FT Simple Soarer - BUILD

Don

Junior Member
Cool! thanks Craftydan. I knew it was a cheap thing to replace, so i wasn't too worried. But I really need to pick up a low voltage alarm.
 

Don

Junior Member
Crashed and re-built my powered SS. I extended the powerpod a couple inches and moved the wing forward perhaps half an inch, and removed the paper on the elevator (had some water . (I got sick of loading the nose up with clay.)
My brother flew it beautifully, but the battery died after the first 1-2 mins. Time to order a new one.

Also, my second wing folded on me while trying to do a high start. Maybe my brother was running too fast, and maybe my climb was too steep. But I strongly recommend building a better spar/ re-enforcement to the wing. Next time the entire bottom of the wing will be covered in tape. Any really cheap/light/good spar materials? yardstick?
Well time to hit up the Dollartree and hardware store . .
 
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Corbarrad

Active member
Reinforcing the back of the spar with a thin piece of plywood should do the trick. The spar will keep it from bending the wrong way, which will keep it from colapsing. The tricky bit will be putting a joiner into the middle of the wing to ge the dihedral. Of course you can jst choose to omit the center break in the wing. the outside panels shouldn't need reinforcing anyway. A length of strapping tape along the spar on the underside of the wing will help as well
 

DKchris

Member
Hi - New to Flitetest forums, just so U know it.....

I was contemplating starting on a Simple Soarer build, but, living in Europe, the usual issue of having no reasonably priced foamboard available comes up as the very first thing. What i do have available is 6mm Depron, and that in abundance and fairly cheap; I currently get it at german Bauhaus for about 32 euro for a crate of 20 sheets of 50x100cm (~20x40"), if anyone would like to know.
I've had a look at a number of FT's models, and it occurs to me that the foam thickness would become a bit of a snag in a few of the models, due to the plans not always mixing A-folds and B-folds in the same manner - the nose/fuse for the SS being an example. Both are B-folds, meaning that the outside width of the rear fuse would get too wide to fit inside the nose if I built it to the size the plan states, but from 6mm foam without compensating for its thickness.

So I was generally looking into actually scaling up the plans 20%, thereby in a simple way solving any fit problems of going from 5 to 6mm material.

I'm aware that I'll need extra reinforcements, such as in the form of tape on all major exposed edges, and am also thinking of using scrap pallet strapping material (see: http://www.rcgroups.com/forums/showthread.php?t=2047264 ) to reinforce the spar of the wing(1 strip top and bottom spanwise) and probably also the tail planes (strip either side spanwise ~½" in front of the hinges).

For the SS that would mean a span of approx. 180cm (72") and a fuse length of approx 120cm (48"), which actually should make very good use of my foam panel size.
It's also a very suitable size for my needs, as I'm planning to use it in a specific "old school" 2m RE(S) handlaunch golf competition this summer - I figured the cost level would benefit my willingness to take some more chances ;)

But I'd like some opinions......will I be likely to get away with it?
 
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Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
Absolutly. Scaling up 20% is not much, and you might even get away with keeping the diminsions the same. Most of these slots and tabs are gently squeezed into place, so squezing the foam an extra mm will simply give you a tighter fit. you're right, though -- the nesting tubes in the SS will get interesting.

You may run into problems with straight depron -- if it doesn't have a covering layer, you'll need to add one for most of the FT builds. taping or laminating (vinyl contact paper) the sheet may be nesesary to get outer surface to fold on. Spars and re-enforcements are always nice in moderation, but frankly if you cover the surface of the foam first you'll be amazed with the strength and ridgidity you pick up from it.
 

Foam Addict

Squirrel member
Crashed and re-built my powered SS. I extended the powerpod a couple inches and moved the wing forward perhaps half an inch, and removed the paper on the elevator (had some water . (I got sick of loading the nose up with clay.)
My brother flew it beautifully, but the battery died after the first 1-2 mins. Time to order a new one.

Also, my second wing folded on me while trying to do a high start. Maybe my brother was running too fast, and maybe my climb was too steep. But I strongly recommend building a better spar/ re-enforcement to the wing. Next time the entire bottom of the wing will be covered in tape. Any really cheap/light/good spar materials? yardstick?
Well time to hit up the Dollartree and hardware store . .

