Cutting dadoes: How much better is an upcut spiral routing bit?

I need to cut some dadoes and I'm wondering if it's really worth the expense to buy an upcut spiral routing bit? Does it bring that much more joy over a standard router bit?

Thanks,

Mike

Reply to
Michael
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If it helps direct the chips to the dust collector port, it will bring a lot of joy. One of the biggest downsides to cutting dadoes with a straight router bit is the fact that the chips can clog the path very easily, slowing down the entire process.

You *really* want a joyful experience in cutting dadoes? Get a dado set for your table saw. :-D

Reply to
-MIKE-

Not for dadoes.

Upcut is somewhat necessary for deep mortices though . it helps remove the chips. the key word is somewhat, not totally necessary.

Reply to
woodchucker

+10
Reply to
Leon

I think there is an "it depends" that goes with this... I've run into cases where an upcut bit caused splintering on the surface that didn't happen as much with a straight bit.

However, it's been quite a while since I've used a router for mortises (I got a hollow chisel mortiser) so I don't recall the details of what bit, what kind of wood, etc.

You may have to play a bit... ;~)

Reply to
John Grossbohlin

why are you considering it

what info led you to think it would be better

testing your dados is the best thing to do and if the bit you have is not doing waht you want then

Reply to
Electric Comet

The main benefit of the spiral bit is that it clears the shavings more efficiently than a straight bit. There are some downsides. The first one is make _sure_ that the collet and bit are absolutely clean (I work it over with a pistol cleaning rod and lacquer thinner) otherwise no matter how tight you think it is the bit may start pulling out. If you're using one in a table do _not_ trust the thickness of the stock to protect you--I had one work out a full inch in a single cut once and pop through the surface right where my hand had been a second earlier. Another is that they're amazingly fragile--if you're using one in a table be sure that the stock is completely controlled. And the ones I have used (Amana, Freud, Whiteside) all cut just a hair undersized.

Reply to
J. Clarke

Michael wrote in news: snipped-for-privacy@googlegroups.com:

As woodchucker said, generally not for dados. The real question is whether you're cutting a stopped or open cut. If it's open (like most dados) there's an exit path for the chips. If it's stopped (like, in the extreme case, a mortise) the chips will get trapped in the cut unless they are lifted out, which is what an upcut bit does.

If you're cutting stopped cuts with a straight bit, you just need to make shallower cuts and dump the chips out (or vaccuum them out) after each cut. A spiral bit will let you work faster in that case.

John

Reply to
John McCoy

I'll voice a novice opinion and say that that depends on the jig being used for the stopped cuts.

I recently used a jig to cut the mortises for some bed rail hardware. The jig was based on swingman's design as shown here:

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The problem wasn't the chips in the mortise as much as it was the chips that piled up against the stop rails at each end. Those are the ones that I had to keep vacuuming out so that the router could travel the full distance.

I used a straight bit but I don't think that an upcut bit would have helped. The chips had no problem getting out of the shallow mortise with the straight bit, it was the piling up at the stops that was the issue.

I've seen other jigs made with stops that were flush with the surface that the router sat on. If that type of jig were used, then the difference between a straight bit and upcut bit - especially for deep mortises - would be really evident.

Reply to
DerbyDad03

Thanks everyone for the great information. These are not through dadoes, so a dado stack will not work. I once saw Glen Huey using an upcut spiral bit on a woodworking show to cut dadoes for a spice rack. I wasn't sure why he used that bit, but from I read here it appears it does the job for clearin g chips. I'm going to try to cut my dadoes with my regular routing bit firs t to see how it goes.

Mike

Reply to
Michael

Just a FYI, I do not believe that there is any such thing as a "through" dado, that would result in two pieces of material. Perhaps you are wanting a "stopped" dado, one that does not go all the way across the material.

You can do stopped dado's with a stacked dado set but that does require planing and is not always possible.

Reply to
Leon

BTW, Glen Huey is not the guy to gleem info from. He's dangerous. There are more competent and talented people out there.

Reply to
woodchucker

Leon wrote in news:IoWdnZ1vof4TZ0PKnZ2dnUU7-N snipped-for-privacy@giganews.com:

Hmmm, pretty sure I've seen writers use "through" as the opposite to "stopped". I'm not sure what other word you'd use to describe a dado that went from one side to the other of the workpiece.

I'll note that a dado could be stopped on one end or both ends, altho the latter would usually be called a mortise (even if it's long and shallow).

Stopped (at one end) dados with a stacked dado set on the tablesaw would require cleanup with a chisel (or a weird shape on the end of whatever went in the dado). I wouldn't do it that way because I use a sled, and it would be difficult to mark the stopping point.

John

Reply to
John McCoy

I've also seen "blind", in place of "stopped" ("stopped" was commonly used in the UK when I worked there), mentioned when describing dadoes.

In the UK they were also known as "housing" joints (cut across the grain), with many different types, including:

Through housing joint Dovetail housing joint Stopped housing joint Stopped straight dovetail housing joint Tapered stopped housing joint Barefaced housing joint (AKA "locking rabbet" joint in the US)

... and probably some more.

Reply to
Swingman

IMHO through means all the way through. If you cut a through dado on a board you have two pieces left over. Think through mortise The OP said these were not through dado's so a stacked dado would not work.

Shelves are typically embedded into stopped dado's The stop is near the front of the cabinet and a notch is cut out of the front ends of the shelf back from the front of the shelf about the length of the part of the dado that is not full depth.

Reply to
Leon

Leon wrote in news: snipped-for-privacy@giganews.com:

Well it is all the way through. It's all the way through from the left side to the right side.

Exactly. So you either have a notch in the shelf that's longer than it needs to be (which may or may not be visible) or you square up the end of the dado with a chisel (which is probably what I'd do).

John

Reply to
John McCoy

So by that thought process a through mortise would be a dado or grove all the way a cross a board.

Reply to
Leon

This is terminology that i have not heard.

But I went ahead and looked it up.

My apology for being wrong to the OP and you.

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Reply to
Leon

Apologies absolutely not necessary.

Reply to
Michael

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