40% Turbo Laser (scratch built)

[jaguar bone]

	Quote: Originally Posted by forgues research
	WOW I didn't realise how little weight saved for such a large amount of money, thanks for the info. Roger

Something tells me you did.

[jack strickland]

	Quote: Originally Posted by Tony Hallo
	Aircraft Spruce site shows 1 1/2" x .049" tube weights in at .268 lb/ft while TBM states their 1 1/2" x .062" weights 12 ounces, that's almost 5 ounce savings at a premium of $60. TBM states a savings of up to 9 ounces although the facts don't produce the same result? The net saving cost about $12 per ounce or $200 per pound.

Hello Tony
Im a little confused . Does TBM state their tube is 12 oz. per foot? Are you talking about a carbon fibre tube from TBM? A savings odf 9 oz. for what? Please enlighten me.
Thanks

[askforplanes]

TBM states that the wing tube (1.5" x 48" .062" wall (Heavy wall)) weighs 12oz total - http://www.troybuiltmodels.com/ns/ac...s/carbonfiber/

Hope this helps,

JP

[forgues research]

	Quote: Originally Posted by jaguar bone
	Something tells me you did.

Really I didnt' know, but I am not too fond of carbon fibre, mostly with landing gears, they are too stiff with no spring effect.

Roger

[brusty]

Hi Roger,

I agree Carbon Fibre U/C can be stiff, but I think that has a lot to do with the thickness design. I find if the lower legs are not progressively tapered (both in thickness and profile), which seems to induce the spring effect, then yes they are very stiff and all the shock comes on to that top bend out of the Fuz. If anything gives, thats where you are liable to get a delamination fracture. It is surprising how much the lower leg can be tapered and thinned, and as long as your layup is well wetted out, and preferrably vacuumed either over or into a mold, then there can be a good springing effect, from the progressively tapered layup.

I'm sure the quality of the layup has a big effect, too much resin and it becomes brittle, not enough and you face delamination. I like to get the cloth and Uni well wetted out and then suck the excess resin out with paper towels in a pre-bagging and the results seem to speak for themselves.

Very interested in your foam rib wing construction method, its one I've not tried to date... but one never stops learning aye ? Most enlightening thankyou. Regards, B.

[forgues research]

	Quote: Originally Posted by brusty
	Hi Roger, I agree Carbon Fibre U/C can be stiff, but I think that has a lot to do with the thickness design. I find if the lower legs are not progressively tapered (both in thickness and profile), which seems to induce the spring effect, then yes they are very stiff and all the shock comes on to that top bend out of the Fuz. If anything gives, thats where you are liable to get a delamination fracture. It is surprising how much the lower leg can be tapered and thinned, and as long as your layup is well wetted out, and preferrably vacuumed either over or into a mold, then there can be a good springing effect, from the progressively tapered layup. I'm sure the quality of the layup has a big effect, too much resin and it becomes brittle, not enough and you face delamination. I like to get the cloth and Uni well wetted out and then suck the excess resin out with paper towels in a pre-bagging and the results seem to speak for themselves. Very interested in your foam rib wing construction method, its one I've not tried to date... but one never stops learning aye ? Most enlightening thankyou. Regards, B.

Hi Barrie,
You are probably right about the landing gear using carbon fiber, its all in the manufacturing process.
My buddy has a composite arf Yak and as you know the landing gear is round and carbon fiber, well, not too good and we replaced it with aluminum one piece.

I like the foam wing appoach for its simplicity, ease of construction, sturdiness and lightness.

As you can see in some photos, before applying the top sheeting, is the time to install the innards such as servo plate , socket, and I will be cutting the hole to layout the servo wires.

Roger

[jack strickland]

	Quote: Originally Posted by brusty
	Hi Roger, I agree Carbon Fibre U/C can be stiff, but I think that has a lot to do with the thickness design. I find if the lower legs are not progressively tapered (both in thickness and profile), which seems to induce the spring effect, then yes they are very stiff and all the shock comes on to that top bend out of the Fuz. If anything gives, thats where you are liable to get a delamination fracture. It is surprising how much the lower leg can be tapered and thinned, and as long as your layup is well wetted out, and preferrably vacuumed either over or into a mold, then there can be a good springing effect, from the progressively tapered layup. I'm sure the quality of the layup has a big effect, too much resin and it becomes brittle, not enough and you face delamination. I like to get the cloth and Uni well wetted out and then suck the excess resin out with paper towels in a pre-bagging and the results seem to speak for themselves. Very interested in your foam rib wing construction method, its one I've not tried to date... but one never stops learning aye ? Most enlightening thankyou. Regards, B.

Hello B
One thing I do not care for with carbon fibre anything is the epoxy they use for layup. I don't know what heat range epoxy they use. Maybe someone that likes carbon fibre products could inquire about this. Personally, epoxy is not used in any of my planes.

[forgues research]

Just about finished the interior of the wing before sheeting the top.

