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Origins and Design Philosophy of M&M Chippers
Mitts & Merrill, often abbreviated as M&M, was a respected name in industrial wood processing equipment throughout the mid-20th century. Known for their heavy-duty drum chippers, the company catered to municipalities, tree service contractors, and utility crews. The 12-inch model was one of their larger offerings, designed to handle substantial limbs and trunk sections with minimal operator intervention.
Built during an era when durability trumped automation, the M&M 12-inch chipper featured a staggered knife drum, gravity-fed intake, and a robust steel frame. These machines were often powered by Ford industrial engines—most commonly the inline six-cylinder 300 CID—which provided ample torque and reliability in field conditions.
Terminology Notes
While exact specs vary slightly by production year and modifications, typical features include:
A Story from the Pacific Northwest Logging Belt
In 2006, a small logging crew in Oregon inherited an M&M 12-inch chipper from a retired arborist. The machine had sat idle for years but was structurally sound. After replacing the fuel lines, sharpening the knives, and welding new bolts onto stripped blade mounts, the crew used it to process slash piles from thinning operations. The chipper ran daily for two seasons, producing clean chips for erosion control. “It didn’t have electronics—but it had guts,” the foreman recalled.
Maintenance and Safety Considerations
To keep the chipper running safely and efficiently:
Common Retrofit and Upgrade Options
Many older M&M chippers have been modified over time:
Parts Sourcing and Restoration Tips
Finding parts for vintage M&M chippers can be challenging but not impossible:
Final Thoughts
The M&M 12-inch wood chipper is a testament to industrial simplicity and mechanical resilience. Though lacking modern automation, its design allows for high-throughput chipping with minimal fuss. For operators who value raw performance and straightforward maintenance, this machine remains a viable tool decades after its manufacture. In the world of wood processing, sometimes the old iron still bites best.
Mitts & Merrill, often abbreviated as M&M, was a respected name in industrial wood processing equipment throughout the mid-20th century. Known for their heavy-duty drum chippers, the company catered to municipalities, tree service contractors, and utility crews. The 12-inch model was one of their larger offerings, designed to handle substantial limbs and trunk sections with minimal operator intervention.
Built during an era when durability trumped automation, the M&M 12-inch chipper featured a staggered knife drum, gravity-fed intake, and a robust steel frame. These machines were often powered by Ford industrial engines—most commonly the inline six-cylinder 300 CID—which provided ample torque and reliability in field conditions.
Terminology Notes
- Drum chipper: A chipper type that uses a rotating drum with mounted knives to slice wood into chips.
- Self-feeding: A design where the geometry and drum rotation naturally pull material into the cutting chamber.
- Chuck-and-duck: A nickname for older drum chippers that rapidly pull in material, requiring careful operator positioning.
- Governor: A mechanical or electronic device that regulates engine speed under varying loads.
While exact specs vary slightly by production year and modifications, typical features include:
- 12-inch diameter feed capacity
- Four staggered knives mounted on a rotating drum
- Adjustable discharge chute for chip direction
- Ford 300 industrial engine with mechanical governor
- Belt-driven clutch assembly
- Heavy-duty trailer frame with pintle hitch
- Manual or hydraulic feed assist (depending on retrofit)
A Story from the Pacific Northwest Logging Belt
In 2006, a small logging crew in Oregon inherited an M&M 12-inch chipper from a retired arborist. The machine had sat idle for years but was structurally sound. After replacing the fuel lines, sharpening the knives, and welding new bolts onto stripped blade mounts, the crew used it to process slash piles from thinning operations. The chipper ran daily for two seasons, producing clean chips for erosion control. “It didn’t have electronics—but it had guts,” the foreman recalled.
Maintenance and Safety Considerations
To keep the chipper running safely and efficiently:
- Inspect knives weekly and sharpen or replace as needed
- Use high-grade bolts for blade mounts and torque to spec
- Check drum bearings for play and lubricate regularly
- Ensure the governor linkage is clean and responsive
- Replace fuel filters and spark plugs annually
- Keep the discharge chute clear to prevent clogging
Common Retrofit and Upgrade Options
Many older M&M chippers have been modified over time:
- Engine swaps from Continental to Ford or vice versa
- Hydraulic feed rollers added for improved control
- LED lighting and brake upgrades for road compliance
- Knife upgrades from OEM to aftermarket hardened steel
- Safety guards and emergency shutoff switches retrofitted
Parts Sourcing and Restoration Tips
Finding parts for vintage M&M chippers can be challenging but not impossible:
- Knife replacements available from suppliers like Zenith Cutter, Baileys, and Global Equipment Exporters
- Bolts and fasteners sourced from industrial hardware vendors such as Bolt Depot
- Engine parts compatible with Ford 300 CID widely available
- Bearings and belts matched by size and spec from agricultural supply catalogs
- Manuals and diagrams sometimes found through collector forums or equipment salvage yards
Final Thoughts
The M&M 12-inch wood chipper is a testament to industrial simplicity and mechanical resilience. Though lacking modern automation, its design allows for high-throughput chipping with minimal fuss. For operators who value raw performance and straightforward maintenance, this machine remains a viable tool decades after its manufacture. In the world of wood processing, sometimes the old iron still bites best.
