FT Simple Cub modifications

[NikkolaiV]

Hello all!

So I'm currently getting a Simple Cub ready to go, but have a few modifications in mind.

First and foremost, I'm a HUUUUGE fan of STOL planes. As such, Ive decided to make my Simple Cub more of a bush plane design. I have a pair of 3" wheels for my main gear (a whopping half inch bigger than what the design calls for) and am considering a 1/2" tail wheel as well. I designed a pair of leading edge slats on a spare wing to test also.

My main concern is that I'm using a spare power pack I built a while back off amazon before I found Flite Test. My motor is a 1000kv, but the plans call for a 1200kv minimum with an 8x4.5" prop. I'm considering an 8.5x6" prop to compensate, but am worried it isn't enough with the extra weight of the gear and wing modifications.

I suppose what Im looking for is a little insight from a more experienced builder. Is this a bit ambitious, or would this be considered a trial and error situation?

Thanks in advance for any help!

 

[d8veh]

The kv of the motor is nothing to do with power. we need to know what motor you have to be able to comment on it. If it's one of those typical A2216 motors, you need a 10x4.5 propeller and a 3S battery.

 

[Hai-Lee]

I also put larger tyres on my build and I chose the largest SF prop that my motor would support.

Sadly I did not use a tail wheel but rather a skid. Again I did not use any slats on my wing and I definitely did not use any flaperon mixing.

Your setup looks OK for your purpose but check for the largest SF prop your motor will support.

My flight testing was satisfactory but it did not handle or land as I had hoped. I found that by placing a 2mm shim under the wing LE made the plane into a docile and rather adequate STOL design in itself. If you find that the plane doesn't perform as you expect try a little adjustment of the wing Incidence and it might surprise you pleasantly! Mind you whilst i did a very careful and often checked build my results might be just a factor of my own skill or lack there of!

Have fun!

 

[PoorManRC]

I often hear Wing Incidence with the Simple Cub....
Is that a common issue with the design?

 

[NikkolaiV]

For a little more context, I'm using a Propdrive v2 2826 1000kv motor with a 30a speed controller. My last battery got a little puffy so it had to go, so my options on that are pretty open at this point.

I appreciate all the feedback so far, you've all helped a lot and given me a lot to research. Gotta love the RC community!

 

[Hai-Lee]

I often hear Wing Incidence with the Simple Cub....
Is that a common issue with the design?

It is a common issue with my version

Have fun!

 

[Hai-Lee]

For a little more context, I'm using a Propdrive v2 2826 1000kv motor with a 30a speed controller. My last battery got a little puffy so it had to go, so my options on that are pretty open at this point.

I appreciate all the feedback so far, you've all helped a lot and given me a lot to research. Gotta love the RC community!

You could use a 9 x 5 or even a 9 x 6 prop on a 3S 1300mA 20C battery quite happily. Just ensure that you provide adequate ventilation for ESC and battery. If you can use your throttle judiciously and manage the battery temperature it should last a long time!

have fun!

 

[kilroy07]

How far along are you in the build?

I just finished a Storch where I used mostly Gorilla brand White glue (not the wood glue) and it turned out MUCH lighter than previous builds using hot glue. I think even one of my smaller motors (2212) would drag it into the air.

So maybe think thinner than more power (not that i'm opposed to overpowered airframes!)

 

[NikkolaiV]

You could use a 9 x 5 or even a 9 x 6 prop on a 3S 1300mA 20C battery quite happily. Just ensure that you provide adequate ventilation for ESC and battery. If you can use your throttle judiciously and manage the battery temperature it should last a long time!

have fun!

Thanks for the info! I'm planning on some pretty thorough ventilation, and by no means am I aggressive with the throttle, so that sounds like a pretty decent setup!

 

[NikkolaiV]

How far along are you in the build?

I just finished a Storch where I used mostly Gorilla brand White glue (not the wood glue) and it turned out MUCH lighter than previous builds using hot glue. I think even one of my smaller motors (2212) would drag it into the air.

So maybe think thinner than more power (not that i'm opposed to overpowered airframes!)

I attempted a scratch build on my fuselage, but I think I messed up tracing out the parts, because the whole thing was twisted slightly. So I'm ordering a speed build kit in the next few days, and will use that to trace some actual straight plans onto a posterboard for future fixes. Fortunately, that allows me to look into using the glue you recommended! I try to stay pretty light on the throttle, so I'd rather have too much power and not use it than not have enough and need it...but I'm all for a lighter plane too.

Thanks for the info, cant wait to implement what I've learned!

 

[Hai-Lee]

On mine I use a 2812 1534 swinging a 8 x 4 prop with a 25A ESC and a 1300 3S battery. Mine takes off with less than a metre of ground run and lands in just over a metre. It can fly very slowly with a very noticeable stall warning, (a slight loss of directional stability), just before stall.

Dead stick landings can require some speed on approach with a positive loss of lift/stall upon flair. Generally quite a comfortable, though a little boring, performance. OHH! Do not forget to use differential on the ailerons or it can make banked turns a little messy!

have fun!

 

[kilroy07]

This was my first build with it, I like it, it's not a total replacement for hotmelt.
Most people suggest leaving gaps along a line, coming back and using hot glue in the gaps to hold it together as it sets.
(Takes about an hour to firm up.)

Lessons I learned -
Use sparingly! (My first wing turned into a symmetrical airfoil...)
If you run a thin line then come back with a Q-tip you can smear it out and make really solid joints.
I used some blue painters tape to cover some gaps and it seemed to limit the expansion a bit and made really nice surfaces.
It adds HOURS (if not days) to a build... Storch took 3 solid nights of working on it (would have been one night with hot melt glue.)

I suggest playing with it a bit, I like it (I'm not in love with it, but I like it!)

 

[NikkolaiV]

This was my first build with it, I like it, it's not a total replacement for hotmelt.
Most people suggest leaving gaps along a line, coming back and using hot glue in the gaps to hold it together as it sets.
(Takes about an hour to firm up.)

Lessons I learned -
Use sparingly! (My first wing turned into a symmetrical airfoil...)
If you run a thin line then come back with a Q-tip you can smear it out and make really solid joints.
I used some blue painters tape to cover some gaps and it seemed to limit the expansion a bit and made really nice surfaces.
It adds HOURS (if not days) to a build... Storch took 3 solid nights of working on it (would have been one night with hot melt glue.)

I suggest playing with it a bit, I like it (I'm not in love with it, but I like it!)

Great tips! I'm planning on grabbing some cheap foam after I get my speedbuild kit and putting together a couple extra practice planes, so I'll have a couple of opportunities to get it down and get the kinks out. I'm sure that'll take quite a while, but with weather getting worse, I'll probably have the time.

 

[PoorManRC]

I can certainly vouche for the White Gorilla Glue. I've been using it on two builds....
AND to seal the edges of the Foam Board. I really HOPE I could get some pictures taken soon...... I fear I'm losing points here.

But it works well, especially with the gaps for Hot Glue.