Dado/slot variance

[james klein]

Any theories on what might cause a series of face frame slots( which receive the box tenons) to come out narrower. All parts cut simultaeneously on a stationary Freud safety dado set. Doesn't appear to be any problems with the saw.
Thanks

[Ethan Melad]

Narrower than what? The tenon? Guess the tenon was cut too thick...
Either add a shim and make your dado bigger or go back and make your tenon smaller.

[Mike Chalmers]

I believe what the issue is that the slots themselves are different even though cut with the same tool and settings.

[Kent A Bathurst]

Can't be a dado stack problem - not possible, if I understand the tool you have - a stacked dado set, right? 2 outer blades plus chippers?

THis thing right here?? http://www.woodcraft.com/product/840668/freud-sd308-safety-dado-set-8-diameter-14-to-1316-cut-width-with-5-chippers-58-arbor.aspx

Need to know the materials you were putting the dado grooves into, and how you "know" the dados are not consistent width..........

[Rick Potter]

Are those "box tenons" plywood by any chance? If so, check to see how much the thickness varies.

[Rod Sheridan]

Any theories on what might cause a series of face frame slots( which receive the box tenons) to come out narrower. All parts cut simultaeneously on a stationary Freud safety dado set. Doesn't appear to be any problems with the saw.
Thanks

Hi, did you make one pass or did you flip it end for end to center the groove?

Regards, Rod.

[james klein]

Sorry, should have announced sooner...I actually discovered the problem. On closer inspection I found that some hard "curl" or semi-knot material had worked its way between the blades at the chipper tooth location on one side. I am used to seeing some deposit there so it did not occur to me initially that it could be the culprit.