FTFF 2017 92" Ryan NYP
- Thread starter Tench745
- Start date
Tench745
Master member
The struts have me a little concerned, but at this size it should be very forgiving of the weight required to make it work. I'm debating using actual burnished aluminum for the cowl. Depends how much I hate myself. A quick run of the numbers give me 1276 square inches of wing area. For a cubic wing loading of the original at flying weight (not fully loaded) of 8.1, that means it can weigh just under 13.5 pounds. I'm expecting half of that if I use all foam-core.
FAI-F1D
Free Flight Indoorist
This looks like a great project. I have a few suggestions which may or many not be of help.
There are dummy engines available for economical prices (meaning it could cost you more to make your own than to buy one). Worth considering...
A heavy steel wire undercarriage with foam fairings built around it would be simple and light (well, comparatively light). Appropriately installed with wood hard points and the like, it would also be very strong.
Consider another trick: you can make your own buy using 3M-77 to adhere aluminum foil to a foam cowling. A pencil eraser in a drill chuck can be used to create the burnished effect. There are some commercially available burnished coverings as well.
There are dummy engines available for economical prices (meaning it could cost you more to make your own than to buy one). Worth considering...
A heavy steel wire undercarriage with foam fairings built around it would be simple and light (well, comparatively light). Appropriately installed with wood hard points and the like, it would also be very strong.
Consider another trick: you can make your own buy using 3M-77 to adhere aluminum foil to a foam cowling. A pencil eraser in a drill chuck can be used to create the burnished effect. There are some commercially available burnished coverings as well.
All excellent points and worth your consideration. Good call Mr. Finn!
For a brushed aluminum finish, just cover with Aluminum tape! Here's my example on an FT Mustang: http://flitetest.com/articles/metal-mustang
Put the tape on the flat foam BEFORE folding/gluing and assembling!
To get the brushed/burnished look, just take a scotchbrite pad to it. It doesn't take much to knock the shine off. Bonus: The Al-tape takes rivet/panel line and other surface textures really well, making it really easy to add scale details. I "drew" panel lines by applying slight pressure with a flathead screwdriver, and the rivet-lines were rolled on with a tool called a "pouncing wheel".
Put the tape on the flat foam BEFORE folding/gluing and assembling!
To get the brushed/burnished look, just take a scotchbrite pad to it. It doesn't take much to knock the shine off. Bonus: The Al-tape takes rivet/panel line and other surface textures really well, making it really easy to add scale details. I "drew" panel lines by applying slight pressure with a flathead screwdriver, and the rivet-lines were rolled on with a tool called a "pouncing wheel".
Tench745
Master member
I'm familiar with Aluminum tape. We use it in the prop world to metalize things. I've got a roll down on my shelf. Impressive the amount of detail it can take when applied to foam though.
I am not concerned about weight on this build, and I also have a roll of aluminum roof-flashing on my shelf of goodies. I was planning to burnish it with a dowel in a drill press then apply it to the cowl in four pieces like on the full scale.
For the struts I had intended to use music wire with soldered on terminal ends like Wilsonman's Sikorsky build and build in 1/8" plywood hard-points to the fuse and wing.
Because I have no hotwire cutting facilities the wing will likely be a built-up wing with basswood spars.
FAI-F1D, What dummy engines are out there in 1/6 scale? I've only been able to find them by the cylinder for $6-$10 per cylinder. That's $54-$90 just for a fake J-5 radial...
The more I work on this the more I think I'm actually going to have to go through with it.
I have never built a plane this large, so advice on material sizing, etc would be appreciated.
I am not concerned about weight on this build, and I also have a roll of aluminum roof-flashing on my shelf of goodies. I was planning to burnish it with a dowel in a drill press then apply it to the cowl in four pieces like on the full scale.
For the struts I had intended to use music wire with soldered on terminal ends like Wilsonman's Sikorsky build and build in 1/8" plywood hard-points to the fuse and wing.
Because I have no hotwire cutting facilities the wing will likely be a built-up wing with basswood spars.
FAI-F1D, What dummy engines are out there in 1/6 scale? I've only been able to find them by the cylinder for $6-$10 per cylinder. That's $54-$90 just for a fake J-5 radial...
The more I work on this the more I think I'm actually going to have to go through with it.
I have never built a plane this large, so advice on material sizing, etc would be appreciated.
So, scale radials...
