Issue link: https://www.e-digitaleditions.com/i/1545857
A-C engineer documents draper project TO: Larry Gutekunst SUBJECT: Field trip to Limon, Colo. Principle Contacts: Bob Gattis, Custom Harvester, Plainview, Texas; Jim McDaniels, Custom Harvester, Rolling Fork, Miss.; Ken Adrian, Custom Harvester, Hillsboro, Kan.; Roger Patterson, Engineer, MacDon Industries, Winnipeg, Manitoba. The primary purpose of my trip was to evaluate a MacDon 30-foot swather draper header adapted to fit on Gleaner N Series combines. A secondary purpose was to check experimental items on test headers and get an overall view of header performance. Mechanical problems with the developmental header plagued us during much of our testing. The drapers and beater are hydraulic motor-driven with flow controls to vary speeds. We ended up running the fore-aft draper at top speed and the lateral drapers near maximum. The hydraulic pressure required running empty was only 100-psi below relief, resulting in much higher power requirements than anticipated. We had to redesign the hydraulic pump drive from an open double strand No. 50 to an enclosed oil bath Daido LLC50 chain just to be able to run longer than an hour at a time. Despite the problems, we were able to evaluate performance in several crop conditions: CONDITION 1: Tall (52-inch) straw, medium stubble length (14-inch). All conventional headers in the area (Gleaner, Deere and Case) were having trouble cutting in the center. It was the classic problem of straw being too long to lay over and feed under the auger. Most straw fed across the front. The resulting bottleneck in the middle causes a hesitation at the cutterbar, so the header leaves a strip of ragged cutting. The Case 1460 combines in the fields with Bob Gattis' N7s were capacity-limited at about 2.5 mph with their 24-foot headers and therefore suffered little handicap. Bob ran about 2.8 mph with his 27- foot headers to minimize stripping but was only running 10-12 pounds boost at this speed. Stripping was very comparable with the Case combines. The draper header was tested on N6.22, which could run about 4 mph power limited all the time. This was only possible with a 16-inch diameter two-blade beater installed over the fore and aft draper compressing the straw mat and force feeding the feed chain. The beater just cleared the feed chain slats and was about 8 inches above the draper. Material, much of it backfeeding down the feed chain, was thrown out of the header by the beater. Slow beater speeds, about 230 rpm, reduced the amount of material thrown out but could not handle high feed rates. The beater was sped up to about 425 rpm to obtain satisfactory performance. A sloping deflector was placed over the beater with its opening 23 inches above the draper. This deflector eliminated any material discharge problems. We did not have the opportunity to switch the header to one of the N7s in this condition once we got our beater problem resolved. CONDITION 2: Tall (54-inch) green straw, down, tough and tangled. This condition proved to be a weak point of the draper header. Auger flights could get a hold of the straw, turn it head first and tear it apart. Drapers, not nearly as aggressive, merely slid under the crop. The reel had to be used to try and tear the mat apart so it wouldn't feed in bunches. Sometimes, the drapers stopped, so the header had to be raised to break up the mat. A great deal of operator input was required to obtain a barely acceptable feed rate. Another problem area -- the heavy mat of tall straw filled the full depth of the drapers. Heads sliding against the header back were blocked by the beater supports. Some stems were turned, so they fed butt first. The butt-first feeding was not severe enough to hurt feeding capacity; it just didn't look good. CONDITION 3: Tall (48-inch) straw, very heavy-yielding crop (65-plus bushels per acre). The draper header was switched to one of Bob Gattis' N7s. Fed excellent as long as the crop was not down flat. Bob could run against power, up to 23-pound boost. Bob Gattis was operating the combine in this crop and was constantly changing reel height and speed for even feeding. He consequently got much more out of the machine than any of the other operators. In this condition, we ran a power comparison between Bob's N7s in even crop. The combine with the 30- EDITOR'S NOTE: The following is Part II of correspondence on the draper header project from the 1980s. Part I appeared in the Spring Edition of Old Allis News. Because these files were gleaned from 1980s software, some parts may be missing. 36 OLD ALLIS NEWS