Jointer vs planer blade adjustments?

[Brian Penning]

Simple question so maybe there's a simple answer.
Why do jointers require blade height adjustment and planers don't?
TIA

[Mike Harrison]

They do, if you want them to cut properly. Maybe some have provisions for non-adjust blade installation but I'm not aware of them.

[Rod Sheridan]

Brian, planers do require blade height adjustments as the cutting circle of the blades has to be exact.

If the cutting circle isn't correct, one or more blades won't cut.

In addition the feed rollers, pressure bar and chip breaker are adjusted to a specific dimension relative to the cutting circle.

If you change the cutting circle, all those items need to be re-adjusted to the correct setting.

In addition the cutting circle has to be parallel to the table unless you want to plane trapezoids.

Regards, Rod.

P.S. I have a Hammer A3-31 and it has indexed disposable knives, so there is no adjustment required.

[Gary Herrmann]

I believe a lot of the lunchbox planers also have indexed knives. I know my DW735 did. But to echo the others, both jointer and planer knives require adjustment.

[glenn bradley]

The benchtop jointer I once had used indexed knives just like the benchtop planers. Larger machines run knives that need to be adjusted. Some run tersa or other indexed systems or carbide inserts. I now have carbide inserts in both the jointer an planer so I will never have to adjust knives again . . . oh joy!

[Brian Penning]

Hmmmm... I raised the question because my Ridgid TP1300 has never required blade adjustment. Don't think there even came instructions to do so.
So...I ask again, why can't jointers and I guess some planers too have indexed blades?

[Bruce Wrenn]

Simple question so maybe there's a simple answer.
Why do jointers require blade height adjustment and planers don't?
TIAMy planers require height adjustments. They are Delta 15", Rockwell 13" (bought from the dispersal sale from the building of the arc), and my trusty Delta 22-540. Lunch box planer makers figured out that indexed knives help to sell units. Any bimbo could install a set of indexed knives correctly.

[Rick Lizek]

Hmmmm... I raised the question because my Ridgid TP1300 has never required blade adjustment. Don't think there even came instructions to do so.
So...I ask again, why can't jointers and I guess some planers too have indexed blades?

They can if equipped with a Tersa head or Dispoza blades or insert cutters. Planer blade height is just as critical as jointer blade height. Changing the knife projection of planer blades means having to readjust the rollers, pressure bar and chip breakers to allow it to run properly.

[Rod Sheridan]

Hmmmm... I raised the question because my Ridgid TP1300 has never required blade adjustment. Don't think there even came instructions to do so.
So...I ask again, why can't jointers and I guess some planers too have indexed blades?

Brian, as I indicated in my post my jointer/planer has indexed disposable knives so there are no re-adjustments of the planer or jointer required when changing knives.

Obviously during manufacture and again during commissioning the machine rollers, chip breaker, pressure bar, table parallelism on the planer is checked/adjusted and on the jointer the infeed/outfeed table alignment is checked/adjusted.

After that, the changing of the knives doesn't change the adjustment of the machine because the knife circle is set exactly by the knife indexing.

In addition to the larger machines that use this or Tersa type knives, many portable planers use indexed knives as well.

Regards, Rod.

P.S. Here is a link to an aftermarket quick change type indexed knife system.

http://www.estausa.com/

[Jon van der Linden]

The other issue here is that the outfeed of a jointer can require adjustment as the blades wear. Not a huge amount, nor something that most people can't get away with, just something that can make a difference.

Most modern machines do not have adjustable blades. This is because in a shop the time it takes to sharpen and set blades is lost production time. It's financially not worth it for the shop.

Older machines (both jointers and planers) were made with adjustable knives and were commonly sharpened with a special grinder on the machine. The blade has to be moved over time because the blade is getting smaller and smaller.

[Rod Sheridan]

. Any bimbo could install a set of indexed knives correctly.

Obviously my friend isn't a bimbo because he had his in backwards.......Rod.