FT Spear

by FliteTest | October 5, 2016 | (21) Posted in How To

FTScratchBuild

The FT Spear is Flite Test’s newest wing aircraft! The Spear is designed to carry everything you need in a reinforced, lunchbox-like compartment.

The Spear and is made from four pieces of foam board, and it can be built in less than 2.5 hours when using the speed build kit.

Before starting the build, center your two servos and build your power pod. This power pod is not swappable, but it does use an A fold similar to other FT builds.

Don’t forget to test your motor to make sure it’s moving in the correct direction.

Next, build the wing assembly. There will be four spars, two for the wing and two that will be used in the center section.

Once the wing assembly is complete, build the center section. Install the two remaining spars inside the center section. After the center section is built, attach it to the wing assembly.

Install your elevons, your centered servos, your control horns and your push rods.

Connect the rest of your electronics and adjust the rates on your receiver. After your electronics are installed and tested, build the wing tips and attach them to the wing assembly.

Build the FPV pod, and remove the foam from the nose along the score cuts. Install the FPV pod inside the newly removed portion of the nose on the center section.

Test the CG and make any necessary adjustments. Install your prop, and you’re ready for the maiden flight!

FT SPEAR SPECS

WEIGHT WITHOUT BATTERY: 1.45 lbs (658 g)

CENTER OF GRAVITY: 3 – 3.5” (76 – 89 mm) in front of firewall

CONTROL SURFACE THROWS: 16 ̊ deflection – Expo 30%

WINGSPAN: 41 inches (1041 mm)

RECOMMENDED MOTORS: 425 sized 1200 kv minimum

RECOMMENDED PROP: 9 x 4.5 CW (reverse) prop

RECOMMENDED ESC: 30 amp minimum

RECOMMENDED BATTERY: 2200 mAH 3s minimum

RECOMMENDED SERVOS: (2) 9 gram servos

PICK UP A SPEED BUILD KIT HERE!

FT SPEAR PLANS

FT Spear (FULL PLANS)

FT Spear (TILED)

FT Spear (ALL IN ONE)

STORE LINKS

https://store.flitetest.com/ft-spear/

https://store.flitetest.com/power-pack-c-fixed-wing-large/

New to the R/C hobby?

Here are some resources to help get you up to speed!

Beginner Series: WATCH HERE!

Electronics Setup: WATCH HERE!

First Flight Quick Tips: WATCH HERE!

Scratch Building without Knives: WATCH HERE!

Got glue?? Get Some Here!

COMMENTS

udo789 on October 6, 2016

Nice job. Congratulations!
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baskuterkut on October 6, 2016

Great! But, Why dont you give dimensions in your plans?
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anichhatre on October 6, 2016

Hi, Thanks for plans and build video. One suggestion, please mention paper size for printing these plans. (A0, A1, A3.. etc)
Thank you

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Kevalino on November 25, 2022

I did the Cub recently and there was a tiled A3 option which meant I could print at home and it was half the work joining the pages. Seems the only tiled option now is A4
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flying-coqui on October 6, 2016

Please update all the plans to this format speacially the info page and drawing key I love this plans speacially the skill gremlims
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StatGSR on October 6, 2016

Any chance the speed build will be released in plain white foam board in the future? I was hoping to to pick one of these up and fill it with LEDs!
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juliansuse on October 6, 2016

can I fly this with a 10x45 prop and emax 935kv 3s motor (850g thrust) from my quadcopter?
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Jamie Perlingiere on October 6, 2016

When will the wood parts be listed on the site for scratch builders?
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dduelm on October 7, 2016

I think that the last page is for the wood elements
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Jamie Perlingiere on October 9, 2016

I want to order the wood parts! Not build them!
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spannerman on October 7, 2016

Have a new Emax 2215/12 905kv motor can you tell me if it will be suitable for this build? I know it's slower than your recommended.
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FliteGreg on October 16, 2016

@Spanner : It would be a shame not to use that nice motor. By default it likes to spin a large prop (10x5, 10x6) slowly (3S). It'll certainly work well in the Spear if you prop it down to a 8x6R and run 4 cells with a 30A ESC. A side benefit of using 4S instead of 3S is that for the same power output, the 4S setup draws less current than the 3S setup. So you can use a lower c-rating on the 4S pack. Try something like a 4s-2200mAh to 3300mAh in the spear and let us know!
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spannerman on January 9, 2017

Thanks Greg I know it's a late reply but I've been building a few projects and suffering crappy weather. But it worked. You guys really know your onions (well aircraft) Thanks so much for the advice and Happy and prosperous New Year!
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Hank Stroisch on October 7, 2016

Printed and built. This is my 3rd wing from Flite Test and I must say this one looks great. Thinking about making this one a screamer by adding a NTM 2836 2200kv with a 6X4 prop running on 4s 2250mah. I think it'll handle it as my FT Versa rips on a Turnigy 2826 2200kv with a 7x5 prop. Thank you for the free plans.
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Hank Stroisch on October 9, 2016

Well I must say it flies great. I burned up my NTM but oh well I was over 100mph with ease. Now to slow it back down and use the GoPro.

