Trouble with my dato set

[Joe Dowdy]

I bought the Frued Stacked dato set with shims and when making a few passes to make a lap joint there are high and low spots on the dato. Is this normal when removing so much material or do I need to return them. see the attached pic.

[David DeCristoforo]

That looks pretty extreme to me. You can usually expect a small amount of unevenness but that is way too much. What saw are you running this set on? Is it possible that the arbor is badly scored and worn?

[Alan Tolchinsky]

Are you holding the wood down firmly as it crosses the dado set? I like to use push blocks or a finger board to hold the piece down to the table. Is there any way you could have improperly installed the set? Other than that I can't figure out what's going on here. Good luck.

[Peter Kuhlman]

Like David - I wonder about the saw. There are some contractor type saws with undersized or short arbors that are virtually useless with dado sets. My old Craftsman saw was one. Thankfully I sold it! Sometimes some of the stacked blades would drop into the threaded part of the saw arbor.

Can you check that the arbor holes all line up properly? Try to set the blades stacked on a table and verify the teeth from the blades are vertically lined up with the arbor holes as centered as possible. I have never seen a blade with the arbors not centered but suppose it is possible. Highly doubtful with Freud.

Pete

[Peter Kuhlman]

Looking again at your picture, it looks like the problem is that the repeated passes are not cutting at the same height - not that the individual blades in the dado stack are not the same height. If so, this could be caused by the trunnion of the saw not holding the height setting. Again a problem with some contractor saws. That or the wood is not being held down tight to the table on each pass. Again the picture looks like the height is changing with each pass.

Which dado set do you have? Freud makes several different ones.
Pete

[Joe Dowdy]

it is a craftsman hybrid saw about a month old and I downsized the stack fro 7/8th to 1/2 and still the same. Yes firmly holding on the table. When taking a strait edge to the top of the stack, the center chipers are just barly a shade shorter, is that normal.

[Peter Kuhlman]

Are some of the stacked blades sitting on the threaded portion of the arbor? I use the Freud dial-a-width dado set so the arbor has no impact.
Pete

[David DeCristoforo]

Also check that the blades are at a true 90 degrees to the table. They could be tilted a bit which could exacerbate whatever is causing the problem.

[Joe Dowdy]

that is possible. I have to take a closer look. It looks as if the whole arbor is threaded. what needs to be done in this instance?

[Peter Kuhlman]

If you have a micrometer, you can check the arbor diameter. Check the unthreaded part and best you can the threaded part. Supposed to be 5/8" inch - 0.625". If like my old Craftsman and the arbor changes diameter in the threaded area, there is not much you can do. I would think that Sears would have fixed this by now though so should not be the problem.
Pete

[Jim Kountz]

I would blame the saw, when I try to use my good dado set on some of my contractor saws I get ridges, although not near as bad as your picture shows. I can use the same dado set in my cabinet saw and they all but disappear. As mentioned already some arbors on the lesser priced saws are just not machined to the same tolerances as the better cabinet saws. Not trying to insult anyone just stating a fact.
So next time you see someone asking why a Unisaw or a PM 66 costs SO much more than others, you can remember the little things like this and know the reason why.

[Joe Dowdy]

here is a pic of the arbor checked the arbor with dig calipers and came out to .620 Blades are at 90 degrees Dam I'm lost and I know it will be something simple (hopefully)

[george wilson]

Well,that is .005" too small,and if the dado blades get oriented differently around the arbor,it could be that .005 + .005 = .010". Your picture is out of focus,but that is 2 sheets of typing paper's worth of thickness.

[willie sobat]

I have a Freud 8" Super Dado (maybe the same one you are talking about). It is the 3rd Dado set I have owned, each more expensive than the last. I bought it because I had poor results from the 2 previous wobble dado sets I had. When I bought it I had a Craftsman contractor style saw. I was disappointed that even with what was quite an expensive saw accessory to me at the time I still did not get the results I was looking for. I just chalked it up to being the nature of the beast. Then a few years later I bought a Unisaw. My first thought when I went to use the Freud Dado set was that it would not fit on my new arbor. It had always slid on so easily on my older saw. Finally it did slip on (very tightly). Low and behold the difference between the finished dados was night and day. I can't saw it is perfectly smooth. But it is a world of difference. So my suspicion would be that the diameter of the arbor may be slightly undersized.

[glenn bradley]

it is a craftsman hybrid saw about a month old and I downsized the stack fro 7/8th to 1/2 and still the same. Yes firmly holding on the table. When taking a strait edge to the top of the stack, the center chipers are just barly a shade shorter, is that normal.


here is a pic of the arbor checked the arbor with dig calipers and came out to .620 Blades are at 90 degrees Dam I'm lost and I know it will be something simple (hopefully)

What model saw is it? My 22124 hybrid arbor looks a bit different than that. My SD508 Freud dado set works fine. I have to slide the outer blades and the chippers on very perpendicular to the arbor as the fit of the holes are so close. They can be a bit of a pill to get off as they have to be slid straight out.

One C-man oddity (maybe other manufacturer's too) is a gap between where the threads stop just short of the arbor washer. The outer blade and 1/8" chippers are no problem as they straddle this gap. I cannot, however, run the 1/6" chipper in the second position as it will slip down into this gap and be out of round with the rest of the stack. Even this issue does not present the problem in your pic though.

[scott spencer]

Joe - What kind of dado insert are you using? If the insert is flexing, you could see uneven results.

[Joe Chritz]

Are you using the 1/16th chipper? Often that causes problems because of the threads. It is likely the arbor is the culprit but I would want to try that dado set on a saw with known qualities first.

While it is possible to get a dud from any company I believe all the saw blades are CNC ground so it is pretty unlikely to get a bad one.

A dial indicator set above the teeth would show how far out they are.

Joe

[Charles McCracken]

I bought the Frued Stacked dato set with shims and when making a few passes to make a lap joint there are high and low spots on the dato. Is this normal when removing so much material or do I need to return them. see the attached pic.

Joe,

What does the dado look like when you stack the max width spec's for the saw and only cut one pass (no overlap)? If this cut is flat, then the dado set and arbor are likely correct. However, since you measured the arbor at 0.0620" I think you will find that is the issue.

[george wilson]

Please don't have so much faith in CNC. It may be garbage in,garbage out.My friend and I bought 2 Cimmaron .45 pistols,CNC made. His snapped 6 times without firing. The cylinders were off by 1/16". Firing pin missed the primers (good thing,too.) I checked mine out. Cylinders were from 1/32" to 1/16" off. 1 lined up.

He,especially,is a gonsmith. I am also,to a lesser involvement. We called Cimmaron and got the CNC,must be good speech. We sent them back,but had to haggle through the BS first. Those guns cost much more than new Smith and Wesson .38's,$690.00 wholesale,IIRC. I personnaly examined a different make,same repro. Shot o.k..

[Jay Yoder]

I had a C'man 22114 and i thought it was the dado, but turned out when i upgraded to the Jet Deluxe it made a world of difference. just my experience...

[Paul Atkins]

Are you taking all this material out in one pass? I'm thinking that the wood is jumping a bit with your other problems. Try and take 1/8" deep cut and hold the wood firmly against the table and see how it looks.

[Joe Dowdy]

ok guys heres what I found. I checked everything that ccould be checked and re measured the arbor. It actually came up at .002 to small instead of .005 I adjust all the chippers to make sure they where in the right positions and it seem to be doing alot better still not perfect but its pretty good.