Dado Depth

[Jeff Warner]

I am having an issue getting correct depth of dado. What I need is the left over material to be 3/8" not the depth of the dado. I know material varies in thickness. I am measuring off the table not the material and my left over material varies. What I am building are wall frames that need to be exact in width. Please advise with cutting.

[Kyle Stapleton]

make sure to surface table.
Zero to table.
in cut depth put in: z-.375= and hit enter.
what is your hold method?

[Jeff Warner]

Kyle,

I use a vacuum system for hold down, I resurfaced table, and zeroed to table.
I am using plywood and it varies in thickness. Your command (z-.375=) calculates what is left over from my job set up in material thickness (correct)? Is there a command I can use to come up from table surface a specified dim. and it will not matter material thickness?

[Kyle Stapleton]

That is what I gave you.
Ex: ply is .715", so z-.375= will give you a depth of .34".

Zeroing to your bed does math form the bed, so that .375" is from the bed.

What bit are you using?

[Jeff Warner]

3/8" Compression
My example: Ply is .724", Command z-.375= will cut a depth of .349".
If I am correct the command is calculating depth of cut off of Ply thickness and z-.375=.

[Kyle Stapleton]

It is but if you look at sb3 you will see at the bottom of your dato it will say .375" which is the distence from the bed.

[Jeff Warner]

Let me make sure I understand, no matter the thickness of material (varies from corner to corner, sheet to sheet) If I put in a specific thickness on the job set up and cut with command z-.375=, the left over material will always be .375".

[Kyle Stapleton]

As long as you zero to the table.

[Jeff Warner]

Kyle,

Thank you for all of your help,
I am going to cut some wall uprights with a little more confidence.
Thank you again.

[waterwheelman]

I know this may be a stupid question to ask, but do you have the vacuum turned on when you zero to the table surface?

I have the material in place and the vacuum turned on.
The table surface will move down when the vacuum is turned on.
I then surface to the table at a spot near the material I am cutting.
I then do a MZ,0.75 and the ZZ to reset the z axis for the plywood surface.
The cutting files are written for material of 0.75 thickness, even though it may be a bit thinner.
This way the remaining material for dadoes is exact to what I require.

[Doug Hawkins]

That is exactly how I do it David and having the vac on when you set your z can make a little difference.