Sloped dado?

  • Advertise with us

« back to Power Tools, Hardware and Accessories forum

Forum topic by GerardW posted 10-14-2014 07:10 PM 919 views 0 times favorited 11 replies Add to Favorites Watch
View GerardW's profile


44 posts in 1244 days

10-14-2014 07:10 PM

I was using my dado set the other day to cut a slot to fit my digital caliper to use as a gauge to calibrate my table saw. So that means I was using my mitre gauge and a sacrificial fence to cross cut a shallow ~5/8” dado in a thin strip of hardwood. The width came out perfect (yay!), but upon closer inspection I noted something very weird. The dado depth was not consistent. That is, at one end of the cut it was deeper than the other (not left to right, but front to back). I have tried to think through how this is physically possible and have come up with nothing. I have adjusted my throat plate to make sure it is flush with the table.. and beyond that I don’t have any real way of determining how this could happen.

Any thoughts?

-- Gerard in Bowie MD

11 replies so far

View ChefHDAN's profile


797 posts in 2271 days

#1 posted 10-14-2014 07:16 PM

Gerard, what sort of hold down did you use? I’ve sometimes had small pieces “Climb” the blade a bit. Only other thought would be if the blade dropped, did the dado slope up or down?

Hello from the ‘Dorf just a bit south of ya!

-- I've decided 1 mistake is really 2 opportunities to learn.. learn how to fix it... and learn how to not repeat it

View GerardW's profile


44 posts in 1244 days

#2 posted 10-14-2014 07:19 PM

I can’t recall offhand in which direction it sloped, but that’s a good question. I will do a test cut this week and see.

As far as hold down…. umm… does my hand count? I didn’t have anything providing pressure directly over the groove so I suppose a climb of the cut would be possible (and that also gels quite nicely with my understanding of how physics work, whew). What type of hold down would be best in this situation?

I bought my cooktop in the ‘Dorf!! Come up to the Norf side sometime and we’ll make some dust.

-- Gerard in Bowie MD

View ElChe's profile


630 posts in 758 days

#3 posted 10-14-2014 07:39 PM

I think climb cut has to be it assuming flat table, flat inser . I’ve had that happen on dados and it befuddled me. I don’t trust dado blades anymore so I go to my trusty Record router hand plane to clean up. :)

-- Tom - Measure twice cut once. Then measure again. Curse. Fudge.

View knotscott's profile


7146 posts in 2797 days

#4 posted 10-14-2014 08:01 PM

Any chance the blade height dropped?

-- Happiness is like wetting your pants...everyone can see it, but only you can feel the warmth....

View a1Jim's profile


115177 posts in 2998 days

#5 posted 10-14-2014 08:20 PM

If you don’t have an out feed table and the board is hanging off the back of the saw it can make the board lift on the cutting end making the groove shallow on that end.

-- Custom furniture

View jmartel's profile (online now)


6470 posts in 1571 days

#6 posted 10-14-2014 08:26 PM

Use a featherboard directly over top of the dado blade so it forces the piece down. You will get a consistent depth.

-- The quality of one's woodworking is directly related to the amount of flannel worn.

View Dallas's profile


3599 posts in 1908 days

#7 posted 10-14-2014 08:48 PM

Not much to add to the previous posts except to add that you might want to set up a level for your table. Set the level exactly horizontal and parallel to the blade then measure the distance from the bottom of the level to each end of the table.

Have fun! You are in a big wide world of woodworking now, there are more than 3 ways to skin the bark off a tree!

-- Improvise.... Adapt...... Overcome!

View nicksmurf111's profile


361 posts in 872 days

#8 posted 10-14-2014 08:58 PM

Check you insert plate.

-- Nicholas

View Loren's profile


8163 posts in 3069 days

#9 posted 10-14-2014 09:20 PM

This is a reason the radial arm saw is sometimes
preferred for cutting dados.

In any case, it’s an interesting problem and it’s
good that you noticed it. Noticing and addressing
these things is how we learn to excel at the craft.

A dado cut can push the work up if the feed rate
is too fast and downward pressure on the work
insufficient or inconsistent as the work is fed. A
loose height setting can allow the blade to go
down under the pressure of removing the material…
the blade sort of tries to “run away” and gravity
helps it. I have seen this happen with a benchtop

You might try rabbeting the end of a board with
your dado set at full width. This way you can observe
the cut from the side as it’s happening and consider
your feed rate and how you’re applying hold down
pressure. Check the rabbet, cut the rabbet off and
cut another rabbet. Are they all going to be perfect
or is there going to be some variation and why?

Sometimes in working with machines I think of myself
as a ship’s engineer. Over time fussing with machines
one learns their quirks and how to compensate. It’s
an interesting part of the craft for me.

View firefighterontheside's profile


13077 posts in 1278 days

#10 posted 10-14-2014 09:39 PM

If the board has any twist one side maybe off the table as you push it thru.

-- Bill M. "People change, walnut doesn't" by Gene.

View lateralus819's profile


2236 posts in 1311 days

#11 posted 10-14-2014 10:45 PM

What He ^^ said.

The board is probably cupped a little.

Happens to me all the time. Just remember when cutting grooves or dadoes to apply even pressure allong the board. Front and back especially.

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics