DERIVATIVE, New 2X2
#76
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RE: DERIVATIVE, New 2X2
ORIGINAL: cmoulder
Matt,
Simply amazing things you are doing here. Looks very solid and light at the same time. Not without a lot of effort and thought on your part, for sure. Bravo!
Matt,
Simply amazing things you are doing here. Looks very solid and light at the same time. Not without a lot of effort and thought on your part, for sure. Bravo!
The idea is to pass on knowledge and knowhow. To me, that's the main purpose of having the forum in the first place. Folks have forgotten that was the original purpose of the WWW, being used amongst the scientific community.
BTW- Part-All is magic stuff as release agents go. Only needs two coats and a light polish
#78
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RE: DERIVATIVE, New 2X2
A piece of fanfold shaped to serve as the pipe floor. Glassed and vacuum packed; worked out rather well.
Actually, fanfold stock will be sliced with a hot wire, sealed and used in fuse construction just like Herex. Haven't done it yet but I will to see how strong. The pipe floor was a good first step
Actually, fanfold stock will be sliced with a hot wire, sealed and used in fuse construction just like Herex. Haven't done it yet but I will to see how strong. The pipe floor was a good first step
#79
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RE: DERIVATIVE, New 2X2
A photo of it in situ would be nice. I can't quite picture it.
From my very little experience with the ES pipe, it seems to me that the pipe tunnel separator/insulator doesn't require a very robust material as long as the airflow through the tunnel is adequate.
From my very little experience with the ES pipe, it seems to me that the pipe tunnel separator/insulator doesn't require a very robust material as long as the airflow through the tunnel is adequate.
#80
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RE: DERIVATIVE, New 2X2
ORIGINAL: cmoulder
A photo of it in situ would be nice. I can't quite picture it.
From my very little experience with the ES pipe, it seems to me that the pipe tunnel separator/insulator doesn't require a very robust material as long as the airflow through the tunnel is adequate.
A photo of it in situ would be nice. I can't quite picture it.
From my very little experience with the ES pipe, it seems to me that the pipe tunnel separator/insulator doesn't require a very robust material as long as the airflow through the tunnel is adequate.
When completing my Aesthesis fuse, the pipe floor that was used (glassed balsa) weighed 3-4X as much (about 75 grams) as the glassed foam does (20 grams)
#81
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RE: DERIVATIVE, New 2X2
ORIGINAL: MTK
I'll take a couple snaps tonight and post. I think the foam will work out well for noise too. It's similar to 2mm depron without the paper, but sealed with the glass on the pipe side. Turns out this stuff is very resilient
When completing my Aesthesis fuse, the pipe floor that was used (glassed balsa) weighed 3-4X as much (about 75 grams) as the glassed foam does (20 grams)
I'll take a couple snaps tonight and post. I think the foam will work out well for noise too. It's similar to 2mm depron without the paper, but sealed with the glass on the pipe side. Turns out this stuff is very resilient
When completing my Aesthesis fuse, the pipe floor that was used (glassed balsa) weighed 3-4X as much (about 75 grams) as the glassed foam does (20 grams)
#83
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RE: DERIVATIVE, New 2X2
Made significant progress on Delta over the last couple weeks. Here are some pics.
The way I build wings and stabs is to first set the foam up with it's socket before sheeting. Socket installation uses subspars that surround the sockets and extend to the sheeting. This technique forms an "I" beam structure and is much stronger and actually lighter than other popular techniques such as false ribs at the ends of sockets. This enables the use of lighter materials elsewhere in wing or stab construction
The way I build wings and stabs is to first set the foam up with it's socket before sheeting. Socket installation uses subspars that surround the sockets and extend to the sheeting. This technique forms an "I" beam structure and is much stronger and actually lighter than other popular techniques such as false ribs at the ends of sockets. This enables the use of lighter materials elsewhere in wing or stab construction
#84
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RE: DERIVATIVE, New 2X2
The sheeting is 1/32" sanded and measured with calipers to assure the lightest possible structure that has adequate strength and stiffness. Carbon veil under the skins improves stiffness. Epoxy is used.
The easiest way to set up a vacuum bag is to turn it inside out and install the breather stock. I usually use paper towels for breather but I had some felt fabric on hand from lining a wing case so i used that instead this time around. The pink plastic is perforated anti stick film.
The seals were purchased from ACP. The vacuum adapter from AS&S. ACP also sells vacuum adapters but at 50$ each they are pricy. Aircraft Spruce sells a larger adapter for around 7.50$ so I bought a pair and cut then down. Works great
The easiest way to set up a vacuum bag is to turn it inside out and install the breather stock. I usually use paper towels for breather but I had some felt fabric on hand from lining a wing case so i used that instead this time around. The pink plastic is perforated anti stick film.
