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Pumpkin drop event

165% Upscaled FT Sparrow Build (pusher vers)

duckduckgoose

Well-known member
#1
Hi, I recently have been flying the ft sparrow and love it. So much in fact I'm building a 165% version. 165% because it allows me to use a standard firewall motor mount. Any tips or suggestions would be greatly appreciated. Just assembling the plans and I'm already a little nervous about the sheer size of this thing. Will update when my foam board arrives. pic: original sparrow wing on upsized plans :eek::eek::eek: IMG_20190508_215209.jpg
 

Dr. Looping Looie

Well-known member
#2
I made a 200% Sparrow, but with a twin F-pack! And it was amazing! I was able to build it super light, because the motor location helped with the CG. If you use a tail motor, you need a lot of weight in the front to balance it out. And ailerons are nice too!
This thig Just flew like a dream! IMAG0137.jpg
 

duckduckgoose

Well-known member
#3
I made a 200% Sparrow, but with a twin F-pack! And it was amazing! I was able to build it super light, because the motor location helped with the CG. If you use a tail motor, you need a lot of weight in the front to balance it out. And ailerons are nice too!
This thig Just flew like a dream! View attachment 130795
Nice! Yeah the CG issue was pretty annoying at first, but I ended up adding a nose extension (basically a slide over 125% nose) that both sorted out the CG issue and added a nice thick layer of protection for the battery. Im not sure if I'll build the extension into the plans or just do another slide over extension. It definitely isn't pretty, but it's been quite practical. If I have any unexpected landings, I usually just need to slide off the extension, and repair IT while the original nose remains unharmd. IMG_20190507_135907.jpg
 

duckduckgoose

Well-known member
#4
(regular size) sparrow update: put an fpv setup on it and flew it for 5 mins very sluggishly untill It dived and the gyros spun it out of control. Worst of all, in the excitement I forgot to press record :eek: RIPieces sparrow, you served me well and your lessons learned will help future generations. Onto the upscale build! IMG_20190510_073150.jpg
 

duckduckgoose

Well-known member
#5
Plans glued onto FB and ready to cut tomorrow, I've opted to just stick with adding a slide over extension. Half because I like the extra protection (I'm still very much a beginner) but mostly because I don't have a big enough piece of FB (this is already A1 size) haha. Note to self: won't use celotape next time, it just bubbles with the glue applied underneath.
IMG_20190510_221410.jpg
 
#6
I have often wondered about the same possibility, I decided to just enlarge the wing and V-tail keeping the comically small fuselage, I put paint sticks in the wing to keep it aligned and it will soon have it's maiden flight, for that size of the flat v-tails I would either minwax or paint it even with the Flite test foam in order to prevent warping. I also added ailerons and programmed differential. By the way, my first Flight ever also ended in a nosedive (forgot to screw in servo arms)
 
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duckduckgoose

Well-known member
#7
I have often wondered about the same possibility, I decided to just enlarge the wing and V-tail keeping the comically small fuselage, I put paint sticks in the wing to keep it aligned and it will soon have it's maiden flight, for that size of the flat v-tails I would either minwax or paint it even with the Flite test foam in order to prevent warping. I also added ailerons and programmed differential. By the way, my first Flight also ended in a nosedive (forgot to screw in servo arms)
How big did you upscale the wing and tail? Very interested to hear how the maiden goes. Also I want to see this thing
 

duckduckgoose

Well-known member
#8
Update: Almost structurally complete, just need to add power pod, ailerons, and extension nose. Added carbon spars to the tail straight away this time as I had the tail bend on the regular sparrow. I might add some sort of cross piece between the v-tail fins for added strength It does seem to be getting slightly heavy but I guess it is pretty big. Does anyone know what the difference between the regular sparrow and the twin sparrow are (apart from the twin motors and the removable nose)? Thinking I might be able to convert to a twin motor later on, if it survives the maiden that is. IMG_20190511_202822.jpg IMG_20190511_202139.jpg
 
