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*Unofficial* FT Simple Cub

Sure. Don't know what your previous flying experience is, but the Simple Cub (with standard control throws) can be a handful at first. If you're using it as a trainer you can dial down the ailerons and rudder for the first couple flights (I think my ailerons are 1/2 the low gauge setting) to make it more "cub-like". I plan on using expo settings at some point and adding flaperons into the mix (about 1/2 flap) for landing. I don't need any help with take-offs, with the B pack motor, a 9x4.7 APC prop and 1000mah battery this thing can take off in a couple of feet on grass (I'm using Timber 1.5M wheels).
Most of my flying has been with the safe stuff from Horizon. This will be my first plane with out safe. Still trying to get more experience & flying Sim. It may be awhile before I can fly it. I order Batts from HK and my order has been processing since 3/20 and this is from the US warehouse. No telling when they will arrive.
 

Forster

Slow, low and dirty.
What radio are you using for the cub and can you bind it to your safe stuff? I started with a Champ S+ and toned down the throws on the ailerons/elevators in the non-SAFE mode for practice (knowing I could bail out and engage the safe) and that helped a lot. I'm using a DX6E Spectrum and they have settings for most of the SAFE stuff on line (down loadable). I had to rebind, but it was pretty easy to go from the Champ to the Cub.
 
What radio are you using for the cub and can you bind it to your safe stuff? I started with a Champ S+ and toned down the throws on the ailerons/elevators in the non-SAFE mode for practice (knowing I could bail out and engage the safe) and that helped a lot. I'm using a DX6E Spectrum and they have settings for most of the SAFE stuff on line (down loadable). I had to rebind, but it was pretty easy to go from the Champ to the Cub.
I have a DX6 G3. Just got it a couple of weeks ago. I plan on setting it up with Hi & Lo rates with some expo to help out.
 

Forster

Slow, low and dirty.
So, after two flights of less than 10 seconds I figured out my aileron issue (servos weren't centered and my ailerons were both pointed up slightly) and managed a decent flight with a wheels on the ground landing in a plowed field (it's all in the flare). Some day I'll get my pre-maiden checklist down to a science. In the meantime, "Thing Two" is ready to fly. I've got the original B-Pack motor and the shaft is bent, so motor two is on the way.
 
So, after two flights of less than 10 seconds I figured out my aileron issue (servos weren't centered and my ailerons were both pointed up slightly) and managed a decent flight with a wheels on the ground landing in a plowed field (it's all in the flare). Some day I'll get my pre-maiden checklist down to a science. In the meantime, "Thing Two" is ready to fly. I've got the original B-Pack motor and the shaft is bent, so motor two is on the way.
Glad to hear you got it back down. Yeah, I may have to make myself a note checklist for preflight also. I did the same thing for my camper. That way I don't pull off with the awning out or the antenna still up. We had a guy with a new camper a couple of year ago that pulled off with his awning still out. Needless to say he knocked it off of his camper when it hit a tree. Couple of thousand dollar lesson.
 
Hi
i haven't Flown RC in 12+ years and am trying to get back in the hobby. I scratch built the ft simple cub and it was a great experience. I have the current power pack B with a 3c 1300mah. i went out to maiden it yesterday and found i am not going to just get back on the bike so to speak. 8 mph winds and i couldn't keep it in the air long enough to work on trimming it out. I know i have some aileron trim to do it banks left but not sure how much because i think the wind helped it out a bit. I am using a fly sky fs-i6x transmitter.

any suggestions would be great.
 

Forster

Slow, low and dirty.
Hi
i haven't Flown RC in 12+ years and am trying to get back in the hobby. I scratch built the ft simple cub and it was a great experience. I have the current power pack B with a 3c 1300mah. i went out to maiden it yesterday and found i am not going to just get back on the bike so to speak. 8 mph winds and i couldn't keep it in the air long enough to work on trimming it out. I know i have some aileron trim to do it banks left but not sure how much because i think the wind helped it out a bit. I am using a fly sky fs-i6x transmitter.

