Thread: Sources of drill bits, counterbores and slitters for saw handles

I've been looking at one of the McJung saw slitters. Are these supposed to be used in a router table?

Craig

I would say no.
But then plane maker and my self have both used them in a router table..
But and its a huge BUT I can slow my router right down AND YOU NEED TO BE ABLE TO DO THAT
And you need to be extremely careful
If your not 110 percent confident DONT DO IT

The minimum speed of my VS router is about 4k RPM if I remember correctly. I've read that you guys use this technique but the thought of an unshrouded saw blade cutting around curved surfaces that close to my fingers is too scary even for me. Do they catch or bind much? Had any close calls?

The idea of using an unguarded blade at those sorts of speeds worries me a tad. Plus I enjoy owning fingers.
If not on a router, what are they supposed to be used for?

I do have a triton router, and can adjust my speeds, but it still worries me.

Craig

Originally Posted by Morbius

The idea of using an unguarded blade at those sorts of speeds worries me a tad. Plus I enjoy owning fingers.
If not on a router, what are they supposed to be used for?

I do have a triton router, and can adjust my speeds, but it still worries me.

Craig

The slitting saws are designed for use on milling machines where the vise holds the work, the table moves the vise and the blade is mounted to the chuck - no fingers close to the blade.

I prefer to cut my blade slots by hand because I like my fingers too.

Craig .
To be honest ,I've used the slitting saw method in the router table. But it only cuts to a depth of about 20/30mm depending on the slitting saw.
For the few saws I've made ,I now find it easer, more relaxing almost as quick to use the method of laying a saw flat horizontal on the bench packed up to the height I need( I dial in the height using A4 paper as shim material) with the kerf the right thickness ,and just run the saw handle past it a dozen times or what ever it takes.
I can't remember which saw maker on you tube or saw doing it ,but it works well for me .

Thanks for the suggestion.

For some reason, no saw I own can quite get into the area of the handle I need to finish installing the plate. I've purchased one of the Trojan saws that were mentioned earlier in this thread, and made very little further progress. It's out of frustration that I am looking at the slitting saw at all. Heck, yesterday I spent nearly two hours trying to make progress with a modified hacksaw blade and still not even close.

The handle I am working on is a copy of an S&J Sovereign 179. You would not believe how many times I've busted my knuckles on this one handle!

S&J New Handle Progress 01.jpg

I've delayed and dithered over this project for nearly 18 months as the slotting issue has me jiggered.

Craig

I only use slitting saws at quite slow speeds, in my drill press, and for cutting the slots in the brass spines. For this I have a jig that shrouds the blades, and although I hand-feed the brass, I can easily keep fingers well away from the nasty bit.

I tried slitting handles with the slitting saw, but soon gave it away. Slitting saws have no set and (the ones I have, anyway) have no relief so they bind as soon as they get into the wood a bit, which makes it pretty exciting to try & hold onto your handle and avoid getting slit pinkies. I very quickly decided it was far easier & safer to cut handle slots with a regular saw. I've got enough saws that I can always find one to cut the right size of slot, whatever thickness of plate I'm fitting. I score an extra-deep mark with a small marking gauge, and start the saw in that. I flip the handle a few times so that the slot gets cut from both sides. The main thing is to end up with a nice, straight slot, no wobbles or curves. If the slot gets a bit curved, when you tighten up the bolts at the end, you'll find a curve appears in the end of your blade. You can also get that if the spine & blade slots are a bit out of whack. A small curve there won't affect the function of your saw, as it's only at the very end that you never use anyway, but it doesn't look very professional. Or maybe it does, I've seen it on a few old factory-made saws!

For drilling sawplate, you really do need carbide - you'll kill an ordinary HSS drill in just one hole, unless you anneal the saw plate where you want to make the hole. You can do that by chucking a 3 or 4mm nail in your DP, spinning it at a good speed while holding it very firmly against the plate. That will produce a small focus of red-hot metal, which usually cools slowly enough to give you a softer area. But Sutton "Builders drills" ( with carbide tips & blue paint in their lands) will do a good job, they are obtainable in any hardware store & won't break the bank. Their main drawback is that the points on the 5 & 6mm sizes are a bit dull, and they will skate unless you make a pretty significant divot with a centre-punch. The smaller sizes (4mm or 3mm) will start better, so maybe use one of these to drill a pilot hole. I've discovered they work best without any cutting fluid, too - just steady firm pressure sends 'em though in no time.

Cheers,

Originally Posted by Morbius

.......For some reason, no saw I own can quite get into the area of the handle I need to finish installing the plate.....

Yep, I don't know any way to make a curved-bottomed hole with a straight saw! . I've made myself a couple of small, curved saws (that cut on the pull stroke) to do this job. It's a bit tedious, but they get me there. I think it would be harder to do with a stair-saw style of saw, that cuts on the push stroke. The saws I'm talking about are very easy to make - you only need about 20mm of teeth on the curved end, and the teeth can be rough as anything & still work, because only a couple are cutting at any point as you roll the saw on each stroke.

Cheers

I've read that slitting saws can be improved for sticky materials (such as brass or wood) by filing a little off the side of each point so the tip ends up only half the thickness of the saw. This alternates each side. and allows a bit more clearance for cut material. