*Unofficial* FT Simple Cub

Forster

Slow, low and dirty.
The thing to remember about wheels is (I think) larger diameter increases your ability to roll over rough surfaces while larger width increases your ability to land on soft surfaces. That seems logical but it can be counter intuitive. I have 4" tires from a Timber 1.5 on my Cub and 3" skinny tires on my SE5a. The SE5a can take off from grass fields easier because the tires have less resistance in the grass and the tundra-style tires don't really float over the grass. Scale wise, 2" of 2.5" look more normal unless you're going for the Bush Plane look then the tundras look great. It really depends on what look you're going for and what you take off and land from surface wise. On the losses side, I left my battery pack plugged in all day and it was puffed and showing 1.3 volts per cell. That will teach me to rush through things before work.
 

Forster

Slow, low and dirty.
So it begins - Cub #2 could not outside loop. Faced with the choice of flying inverted into my garage and wife's car or putting it down abruptly in the grass I chose "happy wife". Motor pod and front of fuselage are toast, the wing I build two weeks ago are fine. I think it's time to build a stick.
 

m00nsp3ll

New member
Could somebodu say me if this cavity is for Receiver Antennas? Is it very important that the antennas stays outside? Would be getting lower signal they stay inside of plane? To put antennas out of this cavity i have to place receiver at the tail and its hard to connect wires.

P.S: What do you think where is the best place for Receiver+Antennas

Thanks
 

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Forster

Slow, low and dirty.
Could somebodu say me if this cavity is for Receiver Antennas? Is it very important that the antennas stays outside? Would be getting lower signal they stay inside of plane? To put antennas out of this cavity i have to place receiver at the tail and its hard to connect wires.

P.S: What do you think where is the best place for Receiver+Antennas

Thanks
Not for antenna. You can put the antenna wherever you want. I place my receiver between the ESC and tail servos under the wing. The antenna can be entirely inside the fuselage. Doesn't affect range.
 

m00nsp3ll

New member
Not for antenna. You can put the antenna wherever you want. I place my receiver between the ESC and tail servos under the wing. The antenna can be entirely inside the fuselage. Doesn't affect range.
thank you for reply, but im still wondering what for is this cavity :) any ideas? :)
 

Hai-Lee

Old and Bold RC PILOT
Could somebodu say me if this cavity is for Receiver Antennas? Is it very important that the antennas stays outside? Would be getting lower signal they stay inside of plane? To put antennas out of this cavity i have to place receiver at the tail and its hard to connect wires.

P.S: What do you think where is the best place for Receiver+Antennas

Thanks
The hole in the rear underside is for 2 reasons. The first is for ventilation and the second is a minor weight reduction.

As for the Antennas they must be located away from other cables if possible and normally on a dual antenna setup at right angles to each other,

The reason of the 2 antennas. (diversity), is so that you have almost zero chance of a Loss of Signal event due to polarisation loss. If your transmitter antenna and your "single receive antenna are at right angles to each other you can suffer a loss of around 99% of the normal signal strength. As the range is decreased by half for each time the signal is reduced by 75%. In other words if the Tx and Rx antennas are at 90 degrees to each other the Range can be less than one eighth of the original range. Such Loss of signal events normally happen at great height or at long range where reflected signals, (from the ground and any other reflective surfaces), are minimal. Polarisation loss downs a lot of drones unexpectedly.

As for the exact antenna locations they are somewhat orrelevant as long as they are clear of wires and other metal and a right angles to each other.

Have fun!
 

m00nsp3ll

New member
The hole in the rear underside is for 2 reasons. The first is for ventilation and the second is a minor weight reduction.

