Helpo with using a Dado set

[TB Roye]

I am try to cut a centered 1/4" Dado 1/4" deep in a 3/4" piece of stock. I am using a Freud AD206 Dado set. According to the instructions, I am to use the the two outer blades. The picture shows the blades aligned with the teeth touching. When I try it this way the Dado is two large. When I try it with the teeth offset (like when using a chipper) the Dado is too small. What am I doing wrong? This is my first time using my Dado set. I am making Some rails and stiles to hold glass and I will need to make a 1 1/4 deep dado in the the top rail of each panel so I need to use the dado set. I bought this set 3 years ago but finally have a project to use it on. Most of my other Dado's have been done on the router table.

Tom

[LarryG]

Using the too-narrow setup, adjust your rip fence so that one edge of the dado is the desired 1/4" away from the workpiece edge. Then use Nahm's trick of turning the workpiece end-for-end and making a second pass. This should give you a groove that is 1/4" wide, perfectly centered.

Alternatively, put a few shims between the two blades.

[Imadunatic]

I generally use the Nahm trick but just with my combination blade, (unless i just bought a dado stack and needed an excuse to use it, lol ) It works really well and as larry pointed out, perfectly centered.

[TB Roye]

Thanks guys I will give it a try. I thought about it but then got hard headed and was going to make it work. Simple is better.


2:18 PDT Tried it and it worked, just have to move the fence a tad, to make it perfectly centered. Then again I might not. It is so close now that it might not pay to tweak it any more.

Tom

[mikel]

You can use shims too but I like to turn it so the dado is perfectly centered when the cut can be done that way.

...m

[Tom Miller]

The picture shows the blades aligned with the teeth touching.

I know you're all good to go, but...are you sure about this setup, i.e. the teeth touching? I have the Freud SD208, and that doesn't seem right to me. It seems like the two plates of the blades would get warped as they pull together when tightening the arbor nut.

BTW, I wasn't at all surprised to find the two outer blades don't combine to give an exactly 0.25" dado. I would have been very surprised if it had been a tad too large, but since it's a bit undersized, it just requires a shim.

Regards,
Tom

[TB Roye]

Tom

Went the Nahm route and made two passes. Made the plates touch and put the fence 1/4" away and made two passes came out fine. Just marked one side with an X that way when I assemble the panels they come out the same and the dado's will line up. Just didn't feel like messing with the shims and assembling and disassembling the Dado stack. I am going to rout off the back side to the dado after assembling the panels so the glass will fit and be held in place by strips of wood. The project is a display case with glass on 3 sides the door is in the front and slides to one side. Tundra Man has one on his site to look at and also the the Sept 03 issue of Wood Magazine.

Tom

[scorrpio]

When I got my SD206 dado, first thing I did is played with all the chippers and shims, made a bunch of test dadoes in scrap, numbered shims with a permanent marker, and made a table that I printed and affixed to my dado case. This table tells me what shims/chippers are needed to cut a specific width dado.
That said, when I need 1/4" or less, I don't even bother changing the blade and cut it in two passes. I have a Ridge Carbide TS2000, on which every 5th tooth is a flat raker, so it produces flat-bottom kerf.