Strange New Swappable Trainer Can Take A Hit

by CStence | August 14, 2013 | (26) Posted in Reviews


TIP: Scroll to the end to check out the flight video and download build plans!

Intro:

The Smash Drone is a crashable, pusher swappable that will keep you flying even after the most horrific crashes. It is a 3 channel airplane, just like the Old Fogey and uses two sheets of Readi-Board Dollar Tree foam board and one 36" X 1/2" X 1/2" balsa wood square rod. The wing and elevator make up one sheet and are straight from the FT Old Fogey plans. In fact, you can use the wings from your existing Old Fogey, if you have one. The fuselage and rudder make up the second sheet and are now available as .pdf plans. 

 


Spec Sheet: 

 


Power System Options:

The Smash Drone can handle a prop up to 8" in diameter. The Smash Drone has been tested with both 2S and 3S power systems extensively.

Flying with a 2S system gives the slowest, lightest flying. This has been the preferred power system thus far. With a standard tail, the Smash Drone didn't seem to mind being aft CG, up to 1.25" of the wing apex. This is helpful since most of our 2S batteries felll short of the 110 grams needed to get a "perfect" CG. 

Flying with a 3S system gives more thrust and agility. You will have much more authority with a 3S and can fly aerobatics with ease! It is also easier to get the center of gravity at the apex of the wing with 3S batteries, which are normally heavier. A 110 gram battery seemed to do the trick. 

 


Weight Comparison:

The Smash Drone is slightly heavier than the Old Fogey which seems to give it better stability in wind (thanks to higher wing loading). This also means that if you had an underpowered or just-enough-power powerpod for your Old Fogey you might need to upgrade to get the best results. The Turnigy D2822/14 1450KV motor listed in the specs is highly recommended as it is cheap (less than $8US) and bulletproof. However, we have been able to fly with even the cheap (and anemic) Hobby King Donkey 1550KV motor when using a 3S battery.

 


Story Behind The Plane:

The first swappable plane I built was with my brother Matthew - the FT Old Fogey. It was a ton of fun to fly and I found that I loved “low and slow” flying! Learning to fly was fun but costly. Everytime I crashed something usually got bent or broken. Prop savers helped a lot but it was 50/50 chance at best that when the plane crashed something would break.

When I finally felt more confidant in my flying I found that stuff kept getting busted thanks to family and friends. There are always plenty of friends and family who would like to fly and whom I want to share the experience with. Unfortunately, paying for their learning curve can be a pain in the wallet!

"Everytime I crashed something usually got bent or broken."


I kept thinking that what was needed was swappable pusher plane that would protect the parts I had to buy - prop and motor. Unfortunately, swappable pusher's seem to be in short supply. The fowl flyer was one of the only swappable pushers (with plans) I could find but it looked a little big and a little more complicated than I was looking for.

It didn't take long to decide to try and build one for ourselves. The first attempt with my brother was partially successful in that it was a pusher and it did fly. However, it had sad rudder authority and didn’t really keep the prop safe anyway. The second attempt went tremendously well and resulted in what we now call the Smash Drone.


Design Goals For The Plane:

  • Swappable 
  • Easy conversion from Old Fogey (Use wings & tail, same power setup, etc.,)
  • Slow flight
  • Stable flier
  • Protect the prop and motor

(Unexpected extras:)

  • Capable flyer – even mildly aerobatic depending on how you set up the throws (We've down outside rolls, inverted flight, spirals and much more)
  • Large CG range (Flies stable with Old Fogey CG AND up to 1.25" AFT)
  • Decent glide ratio
  • Great hauler (Nerf bombs, etc.)
  • Extremely good handling due to "power steering" (prop blowing directly on tail surfaces)
  • Possibly decent intro-to-FPV platform?

It's All In The Name:

The biggest strength of the Smash Drone is that it can take a smashing! Hats off to Josh and the guys at Flite Test for such a cool plane that got me into the hobby, but since building and flying the Smash Drone with friends and famliy, we haven't lost a single prop or motor due to crashes. Because the balsa wood rod runs from the tail all the way to the nose, even the most nose-diving, full power, smash-a-crater-into-the-ground crashes have resulted in only minor foam repairs and the occasional balsa wood splice.

