Cessna T-50 Bobcat, Twin motor "Sky King"foamboard

by Timmy P | October 24, 2014 | (22) Posted in Projects


Hey Flite Testers, I'm working on a project and thought I would share my progress. A little over a month ago I was seaching through images of Cessna paint schemes for my Simple Storch. I stumbled apon a Cessna T-50 and just loved the classic look of it.. And It also had twin motors, yes!   So I collected about 50 pictures of the plane and used a rainy weekend to start my first version of templates. The first version is just a beta version to see if it is air worthy. I plan to add much more shape/ detail and cool paint jobs on the next versions to come. This just has a simple quick tape job for orientation. But man it still looks beautiful.. Im happy with the way its come so far.  Its a fun proccess.  The maident flight was outstanding. Rolling take off in tall thick grass in under 3 feet. And it tracked perfectly straight and had them twin motors singing me a duet. I could climb verticly much much faster than any single motor planes Ive flown....

        A few changes do need to be made on my next versions to really dial it in..   #1.  When I cut the ailerons I had plans of making them dual function flapperons. I thought it would be good to extend them inboard so that the prop would push air on them. Well I tappered them real fat behind the props, then much skinnier at the wing tips.. The result of that is I have lots of roll under throttle but under glide its a bit sluggish. So I just have to change the shape of the ailerons. #2. I need much smaller motors. Im currently running twin Turnigy 2826 2200Kv and they are heavy and way over powered. I like a real slow glide and it sinks a bit at slow speed. Im likely to try 2212 1800kv motor setup. I would also like more flight time. I dont have twin batteries of the same Mah so I get about 6 minutes of flight with a single 2200 3cell.  I would like to eventually get the plans of the final product made into a PDF I can share. So look forward to being able to make yourself a T-50 if you would like..    I have to give thanks to Flite Test for showing me the ease of getting into this hobby. This is my first year flying and I've only flown FT designs. Well other than my modified Spitfire I made into a dorsal finned shark, I took to Flite Fest with me lol.  So all you need to design and build your own plane is dedication.  And a bit of trial and error.  Thanks for checking out my plane and I hope I inspire others to dive in head first.   

####  Heads up!!   I'll be at the Horizon Indoor Electric Festival in my city Columbus Ohio Nov 7-9 if you want to buy a speed build or a full built and painted plane.   Or look for me flying my Shark plane and say hello . ####

 

I used thin strips of foam board to get the wide radius used on the fuselage. and I used the Spitfire wing as "inspiration" for my wing lol.. Thats my mornings cerial bowl as the wing tip haha.. 

 



 Kinda moking things up. Getting a feel of how it will look. 


 Got the airframe done for the most part. Time to figure out motor mounts.

 

With a blank canvas it still looks elegant.  Getting excited!



These are my motor mount/ landing gear mount.  They were supposed to be mirrored but came out identical. opps.  



To make the mounts I soaked a thin ply in CA, then lamitated two layers together. then CA'd them together to form the mounts. Rock solid. 

With the motors mounted it was time to test the CG.  It was very tail heavy. I held the motors back from scale thinking they would make it nose heavy. So I shimmed them out towards the nose with 3/4 plywood and that helped a great deal. battery now mounts at the wing spar.


Now I got some markings on it. Its looking like a plane.( or flying mini-van lol)  I've opted to make it a detachable wing to gain access without making a door or hatch elsewhere. Its worked great so far.


Then came time to make the landing gear.. Only gear Ive made so far has been for the storch so with these I was just kinda winging it and rolling with it....     pun.


So burying the gear mount in foam board and gluing it did NOT work like it does on the storch.  Since then Ive replaced it with melamine thats the same thinkness as foam board and its worked great so far. Could use plywood also. Melamine is quicker to cut.


 

For props I bought some multi rotor props spinning opposite directions. They are 8x4.5   A bit overkill aswell as the motors also. Turnigy 2826 2200kv


 I made the wings overall 4 inches longer than scale. Just to make sure it would fly. Once I find a lighter motor combo I'm hoping I can cut them down a bit.  Still looks awesome with a wide stance.


 The final picture. All ready to launch.  I remove the foam cups during flight till I form something more aerodynamic.  