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leogcam on October 8, 2016

What is the store link for the wooden firewall and control horn piece?
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JohnTx on October 10, 2016

I didn't see a link to the power pod mentioned in the build video. Can someone provide that?
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JMBadger on October 16, 2016

It is tile #12 in the printable plans.
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Rc Aviation on October 27, 2016

I don't think they have it on the store you have to make it or buy the speed kit :)
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bartusimsek on October 10, 2016

Great job, thank you for plans:) I'm planning to mount NTM 28-26s 1200kv with 4s battery and 8.4 props? What do you think guys? good choice or is there any option better than?
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FliteGreg on October 17, 2016

Your proposed setup won't overheat anything but you could find it too slow for the spear to reach stable speed? You could consider a 8x6 prop for more speed.

I ran some bench tests with a NTM28-26-1000kv short shaft and 30A ESC. All I had for the test was an almost discharged 4s-3300. A stiff 8x6 prop gave a peak current of 12A... Low if you ask me, and your numbers should be close to that... The KV difference being compensated by the difference in pitch.

I recommend an 8x6 or similar with your 1200kv motor on 4s.
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bartusimsek on January 6, 2017

Thank you for you comment!
8x6 props make significant difference, setup works great. Also, thanks for plans.
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Damig on October 13, 2016

Josh, josh and the guys!! Another home run.... BTW, the build vids are great, speed build kits are da bom..and. AND, when you guys are having fun.... It's Priceless FliteTest..

Scott

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For some reason I can't find this plane on the "free plans" pages, had to do a search for it. But I was up until 2:00 a.m. this morning building it, and it looks wonderful. My wife is thrilled every time I finish a plane build because it means she gets her kitchen table back.

I got a lot confused building the center cover because the video shows two pieces being assembled while the scratch plans show a single piece. Perhaps this was a change made after the first run?

Lastly, why are there 2 CGs shown on each wing on the scratch plans (pages 7 and 14 on the tiled plans)? Which do I use? Or am I supposed to use them together because wings are so hard to balance?
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bharris215 on October 16, 2016

Howdy all - The Spear is the 5th FT plane I've scratch built, but this is my first comment to the forum. Each plane I've built started from tiled plans, assembled like a puzzle and cut from DT Foam. Every plane has had a perfect maiden - until now. I followed Josh's build video to the T -- but even with proper balance light winds I found the Spear sluggish, almost as if it was fighting to stay aloft. I killed the throttle @ 200ft AGL and she basically turned into a flailing lawn dart. I'm using the recommended motor proper from above and it does easily recover when the power was re-applied .. not as clean a flier as my Versa Blunt Nose.

It feels to me like there isn't enough "wing area" to maintain a good glide ration. Any thoughts from the experience pool?
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Oh - also forgot to mention ... the recommended "C" power pack comes stock with a 10" prop that is too big for the Spear ...
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Yhea that will make it fly sluggish try using a smaller prop :)
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Hi bharris, can you tell us more about your setup, please list all components. If your spear nosedived from 200ft, maybe your cg is too far forward, or maybe you forgot the "reflex" angle in the elevons? They should both be up a few degrees, a gage is provided on the plan. If it feels sluggish, it could be flying too slow. You could try a prop with more pitch... What are you using?
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bharris215 on October 17, 2016

Thanks for the note back Greg. I am using the exact recommended pieces and parts listed at the top of this thread:

RECOMMENDED MOTORS: 425 sized 1200 kv minimum
RECOMMENDED PROP: 9 x 4.5 CW (reverse) prop
RECOMMENDED ESC: 30 amp minimum
RECOMMENDED BATTERY: 2200 mAH 3s minimum
RECOMMENDED SERVOS: (2) 9 gram servos

Basically a c power pack with a different prop. I included the reflex as well. What would you guess the glide ratio for the spear to be?

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jrwpersonal on October 19, 2016

Can you guys post some details on your et vector installation in this aircraft?
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Manjunath on October 24, 2016

What is the paper size of tiles is it A4 or A5?
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A4 for tiled don't know for full size :)

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jupajana on October 27, 2016

Hi guys, my name is Juan Pablo Jaramillo and I am from colombia, i really like the aeromodelling but i have never flown a rc plane, i want to have a flying wing but i dont know which of your wings is better for a beginner like me. the FT Versa and the FT Spear are amazing! and what do you think about FT Delta? is recommended for me or I can go bigger with another model.
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Manjunath on October 28, 2016

thank u very much
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_0CooL_ on October 29, 2016

Hi,

After reading all comments, I don't know witch prop and motor to chose.

