Make-a-blade

[darryl]

I needed something to mount on the table saw to hold square inserts. These will be mounted at a 45 degree angle such that when it is spinning, it will cut a groove with 45 degree sides. It needs to be able to go nearly 1/2 inch deep, and I've determined that the square inserts I bought are just barely able to do it. I started with a piece of 3/8 thick x 2 inch wide flat bar, 6 inches long. Carefully marked and drilled a 5/8 hole for the arbor, then sawed away the steel that wasn't part of the design. I milled two flats where the inserts will mount, and I have a jig gluing up that will let me mount each insert in the exact same place on each arm so it will be balanced, and both inserts will cut.

What I'm hoping to do is carefully mount both inserts, then JB weld a notched piece on each arm that nests up to the insert. This will form the 'pocket' for the insert to set into, and will keep the 45 degree angle correct. Once the JB has set, I'll drill through the notched pieces and into the arms so I can tap for a holding screw. I'll JB the screws into place as well. I may not do it in this order- I might drill and tap before I mount these 'pocket pieces', but I'll still JB these pieces and the screws that hold them into place.

This will give me a tool that I can mount on the table saw and use to cut the grooves I need without having to angle the blade, or come up with weird jigs to hold the material while I cut. Yes, I could set up a router to do this job, but I want to be able to do it with the table saw.

This will essentially be a two toothed blade, so it will be choppy, but it will get the job done, and accurately. I know people will say this is not safe, but it's not going to come apart. To be sure, I'm not going to be standing inline with the blade while I fire it up, and I'm cutting wood only, not metal.

In the end I'll be passing thin plywood over the cutter to notch just a tad into the face on four sides, then I tape over the notches and turn the piece over to notch more deeply. The second cut goes through, but doesn't have to breach the top side of the plywood, so it won't cut the tape. The four corners will fall away, and I'll be left with 5 pieces held in alignment by the tape, which I then glue and fold up into a neat box. I've done this before, and it works great- but only for material thinner than 1/8 inch, and only with a blade with flat topped teeth. This tool should make me happy.

[elf]

Where should we send the flowers?

[CalM]

Have you tried this concept without the carbide inserts? Just fashion a piece of steel and sharpen to a single tooth form?
I worry about stuff flying apart....

But then I've seen stuff fly apart, It's never pretty.

[boslab]

Sounds like a shaper head ( spindle moulder over here) I have one, the thing I have uses HSS blades and important limiters so the cut is done safely.
id look at a shaper cutter bushed to fit your saw, craftsman used to make them but I look at them with suspicious eyes.
however the design may transcribe to your saw.
trend do a miter cutter similar.
mark

[CalM]

Actually, A Dado head would be ideal. There may even be products offered with the correct config. A "left 45" and a "right 45".

Worth looking into. I have a dado set for both the table saw and the radial arm saw. Reconfiguring the two outer blades would be simple. to do. If they could provide sufficient depth of cut, I do not know.

image snagged from a search result. I make no claims as to suitability for purpose ;-)

I have , and have used this one. It works fine.

[darryl]

If I ever see something like that at a thrift store, I'll snag it up. In the meantime I now hold in my hand the body of the cutter with the inserts mounted- but no pockets created yet. I have yet to mount it and rotate by hand to see if the body will clear. I may have to grind away just a bit more. I guess this is a dado head, just another way of doing it. Hopefully I don't make the six o-clock news-

[BCRider]

You COULD make something like a small size dado head to hold the square inserts. But keep the diameter small. And use some other method of securing the cutter bases or cutters directly.

You seriously do not want anything that is merely glued, even with epoxy, on the outer rim of anything even 8 inch in diameter that is spinning at 3600 RPM and smashing into anything. Epoxy is a far cry from welding.

[boslab]

My table saw came with a dado head, it’s multico, the down side is the blade won’t tilt, it’s not a problem as I use it for flat stuff , track saw does all the breaking down these days.
I get the vee groove in sheet , making posts for newels on stairs sort of thing or draw boxes.
I got round that with a small shaper and lock miter cutter, bit of a pig to set up but once set boxes or hollow posts are easy.
mark

[DrMike]

You must have a LOT more faith in JB Weld than I do.
I would not trust the stuff to hold an insert of any kind, even against wood, even in a table saw I didn't care about.
Hopefully the inserts don't get too chipped up when they bounce off the walls, ceiling or floor.

[reggie_obe]

Why not cut the V-slots with a router in mounted to a sled.

[chipmaker4130]

The retention screws, if you're going through the insert as I imagine, are not strong enough to withstand the centrifugal stress + cutting load/vibration for very long.

[deltap]

Actually, A Dado head would be ideal. There may even be products offered with the correct config. A "left 45" and a "right 45".

Worth looking into. I have a dado set for both the table saw and the radial arm saw. Reconfiguring the two outer blades would be simple. to do. If they could provide sufficient depth of cut, I do not know.

image snagged from a search result. I make no claims as to suitability for purpose ;-)

I have , and have used this one. It works fine.

I have one like in the second pic that I picked up at a rummage sale for $5. Box in the stock and fasten box to table saw fence. I used it to run hundreds of feet of pine for baseboard trim for my home. I would at least braze the inserts on and use a third one for better balance. The box forces shavings down under the saw and would protect the operator if parts of the cutter should fly off.

[RB211]

I would silver solder the inserts, using glue is asking for death.

[BCRider]

Why not cut the V-slots with a router in mounted to a sled.

That would certainly be one of the more normal versions.

Another option if you're shaping your own cross section for the stock from square or rectangular wood is to run two 45's from a regular blade canted over and make it so the cuts touch at the depth of the cut and you end up with a little triangular section in the end. No fuss, no muss and you can do it with the blades you already have. And no need to find a shaper head or to flirt with death with a home made option.

[darryl]

There is a grade 8 socket head bolt holding the cutters, the JB is to help keep the steel pocket from shifting. The pocket is pinned in place, and I expect the JB to crack at some point. It's acting as filler, not adhesive in this case.

At any rate, the insert wants to fly out of the pocket, dependent only on the fastener to stay in place. The pocket only serves to align the insert to 45 degrees as it's being tightened. If the screw comes loose or breaks off- well then it's fooked.

Maybe I should be looking at using a custom push stick to push the pieces through the saw with. If an insert flies off, it will have to get through the push stick before it can do any damage. Unless it impacts the stick and throws that in my face-