Cheap and light? Use a strong tongue depressor at the leading and trailing edge of the wing, they add so much strength.

To match the dihedral, just heat the center of the tongue depressor while bending it over something.
It won't crack, and will maintain the dihedral as well.
 

DKchris

Member
You may run into problems with straight depron -- if it doesn't have a covering layer, you'll need to add one for most of the FT builds. taping or laminating (vinyl contact paper) the sheet may be nesesary to get outer surface to fold on.

Thanks for your response.
As an info: For folding 6mm depron i have already had very good experience with adding a single strip of 2" tape along the fold line, and not scoring or chamfering along the fold line, but crushing the foam with the edge of a ruler without sharp edges(NOT a pizzacutter), and then very slowly folding the foam over a table edge. I fold it all the way over till it's flat, open it slightly and maybe add glue to the fold line then - but don't open it completely, it will crack on the inside. Gives a very strong leading edge. Used it for this: http://www.rcgroups.com/forums/showpost.php?p=22138236&postcount=18636, and it's held up to more abuse than i'd ever have expected.....
 
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Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
By all means, do what you're most comfortable with, and that should work great for folding wings, but the wing may turn out a bit flopier, and the A/B fold fuse sections might not fair as well. It's kinda a question of concentrating your re-enfocement into thin strips of heavy materails or distributing it in sheets of lighter materials.

If you have sucess with it, Please post your results -- it'll be handy for other depron users, or ready-board users wanting to cut the weight by stripping the paper :)
 

DKchris

Member
Oh, the above mentioned folding method would only be used for LE and likely also the creases in the wing top surface; all other breaks/folds I'll make as per plan, as sharp corners are needed to get things to fit each other.

I'll try and remember to take a few pictures as I go along.:)
 
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Don

Junior Member
Hey eveybody ! I've been using InstaMorph moldable plastic for my firewalls and other hardware on my FT Simple Sourers. Been working great.

U9Q5m7k.jpg
4rrkmY9.jpg

Used it for high start mechanism as well.

Just really love the Ftss glider. Thanks Flite Test!

Here's a video from the landing gear version flying.

 
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DKchris

Member
Could you convert this into a discus launch glider?

I fly DLGs, and I strongly doubt it would make sense; for one thing the quite immense stresses on the wing spar and especially the tail boom would tear the plane apart quite easily; In that respect the polydihedral and the 2-part fuse do not exactly help. You may be likely to be able to side-arm launch it gently to an altitude similar to what is possible with a javelin throw, but you'll definately have to add extra rubber bands to not tear the wing off.
Now, It is off course possible to add a load of carbon to strengthen it to perhaps be able to withstand a more powerful dlg launch, but in the end the planes basic aerodynamics gets in the way - it's just simply far too draggy to ever go anywhere high from a DLG launch, you need a plane capable of going fast, I.e. something with little drag and a rather thin airfoil.

For comparison The SS wing is about 3/4" thick with a chord of about 8" - that makes it an airfoil with about 9% thickness, which is not that bad, but it also has quite a bit of camber -especially the heavily undercambered wingtips(!!) and a nearly flat bottom on the rest of the wing, slowing it down quite a bit. A similar airfoil suitable for DLG would be something like the Mark Drela AG12-13-14 series (root to tip airfoils), which are about 5-6% thickness, semi symmetrical and has just a slight amount of camber. And it's regarded as fairly slow in DLG respect at that.

Don't get me wrong, there is nothing wrong with the the SS, It's just not constructed for DLG, but primarily for Hi-start, and likely great as such.

It may be quite possible to build a DLG from foamboard, but you'll need to get a bit closer to existing DLG's constructionwise to get something that'll be fun to fly as a DLG. Well, thats my opinion anyway.
If I were to point you in a direction, something like the Dream-flight Alula or other similar thin airfoil flying wing design would probably make a good starting point for a first DLG/SAL type plane, as the flying wing layout solves many of the strength issues quite nicely. In fact, the basic construction principle of a versa wing might very well be a good starting point. Maybe thin the wing down a bit by reducing spar height, maybe try to make it a bit semisymmetrical in shape (may also work nicely as it is...?) and remove the winglets and put on a central fin in stead, and you may be quite well under way already.

