Crosscut weirdness

[RFGuy]

He has a Greenie with a 500 style table.

Okay, so no connector tubes since it is a 500 model. If all other avenues have been pursued, then perhaps try sliding the headstock and main table over so that it touches the aux table. Abutting it may help to stabilize the table a bit and improve crosscut accuracy, if my theory is correct. Certainly worth exploring if the OP agrees table flex could explain this.

[HopefulSSer]

He has a Greenie with a 500 style table.

Okay, so no connector tubes since it is a 500 model. If all other avenues have been pursued, then perhaps try sliding the headstock and main table over so that it touches the aux table. Abutting it may help to stabilize the table a bit and improve crosscut accuracy, if my theory is correct. Certainly worth exploring if the OP agrees table flex could explain this.

Ooo I like this line of thought! Thanks! That certainly sounds like it could explain it. I'm adding that to the list of tests!

[HopefulSSer]

And the answer is.......

Operator error! There is flex in the table but clamping it to the aux table didn't help. The new blade (whilst making a MUCH better cut) didn't help either.

But what I found was that in my effort to ensure that the piece stayed hard against the miter gauge face, I must have unconsciously been putting torque on the miter gauge. Even though everything is tight and there's very little slop in the bar/slot interface, there does seem to be some flex in the gauge. I must have unconsciously been putting counterclockwise torque on the miter gauge when in the right side miter slot, and clockwise torque when in the left. Adjusting nothing, if I consciously put counterclockwise torque when in the left slot, it cuts absolutely true. And it doesn't take much....

For the record, here's what I was seeing BEFORE:

[Majones1]

He has a Greenie with a 500 style table. And that means it's even less stable than the newer table systems. There is a trunnion holding up the front of the table but the back is supported with a much smaller bracket on a pivot pin. Any movement of the table on those supports would skew on two axis and take the cut off 90º. If that is the case it should be evident on the face of the cut which would not be perpendicular to any of the four sides and possibly not flat. But I doubt that is the case.

I forgot about that movement. I have a 500 also, and that movement causes me some significant problems in the past. It is also a problem on my 10ER. I remembered seeing a Rear Carriage Lock mod that Skip made for the 10ER, and I have been using his concept to place 12" trigger clamp to lock the back right corner of the carriage down on to the way tube. I don't do this all the time, but only when I need an accurate cut.

Here's a link to Skip's carriage lock for the 10ER.
http://www.mkctools.com/10errearcarriagelock.htm

[HopefulSSer]

I lied above when I said everything was tight. Snugging the countersunk pivot screw on the bottom of the miter gauge seems to have removed most of the "flex"

[edma194]

That screw was a problem on older miter gauges. I have those set in place with plenty of Loc-Tite. The screw and the threads are not quite right, or possibly I don't have the original screws.

[bainin]

Glad you found the issue !

b

[HopefulSSer]

Glad you found the issue !

b

Thanks! I was beginning to doubt my sanity

[bainin]

I think Brenda was closest to the mark, and earliest on this thread !

Aside from tightening down the interference screw-which makes the miter gauge not slide easily in the slot, what else can be done beside being conscious of these user introduced offsets?

b

[wa2crk]

Did you say that you are using the miter gauge and the rip fence at the same time? That is a big NO NO
Bill V