Advice on frame for quadcopter (first time)

[JaredPS]

I'm building the frame for a quadcopter that will be ballpark ~800g, and house a camera for first-person control.

Can anyone point me toward some existing quads of similar weight that I can get ideas from regarding weight distribution, CoG, size/dimensions etc. Even if they don't have cameras on them.

I am only looking for a bit of a guide at the moment, that I can make some conceptual designs of my own off of, so 4-5 proper builds that display good designs decisions would be really helpful.

Thank you.

 

[GJH105775]

I'm building the frame for a quadcopter that will be ballpark ~800g, and house a camera for first-person control.

Can anyone point me toward some existing quads of similar weight that I can get ideas from regarding weight distribution, CoG, size/dimensions etc. Even if they don't have cameras on them.

I am only looking for a bit of a guide at the moment, that I can make some conceptual designs of my own off of, so 4-5 proper builds that display good designs decisions would be really helpful.

Thank you.

Well what are your preferred materials to work with? Also do you want the basic x quad motor layout?


To get a start I'd suggest you search Google images for H frame quad copter. It is a really strong and easy frame design to build.

 

[JaredPS]

Well what are your preferred materials to work with? Also do you want the basic x quad motor layout?


To get a start I'd suggest you search Google images for H frame quad copter. It is a really strong and easy frame design to build.

A friend who is building it with me is able to source carbon fibre sheets which we can cut to shape/size, we intend to use that to keep the weight down.

We could do X or H frame, the H would be easier to make, but the X would carry the bending better. Am I wrong there?

The main question i have would be about the CoG. I had the idea of housing most of the components below the plane that has the motors on it, that way the propellers could be moved closer to the centre without being obstructed, which would reduce the bending on the arms that are holding them. It would also add more stability, but at the expense of manoeuvrability (I don't need it to be highly manoeuvrable, maybe another drone in the future can be). I noticed most drones house the components at the top though, is that just a convention or would I be making a mistake by housing everything underneath?

 

[GJH105775]

A friend who is building it with me is able to source carbon fibre sheets which we can cut to shape/size, we intend to use that to keep the weight down.

We could do X or H frame, the H would be easier to make, but the X would carry the bending better. Am I wrong there?

The main question i have would be about the CoG. I had the idea of housing most of the components below the plane that has the motors on it, that way the propellers could be moved closer to the centre without being obstructed, which would reduce the bending on the arms that are holding them. It would also add more stability, but at the expense of manoeuvrability (I don't need it to be highly manoeuvrable, maybe another drone in the future can be). I noticed most drones house the components at the top though, is that just a convention or would I be making a mistake by housing everything underneath?

You want then CoG to be in the middle of the motors, and vertically you want it to be in the center of the props. If you put it under then you are likely to end up with a pendulum effect that makes b th control and stabilization hard. You don't have to get the CoG too precise, but enough that it is easy to stabilize and level.


It your design is good you should not have to worry about flexibility ng too much, for example rather than a flat sheet use a tube, U channel, or even just a90 degree angle piec to go along the bottom tomorrow of the arm.