A single little word of warning though: On a HLG/SAL/DLG flying wing, CG will be a bit tricky to get just right. Just a bit too nose heavy, and the resulting increased up elevator will both slow it down quite a bit in level flight, making it more difficult to keep flying(it's closer to stall), and cause it to loop up over you at the high speeds caused by launch. A bit too tail heavy and it'll slam into the ground on launch. Keep it just slightly noseheavy and try to always launch it level to the ground, and build up the force gradually, trimming the CG back till it rises nicely from a level full power throw.


EDIT: The SS should do nicely as a HLG though, i.e. using a Javelin throw.......that certainly is what I'm hoping for myself......
 
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DKchris

Member
120% Depron SS started

Got started on my 120% size Simple Soarer.

So far nothing special, except for the resizing of the drawings - I simply opened the untiled file in Adobe Reader XI and printed it using the poster function in the printer interface in 120% size. Nothing fancy, allthough I did only print page 1 and 3, as I won't need the power pod just yet and only need 1 wing template to make 2 wings, simply by flipping the template over for the second wing. Each of the 3 drawings are made up of 20 sheets of A4 paper, another reason to avoid making more templates than neccesary.

Billede142.jpg
Drawings assembled.

Billede143.jpg
Transferring the second wing outline to the foam.

Billede144.jpg
How i transfer it. First I did one wing from the printed drawing side using a needle to mark all corners, lines, curves etc.. Then I flipped the drawing over for the second wing and simply used the already poked holes to mark it up as well. Then, in this case, I chose to draw up all the transferred lines directly on the foam. I chose to make all the fuse parts as per plan, i.e. with all the reliefs for folding drawn in. I could have just left them out and butted the fuse parts up close to each other to save a bit of foam - I could probably have kept all the parts on 3 sheets that way. Since I'll have to use tape to get the parts to fold together for gluing anyway, It wouldn't have made much of a difference - but I have chosen to keep the build fairly close to the original description, as it makes showing the build here and explaining it simpler.

Billede145.jpg
All parts transferred to foam.
 
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DKchris

Member
120% Depron SS progress

Got a little more work done: (Admitted, pics are a bit crappy quality, but the files are extremely small this way, which improves load time. Hope you can make out the important stuff)

Billede142.jpg
All parts cut out

Billede143.jpg
I skip all 50% cuts where light bends are to be, and do this in stead. Without paper on the inside it works great and doesn't weaken the foam as much as cutting it.

Billede144.jpg
Fuse parts are covered with boxing tape along the outside of all bends and B folds, and foam is removed between the 50% cuts for the B-folds as per plan.

Billede145.jpg
Bit of a hiccup: My hot glue gun isn't usable for depron, it heats the glue too much. Luckily I did a few experiments before starting on the actual parts - this is an example from the one place i got carried away and tried it anyway. Odd really, when you look at the temperature stated on the gun - I thought about 160°C was supposed to be about right? I guess the gun doesn't quite keep what it promises......is a real cheapo piece tho'......
Billede146.jpg

I decided to go with UHU-Por Foam safe contact cement, it'll make a slightly more rubbery joint, but probably a bit lighter. And it also has the capability to improve a joint a bit by smearing it over the surface; I've used it to make hinges for indoor models. The tape also sticks to the glue like crazy, so it should work nicely for improving the adhesion in tape hinges etc. Downside is that it like any other contact cement I've worked with can be a bit of a mess getting on your fingers and everything else and staying tacky very long, and the waiting time for it to first get tacky, and then for curing.

Billede147.jpg
Fuse parts assembled and a bit of extra boxing tape added for strength on the nose part. I tried to keep the tail light though.