The seals were purchased from ACP. The vacuum adapter from AS&S. ACP also sells vacuum adapters but at 50$ each they are pricy. Aircraft Spruce sells a larger adapter for around 7.50$ so I bought a pair and cut then down. Works great
#85
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RE: DERIVATIVE, New 2X2
Matt,
Sorry I haven't checked on your progress lately - what a lot you've gotten done!!
The pipe tunnel separator looks great! Very light and functional, however it looks as if the pipe is going to be tough to access.
I see the lord mount on the front neck of the pipe... how are you securing the "stinger" tail?
Hard to believe you got a 55cc completely under the hood of that cowl with only a little header sticking out. I guess that with the soft mount the finished header cutout will have to be a little bigger.
I like the way you did the wing tube socket. Looks much stronger having contact all along the socket. That looks like a thinner airfoil compared to most these days.
Sorry I haven't checked on your progress lately - what a lot you've gotten done!!
The pipe tunnel separator looks great! Very light and functional, however it looks as if the pipe is going to be tough to access.
I see the lord mount on the front neck of the pipe... how are you securing the "stinger" tail?
Hard to believe you got a 55cc completely under the hood of that cowl with only a little header sticking out. I guess that with the soft mount the finished header cutout will have to be a little bigger.
I like the way you did the wing tube socket. Looks much stronger having contact all along the socket. That looks like a thinner airfoil compared to most these days.
#86
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Thread Starter
RE: DERIVATIVE, New 2X2
ORIGINAL: cmoulder
Matt,
Sorry I haven't checked on your progress lately - what a lot you've gotten done!!
The pipe tunnel separator looks great! Very light and functional, however it looks as if the pipe is going to be tough to access.
I see the lord mount on the front neck of the pipe... how are you securing the ''stinger'' tail?
Hard to believe you got a 55cc completely under the hood of that cowl with only a little header sticking out. I guess that with the soft mount the finished header cutout will have to be a little bigger.
I like the way you did the wing tube socket. Looks much stronger having contact all along the socket. That looks like a thinner airfoil compared to most these days.
Matt,
Sorry I haven't checked on your progress lately - what a lot you've gotten done!!
The pipe tunnel separator looks great! Very light and functional, however it looks as if the pipe is going to be tough to access.
I see the lord mount on the front neck of the pipe... how are you securing the ''stinger'' tail?
Hard to believe you got a 55cc completely under the hood of that cowl with only a little header sticking out. I guess that with the soft mount the finished header cutout will have to be a little bigger.
I like the way you did the wing tube socket. Looks much stronger having contact all along the socket. That looks like a thinner airfoil compared to most these days.
The pipe mount is at the approximate cg of the pipe. It is the only one used..... the pipe is never supported anywhere else in my soft mounted set-ups and is allowed freedom to oscillate. Carbon pipes survive well and headers don't break unless I screw something up. Such was the case with the very first header I built for the DLE....there was no flex in the header's goose neck and it broke at the flange. My current header is flexed at the gooseneck and has survived about 4 galons of flying. The header was purchased from DA. The Teflon tape covering the gooseneck doesn't survive the exhaust. But I've devised a better alternative to teflon tape which survives much much better. I started using that same technique to couple header and pipe and it is working well so far
It's a stab actually. The section is 9% at the root and tip with area of 260 square inches. Weight including the carbon tube is 3.6 ounces. That's the same as a 500 square inch wing panel weighing 7 ounces which is where mine usually come out before finish
The header will be concealed at the chin cowl. I don't like exposing any parts of the nose if I can avoid it.....
#87
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RE: DERIVATIVE, New 2X2
ORIGINAL: MTK
I'll take a couple snaps tonight and post. I think the foam will work out well for noise too. It's similar to 2mm depron without the paper, but sealed with the glass on the pipe side. Turns out this stuff is very resilient
When completing my Aesthesis fuse, the pipe floor that was used (glassed balsa) weighed 3-4X as much (about 75 grams) as the glassed foam does (20 grams)
ORIGINAL: cmoulder
A photo of it in situ would be nice. I can't quite picture it.
From my very little experience with the ES pipe, it seems to me that the pipe tunnel separator/insulator doesn't require a very robust material as long as the airflow through the tunnel is adequate.
A photo of it in situ would be nice. I can't quite picture it.
From my very little experience with the ES pipe, it seems to me that the pipe tunnel separator/insulator doesn't require a very robust material as long as the airflow through the tunnel is adequate.
