All-Crop Combines Designed for the Family Farm

The versatile Allis-Chalmers tow-behind All-Crop combine, advertised as providing an improved way of life for the farmer, found a ready market.

By Jim Gay
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by Farm Collector archive
The 1936 All-Crop Combine.

Allis-Chalmers entered the combine market in May 1931 with purchase of the Advance-Rumely Thresher Co. Rumely’s No. 2 and No. 3 prairie-type combines, with headers ranging from 10 to 20 feet, were still being produced when the Persian orange High-Speed combine was introduced in 1935.

This pull-type, PTO-driven, rubber-tired combine for the Midwest family farm could be powered by a 2-plow tractor and was advertised as “the successor to the binder.” It was initially called the High-Speed combine, but in the following year, the name was changed to All-Crop.

The cutting width was 60 inches with 66 inches between the crop dividers. A ground-driven 4-bat reel helped lay the crop onto a full-width canvas conveyor that fed the material in a thin, even layer to the 60-inch threshing cylinder. Reel height could be set with a rope to the tractor. The spring-balanced header height was adjustable with a lever to the tractor seat for cutting from 2 to 22 inches above the ground.

A unique 15-inch-diameter cylinder had eight rubber-coated angle bars that worked with a rubber-faced concave and rubber blocks to gently thresh the crop. This action, plus a variable-speed cylinder drive and the adjustable cylinder-to-concave clearance, permitted the successful harvesting of 70 crops.

A variable speed-driven pulley provided a cylinder speed range of 425 to 1,700rpm by adding or removing spacers between the two halves of the pulley. Adding spacers caused the belt to ride lower in the pulley, which increased the cylinder speed. Conversely, removing spacers forced the belt outward, slowing the cylinder. An adjustable spring-loaded idler maintained the proper belt tension at every cylinder speed. Sickle bar and header canvas speeds could also be adjusted with a variable-speed pulley.

Innovative design set All-Crop apart

Another unique feature of the All-Crop combine was the positioning of the separating/straw-walker section across the back of the combine, instead of in line with the material flow from the cylinder. Baffles located in the roof of the separator section deflected material from the cylinder to the left side of the combine and at the front of the straw walkers, which were 10 feet long and 32 inches wide (26 square feet). Grain and chaff fell down to the solid grain pan and were moved to the left side of the combine (front of the cleaning shoe) by a raddle drag. This design provided an even, controlled delivery of grain to the cleaning shoe.

An 18-inch-diameter full-width cleaning fan separated the chaff from the grain through adjustable sawtooth wind control valves as the grain passed through two adjustable sieves and one special finishing sieve. Various sieves were available to match the crop being harvested. A variable-speed pulley was used to drive the long belt at the rear of the combine, and that powered the straw rack, cleaning fan and tailings auger. One noticeable feature of the early All-Crop combine was the rounded corner between the top and back of the straw-walker section.

Unthreshed grain or tailings were delivered in front of the cylinder at the left side, initially for re-threshing. The delivery location was soon moved to the right of the cylinder middle (pictures in a 1937 brochure show both locations). Clean grain was augered to a vertical conveyor located inside the 18-bushel hopper. This conveyor also served the double purpose of unloading the grain tank in 1-1/2 minutes by repositioning the discharge chute.

All-Crop finds enthusiastic market

According to Allis-Chalmers Farm Equipment 1914-1985 by Norm Swinford, annual production of the combine increased dramatically with a total of 550 High-Speed combines in 1935, followed by 7,650 All-Crops in 1936 and 15,300 in 1937. That had to present significant procurement and manufacturing challenges. At the end of 1936, the All-Crop combine was in use around the world. That year, it received the Royal Agricultural Society’s Silver Medal in England for the most outstanding contribution to the world’s agriculture.

During this period, Allis-Chalmers advertising stressed an improved way of life for the farmer when he used their equipment: more time with family and for vacations. The All-Crop combine was no different. With an All-Crop, one trip over a field with direct cut, and the job was done.

With a binder, that same trip was just the beginning of the harvesting process. Plus, there was the cost of the twine and the labor incurred in manually putting the bundles into shocks where they were exposed to the weather and varmints.

When the threshing machine became available, the bundles had to be pitched on a wagon, hauled to the threshing machine and pitched onto the feeder. The advertising also mentioned the farm wife’s role in the operation, because she had to prepare meals for the large hungry threshing crew. It’s easy to see why the small combine was so beneficial to the farm family.

FOB price for the All-Crop combine in 1936 was $595 (advertised as similar to the cost of a binder). By 1938, it was still only $625 (roughly $10,800 today).

War effort interrupts production of the Model 40

For 1938, various sheet metal changes were made to the straw walker housing, which included replacement of the upper rear rounded corner with a square corner using angle iron framework. The dual purpose of the in-hopper clean grain conveyor was split into two separate conveyors; a vertical clean grain-loading conveyor located outside the hopper and a pivoting unloading auger at the front of the hopper.