Billede148.jpg
Pic is a bit unclear, but it shows the strapping material strip added to the stab for extra strength. The standard strip is ½" wide, i split it in half to keep things light. Figured out an alternative way to mount it: Thin bead of hot glue on the strip, let cool a bit, and then I ironed it on the foam with my covering iron set below the temperature needed to melt the foam. Worked like a charm. Put boxing tape over it afterwards to keep it smooth and keep the strapping from splitting at the ends. It splits fairly easy.


Billede152.jpg
Again to save some weight (and because I like the way it works), I decided for pull-spring control instead of rods. Servo end attachment. You can perhaps also see the foam I put between the 2 servos(HS-80's - I figured something slightly more robust than the HXT900's wouldn't hurt for glider golf ;))

Billede153.jpg
And control surface end attachment. Control horns are made out of old plastic magnetic strip cards - I believe the term "gift cards" is common in the US for this type of material. I cut them to stick out 1/4" past the opposite side of the horn, split the protruding piece in half and bent the 2 halfs to opposite sides. You can just make it out on the rudder. Should help transferring the pull force.

Billede154.jpg
The pull spring for the rudder - you can just make out half the spring for the elevator as well. It's just very thin piano wire (guitar string, actually) inserted into the foam under the tape. Both pieces were bent into a squared off U shape and twisted/pre-tensioned before insertion.

Billede151.jpg
The finished fuse. Was out of posterboard, so I used some old laminated paper sheets I had lying around. Bit on the stiff side, but OK. Probably strong. I'm surprised at how long it is, compared to most other traditional old school 60" HLGs/2m RE planes i've seen - I think it just might be a very nicely tracking plane - can't wait to fly it.

Billede155.jpg
I tried balancing out the finished fuse at the marked CG with a bit of lead at the spot intended for the battery so I could weigh it and get a first idea of what kind of AUW I am looking at. I'm starting to take a liking to this construction....just under 208g or just over 7.3oz...damn that's light for a plane this size!!

Billede149.jpg
Starting the wing build; waiting for the contact cement to get tacky......

Billede150.jpg
....and letting it do it's thing. Now it just needs to cure.....yarn!!:rolleyes:

I'll be back soon with the next steps.
 
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DKchris

Member
120% Depron SS more progress

Wing is now well under way - and I decided to up the pic resolution a bit:rolleyes:

Billede000.jpg
2" extra thick boxing tape on the outside of all bend lines - I've decided this will also have to act as spar for any negative G's.
And Iv'e done my experiment with the Strapping material as spar. Ended up OK, but there were a few leaning experiences involved:
1) Hotglue applied to the strapping strip should be spread instantly to a rather thin layer as fast as possible. I did a bead down the middle, and result was that I had to heat the strapping so much with the covering iron that it started shrinking a bit! You can see the warpage at one of the ends. I managed to keep it to a minimum by sort of balancing the heat constantly moving the covering iron from place to place while slowly stepwise making the hotglue melt and spread out under the strip, but it was too tricky to call a recommendable method. At one of the ends I had tried spreading the glue first with mixed success (waited too long before trying to spread it), and that went on far easier.
2) The panel warped a bit due to the shrinkage. I ran the covering iron across the strip again in a very slow fluid motion from the center outwards, and that relieved the tension and let the panel go perfectly flat again very nicely.
3) The covering iron was a bit of a mess of hot glue afterwards, but a thorough rubbing with some paper towel took care of that ever so nicely.

Billede001.jpg
Then I creased and folded over the LE. First crease by pressing a ruler edge into the fold line, really get that sucker in there with force, the panel should lift it's outer edges from this. I went and creased the 2 wing top fold lines right away as well, as I was not sure whether they would be fully accessible after bending the LE. Then I flipped the wing panel over with the top side up and hung the bottom side out over the table with the LE over the table edge, stacked a bunch of books on the wing top part to keep it in place and very slowly bent down the bottom side panel to 90° doing my best to apply the force evenly along the length of the panel. You only bend it, say, 10-20° a time and you can sort of feel the foam giving in to the force applied after a bit of time; then you can give it another 10-20°. If you rush it the tape will split and the foam will crack.

