I'll second Tvad: 3 vs 4 for stability; contact directly with the chassis - placing under the actual component feet will have negligible effect; ignore the component feet - removing didn't make a difference in my experiments.
Fill the rack with lead rather than sand - seems to work better. You can get lead shot #8, e.g. for about $15/25lbs at a gun shop. Although I've read that powdered iron works best although I have no idea where to get it.
Have fun.
Fill the rack with lead rather than sand - seems to work better. You can get lead shot #8, e.g. for about $15/25lbs at a gun shop. Although I've read that powdered iron works best although I have no idea where to get it.
Have fun.