#9
I lengthened the wing instead of enlarging in all dimensions. It is for this project: https://forum.flitetest.com/index.p...19-combat-group-project-members-wanted.58211/. I have installed a motor and am waiting for some adapters. I am running my plane on 4s and I needed to cut a part of the removable nose. I am pretty sure this will be at Flite Fest. As Far as I know the Twin Sparrow wing has the spar as fold over part of the wing which reduces complexity, but may not be worth scaling up. I have run into the same tail heavy problem, and I am thinking of either adding nose weight or adding a runcam 2 to the nose.
1557585372651.png r
 

duckduckgoose

Well-known member
#10
Wow that must have some serious lift. Love the paint job too. I actually hadn't thought too much about paint, but seeing as though this will be a one off build (it used sooo much foam board) that I might need to consider it's visuals haha. Pity we don't have Flite test here in AUS, because this would be so much fun to take along.
 

duckduckgoose

Well-known member
#11
Update: finished ailerons, nose extension/reinforcement and installed power pod today. I added some expanding foam between the front and second nose bay for added strength. Might add some cross pieces all through the fuselage to strengthen things up a bit. (Will cut off/sand down the excess foam when it dries). I'm running a sunnysky x2216-8 1250kv motor with a 9x4.5 prop and a 40A esc. Could Anyone tell me if this should work (I still don't quite understand the capacities of electronics). IMG_20190513_204720.jpg IMG_20190513_204705.jpg IMG_20190513_203652.jpg
 

duckduckgoose

Well-known member
#12
Just about ready for its maiden, need to figure out the nose situation. Thinking of making a platform like the Mini talon for a camera (very cheap and nasty sjcam knockoff than I kinda hope stops working so I can get a refund ;)). I'm also getting a little concerned about the weight. Does anybody know much about how scaling up affects lift to weight ratios? I managed 5o fly my original sparrow at 800g but this one is 1400g @165% which is 100g over weight if following the scale.
 

duckduckgoose

Well-known member
#13
HUGE UPDATE: Maiden day. Been a while since last update asI had to wait for my 4s lipo to arrive (didn't want to risk not having enough zing ) which arrived today. As for the flight, success with a hint of near disaster. I decided to install fpv as I recently completed my first and numerous more, fpv flights with the tiny trainer (installed a larger motor) and now cant imagine flying without it. Had my brother launch it for me and it lifted up without incident with plenty of power. Put on the goggles and soon noticed it was losing signal on and off (I assumed it was my dodgy wirework on the video tx) but soon it was so bad I couldn't see anything. My brother called out "PULL UP!" and so I did just as the video feed came back in and just avoided ploughing it into the dirt (good copilot). I realised that I had bumped the channel + button on my goggles and was on the wrong channel. After that it was fairly easy to handle, although I think I might install a gyro for the ailerons. Flew it again solo later this afternoon and it's a joy. Didn't even dive out of my hand after launch. Might experiment with more weight and see if it can handle a 5000mah 4s lipo (doubtfull). Will upload fpv footage of flight tomorrow.
 

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duckduckgoose

Well-known member
#15
Update, xl sparrow sill flying reliably to date, despite it biting me after a hand launch! Finger needed 13 stitches. It suffered minor damage to the nose after a panic induced "oh crap my finger is pouring out blood, I'd better get this thing down again" landing. I recently got a vector flight controller so it is the best candidate for trials.
 

duckduckgoose

Well-known member
#16
Update, xl sparrow sill flying reliably to date, despite it biting me after a hand launch! Finger needed 13 stitches. It suffered minor damage to the nose after a panic induced "oh crap my finger is pouring out blood, I'd better get this thing down again" landing. I recently got a vector flight controller so it is the best candidate for trials.
 

duckduckgoose

Well-known member
#17
After cutting my finger, I left the sparrow to gather dust for a while until I made a launch ramp. Today after 4 'almosts' he took to the sky once off the end of the ramp. This bird is extremely robust
IMG_20190729_161522.jpg received_381903095728929.jpeg
 
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