Mini chipper not chipping/pulling well

[carsmarco252]

Good morning. I have a skarper c90 and for the last 2.5 years I have been using new blades and the machine has always worked well. Recently I have used all good sides of the new blades and have had them all reground and now I'm using the reground blades. I'm Finding that the machine no longer pulls brash in like it used to and the blades are becoming really dull and pitted along the leading edge after only one hours work. With the new blades I could get at least 20 hours work. I've reset the distance between the blade/anvil after the sharpening and I'm very careful with what I chip so can anyone offer any reasons why the chipper may not be pulling brash in anymore, and why the blades are Becoming blunt almost straight away after fitting reground ones. Thankyou. 

[nepia]

I'll be watching this with interest as I'm getting exactly the same with my Jo Beau; everything's set up right - brand new blades and a tight anvil gap but they just won't drag in.

Chinese steel he asked cynically?  I'll check the edges in a few minutes...

[Khriss]

Have you checked the bearings? Wondering if a little bearing play is dinking the blade on the  anvil? Otherwise,  new blades should be performing as before 🤔 K

[nepia]

Bearings are fine on mine Khriss; the machine's 2.5 years old and gets light to moderate use.

 

The blades are ok; they've probably done 5 or 6 hours work but from new they never grabbed material as they should.

Operator error is always a possibility but I've had two Jo Beau M300s since 2012 and always changed blades myself; never had this before.  Usually with new blades you have to be careful not to feed too much because the grab is so strong the machine will stall itself.  Not now - far from it.

It's true also that a cold starting machine with blades and drum bone dry take a few minutes to really get going; a bit of sap on them makes big difference to performance.

[Andrew McEwan]

Could the tempering on the blades have been knackered if dry ground?

[Jase hutch]

Blade angles are critical on gravity fed chippers. Maybe they have been ground to the wrong angle  ?

[Bob The Dog]

As Jase has said. My CS100 was hopeless after the first blade grind. When I checked, the new angles were incorrect, and not by a great deal. Not sure what your blades are like, but the cs100 blades have front and back angles, and both need to be spot on. Once rectified, it pulled the branches in brilliantly. Blunt or incorrectly ground blades are what stops brash and branches being pulled through from what I know! 

[Mark Bolam]

Were the blades flat ground instead of hollow ground perhaps?

As Jase said it makes a huge difference to a gravity fed machine.

[carsmarco252]

I'm going to buy a new set of blades and compare them to the reground ones for the angles. 

How can I check the bearings to see if they have play and the drum is causing the blades to slap against the anvil? I've not heard any unusual noises thst would indicate metal on metal. 

[PeteB]

Have the belts off and see if you can waggle the rotor shaft. Up/down/in/out!