*Unofficial* FT Simple Cub

Forster

Slow, low and dirty.
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.
The plan has some down angle build in so if you're following the angle the pod sit in you should have enough down angle.
 

Ken Myers

New member
I found the answer to my question about the firewall size. A friend brought over his FT laser cut kit for the Simple Cub on Monday.
It measured just shy of 2" wide and 1-11/16" high.

The Simple Cub has no decalage, or difference in the datum line angle between the wing and horizontal stabilizer. Both the wing and horizontal stabilizer are horizontal to the datum line. Any horizontal line drawn across the fuselage parallel to the fuselage top is parallel to the datum line.

The Fuselage Doubler tops run at -2.3 degrees from the horizontal datum line. If the firewall is attached so that the top of the firewall is a DTFB thickness above the Power Pod front, 1/16" of the firewall protrudes below the bottom of the Power Pod. When the Power Pod is inserted, the front of the Power Pod is raised 1/16" and the resulting down thrust is -2 degrees. Aligning the firewall so that it is flush with the bottom of the Power Pod yields a down thrust of -2.3 degrees.
 

Earl Turner

Member
E2 not so simple cub ready to fly. Finished installing the wing struts, dummy A40 engine & landing gear detail. Its a bit heavy at just 1.01 Kg. Waiting for the snow to melt at the local flying field.
E2 Cub.jpeg
 

FTNoob18

New member
Here are some pictures of my recent build of the FT SIMPLE CUB. My printed and glued on engine graphic looks great, shocks made from straws, and number temple which i spray bombed. entire plane was spray bombed. Tailwheel was a lego wheel which I upgraded to a 1/2"foam wheel now. Used a Coat Hanger for the landing gear and the dowel rods slide up and down inside the foam. 1000mah and 1300mah 3s batteries I will be using. Still have not flown it yet but looks great on the wall!
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and the struts dislodge from the fuselage to remove the wing.
 

Forster

Slow, low and dirty.
Well, the second simple cub had a wing failure today. I blame it on the combination of sunshine and trees. I was flying this morning and put the plane between the sun and myself. The good news is that I wanted to build a modified wing for a cub at some point anyway and I have a box of waterproof foam. The bad news is that the weather is great today for flying and I've got nothing to fly. May need a third receiver. Plane on the bench, plane ready to fly and a spare plane.
 

Forster

Slow, low and dirty.
WIN_20180526_18_27_48_Pro.jpg

Cub #2 seems destine to keep flying no matter what. After more than a dozen wing repairs, a new power pod and replacing the top of the cowling I managed to fly into a tree after getting sun blinded this morning. This is the new wing. 39.5", wingtips cut at 45 degrees and closed up with poster board and I built the underside with no under camber (carried the bottom panel all the way to the edge of the wing). Flies great.
 

Forster

Slow, low and dirty.
View attachment 107915
Cub #2 seems destine to keep flying no matter what. After more than a dozen wing repairs, a new power pod and replacing the top of the cowling I managed to fly into a tree after getting sun blinded this morning. This is the new wing. 39.5", wingtips cut at 45 degrees and closed up with poster board and I built the underside with no under camber (carried the bottom panel all the way to the edge of the wing). Flies great.
Mounted the 10x4.5 prop that comes with the new b power pack motor. Worked great, may have to make that the new Go-to prop.
 

Gazoo

Well-known member
When I installed my power pod on my current cub, I had to cut off the tabs to make it slide in. I'm pretty sure I had to do the same with the first one as well. Do the tabs need to be cut off to make it fit? It kind of makes the power pod unusable in other planes if so.

I didn't see a reference in the build video or anywhere in this thread. Can you point me to it if the reference does exist?
 

Forster

Slow, low and dirty.
When I installed my power pod on my current cub, I had to cut off the tabs to make it slide in. I'm pretty sure I had to do the same with the first one as well. Do the tabs need to be cut off to make it fit? It kind of makes the power pod unusable in other planes if so.

