WOOD ENERGY

CHIPPED

Forestry Machinery’sKen Topham returns to Wood Energy Wales for a chat with father-and-son team Huw and Carwyn Owen about their new chipper, a Mus-Max 11XL Z Wood Terminator

IMAGES KEN TOPHAM

Left: Huw and Carwyn highly rate the quality of chip from the Mus-Max.

Right: Carwyn’s rear view; the 1050 has reverse drive from the factory.

Below right: The new-design drum weighs over two tonnes and has six knives.

THE 11XL Z IS A NEW DESIGN, NOT JUST A BIGGER VERSION OF THE 10X

This image: 11XL Z has a voracious appetite - this pile was gone in no time.

Right: Control interface is fairly simple and largely self-monitoring.

Visiting the edge of Snowdonia

National Park during the ‘Beast from the East’ could have been a disaster, and although snow did fall we managed to see Wood Energy Wales’s new Mus-Max 11XL Z Wood Terminator in action. Huw and Carwyn Owen have been running their accompanying Fendt 1050 since 2017, and after a bit of leapfrogging with tractors and chippers they now think the set up is as good as it possibly can be.

The Fendt 1050 still holds the most powerful ‘conventional’ tractor crown with 517hp (by conventional, I mean big wheels at the back and small ones at the front). This one is an unusual spec, as it was bought for forestry power, so no GPS, no central tyre inflation or agricultural frills. Just reverse drive and lots of grunt. The Owens have a mix of work for their chipper but producing high grade G50 chip for CHP systems is the most important role. And when you have your own system, the quality has to be good.

When we last saw the Wood Energy Wales outfit at work, we were in the woods and the Mus-Max 10XL Z made enough noise to make you think the world was coming to an end. On this occasion, we were at the company’s base and the chipper’s operation seemed smoother and quieter. The 11XL Z is a new design, not just a bigger version of the 10X, and it’s obvious as soon as the first log goes in. The pitch of the chipper is different as the new drum runs more slowly, down to 240rpm if needed. Carwyn says he usually has it at 350, (which equates to 950rpm PTO speed) where the 10X would be over 400rpm. “It’s a far smoother machine to use, more responsive when it’s loaded and the load monitoring

TECH SPEC

MUS-MAX 11XL Z WOOD TERMINATOR

FEED OPENING 80X135CM MAX LOG DIAMETER 80CM OUTPUT 240-270M3 POWER REQUIREMENT 350-500HP KNIVES 6 DISCHARGE CHUTE HEIGHT 5.6M SCREEN AREA 2.05M2 CRANE PALFINGER M70F

is better,” he explained. “The 10X is a very good chipper, but this is a different beast.”

At the heart of the 11X is a redesigned drum weighing 2.7 tonnes. “The new drum is much kinder to the whole system,” Carwyn continued. “There are six blades versus 12 on the old machine, and they are staggered two by two rather than in rows. The weight of the drum definitely smooths out changes in load. We’re

chipping more per hour, with a slight reduction in fuel use per cube of chip – we’re running between 60 and 85 litres of diesel per hour now.”

THERE ARE SIX BLADES VERSUS 12 ON THE OLD MACHINE, AND THEY ARE STAGGERED TWO BY TWO RATHER THAN IN ROWS

Carwyn Owen operates the Mus-Max outfit.

Bed roller adjustable for different sites and loading heights.

CONSISTENCY IS KEY

The new drum also has adjustable shoes before the knife, so chip quality can be maximised from different types and sizes of wood. The operator can set the shoes to vary the thickness of the chip, too. “The biomass systems aren’t as sensitive, but CHP systems need a good quality of chip, and that’s where we think the Mus-Max machine wins with its very consistent size and thickness,” said Huw.

Carwyn and Huw dry and screen their chip no matter whether it’s for a customer or not. There was very little small material coming through their screener, and as Carwyn took a batch from the drying floor we could see the material screened was consistent. Any smalls that don’t make the grade are sold for animal bedding, but the pile isn’t growing much from numerous batches. Carwyn said the 11X needs to be full because “it works best that way, and the chip is better.”