The I removed the books, flipped the panel over again and continued to fold the bottom panel over till the top and bottom panel were flat on top of each other. Then I put the book back on top and let it sit overnight. Could have had taken more pics of this process, but was clear out of extra hands folding the foam.....
But here's a pic of the resulting leading edge:
Billede003.jpg

This morning I removed the books.
Billede004.jpg
Billede005.jpg
I got the shown piece of wood from the shed and used it to do a bit of pre bending on the 2 wing top bends.

Billede006.jpg
I glued the spar in - smear, wait to tack, lay down and apply pressure while the glue cures - last I did by laying the wood piece on top of the spar and stacking books along the length of it. Gave it a couple of hours to cure.

Billede007.jpg
Then I applied a bead of glue inside the LE, smeared glue on the spar and wing top underside and closed the wing. Wood on top(moved it a bit back to get the wing top to be perfectly flat on the spar) and books to keep it in place.....then another couple of hours of curing time.

Billede013.jpg
Finally, I've just glued the rear edge of the bottom panel. I decided to use a different glue for this, as UHU-por is best when there is a lot of surface to make the bond. I used PATTEX 100%, You can see the bottle on the table behind the wing.

Here are a couple of pics of the final panel airfoil and leading edge:
Billede008.jpg
Billede009.jpg
I had expected the bottom to be more flat, but this slight upwards rounded lower front could very likely cause the wing to have a greater speed range and glide ratio than I would have first expected - again, can't wait to fly it. And I am quite satisfied with the straightness of same LE.

Next is the polyhedral, a fast radio install and then it's hopefully finally time for maiden!!
 
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Tactical Ex

Senior Member
Has anyone rebuilt the fuse to wrap around the outside of the power pod like the rest of the swappable planes? I have already used re-enforcements on my pods that made nesting the fuse inside the pod impossible. I will be converting the plans to fit my idea but I was wondering if anyone has already attempted it and overcame any unexpected issues.
 

Foam Addict

Squirrel member
Wing is now well under way - and I decided to up the pic resolution a bit:rolleyes:

View attachment 26419
2" extra thick boxing tape on the outside of all bend lines - I've decided this will also have to act as spar for any negative G's.
And Iv'e done my experiment with the Strapping material as spar. Ended up OK, but there were a few leaning experiences involved:
1) Hotglue applied to the strip should be spread instantly to rather thin a layer as fast as possible. I did a bead down the middle, and result was that I had to heat the strapping so much that it started shrinking a bit! You can see the warpage at one of the ends. I managed to keep it to a minimum by sort of balancing the heat constantly moving the covering iron from place to place while slowly stepwise making the hotglue melt and spread out under the strip, but it was too tricky to call a recommendable method. At one of the ends I had tried spreading the glue first with mixed success (waited too long before trying to spread it), and that went on far easier.
2) The panel warped a bit due to the shrinkage. I ran the covering iron across the strip again in a very slow fluid motion from the center outwards, and that relieved the tension and let the panel go perfectly flat again very nicely.
3) The covering iron was a bit of a mess of hot glue afterwards, but a thourough rubbing with some paper towel took care of that ever so nicely.

View attachment 26420
Then I creased and folded over the LE. First crease by pressing a ruler edge into the fold line, really get that sucker in there with force, the panel should lift it's outer edges from this. I went and creased the 2 wing top fold lines right away as well, as I was not sure whether they would be fully accessible after bending the LE. Then I flipped the wing panel over with the top side up and hung the bottom side out over the table with the LE over the table edge, stacked a bunch of books on the wing top part to keep it in place and very slowly bent down the bottom side panel to 90° doing my best to apply the force evenly along the length of the panel. You only bend it, say, 10-20° a time and you can sort of feel the foam giving in to the force applied after a bit of time; then you can give it another 10-20°. If you rush it the tape will split and the foam will crack.

The I removed the books, flipped the panel over again and continued to fold the bottom panel over till the top and bottom panel were flat on top of each other. Then I put the book back on top and let it sit overnight. Could have had taken more pics of this process, but was clear out of extra hands folding the foam.....
But here's a pic of the resulting leading edge:
View attachment 26421

This morning I removed the books.
View attachment 26422
View attachment 26423
I got the shown piece of wood from the shed and used it to do a bit of pre bending on the 2 wing top bends.

