Jet Jointer troubles

[Jeff Lusczynski]

Hello everyone,
I have a JET 708455 JJ-6OS 6-inch 3/4-Horsepower Open Stand Jointer and I have been having trouble with it recently. When I feed a board through, the jointer takes off much more material from one side of the board than the other (width wise). It also seems to be having a little more trouble making each pass. This has never happened before and I have had the jointer for about 1 year.

What is causing this problem?

Do I need new knives?

If so, I have heard the the knives available through Jet are not very good quality. Where can I buy knives that will fit my jointer (6-1/16 x 5/8 x 1/8 knife size)?

Finally, do I need to buy knives that are exactly the above dimensions or will other sizes fit my jointer?

Thanks.

[Chuck Wintle]

Sounds like the knives are dull and need sharpening/replacing. What did it cut like when it was new? Have you checked the tables for flatness and if they are coplanar? :D

[Scott Rollins]

I don't have the jet, but I have had good luck with the Infinity blades on my jointer.
http://www.infinitytools.com/products.asp?dept=1110

[Eddie Darby]

I have been having trouble with it recently. When I feed a board through, the jointer takes off much more material from one side of the board than the other (width wise).
This has never happened before and I have had the jointer for about 1 year.
What is causing this problem?
Do I need new knives? Thanks.

If the machine use to cut just fine, and is only 1 year old, then I would say that your knives/blades are high on one side. If you have never changed your blades before, then something might have worked itself loose.

Check the height of each knife at Top Dead Center, at each end. They should be the exact same.

[Eddie Darby]

Do I need new knives?
Finally, do I need to buy knives that are exactly the above dimensions or will other sizes fit my jointer?

Since your machine is a popular brand there will be several options for buying various types of blades that will fit your machine exactly, so don't mess with changing the size.

You will have the option of buying a different blade material, such as carbide which is $$$$ but last longer, or High Speed Steel blades with a higher tungsten content of say around 18% which makes the blades more durable.

Having two sets of blades will help with minimizing the down time when sharpening is needed.

In the good ol' US of A these guys sell blades.

http://www.infinitytools.com/departments.asp?dept=1108

In Canada these guys sell jointer blades.

http://www.sharpco.ca/welcome.html

http://www.dimarcanada.com/products/product_details.php?familyIDVar=5&pLineIDVar=2&categoryIDVar=111&groupIDVar=370

[Eddie Darby]

Where can I buy knives that will fit my jointer (6-1/16 x 5/8 x 1/8 knife size)?

I should mention that the length that you measured for your knives is 6-1/16" which is I think due to a metric conversion.

The manufacturer probably makes the knives at 155 mm in length. Imperial listings will just give you the approximate measurement of 6" in the catalogs.

I went through this one with a salesman before, so I thought I would spare you the trouble.