Give ParkFlyerPlastics.com a go but for a lot more scale fidelity you can always go with Williams Brothers. The problem is that the R-790 would be 7.5" in diameter at your scale. PFP does not have anything at that specific size and a general wasp engine could probably be modified to look more the part. Generally, the Wasp engines at that scale will be slightly oversize but that may be a small detail that you could give into. 8" diameter vs 7.5 will not be that big of a deal to the average person. The Williams Bothers kits are also fun because you can really dress them up. I used on my O1 Tummelisa and make valve springs from guitar strings, paint washes to makes it look dirty, and you can make spark plug wires that make it all come together to make a really nice first impression on the flight line.
Scaleaero also has a 1/6 scale too.
Give ParkFlyerPlastics.com a go but for a lot more scale fidelity you can always go with Williams Brothers. The problem is that the R-790 would be 7.5" in diameter at your scale. PFP does not have anything at that specific size and a general wasp engine could probably be modified to look more the part. Generally, the Wasp engines at that scale will be slightly oversize but that may be a small detail that you could give into. 8" diameter vs 7.5 will not be that big of a deal to the average person. The Williams Bothers kits are also fun because you can really dress them up. I used on my O1 Tummelisa and make valve springs from guitar strings, paint washes to makes it look dirty, and you can make spark plug wires that make it all come together to make a really nice first impression on the flight line.
Scaleaero also has a 1/6 scale too.
jim_buxton
New member
I was really considering a Spirit of (FliteFest), and spent some time thinking about it. I was concerned about huge wheels, but they only scale to about 5" diameter which would be manageable to turn on my lathe. The bracing on the wings and tail of the Spirit would also allow for a very light but strong airframe. I was thinking of making it a big slow-fly type. I envisioned using the foam for the wings in the 30" direction, with the center 30" being fixed to the fuselage. The outer panels would plug onto the center section to get me the full span of 90". The last couple inches per tip would be the bevel down and up to shape the curves.
I am not sure I will get to it, I have a bunch going on. I am also a bit apprehensive about putting so much effort into an event that may fall on a weekend that I cannot make, so my efforts will be hard to mobilize until we know FF2017 dates.
Here is a great resource. 1979 Flying Models had a 93" span sport scale version. (Which honestly if I build I would rather build balsa, but here we go with the Spirit of Flite Fest thing again This set of plans will be a great resource in your build. Landing gear and engine/wheel details are all solved one way here.
http://www.outerzone.co.uk/plan_details.asp?ID=7966
~Jim
I am not sure I will get to it, I have a bunch going on. I am also a bit apprehensive about putting so much effort into an event that may fall on a weekend that I cannot make, so my efforts will be hard to mobilize until we know FF2017 dates.
Here is a great resource. 1979 Flying Models had a 93" span sport scale version. (Which honestly if I build I would rather build balsa, but here we go with the Spirit of Flite Fest thing again
This set of plans will be a great resource in your build. Landing gear and engine/wheel details are all solved one way here.http://www.outerzone.co.uk/plan_details.asp?ID=7966
~Jim
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Tench745
Master member
Here is a great resource. 1979 Flying Models had a 93" span sport scale version. (Which honestly if I build I would rather build balsa, but here we go with the Spirit of Flite Fest thing again
http://www.outerzone.co.uk/plan_details.asp?ID=7966
~Jim
Already downloaded that one, but thanks Jim.
Wilsonman: I'll have to look those radials over. I'm a big fan of the fiddly, little things.
Tench745
Master member
Normally I can figure this out, but I might need some help this time. Can anyone help me choose a motor/prop/esc combination for this plane? I'd like to swing a scale 18" prop. Master Airscrew has 3 pitches available at this size, 6,8,or 10. I cannot for the life of me figure out how big a motor I need or what pitch to buy.
Also I'm starting to realize that this will mean a much larger battery than the 2200mah 3s I'm used to.
Near as I can figure if I used my current batteries, put two parallel banks of two in series I'd have a 4400mah 6s, which would just barely be enough power for a short flight. Am I crazy, or is this right?
I'm aiming for 130oz or less and I'd like to fly at a scale looking cruise of 50mph.
Also I'm starting to realize that this will mean a much larger battery than the 2200mah 3s I'm used to.
Near as I can figure if I used my current batteries, put two parallel banks of two in series I'd have a 4400mah 6s, which would just barely be enough power for a short flight. Am I crazy, or is this right?
I'm aiming for 130oz or less and I'd like to fly at a scale looking cruise of 50mph.
