Do I need to rotate my jointer's inserts?

[Mark Gibney]

Here's a photo of some alder after surfacing on my jointer.

Screen Shot 2020-07-20 at 9.36.31 AM.jpg

I've had the jointer since September 2018, and it gets moderate use.
Is the rough surface on this board an indication I need to rotate the inserts? - I have not rotated them previous to this.

thanks, Mark

[Erik Loza]

"Maybe", but those particular areas can be troublesome even with fresh inserts. For example, even with fresh knives, white and red oak still rips out a bit for me on the planer in spots like that. I might rotate the knives if it gives you peace of mind but if no improvement, try moistening the board beforehand of feeding it through at an angle (if you have the width). Hope this helps.

Erik

[Andrew Hughes]

I’ve found my bryd head doesn’t do that well on softer woods. It will probably get a little better with a fresh side. Nothing beats fresh sharp straight knives on ordinary wood.
The wood in your pic does have a lot of Character

Good Luck

[glenn bradley]

My first rotation was somewhere around 18 months IIRC. The indicator for me was more resistance when feeding despite nice waxed tables. Also, I was getting lines lengthwise from the cutter path; cutters doing more pounding than when sharper I think.

I would not expect the tearout but, soft tissue is certainly going to tear if not cut cleanly. The same principle applies as when practicing dovetails on maple versus pine for beginners; softer woods crush more easily and are harder to work.

Do you notice significant resistance when feeding? Do you get the tearout when taking a light cut like a 32nd? If yes to either I would rotate. Worst case scenario is that you have a "fifth" side to get you by years from now if you failed to buy replacements soon enough.

[Mark Gibney]

Thanks guys, all good information. Guess I'll go ahead and rotate them. Nice to have that "fifth side" in my pocket!

[Mel Fulks]

[QUOTE=Erik Loza;3038905]"Maybe", but those particular areas can be troublesome even with fresh inserts.

Is there any benefit in reading the grain and running the piece through on a diagonal ? That often helps with conventional
straight knives.

[Erik Loza]

...Is there any benefit in reading the grain and running the piece through on a diagonal ? That often helps with conventional
straight knives.

Mel, I don't ever think it's necessarily a bad idea. I can still rip out certain areas of wood even with brand new helical knives. And ditto for Tersa. In my experience, helical heads do great on figured wood that has some consistency to the grain, like quilted maple. But, they still can rip out a little bit in the "leeward" side of eyes on hard species, etc. At least for me.

Erik

[Alex Zeller]

I wonder if anyone thought about making a push block with a force gauge built in. Something that you could push a board through and a needle would tell you just how much pressure you are using. You could then save the board and check it every so often to see how much harder it is. Trying to decide in your head if it seams harder and how much harder is nothing but a guessing game. Once you rotate them you'll know how much easier it is but I suspect that most people will never spend the time to rotate them back.

[Jamie Buxton]

Alder gives my jointer/planer trouble. Even though alder looks like a nice soft friendly wood, I suspect the silica content is high. It dulls my HSS knives quickly.

[Will Blick]

Good info Erik
Now I dont feel sooo bad...
overall, Byrd heads are amazing...
they seem to go forever without a rotation...
but rare situations I notice some mild tear out..
I often wonder if taking the thinnest cuts wold help
but my jointer is fixed at 1/32", too lazy to alter it, it might go out of square