The 11X has the 50mm screens fitted all of the time. There are a set of G30 screens, but even for clearance jobs the G50s work well. The 11X has a variable displacement pump for the blower drive – the speed is adjustable and Mus-Max claims 18m of blow from the chute which can discharge at a height of 5.6m. Carwyn reckons it’ll blow 25m if you want it to, but it’s the ability to slow the blower he really appreciates. “We usually run it at 450rpm and the wood trickles out nice and steadily. There’s less dust and loading the trailers is easier –

you’re not blasting chip everywhere.”

Behind the blower are two augers to transport chip to the impeller, which is easy to open for a service or unblocking. Starting the chipper is easier, despite the drum gaining over 1.5 tonnes in weight. “It’s easier to get the PTO turning because you’ve only got the drum mechanically connected now – the hydraulics don’t take much power on start-up,” Carwyn explained. Most of the 11X is now powered by on-board hydraulics. The Fendt 1050 provides plenty of oil through power beyond; the load sensing line can deliver 165l/m so is not short on flow for the crane, which is the only external oil draw.

Carwyn has mixed feeling about the change from a Penz crane to Palfinger. While the Palfinger M70F is more protective of its pipes and wires, the M70F doesn’t have as much power as he’d like. “I’m pretty fussy when it comes to feeding the chipper. I try to move the logs to disturb any foreign matter and make sure I can see what I’m loading, as you can end up with knife damage and excessive wear if there’s dirt and stones going in. The Palfinger crane is good and nice to use but could be more powerful.” The Cranab CE280 grab, meanwhile, raised no comment from Huw or Carwyn, which must mean it’s performing as expected.

The process of feeding the beasty 11X has been improved, too. The table is wider and longer than before to meet the 135cm-wide mouth. The feed rollers are also much larger than the previous Mus-Max, though the height increase is only 5cm. The capacity increase comes from the 11X’s 37cm greater width. A wider bed and larger compression system are to be expected.

Above: Hydraulic blower can be slowed to reduce the discharge velocity. Above: The variable speed motor on the outside of the 11XL Z’s blower.

SIGNS OF PROGRESS

Carwyn said the 11X feed monitoring is more dynamic and loads the tractor in a more measured way. “If you made a mistake feeding the old machine, it could stall the engine, which isn’t ideal from full revs. The 11X feeds more smoothly and that causes less variation in rpm, which saves fuel.” The

The 11XL Z has a 80x135cm intake and can take a 80cm diameter log.

Carwyn knocked out three loads of chippings in 20mins - despite the snow.

roller on the end of the feed bed is hydraulically adjustable to accommodate different load heights and varying site conditions. The roller has a one-way ratchet system to stop logs rolling out that might not have been grabbed by the feeder rollers, increasing the level of safety.

Output has pleased Huw and Carwyn. The quoted spec is 240 cubic metres, but Carwyn reckons that’s conservative, saying he can get 240 to 280 with good logs and a flow of trailers, depending on soft or hardwood. “It’s a shade less output than a self-propelled machine, but uses less fuel and provides a more competitive hourly rate,” Carwyn commented. The 11X’s running costs should be less than the older machine, with half the knives, at £105+ VAT per blade. Carwyn has a set of ‘rough’ blades for clearance jobs and a good set for when they know with some degree of certainty that the risk of damage is low to none. Sharpening is done with the blades out – a wet sharpener in the workshop puts a fresh edge and correct angle on the blades. Carwyn says he sharpens the blades every week on average.

Unloading the chip before drying ready for the CHP system.

A FULL HOUSE

Wood Energy Wales has grown its fleet since we last saw the company, adding a forwarder, two tractor-mounted attachments, a log skidder and 14-tonne winch, but the highlight is the new Mus-Max. Huw and Carwyn have been very pleased with their latest addition and continuing relationship with Ben Price who distributes Mus-Max throughout the UK. The trailed machine suits their operation perfectly, providing high manoeuvrability in awkward places and capable of getting across a wet field or woodland, plus transport at 65km/h on the road. An all-round outfit.

THE QUOTED OUTPUT IS 240 CUBIC METRES, BUT CARWYN RECKONS HE CAN GET 280 WITH GOOD LOGS

Above: Screen area of 2.05m2 ; G50 screens default for WEW.

Below: Fendt’s high level spoon hitch; PTO drive line unrestricted.