As for the Antennas they must be located away from other cables if possible and normally on a dual antenna setup at right angles to each other,

The reason of the 2 antennas. (diversity), is so that you have almost zero chance of a Loss of Signal event due to polarisation loss. If your transmitter antenna and your "single receive antenna are at right angles to each other you can suffer a loss of around 99% of the normal signal strength. As the range is decreased by half for each time the signal is reduced by 75%. In other words if the Tx and Rx antennas are at 90 degrees to each other the Range can be less than one eighth of the original range. Such Loss of signal events normally happen at great height or at long range where reflected signals, (from the ground and any other reflective surfaces), are minimal. Polarisation loss downs a lot of drones unexpectedly.

As for the exact antenna locations they are somewhat orrelevant as long as they are clear of wires and other metal and a right angles to each other.

Have fun!

Thank you for the information, i learned something new. According to the information i place the receiver inside the fuselage and set the antennas 90 degree angle.
Thanks

1528660150174.png
 

Forster

Slow, low and dirty.
It was bound to happen sooner or later. On Cub #3 I rushed through the fuse build and ended up with a tilted horizontal stab. Wish I could say I can tell it was that way in flight, but I'm not so good as to notice stuff like that yet.
 

wh1sp3r

New member
I will also share my cub.
IMG_20180508_130402.jpg


I love that design. So I decided to build something bigger. It's about 55% bigger.
IMG_20180623_160308.jpg

I would like to ask if you know about any video of enlarged cub :)
 

Forster

Slow, low and dirty.
Question for the group. Has anyone build the Cub both from a speed build kit and from the plans? It appears that when you build from the plans the engine is set farther back in the nose. Mine prop will barely clear the nose when set at the stops like I did with both speed builds.
 

mrjdstewart

Legendary member
Question for the group. Has anyone build the Cub both from a speed build kit and from the plans? It appears that when you build from the plans the engine is set farther back in the nose. Mine prop will barely clear the nose when set at the stops like I did with both speed builds.

i have and i will say that the Cub plans were probably the "most difficult" tiled plans i ever worked from. just something about them, i could never get things to be right.

me :cool:
 

m00nsp3ll

New member
Does anybody have Printable Version of Lightning Decal. I would like to buy it but i am not living in US. thats why i need a printable version of it.

Thanks
 

Winglet

Well-known member
Recently completed my FT Simple Cub and here are a few observations for those thinking about building one.

This was a fun little build from the FT kit. It went together nicely over about 4 short evenings of work.

To keep it simple and to avoid painting the brown foam, I just used some vinyl trim for the color. My wheels are the ones recommended and purchased from Flitetest. (NICE)

THIS MODEL BUILDS SUPER NOSE HEAVY- With my 1300 3 cell my Scout would have been severly nose heavy had I not located the 9g servos near the tail. Even with that, I shoved the battery as far back as possible and added 1/2 ounce of weight just inside the vent on the belly. Plus I used a shorter and lighter motor than the FT C pack. I used a GForce E400 1250KV motor from Value Hobby with a 9x3.8 prop.

Other than that, the model was pretty much build as per Josh Bixler's instructions except I built the wing with 1/2 the recommended diehedral as I like to fly inverted a lot. Not sure this was a great move as it doesn't like inverted much anyway. If you plan to fly it 3 channel absolutely build it per Josh's instructions.

FLYING- It flies fine. Leaps off the ground if you want it to. With my power setup it nearly climbs vertically but I prefer to power way back and just cruise around. I maidened it at our club's monthy meeting and it got lots of positive response and was awarded Model of the Month. At least 2 club members are now building one because they saw mine. It does nice big beautiful loops and rolls decently. Inverted flight with mine eventually turns into a rapid inverted decent. The stall is fairly brisk. It is pretty easy to spin intentionally. I think it might be easy to spin accidently too, but that hasn't happened to me yet.

IS THIS A TRAINER? Well, I don't think mine is. But I took most of the diehedral out of the wing, I have ailerons and somewhat of a powerful motor setup. With a B pack motor and 2 cells on 3 channel it would probably be a lot different (and not so nose heavy)

Prior to the Cub I built the FT Scout and I use the exact same power setup on it. I LOVE the Scout, but I really like the FT Simple Cub too. If I could only have one I would for sure go the Scout. But...why not build both?

