Combines What makes spec rotor work better than standard rotorIJ

[tj]

Would have emailed this, but I'd like to see if anyone agrees with this. Here's my theory andI think it's essentially correct. The helical spiral of bars on a standard rotor tends to poush material to the rear fairly quickly and it tends to bunch up at the end of the spiral. That's why you;re usually required to set the concaves tighter and the vanes to a slower position for proper thresh -- you have to get the seed out and are also required to tear up the trash more. The vanes are used as a retarding mechanism with this rotor. The specialty rotor, with it's short cross section mounts which are installed all over the rotor, grabs material more frequently and it's spread out more. The short sections, however, also allow stems to wrap around the mounts, and this also requires a tighter concave setting for retarding for thresh. Also usually requires a faster rotor speed for centrifugal force to carry trash to the vanes. With this rotor the vanes are used to speed up flow. Both the specialty and standard rotors are required to squeeze or pinch at the concave surface in order to achieve separation. Our rotor, with much more aggressive bars moves material more easily due to the tooth configuration and spreads it on a broader front. A tumbling, rather than squeezing action is imparted for separation -- it's not as necessary to chew up trash. We maintain a consistent spiral thru the threshing area and feed more evenly. larger components of trash are also more easily carried by the vanes. Vanes are used to speed up flow rather than retard. Operators usually run about 20% to 30% less rotor speed than with OEM. FYI, IH used to build what was called a rice and bean rotor. This rotor had spiralled mounts which carried almost to the rear of the rotor. Between the spirals were small triangular interrupters which were installed to agitate and gain separation. If these were badly worn, or not installed, seed remained mixed in the trash and went out the rotor. The spirals moved material so quickly that vane setting were most always in the full retard position. There are still a few of these around whcih have been sold used out of the rice growing areas. In other crops besides rice and beans, rotor loss virtually cannot not be controlled without installing paddles, etc. to straighten the flow across the concaves and grates. hope this is clear.

 

[Bulldogger]

tj-For someone growing a couple hundred acres of beans (edible and soy) could you recommend an older combine ( 10 yrs or older) of any color, rotary or conventional, that could economically be converted to a fulltime bean combine. Just dont like putting all that dirt through a new combine. What mods would you make to itIJ Maybe there is an older model out there that didnt exactly shine in regular crops but with some drastic mods is a bean eater. Anyone else care to commentIJ

 

[tj]

Harvesting any type of bean esentially requires moving the stems thru and threshing the pods at a rotor_cylinder speed which is slow as possible in order to prevent damage--crack and scuff. This requires a cylinder_rotor which moves material aggressively, and which will allow the product to separate gently (drop out) rather than being forced thru the concave. You also want trash to remain in larger components in order to provide some cushioning to prevent beans from contacting metal surfaces as much as possible. This is the short overview. About any conventional machine which uses spike teeth does best in dry beans, but in soybeans, vines need to be pretty well dried down. last season we helped convert a pair of lilliston peanut combines for dry beans -- basically only change made was to install airfoil chaffers in them and hardface the edges of the stationary teeth. Some withered pods were lost, but bin grade was excellent. I don't believe there was a good bean lost and tare was zero from scuff. These are pull type combines, but the operator was able to purchase them for very little. New Holland (TR70_85) rotors are very good in beans of all kinds. You have the advantage of 2 rotors to carry material thru, good separation, and rotor speed can be fairly fast for throughput with a minimum of crack since peripheral tip speed is much less than other machines. We modify these rotors by installing rasp type bars and changing the mounting configuration to 90_45 degree spiral as opposed to 180 degree placement. We also install an airfoil chaffer so we can put wind on the shoe. Required rotor speed drops by about 30% or more, and damage is virtually eliminated due to lessened amount of beans returned to the rotors when they're in an unloaded condition. We've modified all IH models, and have had great success. In newer 2388, rotor speeds in dry beans are as slow as they can be set (220-250 RPM),and we've enabled operators to use keystock grates for better separation, and actually set the rear vanes at full retard--tare from damage has been about 0.1%. Same results in soybeans, except rotor speeds are a little higher. I believe, however, that the best results have been in 20 and 60 series machines, especially the 20 series. Peripheral tip speed in comparison to RPM is greatly reduced with good throughput and we've enabled operators to harvest specialty crops such as seed beans, onion seed, sweet corn seed and radish seed with almost 100% recovery and pretty close to 100% germination. We also recommend airfoil chaffers in these machines. The advantage with using our mod rotors is that they perform very well in other crops, as well. I will say that in white cob corn we're still seeing some cob breakage, but we know some of it comes from the feeder chain, and we don't know for sure how much is done by the rotor. The breakage is quite a bit reduced, however. This has been a little difficult to write-- it's a little hard to do this without tooting your own horn, but we've been tinkering with combines for many years, and this is where experience has led us. Hope this is complete enough to help.

 

[John_W]

IMHO, a bean machine would be a rotary combine primarily due to lower seed damage. This is especially true for edible beans and for seed beans. CIH machine with a specialty rotor or maybe one of Terrys St Johns Welding rotors would handle the tough bean stalks would be a good choice. The CIH machines are available, have a good record an they have good availability of OEM and aftermarket parts and parts designed to improve performance in special situations. The ingested dirt would make harden threshing components a must. If the beans are undercut or rocks are around a stone trap would be needed. All sharp edges should be removed from all threshing components and all augers should pass over the largest bean without pinching to reduce seed damage. A perforated bottom of the feeder house might help get rid of some dirt. A later model machine with a crossflow fans would be preferred. Maybe a round hole lower sieve. The edible bean growers in Idaho and Washington seem to favor CIH machines over all others.