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Chipper blade change guide - Jensen

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On my A540 the gap between the blade and anvil increases in size along the blade. From memory I think it is smallest near the centre (some weeks since last blade change, I change them every 50 hours). I imagine this applies across the range of Jensen chippers. I set the gap near the centre to be as tight as possible, and check that each of the 3 blades is clearing the anvil. This works fine and stops the chip being too coarse on high roller speeds.
I always turn or replace the anvil every other blade change. The anvil can be skimmed to restore a sharp corner.

I’am guessing by the fact your adjusting the blades each time you have the older style flywheel which has 2 adjusting bolts on the rear edge of each blade!

In most cases the blade angle to anvil is adjusted by moving the main flywheel bearings
This will normally result in adjustment of reducing or increasing the gap but the the blade to anvil closest point is always the edge nearest the centre of the flywheel

If you have new or good flywheel bearings small gap is fine the outer edge is a larger gap still good! As the flywheel will isolate when spinning at speed a little bit and then you stick a lump of wood in its way and so it will then isolate a lot but that’s ok because you have a tapered blade gap

Make your gap to small and one day your be posting pictures of your chipper where the flywheel has been trying to climb out of the chipper or it’s spitting chunks of steel out of everywhere!

Anvil changing well like blades depends what your chipping! Some anvils are single use some are reversible those that are should only be turned once not each blade change or every other but when on inspection it is deemed no longer serviceable, refacing in some cases can be done but caution refacing some anvils could have undesired effects, the anvil has been manufactured the size it is for a reason! and it fits snuggle in position and is just the right height and thickness to do its job also like blades they are ground to angles to assist performance.

Like blades when fitting anvils it is so important to clean every bit of chip, dirt and crap out before fitting. As many will know but possibly some won’t a bit of dirt or wood or stone gets stuck between the anvil mounting and the anvil it will break down over time due to compression and vibrating and fall out like dust leaving you with a loose anvil next to a high speed spinning flywheel!! Or if it’s behind the anvil it could cause it to warp and make contact with the flywheel blades!

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I presume that you mean oscillate rather than isolate? 'wobble' rather than 'set apart'? 


You are right in that a flywheel can minutely change shape as it rotates at speed an bites into wood - added to that motion, a tracked machine also has gyroscopic forces to contend as the chipper is tracked about. This too can cause movement and accelerate bearing wear!

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Yeah your right! That’s what you get for texting faster than you can think..


Also blade set to close can suffer from wood/chip getting stuck between the two forcing the flywheel to flex and causing a undesirable effect!


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