Here is a quick video of me flying it.  Let me know what you think..     This is my first article or Flite Test post. Im assuming I can edit and update this article as it comes along.  Thanks for viewing. And hope to see everyone again at Flite Fest next summer. Look for this and my sharks! lol   Maybe sharks will be the next article ?

 

 

 

COMMENTS

poplton1 on November 7, 2014
Thanks Tim, thats exactly what I needed. Most of my planes have been modified Spits, in fact I have a twin motor Spit on the shelf I haven't finished yet. I maidened my 40in Storch yesterday. Flew good. Love FT and all the cool articles you guys submit. Thanks again.
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jtuttle on October 26, 2014
Out of the blue of the western sky comes 'Sky King'! I have found that if you remove one side of the paper covering from the foam board you can fairly easily form it into a cylindrical shape. Use a rounded object to help form the curve. I've used wooden dowels or you could use a piece of pvc pipe. Just remember to remove the paper from the inside and the foam won't crack.
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ofir77 on October 26, 2014
Amazing plane, great job.
I'm all in for the over power.... :-)
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808aerosquadron on October 26, 2014
Styrofoam cup engine cowlings - Brilliant. Well done.
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Noobi1951 on October 25, 2014
That looks great! The launch looked like it was catapult assisted, wow. Cut down a couple more foam cups and you could use them for the fronts of the necels . All in all a very nice build, and great flier.
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Timmy P on October 26, 2014
You should have seen it before I turned the angle of the motors down to counter act the lift of the nose. It literally didn't roll. It just shot up into the air.. It was wild!
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CJGFX on October 25, 2014
Brilliant. Please keep us up to date with future versions. It certainly is over powered, but fun... I'd be very interested in some plans to have a go doing a slower scaled version.
Great job!
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Yogenh on October 25, 2014
I am with you would like to have the plans. It looks really nice and fun to fly
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Timmy P on October 26, 2014
Anybody know how or where to take my templates so they can be made into plans I can share?
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LordVader on October 25, 2014
I'm all for a set of plans. That is a beautiful plane. Nice work, will be waiting to see V2.

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alibopo on October 26, 2014
What a brilliant looking plane, and great to see how well it flew. When you quoted 2200KV motors I was surprised you matched them to 8" props. Were you flying on 2S batteries? On 3S I think they'd be spinning so fast they'd be better matched to a 6" prop, and draw a lot less current, and still produce plenty of power! Have you had a look at small clear plastic water bottles for your engine nacelles? Some are a bit 'lumpy', but I'm sure there's a base design that would give you that nice round cowl, and if you can find the right height of bottle, a body that closes to a taper on top of the wing. A little shaped and curved block of polystyrene to make up the front windscreen would be my final mod to the appearance. If you ever get bored with it, split those ailerons and add flaps for those really slow crowd pleasing approach speeds. Cheers.
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Timmy P on October 26, 2014
Thank you sir, Im glad you like it.. It is a very fun plane to fly.. It being my first twin I just love the way it sounds. The motors I used, I just had them sitting around. I found them real cheep and got 3 of them for future single prop planes.. So using 2 on one plane I should have made it like a 70" wingspan lol.. And the props I got were closest I could find to the 7" that looked good on the bench, and 8" props are the only ones I could find local that counter rotated in local stores. Maybe you can give me some advice on what motor size to use.. Its a 49" wingspan. I would like to run dual batteries at times for real long run times. So I dont want to go too small with the motors. But still be light for really slow fly-bys. Im not sure If like a 2222 would be good or I found 7$ 2812 1538kv that I'm assuming would be maybe still a bit to big, I just dont have the experience yet to decide.