On my Giant scale P6-E Hawk, I fly an 18x12 prop on 6S. I use two 3S batteries in series. I'm using this motor, this ESC, and 3S 5800 batteries. With the 18x12 prop I can get a max of about 7 minutes of flight time and I usually stick to 5. Keep in mind that its also a 14-pound+ airplane. If you swing the 18x8 prop you will get better thrust, which is what you need for this type of airplane. Your current draw will be quite minimal on this so I could see a 10-minute flight possible using my exact setup.
This is a good starting place for you to look. Use eCalc.
This is a good starting place for you to look. Use eCalc.
Tench745
Master member
So, I've been plugging away with CAD, making progress here and there. I think I have the drawings of the fuselage formers and the wing ribs finalized. I'm moving this week, so as soon as my new shop is setup I'll be cutting foam.
Incidentally, I built myself a little stationary foam cutter so I can make a cardstock template for each part and just zap out duplicates; particularly important for the ribs.
Incidentally, I built myself a little stationary foam cutter so I can make a cardstock template for each part and just zap out duplicates; particularly important for the ribs.
Tench745
Master member
Quick update:
I've finalized (I think) the formers and have printed them all out. All the foam pieces have had their patterns glued to and cut from posterboard as a template. The three 1/8" plywood pieces will get their patterns glued to them directly.
I'm planning on using fiberglass driveway markers as rods for a Keith Sparks-like rig that each of the formers will slide over for proper alignment. Hope to do a step-by step of this build as I figure what exactly I'm doing. The Spirit is going to be a big plane...
I've finalized (I think) the formers and have printed them all out. All the foam pieces have had their patterns glued to and cut from posterboard as a template. The three 1/8" plywood pieces will get their patterns glued to them directly.
I'm planning on using fiberglass driveway markers as rods for a Keith Sparks-like rig that each of the formers will slide over for proper alignment. Hope to do a step-by step of this build as I figure what exactly I'm doing. The Spirit is going to be a big plane...
Tench745
Master member
There are three 1/8" Liteply formers in this model. F4 and F5 have notches which will receive a wood block for securing wing and landing gear mounting points.
These plywood formers were cut out on a scroll saw, sanded to final shape, and then the center section was cut out. Locating holes were drilled in the indicated locations then the interior cutout was lightly glued in place. CA would work, but mine was dried out so I used a little smear of wood glue in each corner.
All the foam formers were cut on the hotwire from their respective templates, as were the first 3 wing ribs required for the center section.
One rib has alternative notches which fit into the notches in F4 and F5 like so:
Templates were laid over and pinned to their respective formers where a t-pin was used to mark the 4 axis of the locating holes.
A 5/16 aluminum tube with a sharpened end was then used to drill out the locating holes.
The locating jig/strongback is made from two 48" fiberglass driveway markers. These ones have metal ferrules on one end which I inserted into two holes drilled into a scrap of 2x4 I had laying around. The rods were marked for the locations of each former based on measurements from the CAD drawing.
Each of the formers is slid on to the marks and squared relative to the locating rods. 1/2" strips of foam are then slid into the notches in each former, starting from F9 and working forward. Each former in then rechecked for square and the whole assembly left to dry. The Horizontal stringers were installed first since they aren't interfered with by the locating rods. These two stringers will lock the formers into square across the fuselage. The upper and lower horizontal stringers will lock the formers into square along the height of the fuselage.
You may or may not be able to tell that the locating rods aren't long enough to mount F1 in place at the moment. We'll address this in the next installment.
These plywood formers were cut out on a scroll saw, sanded to final shape, and then the center section was cut out. Locating holes were drilled in the indicated locations then the interior cutout was lightly glued in place. CA would work, but mine was dried out so I used a little smear of wood glue in each corner.
All the foam formers were cut on the hotwire from their respective templates, as were the first 3 wing ribs required for the center section.
One rib has alternative notches which fit into the notches in F4 and F5 like so:
Templates were laid over and pinned to their respective formers where a t-pin was used to mark the 4 axis of the locating holes.
A 5/16 aluminum tube with a sharpened end was then used to drill out the locating holes.
The locating jig/strongback is made from two 48" fiberglass driveway markers. These ones have metal ferrules on one end which I inserted into two holes drilled into a scrap of 2x4 I had laying around. The rods were marked for the locations of each former based on measurements from the CAD drawing.
Each of the formers is slid on to the marks and squared relative to the locating rods. 1/2" strips of foam are then slid into the notches in each former, starting from F9 and working forward. Each former in then rechecked for square and the whole assembly left to dry. The Horizontal stringers were installed first since they aren't interfered with by the locating rods. These two stringers will lock the formers into square across the fuselage. The upper and lower horizontal stringers will lock the formers into square along the height of the fuselage.