Here using a 5/8 aluminum tubing which I sharpened one end I twisted it on the foam ribs from the root to the servo bay , very easy to do. then I rolled a piece of paper the proper lenght and inserted it in this hole and added a dab of white glue at each rib . This of course is to be able to slide in and out the servo wires , or in this case the servo power wire with the fiber Optic signal cable.

I know there are some light tubes outhere for this but none near me so I made them , and its so easy to do, not even worth purchasing the ready made units,

Roger

[McFueler]

Looking good !

[brusty]

	Quote: Originally Posted by jack strickland
	Hello B One thing I do not care for with carbon fibre anything is the epoxy they use for layup. I don't know what heat range epoxy they use. Maybe someone that likes carbon fibre products could inquire about this. Personally, epoxy is not used in any of my planes.

Hi Jack, Don't know the exact temps, but it doesn't get hot enought here in NZ to bother it. My aircraft are mostly epoxy/composite/ carbon and glass. I guess I've sort of grown into this newer technology, but then I'm a lot younger than you (Just kidding). I take it you prefer to use polyester products, I've not a lot of experience there in using them for layups, only in making molds. I did try a Decathane ?? not sure of the name, I think it was a vinyl ester for making a carbon molded tuned pipe, that worked. I initially tried it in epoxy, and it sortta melted !!

Yes Roger, those round carbon tubes on the yak must be like solid pogo sticks, there would be no cushioning there, wouldn't suit my landings !! Also, what is the pink foam you are using, is that the grade lighter than the blue foam we get here ? and lastly, what thickness are you cutting those wing ribs ? Cheers, Barrie.

[jack strickland]

	Quote: Originally Posted by brusty
	Hi Jack, Don't know the exact temps, but it doesn't get hot enought here in NZ to bother it. My aircraft are mostly epoxy/composite/ carbon and glass. I guess I've sort of grown into this newer technology, but then I'm a lot younger than you (Just kidding). I take it you prefer to use polyester products, I've not a lot of experience there in using them for layups, only in making molds. I did try a Decathane ?? not sure of the name, I think it was a vinyl ester for making a carbon molded tuned pipe, that worked. I initially tried it in epoxy, and it sortta melted !! Yes Roger, those round carbon tubes on the yak must be like solid pogo sticks, there would be no cushioning there, wouldn't suit my landings !! Also, what is the pink foam you are using, is that the grade lighter than the blue foam we get here ? and lastly, what thickness are you cutting those wing ribs ? Cheers, Barrie.

Hi Barrie
Beautiful plane in your avitar. I use epoxy for cowls and pants, and have used polyester from time to time, not all that much though. You surely do have great weather, have kept up with the weather there over the years because it is my dream to live down under someday, but time caught up with me. Also think you folks are really a lot more friendly than us yanks.
Regards
Jack

[forgues research]

	Quote: Originally Posted by brusty
	Hi Jack, Don't know the exact temps, but it doesn't get hot enought here in NZ to bother it. My aircraft are mostly epoxy/composite/ carbon and glass. I guess I've sort of grown into this newer technology, but then I'm a lot younger than you (Just kidding). I take it you prefer to use polyester products, I've not a lot of experience there in using them for layups, only in making molds. I did try a Decathane ?? not sure of the name, I think it was a vinyl ester for making a carbon molded tuned pipe, that worked. I initially tried it in epoxy, and it sortta melted !! Yes Roger, those round carbon tubes on the yak must be like solid pogo sticks, there would be no cushioning there, wouldn't suit my landings !! Also, what is the pink foam you are using, is that the grade lighter than the blue foam we get here ? and lastly, what thickness are you cutting those wing ribs ? Cheers, Barrie.

Hi Barrie,
The pink foam is the same as the blue foam , at least in canada. but from different manufacturers.

I purchase the half inch foam to make the ribs...

Roger

[brusty]

	Quote: Originally Posted by jack strickland
	Hi Barrie Beautiful plane in your avitar. I use epoxy for cowls and pants, and have used polyester from time to time, not all that much though. You surely do have great weather, have kept up with the weather there over the years because it is my dream to live down under someday, but time caught up with me. Also think you folks are really a lot more friendly than us yanks. Regards Jack

Nice comments thank you Jack. Gotta say when travelling your country, we have found the "Yanks" ultra friendly. Have a great mate in SC who just stopped and picked Allison and self up from the side of the road in Oshkosh back in the last century, missed the last bus out of town and 102 degrees at 6.00pm and walking ! He's currently building a plane, a Titan Mustang T-51. Been most interesting watching the full size build. I'm part way into a 106 inch copy of it.

Keep up the good work chaps, watching with great interest. B.

[forgues research]

Inspiration of the day!

First they ignore you, then they laugh at you, then they fight you, then you win.
- Mahatma Gandhi

[mmikeny]

hi roger
i have been following the thread and am building the 34% from jacks plans i hope you wouldnt mind if i ask you a couple of questions
is it ok to cut a slot in the root rib and the end tube fixture to use the hot wire to cut the wing tube socket
and could you explain how the 1/64 plywood goes at the trailing edge to stiffen the wing
i have built many planes but never from just plans and i plan on building the 40% right after i finish this one so thanks for the thread and any answers you have
thanks mike