overweight in ft simple cub

[Belial2801]

Hello, as you can see in my posts, I have been trying to fly my plane for a while although I am not very constant and that has made it slower. However, a few days ago I tried to fly it and it traveled approximately 6 meters without being able to take off. Today I decided to weigh it and noticed that it weighs almost 1 kilogram. I had serious problems with a heavy tail when i built the plane, so I placed the battery a few inches from the motor. Despite that, I added almost 100 grams of weight to stabilize it, I used foamboard although mine is white (different from the one in the video) and I don't know if there is any difference in the weight because of that, is there? Any recommendations to eliminate the greatest amount of weight? ? Or do you recommend rebuild the plane and seeing how to reduce weight?

My setup is:

Battery 3s 1500 mAh
A2212 1000kv motor
10x45 propeller

 

[Foamforce]

Hello, as you can see in my posts, I have been trying to fly my plane for a while although I am not very constant and that has made it slower. However, a few days ago I tried to fly it and it traveled approximately 6 meters without being able to take off. Today I decided to weigh it and noticed that it weighs almost 1 kilogram. I had serious problems with a heavy tail when i built the plane, so I placed the battery a few inches from the motor. Despite that, I added almost 100 grams of weight to stabilize it, I used foamboard although mine is white (different from the one in the video) and I don't know if there is any difference in the weight because of that, is there? Any recommendations to eliminate the greatest amount of weight? ? Or do you recommend rebuild the plane and seeing how to reduce weight?

My setup is:

Battery 3s 1500 mAh
A2212 1000kv motor
10x45 propeller

The foam board you use makes a big difference. The Adam’s foam boards from DollarTree is about half the weight of some others. You can also buy the Flite Test foam board, which is also made by Adam’s, but is water resistant and generally better quality. But yeah, if you’re using Elmer’s or other brands, it’s much heavier.

Heavier foam board usually presents as being tail heavy, because the majority of the foam on a plane is behind the COG due to the weight of the motor and electronics being placed in the front to balance it. Moving the battery as far forward as possible (nearly touching the prop) as well as moving the ESC and other electronics as far forward in the power pod is the best way to balance without adding any weight. After that, extending the nose has the same effect. On the Cub it’s also possible to move the wing back a little for the same affect, although that might reduce handling.

To reduce overall weight, rebuilding with lighter foam board is best, beyond that, a lighter battery is the easiest way. I’ve flown with as small as a 650mah 3s, although I was probably taxing that battery.

 

[Belial2801]

The foam board you use makes a big difference. The Adam’s foam boards from DollarTree is about half the weight of some others. You can also buy the Flite Test foam board, which is also made by Adam’s, but is water resistant and generally better quality. But yeah, if you’re using Elmer’s or other brands, it’s much heavier.

Heavier foam board usually presents as being tail heavy, because the majority of the foam on a plane is behind the COG due to the weight of the motor and electronics being placed in the front to balance it. Moving the battery as far forward as possible (nearly touching the prop) as well as moving the ESC and other electronics as far forward in the power pod is the best way to balance without adding any weight. After that, extending the nose has the same effect. On the Cub it’s also possible to move the wing back a little for the same affect, although that might reduce handling.

To reduce overall weight, rebuilding with lighter foam board is best, beyond that, a lighter battery is the easiest way. I’ve flown with as small as a 650mah 3s, although I was probably taxing that battery.

I was just about to add this, I don't know if it helps but this weighs each thing separately:

Battery: 130gr
Motor, base and propeller: 130gr
Front landing gear: 60gr
Fuselage, servos and rear wheel: 260gr
Wings: 300g
Dead weight: 70gr

It is somewhat difficult to get the foamboard in the video because I live in another country so, before trying anything else, I would like to know where you recommend removing some extra weight.

 

[Belial2801]

Btw, does flite test sell the foamboard you mentioned in their online store?

 

[Foamforce]

Btw, does flite test sell the foamboard you mentioned in their online store?

Yup! I hear that international shipping is expensive but the foam board is really good.

Building Materials - Foam Board Sheets - Flite Test Retail Store

store.flitetest.com

 

[Foamforce]

I was just about to add this, I don't know if it helps but this weighs each thing separately:

Battery: 130gr
Motor, base and propeller: 130gr
Front landing gear: 60gr
Fuselage, servos and rear wheel: 260gr
Wings: 300g
Dead weight: 70gr

It is somewhat difficult to get the foamboard in the video because I live in another country so, before trying anything else, I would like to know where you recommend removing some extra weight.

Removing landing gear is an easy win. That reduces drag too. It‘s also usually easier to take off and land without landing gear. So thats a win win win.

A smaller battery could save 40g if you went down to a 1000mah, that might be worth it. Somewhat borderline.

Is dead weight extra weight you added to balance? You can probably eliminate all of that by moving electronics all the way to the front, moving the wing backwards a little, or extending the nose.

For reference, a sheet of my Adams foam board is 113g according to my scale. You should weigh a sheet of yours for comparison.

 

[Belial2801]

Removing landing gear is an easy win. That reduces drag too. It‘s also usually easier to take off and land without landing gear. So thats a win win win.

A smaller battery could save 40g if you went down to a 1000mah, that might be worth it. Somewhat borderline.

Is dead weight extra weight you added to balance? You can probably eliminate all of that by moving electronics all the way to the front, moving the wing backwards a little, or extending the nose.

For reference, a sheet of my Adams foam board is 113g according to my scale. You should weigh a sheet of yours for comparison.

Yes, it's the extra weight I added for the balance, moving the wings back is literally what the word says? I move my wings back and that's it? All electronics are on the front except for a servo.

 

[Foamforce]

Yes, it's the extra weight I added for the balance, moving the wings back is literally what the word says? I move my wings back and that's it? All electronics are on the front except for a servo.