I didn't see a reference in the build video or anywhere in this thread. Can you point me to it if the reference does exist?
Mine fit tight and the rears needed to be trimmed due to the servo location. I have yet to swap a pod or even have a pod out live a plane so I'm afraid I'm not much help.
 

m00nsp3ll

New member
Hi all,
i almost finished building FT simple cub but i have some issues. The first one is i dont know where to place the battery and how to fasten it there. Second issue is where to place the Receiver and how to fasten it there ( i can not see it in official built video)

if you could reply with pictures i would be appreciated

thanks
 

Forster

Slow, low and dirty.
I'll send pics tonight. The build video shows the ESC under the power pod. It actually goes on top with the battery mounted on the bottom. I route my ESC wires through the provided hole and that gives me plenty of room to adjust the battery position. When I build Power Pods with waterproof foam I use a little hot glue (in addition to the adhesive backing) because it seemed to come off otherwise. I also cover the entire bottom of the power pod (front to back and side to side) with Velcro and do the same with the battery so I have as much stay put as possible. I attach the receiver in front of the rudder servo with Velcro. Placement isn't super important but you do want your antenna to have a place to go in a straight line. Out of old habit, I route mine between the wing and fuselage and hang it outside the model. There is no reason for this with a foam model unless you're gluing aluminum foil to the plane (not something I would consider either).
 

basslord1124

Master member
Well I attempted to maiden my Simple Cub Tuesday night and it ended up in a hard roll to the left and smack down in the dirt. Did suffer some damage, but it's fixable. I was quite surprised since I was only running a 3 channel. I first thought it was a torque roll issue (which I suppose it still could be) but after looking at it my tail is crooked. So anyways, going to fix the tail and any other repairs and may try again next week.
 

Forster

Slow, low and dirty.
Well I attempted to maiden my Simple Cub Tuesday night and it ended up in a hard roll to the left and smack down in the dirt. Did suffer some damage, but it's fixable. I was quite surprised since I was only running a 3 channel. I first thought it was a torque roll issue (which I suppose it still could be) but after looking at it my tail is crooked. So anyways, going to fix the tail and any other repairs and may try again next week.
Good hard chuck if you're hand launching, avoid 10" propellers, recheck the CG and use 3/4 throttle for launch. Try hard to gain some speed in relatively level flight before trying to climb. Even when I takeoff from the ground I find it very easy to stall the wing if I try to climb out before gaining speed due to the combination of low speed and prop torque.
 

basslord1124

Master member
Good hard chuck if you're hand launching, avoid 10" propellers, recheck the CG and use 3/4 throttle for launch. Try hard to gain some speed in relatively level flight before trying to climb. Even when I takeoff from the ground I find it very easy to stall the wing if I try to climb out before gaining speed due to the combination of low speed and prop torque.

Ended up hand launching b/c the wheels couldn't do well on the grass. I've got some bigger ones I may slap on there now. Using a 9x6 prop and throttle was probably at half. I suppose it's possible it could be a speed issue.
 

Hai-Lee

Old and Bold RC PILOT
Ended up hand launching b/c the wheels couldn't do well on the grass. I've got some bigger ones I may slap on there now. Using a 9x6 prop and throttle was probably at half. I suppose it's possible it could be a speed issue.
I do not know if this will help you but I use a 8x4.7 SF prop and it gives me a rapid acceleration and more airflow at low speed for rudder control whilst in the take off ground run. In the air my version can fly very slow but the aileron effectiveness decreases rapidly as you slow down. A bit of throttle with the SF prop actually improves aileron responses and of course tail responses when landing.

Again on mine I fitted 3.5" balloon wheels/tyres and they handle the grass field extremely well. I added the larger wheels mainly due to a need for a little extra weight forward to achieve proper balance.

I do not have dihedral on mine so I cannot give its 3 channel performance but I did need to pack the LE of the wing, (increase incidence angle), about 0.8" to stop it continually starting to climb when throttle was applied.

Just what worked for me!

Have fun!
 

