Cg For 29" Mono

[yz120]

starting to build my 29" d/f copy from skunk works and need to know the c/g.
approx. motor location, batts ect. i will be running 14 ib3600`s and an 9xl for starters.
any help would be appreciated.
thank,
mike

[Bill-SOCAL]

Set the CG at 33% from the transom ~ 8.7 inches. Locate your motor and batteries so the CG is around that point and fine tune the CG by moving the packs forward or aft as needed.

[Doug Smock]

Hey Mike,
I build monos so that I can adjust the CG from 27 (7.8") to 30% (8.7"). I prefer to start with the CG aft and move it forward as I tune the boat. It is never good idea to run a boat wet. You'll start loosing equipment.

Put a piece of masking tape on each side of the deck with the CG marked on it at 27- 30%
Mount your hardware, lay your mounted motor in the hull approx 7" from the transom with the ESC in front of the motor. Place the servo, rec. and rec. pack where you would like them. (I keep mine as close to the transom as possible.)
Lay your cells in the hull on each side of the motor. Now move the cells for and aft and see if you can get the CG in the range mentioned above. When you are happy with the layout and CG, mark the componet location. Now get back to building!!!!
I'd be happy to send you setup pics of some race proven builds.

Good luck and post some pics,

Doug

[Ocean Racer]

Sence u are on the subject what if u have a ob does the CG change?

[yz120]

[QUOTE=D.Smock;32444]Hey Mike,
I build monos so that I can adjust the CG from 27 (7.8") to 30% (8.7"). I prefer to start with the CG aft and move it forward as I tune the boat. It is never good idea to run a boat wet. You'll start loosing equipment.

Put a piece of masking tape on each side of the deck with the CG marked on it at 27- 30%
Mount your hardware, lay your mounted motor in the hull approx 7" from the transom with the ESC in front of the motor. Place the servo, rec. and rec. pack where you would like them. (I keep mine as close to the transom as possible.)
Lay your cells in the hull on each side of the motor. Now move the cells for and aft and see if you can get the CG in the range mentioned above. When you are happy with the layout and CG, mark the componet location. Now get back to building!!!!
I'd be happy to send you setup pics of some race proven builds.

doug,
i would appreciate pics,
thank you,
mike
[email protected]

[Doug Smock]

I'll send them to you tomorrow afternoon Mike. ( I can't access them on this computer)

Doug

[Doug Smock]

I'll send them to you tomorrow afternoon Mike. ( I can't access them on this computer)

Doug

Let me know if you got them.
Good luck!,

Doug

[yz120]

Let me know if you got them.
Good luck!,

Doug

got em

thank you,they will really help out.
thanks again,
mike

also thanks to all that replied to this post.

[Eodman]

Sence u are on the subject what if u have a ob does the CG change?

Hey Ocean racer, sure the CG changes if you have an outboard(I'm assuming you are refering to an outboard) all that weight is now outside the boat rather than inside!

If you don't offset the weight of the motor(s) your CG will move towards the stern!

I think!

[Ocean Racer]

Its going to move towards the stern? Are u sure its not toward the bow.

[Eodman]

Unless I'm all wet(& I've been known to be) the center of gravity as I understand it would move to the stern. The CG would move backward to counterbalance the weight of the outboard(s), more hull weight forward to balance it!

Take one of your boats find the CG on a broom handle laying on a table .. now place a double a battery in the stern -- what happens? How do you offset the effect of the battery ... by moving the boat further forward on the broom stick ... more of the bow now is forward of the old CG! So the new CG is further back!

[Ocean Racer]

Ok i think i get it now

[Ocean Racer]

Eodman I stated to think about what you were saying and all of a sudden it hit me what you meant. Duh if you put a outboard in the back you need to put weight in the front thus your CG moves back. The only thing I did not get was the broom handle? How do u do that i think i have a idea but i need a little more info.

[Eodman]

The reason for the broomstick is to act as a fulcrum or balance point on the table!

[Ocean Racer]

do you rest the hull on it? maybe you could put a pic up to help me out im not grasping the idea.