FARGO, N.D. – High volume manure spreaders demand maintenance. When a solid object jams a steel component designed to handle mush, something’s going to give.
“When we’re filling manure spread-ers with big payloaders, we can’t see what’s going in the box. We’re bound to load things we shouldn’t,” said Paul Degelman of Regina’s Degelman Industries.
“It’s inevitable. There’s rocks, calf skulls, logging chains, old wrenches, steel shafts, old fence posts. Anything that has ever been considered junk goes on the manure pile.
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“You’re not going to prevent junk from getting into the box, so you need to design a machine that handles junk.”
When the 28 cubic yard Degelman M28 was introduced in 2008, the company thought it was close to production with its design.
However, with his revised M28 on display at Fargo, North Dakota’s Big Iron this fall, Degelman said the project is now into the fifth year of development because of an unforeseen problem.
“From the start, our goal has been to build the best manure spreader in the world. We wouldn’t let it into production until we’re sure we’ve got it right.
“We started out with a target of uniform manure depth over a 50 to 60 foot spread. We want good reliability and outstanding performance at the high end of delivery rates.”
The M28 strategy is that a wide spread eliminates the need for subsequent tillage and harrow operations, saving money for producers.
Degelman said the M28 can regularly spread about 28 tons of manure in 90 seconds. A full load of 28 tons is also about 28 cubic yards.
Although high rates of this magnitude will concentrate too much manure on the land, he said it shows that the engineers have made a superior spreader.
Designing a spreader of this size involved more than enlarging a previous spreader. The cart got a new undercarriage, tandem walking axles, new beaters and .75-inch pre-stretched, rust-resistant chains with a breaking strength of 113,200 pounds.
The hitch is isolated from the cart with rubber-suspended doughnuts to reduce the shock load on the tractor. The floor drive is hydraulically powered.
A 12-volt potentiometer controls oil flow to the gearbox, giving the operator infinite speed control of the drag chain.
The engineers installed a heavy duty Berma gearbox with heat-treated gears and splined shafts, plus clutches for added protection. Total hydraulic demand is 20 gallons per minute.
The front wall of the cart is made of perforated steel so the operator can see what’s happening in the box. Instead of the typical sloped sidewalls, which cause bridging and compaction down the middle, the new box has vertical sidewalls. The floor is replaceable one-inch thick poly sheets that eliminate steel-to-steel wear points and reduce icing.
“We tried a number of different back ends. We started with the typical auger-style flighting at the top with flails at the bottom. And it did the spreading, no problem.”
The new design worked well. The live floor with slats pulled by twin high-tensile chains proved to be reliable.
Chain speed was adjustable from the cab and the guillotine style door at the back gave operators precise control of the unload rate. And the walking axles under the chassis worked as intended.
Degelman thought the spreader was nearly ready for production but the weak spot in the M28 turned out to be the same as on all high volume spreaders.
A solid object lodged in just the right spot at just the right time can play havoc with the back end of the machine.
“Everything was looking good going into year four. We’d done lots of field-testing. We were just about ready for production, then we blew the gearbox.”
Degelman said operators were loading rocks mixed in with manure, which can often happen in the real world.
“The auger flighting at the top jammed with a rock. All that energy instantly transferred to the gearbox and the gearbox broke.
“So there we were. Year four into the project with a broken gearbox. You can’t go into production with a potential problem like that. You know that if it happens on a prototype, it’ll happen on customers’ machines.”
Engineers went back to the drawing board. They saw that the flails at the bottom of the twin vertical shafts were working well. So they shortened the auger flighting and extended the flails one tier higher. They tested this model and found that jamming persisted only at the auger screws.
The augers were the most temperamental components in the system because of balancing issues. And they were the only spot in the system with tight clearances that could catch a rock.
“Auger flighting is mounted solid to the vertical shaft. There’s no compromise when a solid object comes through.”
So the augers had to go. The flails could take the abuse from rocks because they had plenty of space around them for solid objects to fly through.
“Now we’ve got flails going from the bottom of the vertical shafts right up to the top of the vertical shafts. No more augers.
“I think we stumbled across something nobody else ever thought of. It’s a truly indestructible back end. We call it the Rock Bypass System.”
Degelman said that the flails pivot at the point where they attach to the vertical shafts. They expand out to their working position by the centrifugal force of the shafts. When a rock passes through and strikes a flail, the flail collapses into itself and the rock sails through.
“The flail system has all kinds of forgiveness built in. It doesn’t fight the rock.”
Degelman said the spinning flails also grind the manure into a smaller mulch, further reducing the need for cultivation.
The latest improvement came when they hit a batch of particularly wet, sticky manure mixed with clay in southern Alberta. The material would not release from the flails.
“We needed a different configuration on the flails. We came up with something that looks like a hammerhead shark with rippled teeth edges.
“That did far more for us than we expected. It not only lets that sticky manure slide off easier, it’s extended our range quite a lot in less demanding conditions.”
Degelman said they now have 10 pre-pilot spreaders in the field working through dealers and custom operators.
The hammerhead flails have been retrofitted to all 11 machines.
“Now we’re throwing manure over a 100 foot spread and we’re getting total uniform consistency up to 80 feet. That’s far better than our original target. ”
Degelman plans to build about two dozen M28 spreaders this winter. They are expected to sell for $118,000.
For more information, contact Paul Degelman at 306-543-4447 or visit www.degelman.com.