"For the established pilot, the Smash Drone enboldens a sense of adventure."


For the established pilot, the Smash Drone enboldens a sense of adventure. Low-level stunts, flying close and tight and general revelry are sure to ensue. Damage to persons and property on the ground is drastically reduced when there is no lawn mower blade hanging off the front!

 

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Build Your Own:

The Smash Drone is a 3 channel airplane, just like the Old Fogey and uses two sheets of Readi-Board Dollar Tree foam board and one 36" X 1/2" X 1/2" balsa wood square rod. The wing and elevator make up one sheet and are straight from the FT Old Fogey plans. In fact, you can use the wings from your existing Old Fogey, if you have one. The fuselage and rudder make up the second sheet and are now available as .pdf plans.

"The airplane is very simple to build and can be built in a few hours."

Build Plans:

Smash Drone Fuselage Plans (1 of 2)

Build Video & Tips: Smash Drone Build

FT Old Fogey Wing & Elevator Plans (2 of 2)

Build Video: FliteTest Old Fogey Wing Build

FliteTest Powerpod

Build Video & Article: FliteTest PowerPod Build

The airplane is very simple to build and can be built in a few hours. For a little extra panache, landing gear, a steerable tailwheel, bomb drops and more have been added to this capable plane. A gear platform is included in the plans which allows you to use the Old Fogey landing gear.

Check out the upcoming build article for helpful tips. 

 

 

 

COMMENTS

blackkrystal73 on September 3, 2013
So, I'm building 3 of these, 2 for my kids and 1 for my flying buddy's boy. ( I have more time than him). We like the concept of a pusher trainer. I lost count of how many broker props and bent motor shafts the kids and even us adults have been threw. I'm almost done with the first one and I'd like to point out a mistake on the plans.

The folded pieces that hold the power pod are too wide. The correct measurement should be 2 3/4 inches. This allows room for the extra side pieces and still gives you the 2 inches it needs for the power pod.

Other wise it looks very sound and sturdy. Can't wait to trim it out and pass it to the kids. They'll have a blast with them, I'm sure!

