<span style="font-size: larger">I have a Gemini mk3 that I bought 2nd hand (not sure who it is made by - but is an old model!) and I wondered if anyone could help me with the CG as I have just starting to set it up and have changed the tank size from a 4oz to a 12oz and I want to get CG right before I take it to the field. It is a low wing model with a wing span approx 52in with a .46 super tigre donk up front. Any help appreciated -Ta</span></p>

You could measure your airplane and input the data into one on-line calculator:

Look for "Online calculators and simulators" here:

http://www.rcuniverse.com/forum/m_9346279/tm.htm

Thanks Lnewqban I'll give it a shot