x and y square? trying to cut dados and end rabbets

[jbarkee]

need some help. in the attached pic. i attached a narrow (black) piece of MDF. I milled it on the edge along the y direction. next a scrap piece of MDF was put tight to the milled edge. a 3/4" wide
dado was then cut in the x direction with a 1/2"end mill. dado is about an 1/8" out of square. any help would be greatly appreciated

.


Thanks,

John

[sharkcutup]

Are you Certain that the Y-Axis is running true from one End of machine to the other?

And if so Check your material board by lining up the spindle/router with a V-Bit to the material board at one end the move Gantry along the Y-Axis to the other end of material board. Do Not move the X-axis while performing this operation. Did the Material Board match at the other end??? If it is not then carefully move material board to match the Spindle/Router with V-Bit. Then run the Gantry back to the other end without moving the X-Axis then check to see if it still matches. If all is good and Material Board is Clamped Down run DADO Program again then check Squareness again.

Sharkcutup

[jbarkee]

thanks for the reply.

I will give that a try

[sharkcutup]

Great!!!

Be sure to come back to let us know how things have turned out because this can maybe help someone else on this forum.

Sharkcutup

[ffloyd]

I made a fence along the Y axis and then cut a pocket toolpath to just touch the newly installed fence. This assures that the cut will be square as you desire when the workpiece is butted against the fence. The exercise of making a fence is well worth it. I just used MDF and attached it to my spoil board. If I have to remove it and replace it later, then I'll re-true the fence. When doing flat stuff that is within the limits of your machine, a fence on both x and y axis (that have been trued) makes for easy and repeatable placement of the workpiece.