Thanks
K
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CStence on September 3, 2013
Thanks for the feedback!
Can't wait to see some photos or video of your kids flying. I've had my 5 year old fly mine as well as numerous relatives. Everyone in my family is now building their own and we just did the maiden flights on two of them this past weekend.
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alibopo on August 30, 2013
I like this! Great design - looks a lot of fun to fly too.
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firenice on September 15, 2013
It appears that from some of the photos that you have mounted the servos back by the tail feathers. Did that balance out OK?
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CStence on September 15, 2013
Not sure which photos you mean...the servos are installed about 6-8" inches forward of the prop - at about the apex of the wing. Check out the new build video, it should clear things up. :)
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firenice on September 17, 2013
The 2nd photo is of the power box and on the boom is two wires. What are they going too.
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CStence on September 18, 2013
Ah! I see what you are talking about. Those are actually red and white coffee straws I use for pushrod housings. What you are seeing is the straws going from the servo to the back of the tail. The build article (which still hasn't published) has better close-up pics of the servo tray installation, along with those handy-dandy coffee straws.
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Neilyboy on September 16, 2013
Just wanted to throw two thumbs up on the build video!! Excellent work and its much appreciated. I will be building one of these very shortly!
Neil
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PeanutsAreYum on September 3, 2013
Looks like it fly's amazingly!
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firenice on September 4, 2013
I built 4 of Flite Test swappables. Kept hoping that someone would build a pusher trainer. So I am flying the Fowl Flyer. I am going to add the Smash Drone to my fleet.
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mrmattstence on August 30, 2013
Lookin' good bro!
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solarflash on August 30, 2013
Please do the build video. I'm a total noob, took the FT Flyer out this morning, three flights, and three props. It flies well enough, but landings are a whole other story and it cost me a prop each flight.
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CStence on September 2, 2013
Working on it! It's about 80% there. In the meantime, feel free to download the plans. There are some tips and such that will be shared on the build article, but you'll find the plane is easy to figure out without them.
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CStence on September 15, 2013
Build video link added. Happy building! :)
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Miracle Air on September 18, 2013
I tried to build a Blu-Beagle about seven years ago. It was a false start in RC. I had flown it on FMS and liked it, but it didn't go well. This reminds me of it. Love how this thing flies. I think I need one.
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pintokitkat on September 7, 2013
Thank you for this. I made the Old Fogey and never managed to get it to fly properly - it would just see saw from side to side, then crash and smash the prop.
So I built your version and got one proper flight before it too crashed. The problem was with the balsa stick - it twisted along its length when I applied any control input.
However, it looked good for a while. so building the Fogey wing wasn't a complete waste of time.
Thanks again.
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alibopo on September 17, 2013
Regarding your Old Fogey - have a look at my solution. "Surgery on an Old Fogey! & Blustery Old Fogey" Or if that's too drastic just try moving the CG forward from spec about 10mm. I used a pile of coins taped on top of the nose with insulating tape. Regarding the broken balsa - I've been looking to build my smash-drone with 6mm (1/4 inch) dowel rods (because I've a few sitting around). 3 of them grouped in a small pyramid would make a good boom and bound every few inches with a few winds of CA soaked thread would give the stiffness needed. I've also got some old fibreglass tent poles from a lightweight tent that would make a good boom. As long as you get the plane to balance I don't think weight is too critical an issue. That Old Fogey wing can produce a lot of lift! My Old Fogey has an All Up Weight of 688g - just over 24 ozs - and it flies fine. Happy flying!
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CStence on September 17, 2013
If there was a "like" button on those rod ideas I'd be clicking it. That seems to be the weak point- the balsa. We've considered using basswood or perhaps a 1/2" Dia PVC tube. You're idea of a bundled smaller rods sounds promising!
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alibopo on September 18, 2013
Hi CStence, another thought on the boom - this smash drone is very elegant as it looks, but I don't think it needs to be as long. On the SD the distance from the front of the tailplane to the back of the wing looks to be about 300mm - 12 inches, but on my modified Old Fogey it's only 160mm - just over 6 inches and it flies fine. The long boom will give the Smash Drone super stable performance - but again my Old Fogey is pretty stable too. Apart from looks, I feel the main 'advantage' of the long tail boom is that it makes the CG less critical, as the tail has more influence on the fuselage due to the old 'force x distance' engineering rule. But a shorter boom means less bending forces on the boom due to the same rule - making it less vulnerable. If you get your CG right, so that the plane balances on the wing's 'sweet spot', the length of the boom isn't that critical, just as long as it can apply an up/down left/right influence on the fuselage. A shorter boom would also reduce the length of the control rods eliminating another problem mentioned in this thread. I might try a 'stubby' Smash Drone - the CG might be more critical, but it would probably be even tougher than the original Smash Drone, which I still think is a great design.
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CStence on September 18, 2013
My brother, MrMattStence (http://www.flitetest.com/authors/mrmattstence) had the same idea about shortening the rod. Definitely worth a try! I hope you'll post your results - if it works great it would be worth tweaking the plans.
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CStence on September 7, 2013
We've had great luck reinforcing snapped balsa wood by hot-gluing a Popsicle stick at the top and bottom of the break. These things are meant to take a beating - as long as the expensive stuff (props and motor) are unharmed you can just keep on gluing and reinforcing to get it going again. :)
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Purplezinger on September 18, 2013
Walmart in our area sells 32" carbon fiber arrows for $3.50 ea. 3 of these bundled together make an extremely strong and light tail boom.
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CStence on September 19, 2013
Great idea! Alibopo mentioned some similar ideas for the boom. Depending on which method works best it will probably make its' way into the plans.
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alibopo on September 23, 2013
