Greemech 220

[PeteB]

On our tools, the gap is set in production and is fixed. If it increases, either a locking collar or shim is faulty or there is bearing wear. Or worse still, fabrication damage from an RTA or some such or it has been used as a high speed winch with a climbers rope!

 

Shear bars and blades are a sacrificial item in that they do loose their edge and the efficiency of the machine drops. Blades can be rotated or changed, but the shear bars are designed to be efficient for a longer period. They loose their supportive profile over many hours depending on the material being chipped so some will last for a long time while others being fed dirty brash etc won't.

 

I would have said that checking things like anvil wear and bearing condition would be part of the "Good Housekeeper's Guide" for chipper owners. Same as adjusting the brakes and ensuring that the lights work.

[WeFixIt]

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Edited December 21, 2014 by WeFixIt

[Mountain man]

Ok Pete, I've been in the workshop this morning acquainting myself with it.

Here's a stupid question, in this picture you can see the rotor will be turning clockwise as we look, the scoops or wings we can see seem to be curved the wrong way for maximum "scooping"

I checked behind the wheel on my TW and the scoops are the other way round to this.

Now I know I'm being stupid, please explain how.

Sorry pic is upside down.

[WeFixIt]

On our tools, the gap is set in production and is fixed. If it increases, either a locking collar or shim is faulty

 

 

They maybe set in production but the mere fact it has a adjustable collar and shims would be implying there is adjustment!

[Breezeblock]

Ok Pete, I've been in the workshop this morning acquainting myself with it.

Here's a stupid question, in this picture you can see the rotor will be turning clockwise as we look, the scoops or wings we can see seem to be curved the wrong way for maximum "scooping"

I checked behind the wheel on my TW and the scoops are the other way round to this.

Now I know I'm being stupid, please explain how.

Sorry pic is upside down.

 

I've seen this done on rotors to cut down on noise

[PeteB]

They maybe set in production but the mere fact it has a adjustable collar and shims would be implying there is adjustment!

 

There is adjustment - for the initial set up in assembly. As the distance between the blade and the shear bar changes so little over the blade live - no further adjustment is therefore necessary. If the rotor is removed for some reason then adjustment is advisable. The rotor is moved back and forth in the bearings and the pulley side bearing has a carrier that makes it easier for the assembly crews and future service engineers to do it accurately and with minimum fuss. Each bank of blades is passed past the shear bar until the optimum distance is reached then the carrier is locked off followed by the eccentric collars on the bearings. Job done....

 

Our paddles are put that way around as we believe from testing that they are more efficient at moving air and pumping it up the discharge chute. As they rotate close to the chute opening, they are trying to shear or scoop air away from the opening - this helps with both flow and noise.

[Mountain man]

Ok so I got the new discs and they match up perfectly with the anvil 1 to 2 mm clearance so that simplifys things! What's the torque setting for tightening the retaining bolts?

Ps I'm getting excited!

[PeteB]

Torque settings are written in the manual which is available as a download from the GreenMech website or viewable on a tablet or smart phone. If you have plane washers then I would say that 150nm is okay but some go upto 250nm if the fit Nordloc washers in place of the plane washer. A few simple rules are that the blade pocket and surrounding area is clean and also the back of the blade too. Also make sure that the nut orifice is also free from debris to ensure a complete metal to metal contact. Put a smear of grease in the blade pocket before placing the blade and in it and use a torque spanner or bar to get the correct setting. Same as any blade set up tbh....

 

I take it as the blade/bar gap is now down to something like original, someone had sharpened the wrong face on the old blades?

[Mountain man]

Torque settings are written in the manual which is available as a download from the GreenMech website or viewable on a tablet or smart phone. If you have plane washers then I would say that 150nm is okay but some go upto 250nm if the fit Nordloc washers in place of the plane washer. A few simple rules are that the blade pocket and surrounding area is clean and also the back of the blade too. Also make sure that the nut orifice is also free from debris to ensure a complete metal to metal contact. Put a smear of grease in the blade pocket before placing the blade and in it and use a torque spanner or bar to get the correct setting. Same as any blade set up tbh....

 

I take it as the blade/bar gap is now down to something like original, someone had sharpened the wrong face on the old blades?

 

Exactly, I think they had rubbed down the face of the blade to get an edge,Thereby taking it away from the shear bar, coupled with blades so blunt it was unreal, made for a unhappy machine.

I got the manual download whilst googling.

I ran some firewood through it but tomorrow's it's first day earning its keep.

I like it already!

Thanks Pete.

[Mountain man]

Ok, so this may be of interest to some. We had it out today and although it was great on the big stuff I was underwhelmed by its pulling in of smaller brash.

So the first thing we did was slow the rollers (did not know that was possible until I checked the downloaded manual) then we took it home and tarted up the rollers with a lapping wheel, hey presto! It's now operating as it should, a chipping tyrannosaur!

Time will tell if it is a real bargain, but at 1/3 the price of a new one with only 700 hrs im happy it's a risk worth taking.

I don't imagine for most of its hire life it was working to its potential.

Special thanks to Swinny for tipping me the wink on it.