When completing my Aesthesis fuse, the pipe floor that was used (glassed balsa) weighed 3-4X as much (about 75 grams) as the glassed foam does (20 grams)
#88
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RE: DERIVATIVE, New 2X2
ORIGINAL: MarkGrabowski
Uh, I'm having a brain freeze.... what is this 'fanfold' material you are using?
Uh, I'm having a brain freeze.... what is this 'fanfold' material you are using?
I have the stab set in the fuse. I will post a few snaps tonight. My fixture is a simple piece of 1/16" lexan. I will explain more with the photos.
BTW - I always set the stab first to make certain it is square to the fin; then align the wing to the stab. It is the easiest way to do alignment of this type
#89
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RE: DERIVATIVE, New 2X2
ORIGINAL: MTK
Foam, blue or pink; Home Depot....
I have the stab set in the fuse. I will post a few snaps tonight. My fixture is a simple piece of 1/16'' lexan. I will explain more with the photos.
BTW - I always set the stab first to make certain it is square to the fin; then align the wing to the stab. It is the easiest way to do alignment of this type
ORIGINAL: MarkGrabowski
Uh, I'm having a brain freeze.... what is this 'fanfold' material you are using?
Uh, I'm having a brain freeze.... what is this 'fanfold' material you are using?
I have the stab set in the fuse. I will post a few snaps tonight. My fixture is a simple piece of 1/16'' lexan. I will explain more with the photos.
BTW - I always set the stab first to make certain it is square to the fin; then align the wing to the stab. It is the easiest way to do alignment of this type
Mind sharing what weight glass you used in this layup
#90
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RE: DERIVATIVE, New 2X2
ORIGINAL: MarkGrabowski
Matt, how thick is this fanfold layup you're using? I'm surprised it's stiff enough for flooring useage
Mind sharing what weight glass you used in this layup
Matt, how thick is this fanfold layup you're using? I'm surprised it's stiff enough for flooring useage
Mind sharing what weight glass you used in this layup
The structural component will be the one piece servo tray that will essentially cover the whole canopy area. I will be laminating honeycomb stock for that job. The wing tube socket will be attached to the servo tray producing a monocque structure. My expectation is that this model will fly for 2000 flights just like my last one, unless I dumb thumb it; with the DLE55 up front
#91
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Thread Starter
RE: DERIVATIVE, New 2X2
ORIGINAL: MTK
I have the stab set in the fuse. I will post a few snaps tonight. My fixture is a simple piece of 1/16'' lexan. I will explain more with the photos.
BTW - I always set the stab first to make certain it is square to the fin; then align the wing to the stab. It is the easiest way to do alignment of this type
I have the stab set in the fuse. I will post a few snaps tonight. My fixture is a simple piece of 1/16'' lexan. I will explain more with the photos.
BTW - I always set the stab first to make certain it is square to the fin; then align the wing to the stab. It is the easiest way to do alignment of this type
I have another where I've drawn several horizontal lines to help align the anhedral stab on Aesthesis a couple years ago. Worked as expected. The stab support crutch inside the fuse is lite ply. It extends 12 1/2" from rudder post forward, past the front base of the fin to provide much needed strength in this routinely weak area in most composite fuses.
Here's a simple way to make your own stab adjusters. I started with a short section of phenolic stock, 1/4" ID by 3/4" OD. Cut the sides, drilled and tapped for 6-32 set screws and voila. It took all of maybe 15 minutes to shape the pair. Each weighs next to nothing (2 grams). Gorilla glued in place
#92
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RE: DERIVATIVE, New 2X2
Matt, Excellent work! It seems you are nearing the finish line on this project.
Looking forward with great anticipation to seeing the final result - hopefully this summer!
Looking forward with great anticipation to seeing the final result - hopefully this summer!
#93
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RE: DERIVATIVE, New 2X2
ORIGINAL: cmoulder
Matt, Excellent work! It seems you are nearing the finish line on this project.
Looking forward with great anticipation to seeing the final result - hopefully this summer!
Matt, Excellent work! It seems you are nearing the finish line on this project.
Looking forward with great anticipation to seeing the final result - hopefully this summer!
Anyway, Stab weight plus elevator to this point is 54 grams per side, 1.9 ozs. I'll detail the covering next where I will be doing a different technique than the norm. All glass of course
#94
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RE: DERIVATIVE, New 2X2
Here's a different technique for glassing skins.
Prep the balsa with a fine sanding as though you were going to cover "normally".
Seal the balsa with nitrate, hair spray etc. I used hairspray this time.