I chose these parts, but are they good ?
- Turnigy L2210C-1200kv
- ESC 30A UBEC/3A
- APC Propeller 10x5

Thx for this awesome plan ;)

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larryoakley on October 29, 2016

Hi guys, what CG you getting on the Spear? I am finishing mine with FPV setup (Runcam2 as FPV&recording camera, 600mw VTX, Eagletree OSD pro, 3200mAh battery, 40A ESC, NTM 3035 / 1400Kv motor), simply cannot get the recommended CG between 3"...3.5". what I get is a CG around 4.25"..4.5", already tried putting everything as forward as possible without success.

Just to clarify, I'm taking the CG reading at the wing root / leading edge, attached you will find a picture of the electronics arrangement while trying to get the CG right.
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Wisedawg on October 31, 2016

Just wanted to let the Flite Test crew know how much I have enjoyed the site since I discovered it this summer.
Your effort to advance the hobby is impressive.
The spear is a great design and comes together well. I am already on my second build.
Keep up the great work promoting the hobby.

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new to rc on November 24, 2016

Is it some what easy to fly for beginners?
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efhlith@gmail.com on November 27, 2016

I just came across this site (through youtube) & I have a private pilots license, multi engine, & commercial license, none of which I have used since going through flight school in 1976. My first love is homebuilt aircraft which I 'admire from afar'!!
For stronger wings, especially if you extend the the wing span, coat the foam wings in a gelcoat or fiberglass. I don't know how this particular foam might react to gelcoat or fiberrglas, so be sure to test on a small piece of foam before proceeding. You might want to beef up the spar, if you go much wider. I built a amall (12"-18", can't remember for sure) delta wing(no engine or 'cockpit area) with adjustable pitch, as a class project to demonstrate the effect of wing pitch & stalling by pinning 1" lengths of yarn all over the wing then mounted it outside of a car & drove down an access road & took pictures of the yarn at different pitch angles until the wing 'stalled' as noted by the yarn no longer following the wing flow. I used balsa wood for the wing layout & green foam between the balsa wood wing design & 'sanded' it smooth the the wing layout pieces using foam to sand it smooth. Using foam to sand foam works great as sand paper would quickly 'fill' with the 'foam dust', but be warned, it creates a terrible 'foam dust' mess. GOOD LUCK & BLUE SKIES!!
Eddie H.
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P.S.I hoped the wrap the wing (after cutting it in half to add a fuselage) but I didn't know that the instructor kept all the different projects.
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marius1117 on December 9, 2016

hello, i recently finished building the spear, it flies fine, i used XA2212 1400KV motor, but it its a bit weak, i need more power. i have Emax GT3520/05 925kv motor, Emax Simon 80A ESC and two Turnigy nano-tech 2200mah 4S 25-50C lipos. would spear be able to handle all this stuff, weight wise, motor is 220g, esc is 80g, lipos 240g each, all this would be 780g. would spear be able to handle it and not break its back or wings from g forces?
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Aristhebeast7 on December 9, 2016

Hi my spear is 820 grams with apm mini and 2200 3s lipo and I dont have any problem! It flys superb! I use 1400 kv SunnySky motor with apc 90x38 prop....
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konraddi on May 1, 2017

Mine is 1200 grams with Turnigy D3530 1100kv, 9x6 Prop and 30A ESC. 2x 1800mah 3s in the back, Gopro in the front. No problems at all...
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Cellborne on December 29, 2016

Hi, Just wanted to say that the build experience was really nice with the FT Spear. I also installed the vector fpv / osd and did my first flight yesterday. Only a few clicks of trim was needed this wing flew pretty much perfect right out of the gate (with controller disabled). Very nice build and design! Plenty of room for everything.
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tjlowery2005 on January 28, 2017

Just took my Spear out for her maiden flight and she flew amazing! Needed almost no trim a flew great! The build was straightforward and quick. Now it's time to get some paint on her to make orientation a bit easier and then it's time to get the FPV gear installed! Thank you guys for another awesome build and fly experience. Keep doing the great work you guys do. Looking forward to see the next design you guys come up with
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Some Gopro footage of my FT Spear in the German / Austrian mountains. Have fun!

https://youtu.be/BngZwJ0_BDA
https://youtu.be/S-AVs-6xp1w
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Nerd on May 27, 2017

What foam compound is best for the build, KT,EPP,Depron etc.
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GoMartin300 on June 20, 2017

could this plane be made with a puller setup? i'm trying to make a wing capable of hovering in place.

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Jmckinney on September 6, 2017

I'l looking at building the Spear as a AG analysis Drone (similar to the eBee SQ), because of this there will be extra equipment installed. What is the "cargo" capacity or can you recommend a setup that allows for the heavier equipment with a long flight time?
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groovemachine on March 21, 2018

Had a lot of fun and learned you can build on a budget...
Here's my very first build album... a little rough and ugly with the extra glue, and a few noobie techniques that i will change on the next build (FT Explorer), but despite some of the rough looking seems this baby feels pretty tough.

https://photos.app.goo.gl/eWbYZa93gsKHYOTc2
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