Thanks Dave, wonderful suggestions on both
Biggest problem at the moment is stabilizing the temp. when we built the fire box we made it 350 x 350 mm.. our smoke and hot gas outlet is 200x75 mm and the bottom edge is 175 mm from the grate. we think there is too much charcoal between the grate and the outlet to get decent gas flow though it, and the charcoal her burns very hot. What we are going to try is to raise the grating up and then see if we get a better burn.
your comment about the wood in the chute is very valid, we did that on the first burn and over did the wood and wound up with toooooooo much smoke LOL
Have a great day