The All-Crop combine became the Model 60 when a smaller 40 All-Crop was introduced in 1938. With a 40-inch cut, the Model 40 was sized for use with the 1-plow Allis-Chalmers B and similar tractors. It was a 36-inch straight-through combine with an 11-bushel hopper. Production of the 40 ended in 1940 because steel allocations during World War II were better used to build model 60s.

In 1943, a crank-type mechanism was added to fine-tune the speed within any one of three cylinder speed ranges that were still set by adjusting the number and thickness of spacers between the two halves of pulleys. The ranges were 450 to 700rpm, 700 to 1,250rpm and 850 to 1,600rpm. The crank moved one side of the adjustable speed pulley through a lever system, pushing against a thrust bearing. One turn of the crank changed the cylinder speed about 25rpm in the highest speed range; it took two rotations to make the same change in the slowest range.

Optional attachments for every need

Several attachments were available for the All-Crop combine. Full-width reel-type and draper-type pickup attachments were available for harvesting windrowed crops. A steel finger that moved back and forth above the lower canvas was offered to spread the windrow across the width of the cylinder.

Another option was a sacking platform that replaced the grain hopper. It provided two sacking spouts with a diverter valve and a chute to slide the filled sacks to the ground. Another sacking platform that mounted in front of the grain hopper was also available. This included a horizontal auger over the top of the hopper and provided the convenient choice of either bagging the grain or loading the hopper.

Various straw-handling options were available, including a spreader, an elevating conveyor that could load the straw into a wagon pulled beside the combine, and a windrower. The windrower could place the straw from two side-by-side 5-foot swaths, making an ideal windrow for a hay loader or the Roto-Baler.

Other attachments included offset tandem wheels, dual wheels, tachometer for indicating cylinder speed, a 6-bat reel and Hart Scour-Kleen for removing weed seeds. The PTO could be replaced with a 4-cylinder 125.2-cubic-inch-diameter 29hp auxiliary engine for tractors smaller than 2-plow size or those without a PTO. By 1950, this same engine could also be used to power the A-C Roto-Baler, forage harvester and forage blower.

An aftermarket Weishaar wagon loader was available for the model 60 All-Crop combine. It consisted of a horizontal auger that conveyed the clean grain over the top of the separator housing back to a wagon pulled by the combine. A rope-controlled clutch was provided to stop the auger and divert the grain into the combine hopper.

The versatile Model 60 All-Crop

By 1945, the number of crops harvested by the 60 All-Crop had grown to 106, ranging from alfalfa seed to zinnia. A chart in an operator’s manual at that time provided the recommended cylinder speed, number of concave bars, cylinder-to-concave clearance, part number of the finishing sieve, and weight-per-bushel for all 106 crops.

The manual also included a short paragraph for each crop, although soybeans required two full columns because of the many varieties. The paragraphs told whether the crops should be harvested standing or windrowed, and provided settings for the adjustable sawtooth fan control valve and the adjustable sieves.

Some seed crops (sugar beets, onions, okra and radish) had to be topped by hand, thoroughly dried in a shed and then fed into the stationary combine. Other crops (kaffir corn, cane and maize) were too tall for direct harvesting and were bundled into shocks. The combine reel was removed, a vertical cutter bar was installed and the combine was towed from shock to shock. The bundles were topped by manually feeding them down over the cutter bar.

A high-lift header attachment provided cuts from 28 to 42 inches above the ground and was recommended for harvesting sweet clover seed to reduce the amount of material going through the combine. With what appeared to be a reference to the All-Crop combine, McCormick-Deering in a 1944 brochure stated their combine was “suitable for all threshable crops.”

Launch of the Model 66

The A Series of the model 60 All-Crop harvester was introduced in 1949. This unit had several small changes such as a hydraulic lift header, a cross-auger in the bottom of the grain tank to facilitate unloading, addition of steel bracing to reinforce reel arms and new disc wheels for easier installation of duals. The front part of the PTO shield was now two sections with a flip-up portion to facilitate attachment of the PTO to the tractor. A new flax roll attachment was available and changes were made to make it easier to install.

More than 250,000 units had been built when production of the Model 60 combine ended in 1953, followed by introduction of the Model 66 with a 66-inch cutter bar. For anyone interested in collecting a 60-inch High-Speed or All-Crop combine, an early one with the rounded separator housing, in-hopper unloading conveyor and the tailings returned to the left side of the cylinder would be a prized find. FC

Jim Gay was raised on an Iowa farm and received a degree in Agricultural Engineering at Iowa State University. He is a lifelong collector of farm and construction equipment literature and information. Email him at

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