For this tool you will need to gather together the following unlikely items- 2x Clothes pegs of the nip variety,2x single edges razor blades,a block of balsawood and some cyno,suitable rod to fit into the respective item to be balanced,2x small tapered plumb bobs drilled on a drill press vertically to fit and slide over the rod. Method. 1/ glue the two pegs into slots 2 inches apart ( for most prop sizes,for larger ones space wider) onto the balsa with cyno,but first cut off one leg each side of the peg,this allows you to spring the pegs apart on the base,all will become clear in a moment. 2/ Simply slot the two razor blades into the jaws of the pegs so they are level. 3/ Place the device onto a flat surface,glue a small spirit level onto the base for a luxury version ! 4/ Slide one of the cones onto the rod followed by the propeller then another cone,just press together to centralise. 5/ Place the gadget over the edge of a table and spin the prop,note which blade is the heaviest ( which it will be !) then mark it. 6/ Use Tip-ex or similar correction fluid and apply to the light blade,re-spin and keep adjusting with fluid until the prop balances just level. Note: Really out of balance props ( usually those that have air holes moulded into them need discarding ) if they are new take back to shop for replacement. Try to avoid removing material on the heavy blade unless the amount is minimal,avoid nicks as these exacerbate blade failures which can prove dangerous,best to sand the blade with wet & dry paper. For moulded plastic or fibreglass props it is best to boil them for a few minutes in water to relieve the stresses in the blades.The best thing to use for this is one of those long tin cake tins,buy one dont nick it from the kitchen ! Never use defective propeller blades,use these for stirring paint because that is all they are good for. To balance flywheels first place a mark in red paint anywhere,spin the wheel and mark the heavy side with tip-ex,remove any material as necessary. No excuses now to be out of balance.