Also thanks for the recommendation on using bottles for the nacelles.. I was thinking of forming something from pink foam which I still might do.. Because I dont think I can get a "compound radius" as in ballooning the fuselage along the length of the top. So that will likely be pink foam. Then who knows I may make the entire nose out of a block of foam to get the roundness.. I just looked up Polystyrene.. yea that stuff haha.. Thanks again.
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PeterGregory on October 27, 2014
This is the Bamboo Bomber, and Songbird, the star of Sky King, the TV show in the early 50's. You can watch the shows on Youtube. Great pick for an airplane. I have plans for the balsa twin but have to build up some flying skills before I undertake that project.
I did a FT article on using EPO foam for a turtle deck for the Ripslinger, you can check it out. You will find you will start cutting and shaping pieces for the nose, nacelles, cowls, fairings, etc. . It is really, really easy to use. I used light spackling compound to smooth out the surface and create a barrier to rattle-can spray paint.
Flies really well in your video - I like your idea of starting out with too much wing and cutting it back.
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alibopo on October 26, 2014
I have one of those cheap 2200KV motors, and I found it hard to find a use for it. Just too fast for me and my slow, plodding planes (and a bit noisy and screamy). I think they're great for pushers where there's limited space for the prop, but not so good for something you want to coast along, though your Bobcat looked great, and didn't sound like it was too noisy. I found mixing too large a prop with a motor that performs best when its spinning fast resulted in a lot of wasted power (short flight times) and the engine getting very hot. Slightly too 'big' a motor isn't an outrageous idea - having the motor performing comfortably in its mid range where it's most efficient in terms of 'fuel use' (battery) makes sense. I'm a 3S battery user and tend to stick around the 1000 - 1500KV range swinging 10" to 8" props. But to get the 'scale' look on your bobcat maybe it needs a smaller prop? A 6" APC might be a better fit and would work with the higher KV motor. Probably still plenty of thrust, and I'm pretty sure you'd get better flight times than with the 8" props. I'm sure I've seen both rotations at that smaller size on the HobbyKing website. I'm sure your plane can't be heavier (1020 grams) than my 39 inch wingspan 'morphocoupe', and I get about 12-14 minutes on 2000mah of battery. Yep, polystyrene foam can be pretty soft, but add a coat of dilute PVA (white glue) and it toughens-up nicely, plus with the added PVA it can be spray painted without 'eating' the foam. Regarding the nacelles, I'm sure I've seen a couple of water bottles (evian?) that fatten and then taper along their length. But watch out, you can get a bit obsessed with checking food packaging for alternate uses, especially those clear blister packs for aircraft windscreens. :) Cheers.
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anonymous rc pilot on October 26, 2014
great build! although i recommend using same-direction props, there cheaper and the torque isn't that bad at least with appropriate speed motors. If you end up having toque problems just give it some left-rudder trim
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poplton1 on November 7, 2014
PS You can catch a lot of Sky King on YouTube

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earthsciteach on October 25, 2014
Very nice build! Love the use of the styrofoam cups. Where did you get those awesome diamond pattern wheels?
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Timmy P on October 26, 2014
The wheels are awesome right? Everyone that sees them says something.. They are DuBro Diamond light 3 inch wheels, I got them at a local shop. Extremely light for their size. Glad you like my plane.
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poplton1 on November 5, 2014
Great article, thanks. Could you please give the basic specs for the wing and fuse. I love Sky King. Making this my next build.
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Timmy P on November 7, 2014
Cool I'm glad you like it.. I need to watch the TV show so I know what its all about.. The Specs are all In Inches. Wingspan 49" Length is 31" And fuselage is a 5.5" square box at its widest. Not sure what else could be helpful.. the wing is basically a modified spitfire wing, I just made it longer and changed the angle at the seam to sweep the wing back just a bit.. Good luck.
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WildWillie on November 1, 2014
With some slight changes you could convert this into a Bristol Beaufighter or a Bristol Blenheim.
Both of these planes are British WW2 aircraft.
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SnapPunchRobert on December 8, 2014
I'm such a noob still, any plans yet. I really like your plane.
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Michael9865 on July 18, 2015
I like your motor mounts. I am going to use the design for my Puddle Twin instead of stick mounts. Such a simple solution, but I just could not wrap my head around how I wanted to do it. Thank you!
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planebreaker2000 on July 22, 2015
Cool Design any progress on version2 or plans?
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Webco710 on June 23, 2017
Hi guys , I'm Tom I am interested in building this Cessna t50 . I would purchase the kit if it's still available. You can email me at user500000@aol.com
Thank you
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Webco710 on April 9, 2019
Hi guys , I'm Tom I am interested in building this Cessna t50 . I would purchase the kit if it's still available. You can email me at user500000@aol.com
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Cessna T-50 Bobcat, Twin motor "Sky King"foamboard