I made a new fuselage for the easystar to get more room for payload. This proto is made in 2 layers of carbonfiber. The carbonfiber is very easy to work with, so if any one out there like to make some modifications just go for it.I got the carbonfiber from hereThe weight of the T-REX fuselage is about 140g = 4.93 ounces - still need to make the inner fuselage so the fuselage can be fasten to the body and still be removerable. Think the whole carbonfiber fuselage will be about 160g = 5.64 ounces.
Mike,
I Like the Idea of adding a "spacer" sheet of foam to increase the fuse width. What a great idea, Maybe you could fashion an interlocking puzzle piece to hold the wings together. Not to stray too much on this thread but I assume most people fly a foamy for its durability and protection of the equipment. I first started out with balsa built up planes (as a kid) moved on to composites and now almost always use epp foam. In my mind there is no substitute in the "forgiveness factor" that a foam provides. I love teaching people to fly RC with my Epp/Coroplast polyhedral trainer. When they inevitable nose it in, Just pick up the pieces and reassemble it and jive it a toss back into the air. Combining the two materials, not sure of the advantages. Kinda hard to avoid a stress riser.
As for the carbon fibre, I think there is a market for that too, If the carbon piece was more like a canopy, just faired in the upper half of the fuse, then it could be lightweight and flexible to some degree. That is what I use on my flyingwings, otherwise I would go with a full CF pod with a CF tube tail boom but I see that as perhaps for the more advanced user (with lots of open space).
Wendi has a good point about safety, I would feel uncomfortable fly a CF model around a populated area (overflights) but I live in a pretty dense area and that is probably not the norm for everyone on here. I've only hit one person with a plane before ;) he walked right into the marked landing zone and I nailed him with my 6' wing. Knocked him off his feet and he did not get up right away! thought I killed him. He was o.k. though, If the plane was CF I think the injuries would have been more severe. (no, I did not get sued, he was a tourist ;)
An neat way to moderately increase the volume in an EZ* is to make a foma sandwich. A 10-20mm (15mm is probably optimum) thick sheet of foam can be glued between the two halves of the fuselage making it wider by the corresponding thickness.
Immediately behind the wings the foam sheet should be tapered to nothing by the time it gets 1/2 to 3/4 of the way down the tail boom so that the tail section goes together as originally designed.
The wings don't lock together as designed so you may want to add some additional security.
No Hooks, I'm not. I don't make jokes over serious matters. It's the typical fracture behaviour pattern of carbon fibre. You will be surprised how little impact force will shatter a thin CA shell. One of the first thing I learned when we started to work with that material in the 80s. Watch out for small splinters when you work with that stuff; they can cause nasty inflammations.
The carbon laminate starter kit costs £ 39.10 ~ Euro 43.- at carbon mods in the UK. I think that's quite stiff.
If you go to R&G in Germany you pay a lot less for a lot more :-), well let's say around half the price and for carbon there are even cheaper sources available.
But here is something else which I think is important and should be considered when you change the design and material of a well made plane: the original advantages and beneficial features of the design should not be altered to the detriment of the usability and versitality.
Carbon fibre composite is a fantastic material when used appropriately. You should use it if you need the strength and high modul of elasticity (rigidety).
Material change on an airframe must be carefully considered so as not to create areas of high stress where there have been none originally.
Both of these design principles unfortunately (and probably unintentionally) have been violated in case of this EZ.
One of the biggest advantages of the original EZ (by all accounts given in various group postings) is it's ability to absorb damage by crumbeling foam - specially at the front end. EZ will not (substantially) injure people or property when contact is made because the material and the design affords a great deal of energy dissipation.
A thin carbon shell will not give on impact but shatter into dangerous fragments with needle sharp edges and a very high risk of serious injury.
From a safety point of view and insurance considerations such a design should not be used on, what basically amounts to toys.
The user will also not be served positively, since the airframe will tend to break at the joint of the high rigidety part to the originally softer material.
I think the only way to enlarge the loading bay of the EZ is again to using foam material, perhaps covered with thin glass fabric applied not with Epoxy but WBL. You can create the same space for less money and preserve the positive aspects of the original design.
The fashionable "carbon look" must not be criterium to select this material - I think we are grown up rational people.
Comments
Foster
I Like the Idea of adding a "spacer" sheet of foam to increase the fuse width. What a great idea, Maybe you could fashion an interlocking puzzle piece to hold the wings together. Not to stray too much on this thread but I assume most people fly a foamy for its durability and protection of the equipment. I first started out with balsa built up planes (as a kid) moved on to composites and now almost always use epp foam. In my mind there is no substitute in the "forgiveness factor" that a foam provides. I love teaching people to fly RC with my Epp/Coroplast polyhedral trainer. When they inevitable nose it in, Just pick up the pieces and reassemble it and jive it a toss back into the air. Combining the two materials, not sure of the advantages. Kinda hard to avoid a stress riser.
As for the carbon fibre, I think there is a market for that too, If the carbon piece was more like a canopy, just faired in the upper half of the fuse, then it could be lightweight and flexible to some degree. That is what I use on my flyingwings, otherwise I would go with a full CF pod with a CF tube tail boom but I see that as perhaps for the more advanced user (with lots of open space).
Wendi has a good point about safety, I would feel uncomfortable fly a CF model around a populated area (overflights) but I live in a pretty dense area and that is probably not the norm for everyone on here. I've only hit one person with a plane before ;) he walked right into the marked landing zone and I nailed him with my 6' wing. Knocked him off his feet and he did not get up right away! thought I killed him. He was o.k. though, If the plane was CF I think the injuries would have been more severe. (no, I did not get sued, he was a tourist ;)
Immediately behind the wings the foam sheet should be tapered to nothing by the time it gets 1/2 to 3/4 of the way down the tail boom so that the tail section goes together as originally designed.
The wings don't lock together as designed so you may want to add some additional security.
all the best
W.
You must be kidding me...
I see some of points as good info, but I do not entirely agree on how you see things.
If you go to R&G in Germany you pay a lot less for a lot more :-), well let's say around half the price and for carbon there are even cheaper sources available.
But here is something else which I think is important and should be considered when you change the design and material of a well made plane: the original advantages and beneficial features of the design should not be altered to the detriment of the usability and versitality.
Carbon fibre composite is a fantastic material when used appropriately. You should use it if you need the strength and high modul of elasticity (rigidety).
Material change on an airframe must be carefully considered so as not to create areas of high stress where there have been none originally.
Both of these design principles unfortunately (and probably unintentionally) have been violated in case of this EZ.
One of the biggest advantages of the original EZ (by all accounts given in various group postings) is it's ability to absorb damage by crumbeling foam - specially at the front end. EZ will not (substantially) injure people or property when contact is made because the material and the design affords a great deal of energy dissipation.
A thin carbon shell will not give on impact but shatter into dangerous fragments with needle sharp edges and a very high risk of serious injury.
From a safety point of view and insurance considerations such a design should not be used on, what basically amounts to toys.
The user will also not be served positively, since the airframe will tend to break at the joint of the high rigidety part to the originally softer material.
I think the only way to enlarge the loading bay of the EZ is again to using foam material, perhaps covered with thin glass fabric applied not with Epoxy but WBL. You can create the same space for less money and preserve the positive aspects of the original design.
The fashionable "carbon look" must not be criterium to select this material - I think we are grown up rational people.
all the best and have fun - nevertheless
W.
Craig
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