Woodmaxx WM-8M 8-inch Mechanical-Feed PTO Woodchipper Review (2026): 8-inch Self-Feeding PTO Woodchipper
8-inch mechanical self-feeding PTO chipper — the lowest-cost way into 8-inch capacity in the Woodmaxx line.
WM-8M Mechanical Auto-Feed PTO Wood Chipper Assembly Video
Manufacturer assembly and walkaround of the WM-8M covering the mechanical auto-feed roller, 8" capacity, and PTO driveline.
- 8-inch capacity at mechanical-feed pricing
- Wide 25–70 HP tractor range
- Mechanical feed can stall on forked or crooked wood
- 3-year WM warranty vs 7-year MX
Woodmaxx WM-8M 8-inch Mechanical-Feed PTO Woodchipper specs at a glance
- Brand
- Woodmaxx
- Model
- WM-8M
- Power type
- pto
- Max branch diameter
- 8"
- Power
- PTO-driven, 25–70 HP tractor
- Feed system
- Mechanical self-feeding
- Weight
- 1150 lb
- Price (MSRP)
- $3,995
- Warranty
- 3 years
Will the WM-8M fit my tractor?
The Woodmaxx WM-8M 8-inch Mechanical-Feed PTO Woodchipper needs 25–70 PTO HP. Here’s how 26 common compact and utility tractors match up — rated PTO HP, not engine HP (after typical 10–15% drivetrain losses).
| Tractor | Engine HP | PTO HP | Hitch | WM-8M verdict |
|---|---|---|---|---|
| Kubota BX23S | 22 | 15 | Cat 1 | Too small |
| Kubota LX2610 | 25 | 19 | Cat 1 | Too small |
| Kubota L2501 | 24 | 19 | Cat 1 | Too small |
| Kubota L3301 | 33 | 26 | Cat 1 | Fits |
| Kubota L3901 | 37 | 30 | Cat 1 | Fits |
| Kubota L4701 | 47 | 38 | Cat 1 | Fits |
| Kubota MX5400 | 55 | 45 | Cat 2 | Fits |
| Kubota M4-071 | 70 | 58 | Cat 2 | Fits |
| John Deere 1025R | 24 | 18 | Cat 1 | Too small |
| John Deere 2025R | 25 | 19 | Cat 1 | Too small |
| John Deere 3025E | 24.7 | 19 | Cat 1 | Too small |
| John Deere 3032E | 32 | 25 | Cat 1 | Fits |
| John Deere 3039R | 38.2 | 30 | Cat 1 | Fits |
| John Deere 3046R | 45.3 | 37 | Cat 1 | Fits |
| John Deere 4044M | 43.1 | 35 | Cat 1 | Fits |
| John Deere 4066R | 65.9 | 53 | Cat 2 | Fits |
| Mahindra 1533 | 33 | 26 | Cat 1 | Fits |
| Mahindra 2638 HST | 37.4 | 29 | Cat 1 | Fits |
| Massey Ferguson 1735M | 35 | 28 | Cat 1 | Fits |
| Massey Ferguson 2705E | 49 | 40 | Cat 2 | Fits |
| New Holland WORKMASTER 25S | 24.7 | 18 | Cat 1 | Too small |
| New Holland WORKMASTER 35 | 35 | 28 | Cat 1 | Fits |
| Kioti CK2620 | 24.5 | 20 | Cat 1 | Too small |
| Kioti NX4510 | 45 | 38 | Cat 1 | Fits |
| LS MT225S | 24.4 | 18 | Cat 1 | Too small |
| LS MT342 | 41.3 | 32 | Cat 1 | Fits |
“Fits” = within the manufacturer’s rated PTO HP range. “At limit” = below the minimum by 5–15%, will feel underpowered on seasoned hardwood. “Too small” = undersized for reliable chipping. “Oversized” = above range (works but overkill).
Who should buy the WM-8M — and who should skip it
- You own a tractor with 25–70 PTO HP and a Category 1 or 2 three-point hitch.
- Your typical branches are 6–8 inches in diameter.
- You chip mostly straight material and want the simpler, more reliable self-feeding mechanism (fewer hydraulic components to service).
- You don't own a tractor. A gas-standalone chipper of comparable capacity is the right category for you.
- You regularly chip forked or crooked wood. Mechanical feed hangs up on these; consider a hydraulic-feed chipper in the same capacity tier.
WM-8Mblade replacement & sharpening
Two A8 flywheel knives on the 8-inch disc — larger and thicker than the MX-8600 stock.
Mechanical self-feed puts more load on the bed-knife gap: keep it set to 0.030–0.040" at reinstall, or the feed will stall on springy limbs.
