Cessna 337 Skymaster Inline Twin. Full Fuselage

[Timmy P]

Timmy P, this looks like a great plane...your video/plans inspired me to build my first foam-board plane and actually register on this site. I'm nearing completion on my build - just need to solder everything up and put the posterboard on.

Couple of things that have been confusing to me on the build:
1. In the description you have 1" thick aluminum bar, but it's apparent when putting it together that you used .5" - was too lazy to go back to the store so I hacked the 1" that I bought down to .5" with a grinder
2. I don't see in the plans or the build video how to attach the swappable pod. Based on the finished models, it looks like maybe you put skewers all the way through and did rubber bands on the inside where the pod guide is?
3. I guess the dots in front of the booms are the CG markings...maybe make a note in the plans and I took this to be a cut indicator (so there are two holes on top of my wing, lol.
4. Maybe note in the plans that the second hole on the boom (for rudder) is an option (I learned the number 3 lesson and didn't punch that hole!)

You've done a fantastic job putting this together, and I cannot wait to fly it - when I do, I'll be sure to post pics and video. Oh, how did you do all those fancy graphics for the O-2, they look great!

Greg

Edited with semi-finished plane, done up as O-2, and link to maiden flight:

Hey Greg sorry for the late reply. Thanks for the pointers. There are a few things that need a note attached. As far as the Power Pod goes I use one skewer under the front end of the power pod. and another skewer goes though the pod, located between the motor and the battery location. I appreciate you posting your flight. Looks like everything went well.. When I launch, I toss it hard like a football and then throttle up so I dont get cut by the prop. Hand launching is the only thing not awesome about this plane. The decals I use I make myself with a vinyl plotter. I pretty much just make everything in photoshop and then cut it out, stick it on.

 

[tnkgnr]

Yea, my first flight was really tail heavy - adjusted the battery forward and it flies much better now. For my launches I go to about half power and do sort of a shot-put type launch where I'm pushing up and forward (my video above was really bad because I didn't have the CG set properly). I've flown this at least twenty times now and don't feel it's dangerous at all.

Like you note in your videos, this thing will float for days! It's funny getting to altitude, cutting the power, and just watching it hang out up there. One quirk I've noted though is when you really push the speed on this thing the tail section seems to flutter up and down - when I've been going full throttle and descending is the only time I've noticed this though.

Again, great plane - thank you for putting this all together!

Greg

 

[Seahunter]

Hi Tim, I'm sorta a newcomer and just found your thread due to the recent post by tnkgnr. Really liked your posts and want to build one, seeing you fly it stirs up old memories of these Cessna's. The USAF used them in NAM for recon missions and used to fly them over in small squads. I was stationed on Kure Island Hawaii Loran C station back in 1967 and they would stop there and we would refuel them and top off the pilots with chow and coffee and send them on their way, I knew they were headed for NAM so I never felt the desire to go with them. We had 24 of us there keeping the loran signal online, had to serve out there for a year. Loran C triangulation was the navigation used by ships and aircraft in case any newbies are reading this. Was the most accurate method of triangulating your position before we got satellite's. Google Kure Island Hawaii for a photo of the Atoll. The runway is still there. It's a wildlife refuge now. No trying to steal your thread, just felt like adding a little history and telling a "Sea Story". Great Job, Thanks. Do you plan to come to Texas?
Fred "Old Seahunter Guy"

 

[Timmy P]

Yea, my first flight was really tail heavy - adjusted the battery forward and it flies much better now. For my launches I go to about half power and do sort of a shot-put type launch where I'm pushing up and forward (my video above was really bad because I didn't have the CG set properly). I've flown this at least twenty times now and don't feel it's dangerous at all.

Like you note in your videos, this thing will float for days! It's funny getting to altitude, cutting the power, and just watching it hang out up there. One quirk I've noted though is when you really push the speed on this thing the tail section seems to flutter up and down - when I've been going full throttle and descending is the only time I've noticed this though.

Again, great plane - thank you for putting this all together!

Greg

Good to hear Greg. I just love the way this thing flies. I just cant crash this thing. I still never have, Its just so predictable that it never gets squirrely on ya. Nothing but perfect landings also. Soo Ive never seen it tail wag before. Im still flying the same slow 880kv motors. What size/Kv motors are you using? Im about to order some faster motors. I am stoked that your build is giving you the same experience. Its just awesome how pdf plans make that possible to reproduce it anywhere. Thank you for sharing your build.

