Trouble adjusting size of dado cuts

[jhelfer]

I needed to cut some 1/4"x1/4" rabbets for some pieces that would be joined together at 90 degree angles (like abox).

I used a dado stack (1/4" stack) on my BT3100 and used the rip fence (with sacfricial wood against the bladse). This seemed to me to be the way to do it.

Unfortunately, I had a devil of a time getting it adjusted to the proper dimensions. The width was always off just enough so that the pieces did not fi together properly. Very frustrating.

Is there a trick ot this that I am missing?

[LCHIEN]

I needed to cut some 1/4"x1/4" rabbets for some pieces that would be joined together at 90 degree angles (like abox).

I used a dado stack (1/4" stack) on my BT3100 and used the rip fence (with sacfricial wood against the bladse). This seemed to me to be the way to do it.

Unfortunately, I had a devil of a time getting it adjusted to the proper dimensions. The width was always off just enough so that the pieces did not fi together properly. Very frustrating.

Is there a trick ot this that I am missing?

Offhand,
was any part of the wood being cut supported on the SMT even if the SMT is locked in position? With the SMT generally set .020" above the main table height, it can raise the wood that much or titl it depending upon the actual position. If making grooving cuts (e.g. dado) and the depth is critical, then you might try the Aux table on the left.

fine tuning the depth and width, a microadjuster (1/16th inch per turn or .016" per 1/4 turn) works great for the width, otherwise you have to bump it back and forth without much control. The depth can be microadjusted with the elevation crank, its 12 turns per inch or .083 inches per turn (or .021" per 1/4 turn).

Measuring tools are important. I would normally use digital calipers to check this and then make the height and depth adjustments accordingly.
Using a ruler is hard at those small dimensions.
A good way is to use a 1/4 x 1/4" setup bar. Or get a 1/4 x 1/4 x 12" bar at the hardware store. Lay that in your groove and you can feel if you are over or under.

[mdutch]

Maybe I'm just lazy, but after I got my Ryobi router mounted in the accessory table, I don't use my dado set at ALL. A nice router bit makes the cleanest sides and bottom with VERY little set-up.

Which doesn't really answer your question, but I've got to say, for my money it's way faster, more accurate, and cleaner than a dado-set IMHO.

[jhelfer]

Thanks, those are good points. I think I do need a set of diital calipers and a microadjuster.

Unfortunately, I'm still not very happy with the way my fence moves, and reads. I guess I need to set tat up properly first.

[jhelfer]

I thought about that, unfortunately, my "router table and fencing system" stilll needs to be built. I have all the pieces and parts, it just needs to be done.

[Tom Miller]

Do you know that your 1/4" dado stack is cutting 1/4" dados? It's not that big a deal if it's not, as long as it's undersized, and as long as you know by how much.

Some good measuring tools will help you immensely, IMO.

Regards,
Tom

[jhelfer]

Heh.. This is becoming evident to me.

In my case, I did know that the dado stack wa 1/4" exact because I earlier cut some 1/4" wide dadoes with it.

[meika123]

One thing that may work. It's also very simple, and very much overlooked. When installing your dado blades, make sure the cutting teeth are offset, ie: stagger the teeth so that they aren't side by side when installed.
Worth a try, huh?
HTH

Dave in NC

[meika123]

Heh.. This is becoming evident to me.

In my case, I did know that the dado stack wa 1/4" exact because I earlier cut some 1/4" wide dadoes with it.

Are U sure the rip fence is 90 degrees?

Dave in NC

[jhelfer]

Le Sigh

I just thought off two things that I should have done to solve my problem.

I could have run a piece of scrap through the saw to make a dado, and just marked the far edge of the dado. That would have told me exactly where to place the work on the miter fence.

Also, I do have a beatiful new mortising gauge which I inexplicably forgot I owned.

And I kept dropping things, That should have been a sign that things weren't likely to go well.