When to change chipper knifes

[escavader]

Ive chipped an unreal amount of wood with my new hydraulic feed salsco .my other grAvity feed chipper would start feeding hard and give iindication the knives were dull long ago
With the feed rolls driving everything through with ease how will i know when the knives are dull,and can i hurt the machine by running too long?the tractor just idles along effortlessly and never changes its tone.what do you all think

 

[gwdixon]

If you can see, or reach, the knives you can evaluate the sharpness. Be careful if running your finger along the edge.

It is always nice to have a spare set so the original set can be sharpened while work continues with the replacement set.

Dullness creeps up so slowly that it is hard to notice on a hydraulic feed. The manual feed chippers would certainly let you know when it is time for a sharpening as you point out.

 

[5030]

Carefully feel the edge on the blades. If it's still sharp....... forgetaboutit. If not change them out or reverse them. As a rule, I change mine yearly (flip them) and then regrind them. I use a surface grinder and an angle jig.

Second best way is look at the chips. If they are getting long and stringy, your balades are getting dull.

 

[groundcover]

When it starts making cole slaw it's time to change em ! Brush Bandit has a 'blade saver' - looks like something you would use in the kitchen to sharpen your knives. A few swipes while the knives are on the machine really spreads out the removal and sharpening. Not sure if you have enough room to reach the knives on your machine though.

 

[5030]

Owning a machine shop and having precision surface grinders it was a simple solution to purchase an angle table that I can set at the correct inclination to sharpen blades. I just got done sharpening a backup set at 27 degrees. I'll change out the set thats in the machine this winter and sharpen them when I get a chance. The shallower the angle, the better the blade pulls the material in, to a point and that point is overloading the chipper. 27 works well for my uses.

The angle table was around 120 bucks which paid for itself on first use, plus I can sharpern any length blade at any angle.