<p>This aircraft is &quot;close coupled&quot; meaning the tail is very close to the wing.  Lengthening the fuselage will make it easier to balance.  This can be done both fore and aft of the main wing.  Then add weight to the nose as needed.</p>
<p>Secondly, the tail can be flat. Let the wing do the lifting.  Airflow interactions between a fore and aft wing can affect stability.</p>
<p>Finally, have the tail pitched down a bit to help raise the wing angle of attack in flight.  You can do this with &quot;elevators&quot; or with the whole tail.
The <strong>leading edge</strong> of the tail should be lower than its trailing edge, providing some &quot;down force&quot; in flight.</p>
<p>A little experimentation may be needed to get it right.  Use balsa wood to save weight.</p>

CC BY-SA 4.0
2023-01-23T10:45:46.720Z
this answer is very helpful. However, I made a triangle truss out of cardboard to save weight and it is very rigid. I think that balsa wood would work as well.
The Rocket fan
CC BY-SA 4.0
2023-01-23T10:16:51.180Z
2023-01-23T10:43:45.497Z
2023-01-23T10:43:45.497Z
Robert DiGiovanni
<p>For starters put the CG at about 25% of the wing chord line.  If you don't want to bother with the math, just balance it on your fingertips.  Then <em>slowly</em> work the CG further aft to suit your taste.  Further aft = more responsive elevator and rudder, but less inherent pitch stability and less directional or &quot;weathervane&quot; stability.</p>

CC BY-SA 4.0
2023-01-22T18:39:29.467Z
I am new here, could you tell me what CG stands for? Is it central gravity?
The Rocket fan
CC BY-SA 4.0
2023-01-22T22:10:29.273Z
@TheRocketfan CG stands for center of gravity - where the balances and where it will rotate around
ThatCoolCoder
CC BY-SA 4.0
2023-01-23T05:26:27.863Z
@ThatCoolCoder. Thanks for the Info.
The Rocket fan
CC BY-SA 4.0
2023-01-22T17:50:09.337Z
2023-01-22T17:50:09.337Z
quiet flyer
<p>I have built this plane: <a href="https://i.sstatic.net/HUydn.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/HUydn.jpg" alt="enter image description here" /></a></p>
<p>But the nose cone is too light. I have tried adding different objects in the front but each thing was either too light or too heavy. How can I calculate the weight needed in the front?</p>
<p>Wingspan: 30cm (front wings)</p>
<p>Wingspan: 18cm (back wings)</p>
<p>Length of plane: 30 cm</p>
<p>Weight of plane: 12 grams</p>

<diy>
How can I calculate the weight needed in the nose?
The Rocket fan
# How can I calculate the weight needed in the nose?

(Asked by: username_0 on 2023-01-22)

I have built this plane: [![enter image description here](https://i.sstatic.net/HUydn.jpg)](https://i.sstatic.net/HUydn.jpg)

But the nose cone is too light. I have tried adding different objects in the front but each thing was either too light or too heavy. How can I calculate the weight needed in the front?

Wingspan: 30cm (front wings)

Wingspan: 18cm (back wings)

Length of plane: 30 cm

Weight of plane: 12 grams

**Tags:** diy


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## 2 answers

### Answer by username_1 on 2023-01-23. Score: 1 | Accepted answer

This aircraft is "close coupled" meaning the tail is very close to the wing. Lengthening the fuselage will make it easier to balance. This can be done both fore and aft of the main wing. Then add weight to the nose as needed.

Secondly, the tail can be flat. Let the wing do the lifting. Airflow interactions between a fore and aft wing can affect stability.

Finally, have the tail pitched down a bit to help raise the wing angle of attack in flight. You can do this with "elevators" or with the whole tail.
The **leading edge** of the tail should be lower than its trailing edge, providing some "down force" in flight.

A little experimentation may be needed to get it right. Use balsa wood to save weight.

> **Comments:**
> **username_0**: this answer is very helpful. However, I made a triangle truss out of cardboard to save weight and it is very rigid. I think that balsa wood would work as well.  

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### Answer by username_2 on 2023-01-22. Score: 0

For starters put the CG at about 25% of the wing chord line. If you don't want to bother with the math, just balance it on your fingertips. Then *slowly* work the CG further aft to suit your taste. Further aft = more responsive elevator and rudder, but less inherent pitch stability and less directional or "weathervane" stability.

> **Comments:**
> **username_0**: I am new here, could you tell me what CG stands for? Is it central gravity?  
> **username_3**: @TheRocketfan CG stands for center of gravity - where the balances and where it will rotate around  
> **username_0**: @username_3. Thanks for the Info.  

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