G0490 Jointer Tables - How Flat?

[Jeff Cord]

I just picked up the Fine Woodworking "Powertool Basics" issue and was reading the "Tune-Up" article. Nothing really new but I decided to measure the beds on my jointer (it's about 6 months old).

I found that on the infeed table (haven't measured the outfeed table since I'm not pulling the tool from behind the saw) that my straight-edge "rocks".

I have a 36" Lee Valley straightedge (so it's should be pretty straight) and when I lay the edge on the table I was able to slide a feeler gauge under the edge.

I then pressed on one end of the straight-edge (pushed it down onto the infeed table )and was able to slide a .005" gauge under the other end (near the cutter) of the straight-edge and move the gauge about 12" along the table before I felt any pressure between the straight-edge and the table.

Is this normal? Should I expect the table to be flatter than this?
thanks,
Jeff

[glenn bradley]

I would hope that could be improved. Maybe Shiraz will chime in and tell us what Grizzly's tolerances are. I got a surprise when I called to complain about .004 on a non-Griz product and was told the manufacturer's tolerance was .01. Ooops!

[Shiraz Balolia]

I found that on the infeed table (haven't measured the outfeed table since I'm not pulling the tool from behind the saw) that my straight-edge "rocks".

I have a 36" Lee Valley straightedge (so it's should be pretty straight)
Jeff

You might want to check with a Starrett straight edge. They cost about 5 times more than the Lee Valley, but will be far more accurate.

[Jeff Cord]

.003 over the entire length isn't accurate enough to measure the tables.

With a more accurate edge what should I expect to see?
What is acceptable?

Jeff

[glenn bradley]

Sounds like from Shiraz' response that it should be better than .005 over a couple of feet. I wish he would have stated Griz' specs by number though, so you'd know.

[Joe Chritz]

A precision straight edge from starrett is .0002 per foot. I have access to one and it is very nice ideed.

.003 over 3 foot isn't bad and wouldn't likely be enough to cause a rock. Unless the jointer is new and unused that much of the table being out of plane should have shown up as poor performance already.

I would try to confirm the edge is still true before I went to much farther.

Any chance it was banged once? I have a 12" straight edge that isn't very straight anymore do to it being dropped once.

Joe

[robert micley]

i have a grizzly 8 inch jointer.it is dead flat.i borrowed a friends 3 foot starrett straight and feeler gauges.i have a delta table saw with wings.was not flat on multiple axis-front to back,diagonal, and side to side.all of these companies have tolerances of 1/100.i called and asked.you will do better to tell the company that a straight rocks across it as opposed to telling them you are off by5-10/1000.

[Jeff Cord]

I can access (rent?) a starrett gauge in the LA area?
Jeff