

However, take a look at F3J. You can buy a glass Perfect for a whole lot less than a spread tow carbon one. Surprise surprise, the carbon one is lighter. This is beause in F3J lightness mean HIGHER performance. But you still need the SAME strength from that lighter weight, so of course, you use carbon as you say.

You are paying for performance, rather than the cloth type. Having the lighter models made from glass not carbon is simply a reflection of the fact than when performance is not inextricably linked to lighter weight, the light weight carbon cloths simply make no commercial sense. However, when performance IS linked to lighter weight, you see these cloths used. RCRCM's Sigma II for example, offers a glass lay-up, a carbon layup (heavier cloth) and a special lightweight carbon layup, which costs a heck of a lot more due to the use of lightweight cloths. And it is roughly the same weight as the glass wings, but a whole lot stronger.

So they're not daft - just that there are different compromises for different reasons to be made in this sport than windsurfing I guess.

Cheers

Z

Doh.  I think your'e going to have to spell that out to me in words on one syllable, zim..

where light weight is needed expensive thin carbon is used.
Where weight is a good thing, they use thick cheeper carbon.

Thing is, gt is never going to go as mct, the wing will get bendy. the mct to my understanding does not break in the air. there is always the linkages or something else that fails before the air frame breaks, point heavier carbon will be much much much stronger than the glass version.

Doh.  I think your'e going to have to spell that out to me in words on one syllable, zim..

Forgetting fabric type for the moment:

In windsurfing, light = more performance = more expensive.

In DSing light = less performance (needs less strength) = less expensive.

In DSing heavy = more performance (needs more strength)= more expensive.

In F3J light = more performance = more expensive.


Where carbon is affected by this is that lightweight carbon cloth is MASSIVELY more expensive per metre than regular weight. For example, 200g carbon is less than half the price per metreof 93g carbon. Don't ever ask about 65g carbon - monster money.

So in DS if you're wanting to make a model which isn't laid up to go to 300mph, then you're not making a model which justifies a high price tag and it doesn't need to be as strong either. and if you use those light weight carbon cloths you WILL have a high price tag! So you make it from glass - no you don't make it quite as light as if you made it from carbon, but it's the right price (and weight) for its purpose.

In F3J however, light = high performance, so people will pay more for a lighter model, and this is where those high priced lighter carbon cloths get used, just the same as windsurfing.

So the glider manufacturers don't have it wrong - they are just faced with different compromises than your windsurfing guys.  

Z

OK, unfortunately the first two categories aren't really of personal interest, as I don't have DS planes (I know this is the DS forum, my apologies ). 

In my world light = better performance (always)(as long as strength is not compromised).  Across the board, the norm still is that the carbon versions of the type of planes I'm interested in are heavier (AND more expensive) than the glass versions.  The only exception I can think of is my Voltij: all carbon version, and it's light.. 

Are you saying that there are carbon F3J planes out there that are lighter than their glass counterparts?  If so, that would be news to me, and that would then put my original concern completely to rest.

To add one final point Chris, when I was working with Pryde the big reason for '100%" carbon was always the reflex response, NOT the weight saving. I tested a few rigs they'd made and saw the difference. A carbon mast always felt more alive. I was luckier than most being given unlimited amounts of new carbon kit to test and destroy.
Board weights could be amazing then we had the spate of discoveries that most riders coouldnt cope with with boards under a certain weight and then when kitesurfing came round we found that handling and releasing flex was more important than stiffness. This may impact on DS at somepoint..
Wanna buy a seriously cool McCulloch 137 directional?

OK, unfortunately the first two categories aren't really of personal interest, as I don't have DS planes (I know this is the DS forum, my apologies ). 

In my world light = better performance (always)(as long as strength is not compromised).  Across the board, the norm still is that the carbon versions of the type of planes I'm interested in are heavier (AND more expensive) than the glass versions.  The only exception I can think of is my Voltij: all carbon version, and it's light.. 

Are you saying that there are carbon F3J planes out there that are lighter than their glass counterparts?  If so, that would be news to me, and that would then put my original concern completely to rest.

Pike Perfect 65 Carbon and Pike Perfect Spread Tow (even lighter). Spread tow takes less resin to wet out as there are less voids created between the warps and the wefts as there are less of them per square metre, hence the weight saving, whilst maintaining the same number of fibres per sq metre.

But I disagree that light always = better performance for most slope flying. Sometimes yes, sometimes no. Otherwise why would we ever need ballast?

Z

I must be preaching to the converted here Zim:  your'e the man with all the theory sewn up !

You probably know that ballast has the advantage that it is used only when we need it, so a light frame has good light air performance, but can also be ballasted for heavy air.  It is also located right on the centre of the plane.  A heavy overall build has weight all over the shop, which has various unwanted pendulum effects.

That said, my Vikos for instance has pretty heavy (and therefore strong) wings, and I have to admit that any pendulum effects are not noticable in flight (to me anyway):  it has very sensitive roll response..  The weight does, however, limit it's use for light air: it doesn't do that well.

It's a tricky one. I don't really have the answer. The light wings thing regarding pendulum effects - I don't know where the ideal lies. Whilst a heavy wing may well have a pendulum effect, there is also the argument that it will be bumped off course less in turbulent conditions because of those heavy wings. But once knocked, they may need more correction. I think for DS where turbulence is an inalterable fact, wings with a bit of momentum to them are always good. I guess for F3J and superlight air you WANT to see those bumps and wings getting knocked gently, as this could indicate thermic activity.

I guess it all should always boil down to how it feels to the pilot, simple as that. For example, the Wizard F3F is very non-vogue in the sense that the EMPTY airframe weighs 2.7kg but it really does not seem to suffer from that at all. My RaceM at 2.6kg empty is fantastic in light air - even almost dead air, as you've seen it on the Lawley.

Oh and also pretty good in DS with 5 slugs in on Saturday 

Z

Hey, I love the wizard f3f, but its no light weight with its 95oz of ballast.would be interesting to ds it.its been to long a gap i will ds again this year.
Scott

Hey, I love the wizard f3f, but its no light weight with its 95oz of ballast.would be interesting to ds it.its been to long a gap i will ds again this year.
Scott

steady scotty the tail,s blow of at around 150mph