Shopsmith Forums

Hi everyone. I’m considering adding a dado blade to my collection. After my last post, I bought a set of cheap Dewalt saw blades (rip, general purpose and cross cut) figuring whichever blade I wear out first, I will replace with something better.

My next idea requires making a 1/4 inch deep dado about 3x1.5 inches square. I want to leave 1/4 inch protruding on each side, like a U shape.

If I did get a dado blade, would 6 or 8 inches be a better choice? Also, I need the dedicated Shop Smith dado arbor, correct? If this is a bad idea, I could cut the edges with a table saw to make them crisp then rout the center. Conceivably I rout the entire thing but I don’t know if there would be solid support for the base. I don’t think a bandsaw would leave it smooth enough but I guess it could be sanded or chiseled???.

Many thanks,
Karl

A dado creates a groove. What you are describing (1/4 x 1.5 x 3) is not a groove.

Seems to me a job for the SS router bits in drill press mode. The fence can provide the straight edges, the quill feed the ability to plunge rout, the main table provides support.

Karl,

Like JPG I am confused as to what size of a Dado you are wanting to make from what you said in the following.

My next idea requires making a 1/4 inch deep dado about 3x1.5 inches square. I want to leave 1/4 inch protruding on each side, like a U shape.

A 6" or 8" would work but the difference is the 8" could cut a deeper Dado than the 6". Dado sets do have a limit as to how wide of a cut they can make. Wider Dados would require more than one pass to get to width.

You would need a Dado Arbor. From Shopsmith that is part number 505506 the Molder/Dado Arbor previously known as the 5/8" Universal Arbor. There have been 4 versions of it with that part number (505506) since 1964 as seen in the picture below.

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Prior to the change in 1964 there was 3 versions of a 5/8" Universal Arbor simply called the 5/8" Arbor and were part numbers (in descending order) 22 031, 12 031 & 126-1X. Those three did not have the black protective coating which also started in 1964. The picture below shows those 5/8" Arbors plus some others used for different purposes.

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Thanks guys. I appreciate the advice. I’m sorry if my description was confusing. A picture might have been better.

kas20amc02 wrote: ↑Tue Jun 24, 2025 7:37 am Thanks guys. I appreciate the advice. I’m sorry if my description was confusing. A picture might have been better.

Just to be clear, you can only do through cuts with dados and saw blades. You can plunge cut with a tracksaw, but on a table saw, every cut should be a through cut. The description you gave has at least me worried with how you intend to make what you describe.

PS: By through cut, I mean cutting from end of the board to the other, NOT through the depth of the board.

RFGuy wrote: ↑Tue Jun 24, 2025 8:27 am

kas20amc02 wrote: ↑Tue Jun 24, 2025 7:37 am Thanks guys. I appreciate the advice. I’m sorry if my description was confusing. A picture might have been better.

Just to be clear, you can only do through cuts with dados and saw blades. You can plunge cut with a tracksaw, but on a table saw, every cut should be a through cut. The description you gave has at least me worried with how you intend to make what you describe.

I think this use of 'through cut' adds to the confusion. To me, a dado is generally an example of a non-through cut. Because, to me, a through cut is one in which the blade goes through the material (for example a typical rip or crosscut) while a non-through cut is one in which the blade is adjusted to not penetrate the material (example, a typical dado or rabbet). In other words, as I use the term, a 'through cut' can usually be done with the upper saw guard in place and a non-through cut can never be done with the upper saw guard in place. Thus, Shopsmith offers a Non-Through Cut Riving Knife for 510 and on. You're using the term 'through cut' to describe something else, and while I understand your intent I'm not sure a "Total Rookie" would.

My thoughts about dado blades: There are two common types, a "wobble" dado and a stack dado. In operation, a wobble dado is less expensive but creates an imperfect cut. In particular, the bottom of the "U" shaped channel will have a radius to it. While this is okay for many uses, a stack dado cuts a better dado or other cut. I have a 6" stack dado and it is pretty good, but I occasionally run out of depth of cut especially with a sled. All things considered, my preference would be a carbide 8" stack dado.

A picture or drawing of what you want to cut is a good idea.

- David

DLB wrote: ↑Tue Jun 24, 2025 9:27 am

RFGuy wrote: ↑Tue Jun 24, 2025 8:27 am

kas20amc02 wrote: ↑Tue Jun 24, 2025 7:37 am Thanks guys. I appreciate the advice. I’m sorry if my description was confusing. A picture might have been better.

Just to be clear, you can only do through cuts with dados and saw blades. You can plunge cut with a tracksaw, but on a table saw, every cut should be a through cut. The description you gave has at least me worried with how you intend to make what you describe.

I think this use of 'through cut' adds to the confusion. To me, a dado is generally an example of a non-through cut. Because, to me, a through cut is one in which the blade goes through the material (for example a typical rip or crosscut) while a non-through cut is one in which the blade is adjusted to not penetrate the material (example, a typical dado or rabbet). In other words, as I use the term, a 'through cut' can usually be done with the upper saw guard in place and a non-through cut can never be done with the upper saw guard in place. Thus, Shopsmith offers a Non-Through Cut Riving Knife for 510 and on. You're using the term 'through cut' to describe something else, and while I understand your intent I'm not sure a "Total Rookie" would.

My thoughts about dado blades: There are two common types, a "wobble" dado and a stack dado. In operation, a wobble dado is less expensive but creates an imperfect cut. In particular, the bottom of the "U" shaped channel will have a radius to it. While this is okay for many uses, a stack dado cuts a better dado or other cut. I have a 6" stack dado and it is pretty good, but I occasionally run out of depth of cut especially with a sled. All things considered, my preference would be a carbide 8" stack dado.

A picture or drawing of what you want to cut is a good idea.

- David

David,

Nitpicky, but okay, please give your alternate way of saying what I intended to say. Otherwise I will ask admin to delete my post to avoid the confusion, but you are NOT clearing it up by not explaining it differently from me either. I edited my post above to make it a little clearer.

Why is a discussion re through cut occurring? The OP said 1/4" (deep).

Missing is the inability of a circular saw to cut a square corner. A circular saw cuts an arc with a plunge cut.

JPG wrote: ↑Tue Jun 24, 2025 10:45 am Why is a discussion re through cut occurring? The OP said 1/4" (deep).

Missing is the inability of a circular saw to cut a square corner. A circular saw cuts an arc with a plunge cut.

JPG,

What he describes, implies a plunge cut, which would be a no-no on a tablesaw, which is why I tried to question what he is doing. Sans a picture, it is difficult to discern what he meant. Routing may be the best choice for what he intends to do...

Karl,

Going back to your first post you said,

My next idea requires making a 1/4 inch deep dado about 3x1.5 inches square. I want to leave 1/4 inch protruding on each side, like a U shape.

With what RFGuy questioned, are you looking to make a Dado cut at 1/4" deep and have it 1-1/2 " wide by 3" long and not going the length of the board? That, for me, seems to be a better explanation of what you desire to make from the text above. I agree a picture or drawing of what you are looking to do would better explain it. If it is what I describe, a Dado would not be the way to go. I could be wrong with my guess at what you are trying to achieve.

As David said about using a Dado Blade,

the bottom of the "U" shaped channel will have a radius to it.

It would not be 1/4" deep for the entire length of the cut. Routing it would make it easier and more importantly safer.

I have not thought about what a term should be for making a saw or Dado cut that does not run the entire length or width of a board although I may have known one at some point in time and forgot it. I do understand the confusion of the "Through Cut" term used for that, but does anyone know an actual term for this type of cut?