any suggestions would be great.
I may be the wrong person to give advice since I'm the king of the 12 second maiden flight, but here goes. After building my first and crashing it twice in under 12 seconds I decided to get it ready to fly, power-up everything and run with it in hand letting it go briefly to see what trim it needs. When I had it gliding without stalling and relatively straight I flew it long enough to get it trimmed (only trimming into the wind). I've also reduced the aileron throws to about 75% of the low rate to start (because I was a crappy pilot 38 years ago who now has 38 years of non-flying to make be worse). Of course when I finally killed the first simple Cub I built a second one and did exactly the same thing (crashed twice before figuring out what I was doing wrong). So I would do the glide test a few times (in tall grass if you can find it) then go for it. I highly recommend hand launching with 75% throttle and once you get a few mistakes high trimming it at 50-60% throttle. Another trick I stole from someone was to build the power pod with a little down and right thrust angle built in (I make the lower right corner (airplane right/your left as you look at the front of the pod) 4mm shorter, the upper right and lower left corners 2mm shorter). You can cut that with a blade or sand it in (I use a disc sander because I can set the table and miter gauge) before you add the engine mount. You can do this later by ungluing the mount or you can add washers to change the thrust angle. I find this method keeps things pretty squared away until 90% throttle, then the Cub is gonna climb. As an aside, I'm using Timber 1.5m wheels with 1/8" music wire gear mounted into a plywood plate (glued in the traditional mount location) with the wheels 1" forward of where the plans show them. I think the extra weight keeps things manageable on maiden flights as it reduces performance and roll slightly.
 

Hai-Lee

Old and Bold RC PILOT
Hi
i haven't Flown RC in 12+ years and am trying to get back in the hobby. I scratch built the ft simple cub and it was a great experience. I have the current power pack B with a 3c 1300mah. i went out to maiden it yesterday and found i am not going to just get back on the bike so to speak. 8 mph winds and i couldn't keep it in the air long enough to work on trimming it out. I know i have some aileron trim to do it banks left but not sure how much because i think the wind helped it out a bit. I am using a fly sky fs-i6x transmitter.

any suggestions would be great.
I fly a lot of different types and do a lot of maidens, (I build lots of prototypes etc), the first real problem you may be suffering from is the standard lifting off too soon on take off. My test flights which are only done after taxi trials and a few "Hops" are accomplished after the longest and fastest take off run I can perform. This approach allows me to do a slow lift off to a few feet to see if I have any serious issues. After a small amount of the low flight I feed in elevator, (or elevon), to climb to around 3 mistakes high where I can trim and give the design a good test. (check stall, roll rate, elevator response, rudder response and the like).

After a short flight I then bring the plane for a hot landing, (somewhat faster than i would normally). Upon landing I adjust control deflections, Expo and the like and then do another high speed take off run to check my changes.

I do still have the odd crash on a new design but they are now, (thankfully), infrequent to rare.

Planes need speed to fly! The faster the plane is moving the more effective the control surfaces will be. Taking off too slow will ALWAYS cause a plane to either wobble or roll and dive into the ground.

I hope this helps!
 

Forster

Slow, low and dirty.
Interesting day: Straightened out the prop shaft on my CF 2822 (old b-kit motor), I guess I crashed a time too many times for that particular motor to stay straight. Went ahead and enabled my flaperons while I was working on the Cub. Funny how difficult I made that task. First they my ailerons were going the same direction, then I took a while to figure out that I had to change the throws to match (right aileron was at 50% and left was at 100%). Once I'd "undumbed" things, the radio set-up was a breeze. Should have calm skies tomorrow. I'll see how it goes.
 
I got out again last night it was much calmer....that helped a lot. i looked at my ailerons and found that the left was sitting slightly up when the radio was on, so i loosened the set screw and corrected that. also i went to 50% on the range limit in the radio for both and added some expo as well. it is getting better but then my rudder control horn came unglued and we called it a night. i am really impressed with the foam board it is holding up to the crashes, granted we still have a good amount of snow here so even the harder ones have a soft hit. i think next build i might invest in the water resistant foam board or buy the speed build.

right now i am just having fun with it!

Thanks for all the advice.
 

Forster

Slow, low and dirty.
Yup, at $2/sheet, it's pretty amazing building material. I like the speed builds because it's pretty time intensive for me to lay out and accurately cut everything, but I can have a cub out the door in around 2 hours. I may actually paint this one since I think it will last a while. What I'd really like to find if Packing tape, that's repositionable, and shrinks to fit in a 2' wide roll. ;)
 
Firewall 2" x 1-11/16", Why?

From my research the FT Swappable Firewall is 2" wide and 1-3/4" high.
The Firewalls, drawn on the plans of the Simple Cub and the Simple Scout are 2" wide and 1-11/16" high.
Yes, that is only a 1/16" difference, but on the Simple Cub, that changes the down thrust some, probably not enough to worry about, but I am confused as to why the info in the Power Pod Build, and on other plans, notes that the height is 1-3/4".

Can some explain what's up with that?

Thanks
 

Forster

Slow, low and dirty.
Don't know the answer to that, but I did find a post somewhere that showed a modification to the power pod where they added down and right thrust angle by trimming the power pod by 2mm on the left lower and right upper corners and 4mm on the right lower corner and then connecting the lines. Seems to work pretty well.
 
Thanks for that information.

The Simple Cub has down thrust built into the design. That is the reason for my question.

