Pete To work it all out, you need to use a ratio of your header whit to your sieve and rotor outlet whit! (using R62) 30ft front to sieve of 5.1ft and rotor discharge of 1.5ft Wheat (here in Oz) works out to be about 14000 grains per lb. theres 43560 sq ft to one acre. So! Now you have all the numbers, you can now work out the numbers of grain per sq ft Say you sow at say 60 lbs an acre, thats 840000 grains_acre or 1.928 (2) grains per sq ft! So if you have your sq ft template made out of say some n 8 fencing wire!
12"X12" sq ( I call ours a quad) You can throw the quad out under the front of the combine and see how many grains you have in quad. You can quickly see if you need to change something on front to stop grain losses there. Next, with spreaders and spinners up and or removed. Using your quad, throw it out behind combine at sieve output! Grain loss numbers will now be a ratio of the grain loss from the front! So using the 60lbs_acre = 2 grains_sq ft, and the formula below, 30ft front _5.1 sieve ratio =5.88 times more grains in quad to get to your 60lbs_acre! So 5.88 X 2 grains sq ft= 11.76 grains per quad to = 60lbs_acre. Do this with Rotor output! 30ft front_1.5 ft =20 times the front loss required in quad to get lbs_acre loss out rotor! 2 grain sq ft loss per quad for 60lbs _acre loss you would need 41.33 grains inside the quad, when under the rotor output to get the 60 lb_acre loss! Always to throw quad out a few time to get an average number of grains per quad to work out your loss! This is ever so much easier to do in metric! :grin: I made up an Excel spread sheet (in metric) for our combine_header combination, and got the local elevator testing stand girls (before harvest) to do some grain counting of diffrent grains to give me a pretty good guide of how many grains per kg (grains per lb) they are! Ive taken my quad to a few next door neighbors and asked them if I can do a loss calculation! (After they have given me a dig about the loss out of our machine!) ( R series rotor loss makes most people cringe! Its just that its compress in to a narrow row!) When you start showing them 100lb + acre losses, they get very keen to see what can be done about it!
Sorry for long winded response, might try and get my loss sheet on to the hyper site! Rolf
