Combines shiming heilicals

Shimmed the helicals in our N7 in about 1992 with 2 or 3mm flat. We allowed about 12 mms [ 1_2 in" ] to protrude to the left or to the live side of the helicals. It needs to have sufficient smooth surface to enable the material to slide along the helical and avoid being caught and held by the cage holes. It made a very big difference when we hit tough, ropey, green material that the standard N7 set-up balked at. We got the idea from John Ryan in N.E Victoria, Aust. I think John was the first to come up with the idea. Will now use 2mm thick, high grade, wear resistant stainless for our R62. Cheers

Thanks for the help, R.O.M. Sounds like your setup would have worked good for me last summer when the weeds got bigger than the wheat. Did you have flat or channeled helicals. The reason for my asking I was planning to use shimms about twice that thick with my flat helicals(1_4"). Or do you use thinner stuff if you protrude to the pressure sideIJ local gleaner mechanics told me shimming makes it grind dry straw worse, and I was wondering if the protrusion would help scoot it through without grinding. Was wondering if this would adversely affect seperation due to lack of turbulance...or is rotor loss not a problem in wheat for youIJ My limiting factor with stock setup has always been shoe loss. Thanks.

Our N7 was sold in 1994 so this is from memory. We had the standard flat helicals that came on the 83 models. I think they were 1" wide by 1_2 thick flat bar. No internet and no Hyperisation in those days so we had to guess for our selves. We used the thin shims under the helicals purely to get a smooth corner against the helicals to allow material to flow instead of being held by the cage holes adjacent to the helical and ground up or to form slow moving wads which always carries seed out. I would have reservations about a very thick protruding shim as it is almost a repeat of a flat helical with the same material flow trouble. Can you use channel helicals with thin flat protruding shims. The channels give a double bite at getting material to flow. The smooth corner created by the shims helps even more with the flow. Just don't cover too much of the cage holes which allow seed and etc to escape from the material. A very thin, very fast moving and moderately turbulent material flow around the cage allows seed to be centrifuged out through the thin layer of material and then through the cage. Interestingly, nobody seems to have had the courage to try using small section, heavy angle iron with the flat towards the live side, as helicals in the P1 series cages instead of the flat bar helicals. I think it could work very well. Yes, we still have, at times, serious losses out of our R62's rotor in the odd crop but have come a long way using the hyperisation ideas on this site as well as trying some of our own, some of which work and some don't. We are going to thin shim the helicals in our R62 this coming season [ Dec 2005 ] and also shim our rotor bars out 10mm across the entire thresher and seperator. We shimmed out the last seperator and discharge rotor bar section 12mms this season [ A terrible season, rainfall, yield and price wise! ] with excellent results in that section, particularly in some very green tough thistles. Shoe loss has never caused us any problems except when the accelerator rolls are worn or in a couple of very small, light seeded type crops. Our harvesting conditions, which are all small seeded crops, ie. wheat and etc. are probably matched some where in the US. but in general are very different to most of the rest of the world so what works in one place does not necessarily work else where. Good luck and Cheers.

We sold something over 150 1_4" shim kits for the old 3_8"X1" flat iron helicals. We did not protrude shims like the Aussies. We likely would of used a thiner shim and protruded it if we knew about that idea. We've installed lots of the channel iron kits in them older machines also for they certainly handle the tougher straw somewhat better. If you are going to shim the original helicals be sure to add the green stem helical kit while your at it. Also adding two more discharge paddles is recommended. Hard to say what your local mechanics found with to high of helicals grinding the dry straw. Thats a little hard to believe but maybe they still had reverse bars in and maybe they double stacked helicals!! Maybe didn't install green stem helicals!! Be sure your accelerator rolls are good and you'll have no shoe problem. If you do have shoe problem check air pattern comeing under accelerator rolls. While laying a straight edge on last few inches of ducting just ahead of the rolls you should find edge to run paralell to floor under engine. Good luck