If the Simple Cub's firewall is attached with the bottom of the firewall aligned with the bottom of the Power Pod, the angle of down thrust is 2.3 degrees. That is the angle created by the top of the fuselage doublers. From the build video it is clear that the firewall is NOT attached that way.

If the Firewall is attached to the Power Pod with the top of the firewall a foam thickness above the top front of the firewall, as suggested in the video, the down thrust is 2 degrees if the firewall height is 1-11/16" or 1.7 degrees if the firewall height is 1-3/4".

All of that is a pretty minor deal, but I'd really like to know what's going on with the firewall height on the SPONZ plans for the most recent builds.

I assume that the Simple Cubs being built to create the video used the FT laser cut firewalls which are, at my best guess, most likely 1-3/4" high, since that is how they started cutting them on their earlier kits and what was noted on the DIY plans.
 
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Forster

Slow, low and dirty.
I'm pretty convinced that the video build shows a generic power pod build. Josh mounts the ESC on the bottom where the battery goes (at least on the builds I've seen and done). On another note, I re-maidened my Cub after painting. I got really lucky because I forgot to treat the re-maidening as a true maiden flight. So many little things change when you add paint: balance (if you don't adjust your battery position), trim settings, power settings... I got lucky with the first 15 seconds of flight and recovered a plane that was far out of balance. Second flight, really good. Two minor near disasters, clipped a tree and recovered and stalled in a turn pretty near the earth. Recovered both.
 
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Forster

Slow, low and dirty.
Windshear and Tree Lines. Important lesson of the day: Forecast indicates light winds from the North at 5mph shifting to the North-Northeast at 7mph. I take off in my yard (surrounded by a 30' tall tree line on the North and West sides. Plane climbs out and almost immediately hits the boundary layer causing a loss of control. I recover the plane relatively successfully (no repairs required) and stupidly try again. History repeats itself (20 minutes of repairs required). Then I walk to the west of the tree line and actually launch into the West wind. After 3 minutes of hovering and 3/4 throttle I land on the same spot I launched from (how many folks can land a simple Cub in a plowed field against the direction of plowing and not ground loop or nose over? This guy can - at least once). Turns out the real winds (based on my wind gauge that normally stays with the target shooting bag) are 12 mph from the west. My Cub is ugly but undaunted. I think my next project should either be a parachute recovery system (no use today though) or a shock absorbing engine pod.
 

AkimboGlueGuns

Biplane Guy
Mentor
Gotta love that mechanical turbulence. Even with relatively light winds these foamies get tossed around like an Archer in moderate turbulence (ask me how I know.) Good news is as long as you stay below the obstacle they still fly great!
 
I'm building a Cub from plans and am planning to install the electronics on a shelf semi-permanently installed where the power pod would normally go - only the battery is going to consistently get handled between the maiden flight and the final, tragic landing, hopefully months later. If I'm gluing the firewall directly into the fuselage, what considerations (e.g. thrust angle, accessibility) should I keep in mind?
 

Forster

Slow, low and dirty.
I'm building a Cub from plans and am planning to install the electronics on a shelf semi-permanently installed where the power pod would normally go - only the battery is going to consistently get handled between the maiden flight and the final, tragic landing, hopefully months later. If I'm gluing the firewall directly into the fuselage, what considerations (e.g. thrust angle, accessibility) should I keep in mind?
I'd use at least a truncated version of the power pod as it sits at an angle to the angle of incidence. I also add a little right thrust angle when building my power pods (right side is 2mm shorter than the left). The reinforcement provided by the tape to the firewall is pretty critical to the structural integrity. You could build a mini pod from plywood and glue it in permanently, but you'll want to do something other than just hot gluing the ply to foam board. Cubs are pretty dang rugged as designed and I have learned to appreciate the durability the powerpod concept brings to the model.
 
I'd use at least a truncated version of the power pod as it sits at an angle to the angle of incidence. I also add a little right thrust angle when building my power pods (right side is 2mm shorter than the left). The reinforcement provided by the tape to the firewall is pretty critical to the structural integrity. You could build a mini pod from plywood and glue it in permanently, but you'll want to do something other than just hot gluing the ply to foam board. Cubs are pretty dang rugged as designed and I have learned to appreciate the durability the powerpod concept brings to the model.
Since I'm planning on slapping a C pack on this poor beast, thrust angle is a big deal for me. Do you think I ought to throw some down thrust in as well for that motor?

I might design and 3D print a truncated pod and avoid the tape issue altogether - that'll also allow me to put in thrust angle without relying on my mediocre foam skills to get it right. Building one from foam might be less effort the first time, but if I can successfully design the pod, then everyone gets to benefit from the STL, including me on future builds.