When to Replacing helical head cutters?

[Charles Grauer]

How do you know when to rotate the cutters on a helical head planer or jointer? Seems like I am getting more tear out on end grain and narlie grain than before. Do you rotate all of them at once, there isn’t any ridges in them. Used the planer on lots of dirty sawmill cut lumber that was left out in the weather. Had the planer now 2 1/2 years of hobby woodworking, retired tho.

[glenn bradley]

I think my jointer went 18 months before I rotated the first time. The indicators for me were increased effort to feed and tracks being left where fibers were compressed rather than cut cleanly. Certainly tearout on a planer would be an indicator. At 2-1/2 years of hobby use you could still be due depending on use. With a good setup, the right tools and a small work surface nearby I got through the 70-odd inserts on my planer in under 2 hours.

You do need to take your time and clean the parts and seats thoroughly or you may end up with sub-optimal results after all your hard work. So much easier to take a little more time the first run through than to go back and troubleshoot. Thanks to horror stories on the forums I learned to be diligent and thorough. Machine performance was like new after the rotation. The prime offender to those who had failures seemed to be not paying enough attention to the cleaning steps.

Good light and a comfy stool.
Electric impact to remove screws.
Small bowl of mineral spirits and brush for cleaning.
Compressed air for cleaning.
Torque wrench for setting screws properly.
A few spare parts in case of damage and you're all set.

[Charles Grauer]

Thanks Glenn, good information and help. Charles

[Patrick Kane]

The dirty lumber may have done a number on your edges. From my understanding, insert carbide should last a hobbyists many years between rotations. I spoke to several 1-2 man shops that get a year or more out of their carbide edges. I swapped mine after two years assuming it had to be time and i was like the frog slowly brought to boil. Gradually becoming accustomed to dull edges. Not the case, i spent 2-3 hours cleaning and rotating, and didnt notice a lick of difference. Going through 2,000 board feet a year, im guessing i should see 3-4 years before needing to rotate the edges. I think its supposed to last 10x longer than most HSS, and i replace my jointer knives twice a year, so that checks out.

[Joe Jensen]

I can say that running 100 year old oak beam material, despite having run all surfaces with a Makita wire brush sander, trashed the insert face on my jointer and planer. On the planer the wood no longer wants to feed without frequent bed lube and on the jointer it no longer makes flat surfaces as the knives are now too low relative to the outfeed table.