Wrong size jointer knives

[jeffss]

I'm replacing knives on a older Powermatic model 60. The new blades are 1/8" shorter. They fit in the head ok but I will have to lower the outfeed side. Lowering it will also move it slightly away from the cutters. Will this be a problem?  thanks

[fredhargis]

Lowering the outfeed table shouldn't be a problem.

[Woodenfish]

The only problem might be resharpening.

[ajkoontz]

Shorter how? Like they are 7-7/8” long not 8” or like 1/2” wide instead of 5/8”? I don’t see how length would affect the outfeed height so I assume you are talking about width. How are you setting your blades? I assume you had to lower the blades so the cutterhead screws made full contact? I’m used to setting them to the height of the I feed table so making sure I understand your question. Setting from the I feed side I sometimes have to make a slight outfeed adjustment and this is normal. But if you had to lower your knives in the cutterhead then you might have to make a significant outfeed adjustment. If so, this shouldn’t be a problem. Your scale might be off (if you even use it) is the only thing I can think would change.

[jeffss]

Should have been more clear. Old blade is 8"x7/8"x1/8". New blade is 8"x3/4"x1/8".

[fredhargis]

Doesn't that jointer have jack screws to raise the knives up?

[Bob Vaughan]

Should have been more clear. Old blade is 8"x7/8"x1/8".  New blade is 8"x3/4"x1/8".

That's pretty much the way our world is these days if you're stuck with off-the-shelf knives.  Actually 13/16" is about the best width for those cutterheads.  Both the 6" and 8" jointers of that era used the same cutterhead dimensions other than length.  Even starting out with 3/4" wide knives, you've still got some room for a few more re-sharpenings.

Consider having the old knives sharpened.  Chances are what's available today that the sellers call "High Speed Steel" won't be hardened and tempered like the original blades.

I Have even put in 5/32" thick knives in that cutterhead with no ill effects.  There's plenty of room in there.  

   

[jeffss]

Yes on the jack screws. I guess my concern was raising them to the point of not getting a good grip. Raised them and it looks good. thanks.

[Kudzu]

Just an FYI.  There are lot of companies that will make knifes for you. With a little searching on Google you can find them. Odds are one of them have the right size in stock.

[kurt18947]

Just an FYI.  There are lot of companies that will make knifes for you. With a little searching on Google you can find them. Odds are one of them have the right size in stock.

Don't even need Google. Did everybody forget about Holbren? 3 piece set 8" x 7/8" x 1/8" V2 HSS $40.74. He at least used to do 10% off for Woodnetters. I don't recall just how to get it, might require a phone call.