Forster

Slow, low and dirty.
I'll send pics tonight.
Top photo shows the receiver location. There's no real rule about location but I try to put it where I can reach it so if I remove the wing or powerpod I can pull the connectors with the receiver in my hand rather fixed to the fuselage. Bottom photo shows the battery location. Folks tend to add a battery strap in addition to the Velcro. I haven't had a problem with my second Cub build. As mentioned earlier, I cover the entire bottom of the power pod with Velcro as well as the entire side of the battery. I use a little hot glue under the self-adhesive Velcro on the powerpod because mine was coming off the waterproof foam board (I run a thin strip of glue under the Velcro, place it on the pod and use a piece of scrap FB to flatten it before the glue cools). I routed the ESC connector through the provided hole but on my SE5a build I waited until I had the plane finished and determined that I could route the ESC connector through the rear of the power pod and have less trouble with the location of all the wiring. Moving forward with builds, that's my plan. Build the plane and before paint, do a few experiments with wire routing and battery location before finishing the project. A few notes on the cub. My first motor was the old b-power pack motor and it was light so my battery was all the way forward. My second motor is the current motor and it's heavier. My landing gear and tires are also pretty heavy and move the CG forward so my battery pack is pretty far back (further than shown in this photo). You want to make sure your CG is correct or slightly nose heavy, especially for your maiden flight.
WIN_20180608_06_14_33_Pro.jpg

WIN_20180608_06_13_23_Pro.jpg
 

basslord1124

Master member
I do not know if this will help you but I use a 8x4.7 SF prop and it gives me a rapid acceleration and more airflow at low speed for rudder control whilst in the take off ground run. In the air my version can fly very slow but the aileron effectiveness decreases rapidly as you slow down. A bit of throttle with the SF prop actually improves aileron responses and of course tail responses when landing.

Again on mine I fitted 3.5" balloon wheels/tyres and they handle the grass field extremely well. I added the larger wheels mainly due to a need for a little extra weight forward to achieve proper balance.

I do not have dihedral on mine so I cannot give its 3 channel performance but I did need to pack the LE of the wing, (increase incidence angle), about 0.8" to stop it continually starting to climb when throttle was applied.

Just what worked for me!

Have fun!

Hmm, I didn't know that about 4.7SF pitch props. I'll have to give them a try sometime. I had bought the 3.5" foam wheels that FT carries to use on my FT Storch. I ended up ditching the scratchbuilt landing gear for the Storch and am moving it over to pre-made landing gear. So that will leave my foam wheels free to use. So I'll slap em on the Cub. Think I am using about 2" to 2.5" wheels now.

Hoping to get most of those repairs done this weekend so perhaps I can re-maiden it next week sometime.
 

m00nsp3ll

New member
Top photo shows the receiver location. There's no real rule about location but I try to put it where I can reach it so if I remove the wing or powerpod I can pull the connectors with the receiver in my hand rather fixed to the fuselage. Bottom photo shows the battery location. Folks tend to add a battery strap in addition to the Velcro. I haven't had a problem with my second Cub build. As mentioned earlier, I cover the entire bottom of the power pod with Velcro as well as the entire side of the battery. I use a little hot glue under the self-adhesive Velcro on the powerpod because mine was coming off the waterproof foam board (I run a thin strip of glue under the Velcro, place it on the pod and use a piece of scrap FB to flatten it before the glue cools). I routed the ESC connector through the provided hole but on my SE5a build I waited until I had the plane finished and determined that I could route the ESC connector through the rear of the power pod and have less trouble with the location of all the wiring. Moving forward with builds, that's my plan. Build the plane and before paint, do a few experiments with wire routing and battery location before finishing the project. A few notes on the cub. My first motor was the old b-power pack motor and it was light so my battery was all the way forward. My second motor is the current motor and it's heavier. My landing gear and tires are also pretty heavy and move the CG forward so my battery pack is pretty far back (further than shown in this photo). You want to make sure your CG is correct or slightly nose heavy, especially for your maiden flight.
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Thank you