CG Sticker placement

Hi Everyone, I'm putting the finishing touches on my first serious mid-power rocket and got some of those cool little CP/CG stickers. The CP sticker will obviously go where my sims tell me to put it, but I'm wondering about marking the center of gravity. I'm realizing that its kind of pointless (apart from looking cool) because the CG is going to change depending on what motor I use. So now I'm wondering what the best practice for using these indicators is? Mark the CG without the motor? move and re-apply every time you change motors? not even bother with the CG sticker?

rob

I'd put it at the location for the motor that you will fly the most.

Good suggestion, thanks. I'm planning on trying out a few different motors anyway.

I just put CP stickers as the CG wafts around a bit depending on motors and everything else. I check balance just before going to the RSO.

If you do fit it it may give you confidence in static stability where skepticism is perhaps warranted.

You could place the Cg sticker one caliber ahead of the Cp sticker (or whatever margin you prefer) and then write the words "Aftmost Limit" next to it. As long as your actual Cg falls forward of that limit you should be stable.

Steve Shannon said:

You could place the Cg sticker one caliber ahead of the Cp sticker (or whatever margin you prefer) and then write the words "Aftmost Limit" next to it. As long as your actual Cg falls forward of that limit you should be stable.

Click to expand...

+1 I like to put it at the 1 cal mark, or whatever you feel comfortable with as a minimum to fly safely. Thus if my actual CG is ahead of it, I know I'm good to fly. Also, easy to show the RSO.

I suppose for a short, squat rocket, that might be less than 1 cal.

Steve Shannon said:

You could place the Cg sticker one caliber ahead of the Cp sticker (or whatever margin you prefer) and then write the words "Aftmost Limit" next to it. As long as your actual Cg falls forward of that limit you should be stable.

Click to expand...

When I mark CG, this is generally what I do.

MCriscione said:

+1 I like to put it at the 1 cal mark, or whatever you feel comfortable with as a minimum to fly safely. Thus if my actual CG is ahead of it, I know I'm good to fly. Also, easy to show the RSO.

I suppose for a short, squat rocket, that might be less than 1 cal.

Click to expand...

Bingo!

put it at it's minimum point, as others have said..

dr wogz said:

put it at it's minimum point, as others have said..

Click to expand...

Brilliant. That's the perfect solution for me. Thanks all.