You may or may not be able to tell that the locating rods aren't long enough to mount F1 in place at the moment. We'll address this in the next installment.
Tench745
Master member
The intermediate stringers were added to the sides of the fuselage and left long to be trimmed later. The two intermediate stringers on the bottom between F4 and F6 were also attached. These stringers simply butt against F6 in this build and are held with T-pins until the glue dries.
The plans will be updated with cutouts so this is no longer necessary. This added structure allows me a little freedom to perform the next step.
Since I planned poorly and the fiberglass locating rods aren't long enough to put F1 in place, I measured the distance between F1 and F2, then cut four temporary braces at that length and glued them to the back of F1. You could probably eyeball this when assembling everything, but I have a better way. Since F10, as designed, doesn't have any stringers attached to it yet I can simply slide the entire fuselage down until enough of the fiberglass rods stick out that I can slip F1 into place. The additional stringers I've added help hold everything in alignment, but be aware that they can still bow under load.
The horizontal stringers are glued into place to lock F1 in place. The supports on F1 are temporary and will be removed in time. The design has been edited to make them unnecessary.
The main stringer on the belly can now be installed, be aware that it cannot fully lock into its slot in F9 until the locating rod is removed, so just bend it off to the side for now. Be sure to check and recheck squareness of all formers until the glue dries. A few of mine slipped as they were drying. It shouldn't affect things too much, but is annoying.
This is where I ran into my first big "Oops moment." I was looking over the best way to get F-10 tied into the structure, and on going over the drawings realized that somewhere along the way I offset something too far. To be scale F10 should only be as wide as 2 thicknesses of DTFB. I can't do that easily, so in this case I had to sacrifice scale somewhat for ease of build, but F10 was far far wider than in needed to be.
The whole tail end had to be rethought and I came up with this:
This whole assembly will glue onto the aft end of F9. This has the added benefit of no longer requiring F10 on the build jig, so F1 can now fit with no issues.
For paper-on builds there will be a cutout in T1 for the rudder to slot into. For this version though, I won't need it.
On this build F9 slid a little on me when I glued the stringers and was out of square. Since the tail assembly is now gluing onto it, it needs to be. Simply cutting the glue joints on the stringers and regluing F9 on squarely fixed the issue. This time I checked it repeatedly as it dried and adjusted as necessary. More to come as I make progress.
The plans will be updated with cutouts so this is no longer necessary. This added structure allows me a little freedom to perform the next step.
Since I planned poorly and the fiberglass locating rods aren't long enough to put F1 in place, I measured the distance between F1 and F2, then cut four temporary braces at that length and glued them to the back of F1. You could probably eyeball this when assembling everything, but I have a better way. Since F10, as designed, doesn't have any stringers attached to it yet I can simply slide the entire fuselage down until enough of the fiberglass rods stick out that I can slip F1 into place. The additional stringers I've added help hold everything in alignment, but be aware that they can still bow under load.
The horizontal stringers are glued into place to lock F1 in place. The supports on F1 are temporary and will be removed in time. The design has been edited to make them unnecessary.
The main stringer on the belly can now be installed, be aware that it cannot fully lock into its slot in F9 until the locating rod is removed, so just bend it off to the side for now. Be sure to check and recheck squareness of all formers until the glue dries. A few of mine slipped as they were drying. It shouldn't affect things too much, but is annoying.
This is where I ran into my first big "Oops moment." I was looking over the best way to get F-10 tied into the structure, and on going over the drawings realized that somewhere along the way I offset something too far. To be scale F10 should only be as wide as 2 thicknesses of DTFB. I can't do that easily, so in this case I had to sacrifice scale somewhat for ease of build, but F10 was far far wider than in needed to be.
The whole tail end had to be rethought and I came up with this:
This whole assembly will glue onto the aft end of F9. This has the added benefit of no longer requiring F10 on the build jig, so F1 can now fit with no issues.
For paper-on builds there will be a cutout in T1 for the rudder to slot into. For this version though, I won't need it.
On this build F9 slid a little on me when I glued the stringers and was out of square. Since the tail assembly is now gluing onto it, it needs to be. Simply cutting the glue joints on the stringers and regluing F9 on squarely fixed the issue. This time I checked it repeatedly as it dried and adjusted as necessary. More to come as I make progress.
planebreaker2000
Active member
Your progress looks good.
Pieliker96
Elite member
Thanks for details on the formers and stringers. I was planning to use one massive spar on my XB-70, but multiple smaller ones seems like a much better option now .
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