View attachment 26424
I glued the spar in - smear, wait to tack, lay down and apply pressure while the glue cures - last I did by laying the wood piece on top of the spar and stacking books along the length of it. Gave it a couple of hours to cure.

View attachment 26425
Then I applied a bead of glue inside the LE, smeared glue on the spar and wing top underside and closed the wing. Wood on top(moved it bit back to get the wing top to be perfectly flat on the spar) and book to keep it in place.....the another couple of hours of curing time.

View attachment 26426
Finally, I've just glued the rear edge of the bottom panel. I decided to use a different glue for this, as UHU-por is best when there is a lot of surface to make the bond. I used PATTEX 100%, You can see the bottle on the table behind the wing.

Here are a couple of pics of the final panel airfoil and leading edge:
View attachment 26427
View attachment 26428
I had expected the bottom to be more flat, but this slight upwards rounded lower front could very likely cause the wing to have a greater speed range and glide ratio than I would have first expected - again, can't wait to fly it. And I am quite satisfied with the straightness of same LE.

Next is the polyhedral, a fast radio install and then it's hopefully finally time for maiden!!

Very nice! It should glide forever at that weight.:D
 

DKchris

Member
Easy now; that's just the fuse weight. Wing looks to come out at about the same weight ......but that's still very light.
 

DKchris

Member
120% Depron SS final and maiden

So, here's the last bit:

Billede015.jpg
Center Poly bend. Used Pattex 100% and let each bend cure for 2 hours before taping each joint and moving on, apart from that everything as per plan.

Billede016.jpg
Crease in TE for tip bends - you dont have to use very much force for this, it just needs a mark.

Billede017.jpg
Tip poly bend

Billede018.jpg
Finished wing - Each of the bends were reinforced with my heavy boxing tape, tip bends got a strip of coloured boxing tape on top of that to make it easier to see which way its pointing in the air.

Billede019.jpg
Final wing weight. I glued and taped a 5" piece of barbecue skewer to the TE and gave the middle section of the LE an extra 5" strip of heavy boxing tape to improve the strength a bit where the rubber bands are going to go.
Billede020.jpg
Final AUW. Me likes.
While the wing poly bends were drying I installed the rest of the radio gear: Frsky XR8, 540mAh 2S Lipo and a 5V 2A Ubec, all placed as far forward as possible, as I had a hunch I'd need to add a lot of lead otherwise. I decided to lock the Lipo in place in the very front of the nose insert by pushing a piece of soft foam into the hole behind it and feed the power connector through the hole intended for the velcro battery strap used in the plan. When the last wing bend had cured for 2 hours I attached the fuse to it and checked the CG balance. As expected it needed another 30 grams of lead at the very tip, which I taped to the underside of the fuse tip inside the "poster board" wrap at the front line hole for the optional tow release - very convenient spot for this if said tow release is not installed. And I gave the nose wrap a coloured tape covering for visibility as well. With that it balanced approx. 1/3 of an inch ahead of the cg mark, which is probably fine for maiden.

And here's the apple of my eye modelling with the finished SS for a bit of size reference - she'll be 5 in a couple of weeks:
Billede021.jpg
Billede022.jpg

And finally the maiden - weather was fairly Ok for these parts, 3-5m/s winds with a few mild gusts above, mostly zero lift to sink at the time as we were on the edge of a rain cloud area.
Video quality is admittedly very crappy, we forgot the good camera at home and had to use my age old mobile phone capable of only 170x144, but it still documents behavior and flight times reasonably. I'm quite happy with the result, it flew straight without any trim and very stable with zero tendency to tip stall, very uncritical stall behavior in general. Only mild hiccup was that it was a bit reluctant to respond to rudder input with roll, making it go through a turn yawing a bit to the inside of it. I might have given the poly bends a bit too short time to cure, causing them to come out a bit flatter than intended - a bit more polyhedral would probably have helped. I'll leave the poly angles as is for now, as they are nicely symmetric, and probably try experimenting with adding a little washout to the under cambered tips by bending the TE tips up a bit, this should likely help with this behavior as well.

Here's the clip:
 
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