Jointer Alignment?

[Dennis McDonaugh]

Man I've been busy the last nine months or so and haven't been posting much. During my last project I noticed my Grizzly jointer was making gently curved pieces of wood instead of nice straight ones.

After a busy summer I finally took a look at it and found the tables are not coplanar--the outfeed sags about 1/4" at the end. I'm assuming this table is sagging and the infeed table didn't somehow rise. What kind of shim stock should I use and where can I buy it to adjust the outfeed table?

[Lee Schierer]

My jointer has adjustments for the tightness of the ways and I was able to tighten them up a tad to get rid of the sag in my jointer outfeed table. SInce the outfeed rarely gets adjusted, having it a bit tight wasn't an issue. If you need to shim, I would suggest brass shim stock so it wears as the table is adjusted and not the cast iron.

[glenn bradley]

DT ways or P-beds on your Griz?

[Dennis McDonaugh]

Dovetails Glenn. I haven't really looked at it yet to determine why the outfeed is sagging. I just put stuck a precision straight edge on it and saw that the tables weren't coplanar. I wanted to have everything on hand so I don't have to stop mid job and find a suitable shim stock. I'm not sure why it sagged because I've adjusted the outfeed tables three times in five years when I've changed the blades.

Brass sounds good Lee, I've got some assorted brass sheets on hand too. Thanks.

[Pete Bradley]

It's very unlikely that your machine needs shimming to correct the sag. The point of the dovetail ways is to hold the tables in the position they were originally ground in, and it takes a lot to wear them down. The two most likely causes of sag, in order, are:
- gunk/dust buildup at the top of the ways - take tables out, clean and oil the ways reassemble (see below)
- loose gib screws, or gib screws improperly tightened - loosen screws, hold end of table up by hand with straightedge on top, snug screws, being careful not to overtighten.

Pete

[Dennis McDonaugh]

It's very unlikely that your machine needs shimming to correct the sag. The point of the dovetail ways is to hold the tables in the position they were originally ground in, and it takes a lot to wear them down. The two most likely causes of sag, in order, are:
- gunk/dust buildup at the top of the ways - take tables out, clean and oil the ways reassemble (see below)
- loose gib screws, or gib screws improperly tightened - loosen screws, hold end of table up by hand with straightedge on top, snug screws, being careful not to overtighten.

Pete

I think you are right Peter.. I adjusted the gib screws according to the manual, but I think the were alright to begin with. Here's what I got. The tables are tight--with the gib screws out and the table adjusting screws loose you can't move them by hand. They do move easily with the hand wheels. I reinstalled the gib screws and adjusted the outfeed table to the top of the knife and then brought the infeed table up to the same height. One or the other is drooping and the jointer produces a convex board.

I'm going to try to remove both tables and clean out the dovetails and start over with the alignment again.

[Chuck Wintle]

Man I've been busy the last nine months or so and haven't been posting much. During my last project I noticed my Grizzly jointer was making gently curved pieces of wood instead of nice straight ones.

After a busy summer I finally took a look at it and found the tables are not coplanar--the outfeed sags about 1/4" at the end. I'm assuming this table is sagging and the infeed table didn't somehow rise. What kind of shim stock should I use and where can I buy it to adjust the outfeed table?

to me 1/4" seems a whole heckuva lot! From what I have read it is fairly usual to see a sag of 10-20 thou. :confused:

[Dennis McDonaugh]

to me 1/4" seems a whole heckuva lot! From what I have read it is fairly usual to see a sag of 10-20 thou. :confused:

Yeah, that was a wild guess. I tried to take a picture, but I'd say its 1/32 halfway down the table.

http://i139.photobucket.com/albums/q320/bmcdonau/jointersag.jpg

I've removed all the hardware and both tables are loose, but still attached to the adjusting mechanism. There is enough play in both tables to account for the sag. Are the gibs supposed to remove the play?

[Pete Bradley]

Yes, the gibs remove the play. However with use, swarf from the cutterhead naturally gets into the top end of the gibs more than the bottom, which causes the top to tighten up before the table levels out.

Before you do anything, I would just try retightening. It's very important to support the table and snug the screws rather than trying to jack the table into place with the screws. It's also important to avoid overtightening as it is possible to crack the dovetail, especially at the ends.

If you take it apart, be sure to note the original locations and orientations of the gibs so they go back the same way.

Pete

[Dennis McDonaugh]

I finally got it aligned I guess. My straight edge is only 24" long and I was able to get the tables coplanar with 12" on both sides of the knives. Thanks for the help.

[Eddie Darby]

Lee Valley sell brass shim stock.

http://www.leevalley.com/wood/page.aspx?c=2&p=40946&cat=1,43456,43407

[Pete Bradley]

I finally got it aligned I guess.

There ya go!

Pete

[Dennis McDonaugh]

I jointed a few short boards this morning and they fit nicely. Thanks for all your help.