 

[Timmy P]

Hi Tim, I'm sorta a newcomer and just found your thread due to the recent post by tnkgnr. Really liked your posts and want to build one, seeing you fly it stirs up old memories of these Cessna's. The USAF used them in NAM for recon missions and used to fly them over in small squads. I was stationed on Kure Island Hawaii Loran C station back in 1967 and they would stop there and we would refuel them and top off the pilots with chow and coffee and send them on their way, I knew they were headed for NAM so I never felt the desire to go with them. We had 24 of us there keeping the loran signal online, had to serve out there for a year. Loran C triangulation was the navigation used by ships and aircraft in case any newbies are reading this. Was the most accurate method of triangulating your position before we got satellite's. Google Kure Island Hawaii for a photo of the Atoll. The runway is still there. It's a wildlife refuge now. No trying to steal your thread, just felt like adding a little history and telling a "Sea Story". Great Job, Thanks. Do you plan to come to Texas?
Fred "Old Seahunter Guy"

Hi Fred. Hey sir first thank you for your service. My parents are also both USAF. My Stepfather was in Nam with the Army. 2nd Lieutenant. I have always been a fan of the 0-2 with the grey paint. Hopefully you seen the flying at the end of the Build VIdeo where I fly my Oscar Deuces a replica from the movie Batt 21. Thats my favorite plane to fly. Here is a youtube link to the Movie. To avoid seeing the stars just move the web browser to the bottom of the screen. Its worth the watch. As for Texas FliteFest, I live just a couple hours from FFohio so thats the only one I plan on going to. -Timmy P .

 

[Seahunter]

Thanks Timmy, I'm planning for Texas, hope to be around for Ohio next year.

 

[tnkgnr]

Good to hear Greg. I just love the way this thing flies. I just cant crash this thing. I still never have, Its just so predictable that it never gets squirrely on ya. Nothing but perfect landings also. Soo Ive never seen it tail wag before. Im still flying the same slow 880kv motors. What size/Kv motors are you using? Im about to order some faster motors. I am stoked that your build is giving you the same experience. Its just awesome how pdf plans make that possible to reproduce it anywhere. Thank you for sharing your build.

I'm using the same 880kv motors, but I think I've got more aggressive props than you have - I'm using 11X7 props.

 

[tnkgnr]

So, a little update - my first one crashed in a spectacular way. I did a full throttle dive and that oscillation I had ripped out the horizontal stabilizer. All the electronics were salvaged so I pretty quickly made a new one. This time I did the paint scheme like the psyops version. I haven't had any oscillation with this one, so maybe I just had some sort of weird build flaw the first time. Anyways, I got some good video of it with a runcam on the plane and my brother filming from the ground. It was really windy that day, so it seems really jumpy - normally that thing flies smooth as silk!

Check it out

 

[BATTLEAXE]

So this bird is ready to maiden.. Everything is installed and tested. CG is set a bit nose heavy for the first flight. And lastnight I made some sweet graphics for it.. So now it just looks rad, And I am so excited to fly this 60" beast. I am curious to see if my motor selection was good.. I may have over powered it it.. But I do that with most of my planes. Soon Ill work on a tricycle landing gear set up. View attachment 89191
View attachment 89192

That looks amazing Bro

 

[eeck62]

Wow, really beautiful flyer!

 

[richb2599]

Tommy, Just did the maiden of my O2 Skymaster. It turned out great! 1380 grams all up weight. I used the Emax GT 2215/09's with 9x6 props, 30 amp Esc's and 2600 3s batts. Also added landing gear. Mains are from the FMS Cessna 182 and added a steerable nose wheel. No problem taking off from out park's rough grass field. I made a few changes to replace the pod with fixed motor mounts and a battery hatch on the bottom. The plane flies great! very little trim required. Thanks for a great design and build video.

 

[tnkgnr]

Long-term update. After several dozen flights, my main wing ended up folding on itself. I'm guessing over time the aluminum spar just built up some metal fatigue and gave way. I will caveat that I fly it like I stole it, so I'm pretty rough on these planes!

 

[BATTLEAXE]

I will caveat that I fly it like I stole it, so I'm pretty rough on these planes!

You and I are on the same team man, that's how you get better

 

[nikbrewer1]

is there a dxf or clean PDF of these plans? I cant really see much in the uploaded plan jpeg

 

[Rl70]

Hi TommyP

Congrats for that beatiful bird. I'm building it but I didn't find any info about the dihedral angle of the wings.

Could you please let me know that?

thanks
rl70

 

[Cobra1365]

I think I’ve just found the airplane I want to build!
im sure I’ll have questions along the way. But, it looks amazing! Great job!

 

[Cobra1365]

Looking at the plans, I don’t see any dimensions. How are they converted over to templates?

 

[Cobra1365]

Most of the supplies are purchased. Would like to see how people have set up landing gear. In particular, steerable nose gear.

 

[Cobra1365]

I went with the 2215/09 motors as well. 30 Amp ESC. 9x6 dual bladed props. I have three 3s 1300mAH batteries and a couple of 3s 2800 mAH batteries. What’s going to be the better choice?

 

[Cobra1365]

Wing is all but finished. Still need to connect control rods.