- Blade count
- 2 flywheel knives
- Bed knife
- Yes — fixed anvil
- Sharpening angle
- 30–40°
- Reversible
- Yes — doubles edge life
- Blade material
- A8 tool steel
- Replacement set
- $160–$220
- Sharpening interval
- 25–40 hours
- Bolt torque
- 50–60 ft-lb
- 01Stop the machine and isolate power
Disengage the PTO, shut the tractor off, and remove the key. Wait 60+ seconds for the WM-8M flywheel to stop completely — it coasts longer than the engine.
- 02Open the discharge or flywheel access cover
Remove the bolts on the WM-8M flywheel access hood (or flip the hinged hood if equipped). Swing it clear so you have line-of-sight to every blade position.
- 03Rotate the flywheel to the first blade
Turn the flywheel by hand until the first of the 2 knives is aligned with the access opening. Mark it "1" with a paint pen so you can keep track of orientation.
- 04Break the blade bolts loose
Use a breaker bar on each of the 2 blade bolts. Woodmaxx and Woodland Mills both thread-lock these at the factory; heat gently if they don't yield. Do not pry on the flywheel itself.
- 05Slide the blade out and inspect
Remove the blade and inspect for cracks, nicks deeper than 1/16", and rounded bevels. A cracked blade goes straight in the scrap bin — never re-sharpened.
- 06Flip or replace the blade
The WM-8M uses 2 reversible knives. If the secondary edge is still clean, simply flip the blade for a fresh edge. If both edges are worn, sharpen at 30–40° on a belt sander — quench every 10–15 seconds to avoid bluing the A8 tool steel.
- 07Balance the set
Remove equal material from every blade in the set. On the WM-8M's 2-knife flywheel, even a 1–2 gram imbalance shows up as vibration at operating RPM. Weigh on a gram scale after sharpening.
- 08Reinstall and torque
Apply anti-seize to the bolt threads (not the heads) and torque in a star pattern to 50–60 ft-lb. Use fresh lock washers — reused washers are the #1 cause of a loose blade downstream.
- 09Repeat for every remaining blade
Rotate the flywheel and repeat steps 3–8 for the remaining 1 knives. Then inspect the fixed bed knife — if the edge is rounded, flip or replace it and reset the blade-to-anvil gap to ~0.030" with feeler gauges.
- 10Close up and test-run
Rotate the flywheel by hand one full revolution to confirm no contact with the bed knife or housing. Close the access cover. Start the tractor, engage PTO at low idle, and listen for 30 seconds before ramping to operating RPM. Feed one small test branch before returning to normal work.
WM-8M — frequently asked questions
- How much tractor HP do I need for the WM-8M?
- The Woodmaxx WM-8M 8-inch Mechanical-Feed PTO Woodchipper is rated for 25–70 PTO HP. That's tractor PTO horsepower after drivetrain losses — rated engine HP is typically 10–15% higher. A 29 HP engine tractor produces roughly 25 PTO HP and would run this chipper at the minimum. The comfortable working range is 31–63 PTO HP.
- Does the WM-8M fit a Category 1 three-point hitch?
- Yes. The WM-8M mounts to a standard Category 1 or 2 three-point hitch and accepts a 540 RPM rear PTO shaft (included). Quick hitch compatibility varies by brand — most John Deere iMatch and Pat's Easy Change hitches accept it with a standard top-link bushing.
- What's the maximum branch diameter the WM-8M can chip?
- The Woodmaxx WM-8M 8-inch Mechanical-Feed PTO Woodchipper is rated for branches up to 8 inches in diameter. Green and softwood branches chip reliably at the rated maximum. Seasoned hardwood at the maximum slows the feed rate and bogs the flywheel more — plan for 7-inch hardwood as your comfortable working size.
- What's the warranty on the WM-8M?
- Woodmaxx covers the WM-8M with a 3-year warranty. Wearing parts (blades, belts) are excluded under normal use; commercial-scale use may require the manufacturer's commercial warranty tier.
- Is the WM-8M self-feeding?
- Yes — the WM-8M uses a gravity + mechanical self-feeding design. Infeed rollers are driven by the flywheel. Works well on clean straight branches; forked or crooked material can hang up on the rollers and need to be manually nudged through.
- How much does the WM-8M weigh?
- The Woodmaxx WM-8M 8-inch Mechanical-Feed PTO Woodchipper weighs approximately 1,150 lb. Check your tractor's three-point hitch lift capacity before purchase — a Category 1 tractor typically lifts 1,200–1,800 lb at the hitch pins; Category 2 lifts 2,500+ lb.
- How often do the blades on the WM-8M need sharpening?
- For typical property use (20–40 hours per year), sharpen the WM-8M's blades once per season. Heavy hardwood use cuts that to every 15–20 hours. A full replacement set runs roughly $80–$250 depending on blade count and material. See our woodchipper blade sharpening guide for the full process.
- Where is the WM-8M made?
- WM-8M chippers are built with a mix of US-sourced and imported components, assembled and shipped from Woodmaxx's Akron, NY facility. The MX-Series is marketed as using upgraded US-sourced bearings and hydraulics versus the WM-Series.