Hi, I have built my drone with the bundled dowel. I'm lucky I made the boom shorter than spec, as it's quite heavy and I needed balancing weights at the front to get it flying nicely. Separation between the tail and wing is 180mm (trailing edge to leading edge), but I think I could have made it less. I really like the carbon fibre arrow shafts idea from purplezinger, that would definitely be lighter. I got about 20 seconds of flight on film before my spec camera battery died (forgot to charge it) but the plane flew well enough. I've a few issues with choosing the right prop for my motor, but I'll get that sorted with a bit of trial and error. I'm not sure about the thrust angle - my SD seemed a bit dead in the air at times - I'm going to try some more extreme angles to see what happens. One thing about the tube bundle - during my build it wasn't so easy to set up the fuselage symmetry and my fuselage ended up a little squint (story of my life) but a little bit of sanding got the wings and tail back in alignment. I'm going to have a look at fibreglass as a possible boom as well, but I think the round tube needs some kind of platform for the tail and flat sides to work into the existing SD design - mine was a bit of a bodged fit.
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Purplezinger on September 18, 2013
I've built 2 Old Fogeys with 4 different wing lengths. No success at all. I've written to the Joshes suggesting they revisit the Old Fogy and offer improved upgrades. This is a very popular plane and on occasion can fly really well. Check out YouTube videos "Old Fogey".
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alibopo on September 23, 2013
Moving on from my recent modification of the Old Fogey - I've now added a second wing -75% of the original wing - to make it a biplane - now it really flies slow. The second wing's removable, so I can fly it in both modes.
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pintokitkat on September 17, 2013
Thanks, cstence and alibopo for the helpful hints. Sadly, when the old dear crashed last time, the prop cut the wing in half as well as breaking the boom, so there was little to persevere with. However, with your hints and the new V tail version, perhaps it might be worth starting again.
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eagle4 on September 13, 2013
Fantastic design mate. I really love it. Now I've just got to go build one myself. I wonder how it'd go without dihedral and with ailerons? Might make it a bit more sporty.
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CStence on September 15, 2013
Great idea! If you beat me to it, post some pics.
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alibopo on September 17, 2013
Regarding ailerons - I was thinking of a similar mod to the Old Fogey wing - but that little dihedral lift adds tremendous strength so I think it'll need a little former glued under the wing near where the dihedral would start to stop the wing collapsing.
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CStence on September 17, 2013
You know on one of my wings I inserted a rectangular piece of balsa, 3/16" by 1/16" in diameter, the full length of the glue joint. It seemed to help. Maybe flatten the dihedral out and do the same thing?
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alibopo on September 18, 2013
Hi I think the balsa would make it stronger, but I don't think it's needed - the strength issue is more about keeping the vee made by the two panels from opening up - like the pitched roof in a house - the critical timbers are the ones at the bottom of the pitch that tie the two sloping sides of the roof together and stop the roof from spreading and collapsing. As long as the wing maintains that vee - it's tremendously strong. At the inboard end the shaped fuselage and elastics reinforce the vee and stop it opening up - at the outer end the 'turn' that creates the dihedral introduces a whole complexity of triangulation and stiffening that resists the forces trying to deform and spread that bit of the wing. Even if all you did was include a very short dihedral at the wingtips that would create the same stiffness - though it would probably be easier just to insert a little fillet or two under the wing.
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91shadowrider on September 15, 2013
I would really love to see the build video Hint, Hint....
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CStence on September 15, 2013
Article updated with build video link and some extra specs! Happy building. :)
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iflyfoam2112 on September 18, 2013
This looks like the perfect set up for an old Wingo wing I have laying around. I will be building this SOON! My 9 year old wants to fly and this could be a great trainer for her as well. i am glad work got slow today and I was able to browse the forum.
Many thanks
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CStence on September 26, 2013
UPDATE: We were wondering why the red, grey and blue Smash drone you see in some of the pictures has NEVER had a rod break. It also took a little bigger battery up front to get the CG at the apex of wing (no matter - the SD flies stable with an aft cg thanks to the long fuselage). Turns out that bird was made with a Basswood rod. The store we purchase our balsa from had both woods side by side and it appears that some got mixed together. The result is a little extra weight but a STRONG backbone! I highly recommend using this and will recommend as much in the plans. With a basswod rod the Smash Drone completely lives up to its' name!
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CStence on September 26, 2013
BTW, this particular Smash Drone was a heavy weight - it had a bomb drop, deluxe landing gear and a steerable tailwheel. It should have been the first to break a rod - but it is the only SD that never did! All of our Smash Drones will now sport Basswood rods - they are the same price and well worth the extra weight.
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alibopo on September 27, 2013
Hi Cstence - that's good news on the durability front! My bundled spar 'stubby' SD is flying, but I'm wondering about some of the flight characteristics. Because of my shorter lever arm (tail boom) I think some design problems are a little more evident. Climbing out from a takeoff can be a bit nerve-wracking - I think it's a combination of opposite forces in conflict. The high incidence of the main wing (plus the fact it's undercamber) produces a lot of lift, but at the cost of drag - to compensate for all this drag I push up the throttle, which, due to the flat or shallow thrust angle, causes the nose to be pushed down - the wing is just winning, but it's a bit of a battle to get that initial climb-out. I could be wrong, but that's the way I see it. Once I'm up and can ease off the throttle and 'level out' the plane picks up speed and flies a lot better. I'm going to experiment with reducing the main wing incidence - VERY roughly it's about 3.5 degrees. I'll try reducing it a degree or so and let you know what happens. To maintain the balance of forces I'll probably need to alter the motor thrust angle at the same time. On the BIG PLUS side, what an easy plane to land!
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CStence on September 27, 2013
That's one of the things I love about scratch built foamies - you can experiment, change, tweak and mod all day long without costing much time or money. Fun stuff!
BTW, where are the pics of all these mods? It would be great to visualize the mods you've been playing around with. :)
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alibopo on October 3, 2013
Oops - one of those links is wrong - here's the 'after' link;