A lot of great design work went into this model. I especially like that it used the full size swapable power pod and it runs nearly the length of the fuselage. Talk about strong. Nice work Josh!!

simple cub for post.JPG
scout and cub.JPG
FTC.JPG
 
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Ken Myers

New member
I did the maiden and trimming flights on my highly modified FT DIY Simple Cub yesterday. It went well.
 

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Ken Myers

New member
I like the looks of yours too! :)

Mine actually turned out tail heavy and I had to add 3/4 ounce of lead to the bottom, front of the power pod.
I did try both the 4-channel wing and 3-channel on previous iterations of mine. This is actually Version 4. I was hoping for another trainer to add to my fleet of trainer planes, as I am a club instructor, but, unfortunately, this is not one that I will be using with my students.

On Tuesday through Friday of this week, I had a friend over and we built two of the kit versions with my modifications using the hot glue method. That reminded me why I don't use that method!!! His number 1 was ready to go Saturday morning, but it was too windy to take him, a low time pilot, up on it, but I did get mine sorted out.

You can check out my modifications here;
https://www.rcgroups.com/forums/sho...-Scratch-Builds-(whose-building-them)/page135

Just scroll down a bit from the top of the page.
 

Hai-Lee

Old and Bold RC PILOT
I like the looks of yours too! :)

Mine actually turned out tail heavy and I had to add 3/4 ounce of lead to the bottom, front of the power pod.
I did try both the 4-channel wing and 3-channel on previous iterations of mine. This is actually Version 4. I was hoping for another trainer to add to my fleet of trainer planes, as I am a club instructor, but, unfortunately, this is not one that I will be using with my students.

On Tuesday through Friday of this week, I had a friend over and we built two of the kit versions with my modifications using the hot glue method. That reminded me why I don't use that method!!! His number 1 was ready to go Saturday morning, but it was too windy to take him, a low time pilot, up on it, but I did get mine sorted out.

You can check out my modifications here;
https://www.rcgroups.com/forums/sho...-Scratch-Builds-(whose-building-them)/page135

Just scroll down a bit from the top of the page.
It appears that we both teach others to fly. As for this being a trainer you are correct but it can be calmed down in handling to fit that role.

Whilst I am using it as a second stage trainer, (take off and landing), I found that by fitting a SF prop, large, (tundra type), tyres, and increasing the wing incidence angle slightly it can be so docile that someone without any air time can get it from one end of the field to the other without any serious issues, (even in a moderate breeze).

In addition I removed the dihedral completely and made the wing from a single sheet, (sheets are double size here), whilst some may think that this upsets the inherent stability I had determined that the stability was too high at times and it was more susceptible to crosswind gust induced roll instability. Being a high wing, (with battery and big/heavy wheels), the pendulum stability is more than adequate to ensure stable hands off flight.

Just what works here for me!

Have fun!
 

Ken Myers

New member
Whilst I am using it as a second stage trainer, (take off and landing), I found that by fitting a SF prop, large, (tundra type), tyres, and increasing the wing incidence angle slightly it can be so docile that someone without any air time can get it from one end of the field to the other without any serious issues, (even in a moderate breeze).

I did increase the wing incidence angle slightly.
Angles for the wing incidence, horizontal stabilizer and motor up or down thrust are based on a longitudinal datum line.
The way this Cub is designed, that datum line is parallel to the top of the fuselage.
Setting the horizontal stabilizer to -1.5 degrees, creates a new datum line using the horizontal stabilizer. Using a 180 degree line, passing through the stabilizer thickness creates a new the horizontal datum line. The angles then become +1.5 degrees of incidence for the wing, like raising the front of the wing some, 0 degrees for the horizontal stabilizer and -1.5 degrees of down thrust.

Be sure to check out the full details in the RC Groups link that I previously posted.