Thanks. The Hobby King receiver weighs 13g according to this:

http://www.rc-radiocontrol.com/hobby...eceiver-6ch-v2
Whatever I get, weight has to be within the ranges specified below for trainers. Or I could calculate wing cubic loading of a model that flies slowly enough.

The Cessna 170 at the

bottom of the page weighs in at 86g and has a span of 24 inches. Assuming a wing area of 24 x 4 = 96 inches and the weight of 3 ounces, plugging it into the calculator below gives a cubic loading of 5.5 and wing loading of 4.5 oz per sq in / 13.5 oz per sq dm and it flies slowly. Keeping this cubic loading for my model should give the same sort of slow flight.

Cubic wing loading calculator

http://www.ef-uk.net/data/wcl.htm