http://www.youtube.com/watch?v=1BcVDhT6R-k

- as you can see the plane now tracks a lot flatter and smoother.
Alibopo
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alibopo on September 28, 2013
Hi, I've put them in a Flite Test article - which hopefully will get published soon. In the meantime here's a couple of video links of flights;

http://www.youtube.com/watch?v=8vE72fRE5l0&feature=youtube_gdata

http://www.youtube.com/watch?v=FRwz4nMJ3D0

Cheers, alibopo.
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Nathan_116 on March 10, 2014
have you tried flying this with the hextronik 24g. I am just starting to fly and keep breaking props on my tractors. I found this and said cool but only have a hextronik 24g 1300kv and 2 1000mah turnigy nano-tech 2s batteries. would this setup work?????
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Go-Up-Rc on December 29, 2013
Great work on the design! I crashed it into the same tree twice on the same day with the same battery charge and it held up pretty well! At first I built the Old Fogey like you, but I crashed many times and broke many props. Thanks for the next to indestructible design, you've just made the learning curve much cheaper! :-)
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shambopyro on June 15, 2014
Has anyone tried this with a beef power package and 1800 3s?
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SGRacer on September 18, 2014
Im running 1450kv motors on a 3s with 8x4 pros and a 20amp ESC, works great!
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SGRacer on September 18, 2014
Thanks for this plane! Been flying this guy for a while and it has lived up to its name. I have even started teaching my wife to fly with it. So easy to fly, just REALLY turn down the rudder other wise you will swing wildly. I love the way it floats, get it up high, gram a lawn chair and glide.
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peabody1929 on May 27, 2015
I believe the current plan contained in the .pdf file has errors. Issues I found are:
- Fuselage profile under the wing does not match the Old Fogey profile. As a result, the Old Fogey wing DOES NOT fit on the Smash Drone.
- Following the red lines on the plan to create the 45 degree folds results in a fuselage that has inside wall spacing of 3 1/4". The rest of the plan creates components for a wall spacing of 3".
- The powerpod brackets show a "A" type joint yet are labeled "B".
- Comparing the Old Fogey fuselage height to the Smash drone height, the Smash drone is shorter. Laying the Smash drone fuselage template over the Old Fogey template, the difference in height works out to 2" * (1 - SIN(45)). The dimensions do not take into account the 45 degree fold in the fuselage wall .

Bottom line: It is not possible to build a functional Smash drone from the pdf file.
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Strange New Swappable Trainer Can Take A Hit