Monohull Balancing (CG)

[jfrabat]

Hey, guys. I am building an FE for my son, a scratch built mono. I was wondering if the balance point (CG) is the same in monos as it is for cats, about 1/3 of the length of the boat from the transom (fine tunning to be done later, but as a starting point). Can anyone confirm this?

[fweasel]

Yes, about 30% from the transom is a good starting point.

[sciesielka]

I have found lots of information on balancing a mono at the CG bow-to-stern, but is there a reason to balance a mono side-to-side? My Pro Boat Shockwave and Stealthwake boats both put the battery on the port side (left as viewed from the rear) and the ESC and radio gear on the other side. The weight distribution side-to-side is off with a 2S and will only get worse with 3S. Should I add weight to the other side along the bottom of the hull, making sure to keep the CG at the 25% to 30% point? Or would careful trim tab adjustments help the boats run level without having to add weight?
Just FYI, as of posting this, I have only run 2S in the Stealthwake and I just got a gently used Shockwave that I haven't run yet. I have a 3S 6500mAh coming from RoaringTop USA for both boats. I also have the OSE upgrade flex shaft + strut coming for the Shockwave. And the Stealthwake is upgraded to brushless with many other improvements as well (just not a flex shaft drive yet). Just trying to prepare so I can hit the water running when I get all my parts. Thanks!

[fweasel]

The Shockwave is a self righting hull and relies on the weight imbalance to help it flip over. The Stealthwake is a relatively deep and stable V hull, and not incredibly fast. Side to side weight distribution is the least of that RTR model's deficiencies. It's not uncommon to bias weight to the port side on some mono's to counteract the roll caused by the prop rotation.