Yeah. My understanding is that the COG is generally a little forward of the center of lift. Since most of the lift comes from the wing, the COG moves when you move the wing. However, as the wing gets closer to the tail, the stability of the plane decreases, so you probably won’t want to move it much more than an inch or so back.

Somebody more experienced, please correct me if that’s wrong.

 

[Belial2801]

Yeah. My understanding is that the COG is generally a little forward of the center of lift. Since most of the lift comes from the wing, the COG moves when you move the wing. However, as the wing gets closer to the tail, the stability of the plane decreases, so you probably won’t want to move it much more than an inch or so back.

Somebody more experienced, please correct me if that’s wrong.

There wasn't much difference, I think I'll leave the landing gear like this so I don't have to add a lot of extra weight. Do you think it's a good idea to cut a large part of the fuselage and instead add wooden sticks so as not to lose rigidity? I would do it from the rear of the fuselage and perhaps simulating the windows of the plane.

 

[Foamforce]

There wasn't much difference, I think I'll leave the landing gear like this so I don't have to add a lot of extra weight. Do you think it's a good idea to cut a large part of the fuselage and instead add wooden sticks so as not to lose rigidity? I would do it from the rear of the fuselage and perhaps simulating the windows of the plane.

What do it mean about the landing gear? I’m just suggesting that you remove it entirely. The Cub is easily hand launched and belly landed.

If you’re going to try modifying anything, you could see if you can remove any paper from the insides of the fuselage. The paper weighs more than you think. If you start cutting parts out, I wouldn’t bother trying to reinforce it with wood sticks, it might end up weighing as much as before. You could just try cutting or triangles so that it looks like a bridge, and then cover the holes with lightweight packing tape to prevent high wind resistance. Frankly though, I wouldn’t bother with that. I would ditch the landing gear, rebalance to remove the dead weight, and maybe get a smaller battery.

 

[Belial2801]

What do it mean about the landing gear? I’m just suggesting that you remove it entirely. The Cub is easily hand launched and belly landed.

If you’re going to try modifying anything, you could see if you can remove any paper from the insides of the fuselage. The paper weighs more than you think. If you start cutting parts out, I wouldn’t bother trying to reinforce it with wood sticks, it might end up weighing as much as before. You could just try cutting or triangles so that it looks like a bridge, and then cover the holes with lightweight packing tape to prevent high wind resistance. Frankly though, I wouldn’t bother with that. I would ditch the landing gear, rebalance to remove the dead weight, and maybe get a smaller battery.

If I can eliminate the extra weight, I wouldn't have to add any more because the landing gear will take care of that. I don't think that launching a plane weighing almost 1 kilogram from my hand is a good idea, although leaving everything aside, do you think that with the current weight it will take off? I could try again before doing anything

 

[Foamforce]

If I can eliminate the extra weight, I wouldn't have to add any more because the landing gear will take care of that. I don't think that launching a plane weighing almost 1 kilogram from my hand is a good idea, although leaving everything aside, do you think that with the current weight it will take off? I could try again before doing anything

The Cub is very easily hand launch-able. It’s actually generally easier to hand launch because a lot of times the landing gear isn’t aligned well so you’re having to fight that with your rudder just to go in a straight line. Plus, you can get a bunch of speed and elevation right away with a hand launch.

But yeah, to your original question it will definitely take off at its current weigh, assuming that you have it balanced properly and the control surfaces nice and straight. However, it will be more prone to stalling and the solution to that is more speed. A lighter plane is more forgiving. For example, with a lighter plane you might only need 10 feet to take off and if you pull up a little too hard at first, it will probably still go up, just slowly. With a heavier plane, you might need 20 feet to take off, and it will be more likely to stall. What that looks like is it will roll one way or another after it gets a few feet in the air and steering in the opposite direction won’t seem to have any effect. That’s because in a stall, the control surfaces are ineffective. So then you come down sideways. Don’t be surprised or discouraged if this happens to you. That just means that you need to stay on the ground and build up more speed before pulling up, and then when you do pull up, do it very lightly so that the nose doesn’t point upward too fast.

Good luck, post videos. They’re good for fun and for diagnostics.🙂

 

[Merv]

...Any recommendations to eliminate the greatest amount of weight? ...

Foamboard & glue are the two largest factors in reducing weight.

Prior to FT, I made planes with ordinary corrugated cardboard, the stuff all of your Amazon packages comes in. If your foamboard is heavy, you might try cardboard.

Hot glue is heavy, use it sparingly. My goal is 1 full size glue stick per plane.

 

[Belial2801]

Update: I tried to fly it and although it didn't fly the way I wanted, it did manage to take off so I hope to start a new project soon being more careful with the weight and other aspects to get a better experience. Thanks for your help guys.

 

[Foamforce]

Update: I tried to fly it and although it didn't fly the way I wanted, it did manage to take off so I hope to start a new project soon being more careful with the weight and other aspects to get a better experience. Thanks for your help guys.

That’s great! I’m curious though, how did it fly? Was it just stalling very easily or something else?

 

[Belial2801]

That’s great! I’m curious though, how did it fly? Was it just stalling very easily or something else?

something like that, I think that also being a beginner I did not achieve the best flight like someone who is an expert, the final weight of the plane was 900 grams, it was a calm day without much wind and I had a hard time taking off (watched some videos), when it finally managed to take off , he did it for a few seconds and fell but didn't crash, as I said at the beginning, I think an important factor was my lack of experience.

I don't know if this would affect it but according to Google the wind was 10 km/h, I don't know how that works but when the plane took off it did so just when a gust of wind arrived, otherwise the plane would advance up to 10 meters without being able to take off.

I decided to stop trying because the Rudder servo came out of his place and I could not repair it at that moment.