Prepare 015 thick mylar skins; cut the skins very close to the surface perimeter. I left 2mm margin all around
You may wax the inside of the skins. It isn't absolutely necessary but if you want to make certain of release, wax
Spray the inside of the mular with primer. Or alternately, paint may be used. I used KlassKote epoxy primer, 2 light coats, and let it cure
Apply the fiberglass, carbon veil, silkspan or whatever reinforcing stock you like. I used 0.6 oz glass cloth
Apply the epoxy. I used Pro Set 125 resin 229 sloooooww hardener. A a 1" brush and a foam roller work great
Cover the stab, wing, rudder. etc. I used blue masking tape to hold the mylar in the right place
Place in vacuum bag and draw vacuum. I used about 8" Hg negative or about 200 mm Hg vacuum. About 4 psi neg
Prep the balsa with a fine sanding as though you were going to cover "normally".
Seal the balsa with nitrate, hair spray etc. I used hairspray this time.
Prepare 015 thick mylar skins; cut the skins very close to the surface perimeter. I left 2mm margin all around
You may wax the inside of the skins. It isn't absolutely necessary but if you want to make certain of release, wax
Spray the inside of the mular with primer. Or alternately, paint may be used. I used KlassKote epoxy primer, 2 light coats, and let it cure
Apply the fiberglass, carbon veil, silkspan or whatever reinforcing stock you like. I used 0.6 oz glass cloth
Apply the epoxy. I used Pro Set 125 resin 229 sloooooww hardener. A a 1" brush and a foam roller work great
Cover the stab, wing, rudder. etc. I used blue masking tape to hold the mylar in the right place
Place in vacuum bag and draw vacuum. I used about 8" Hg negative or about 200 mm Hg vacuum. About 4 psi neg
#96
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RE: DERIVATIVE, New 2X2
ORIGINAL: Rendegade
Wow, you've taken the idea I was planning to try and tried it.
Well done, the finish looks superb.
Wow, you've taken the idea I was planning to try and tried it.
Well done, the finish looks superb.
I tried the technique on a rudder many years ago and the result was a heavier part than I wanted. I had not used the foam roller on the rudder and left too much epoxy behind. The foam roller provides for much more even and very thin coverage. Using epoxy paint will probably work well too, but I have not tried that yet. Renegade when you try this approach, why not try epoxy paint and report back?
Each stab half picks up the minimum weight, around 3 grams for the glass cloth and around 6 grams for the epoxy. The only other variable is the primer. I'll see what the final pick up was when I remove from the vac pac. A guy I know tried the approach without a vac pac (he used lead shot bags) and his results were somewhat variable. A vac pac makes this job straight forward
#97
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RE: DERIVATIVE, New 2X2
Had a problem with my epoxy cure....DRAT!!! Experienced a set-back last night....
Comes with the territory of driving on unchartered roads. When you are trailblazing, sometimes the trail gets you and sometimes the blaze
Comes with the territory of driving on unchartered roads. When you are trailblazing, sometimes the trail gets you and sometimes the blaze
#98
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RE: DERIVATIVE, New 2X2
Just left things alone for a few days to figure out how to salvage the stabs. The epoxy cured more fully and was able to remove the mylar from one panel with minimal damage to the surface. The other panel was damaged substantially but I managed to salvage that panel also. Had to refinish part of that sheeting on one panel.
More importantly, the key lesson learned was that the mylar and the epoxy paint I used (KlassKote primer) had to be more compatible with one another. The mylar prep simply was not sufficient. I opted not to spray PVA on the waxed mylar sheet before spraying the epoxy paint (primer), a mistake.... Spraying paint first on the cover requires PVA barrier for best results. Knew that of course but rushed myself...dumb!!
Since then I acquired teflon sheeting for the wings and rudder. Teflon is bullet proof.
I also completed the landing gear strut build for the plane and am in process of fitting. I'll post pics of the gear detail soon
More importantly, the key lesson learned was that the mylar and the epoxy paint I used (KlassKote primer) had to be more compatible with one another. The mylar prep simply was not sufficient. I opted not to spray PVA on the waxed mylar sheet before spraying the epoxy paint (primer), a mistake.... Spraying paint first on the cover requires PVA barrier for best results. Knew that of course but rushed myself...dumb!!
Since then I acquired teflon sheeting for the wings and rudder. Teflon is bullet proof.
I also completed the landing gear strut build for the plane and am in process of fitting. I'll post pics of the gear detail soon
#100
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RE: DERIVATIVE, New 2X2
ORIGINAL: speedracerntrixie
Matt, did the mylar not release?
Matt, did the mylar not release?
My landing gear clam shell molds are teflon lined. These work perfectly; no additional prep required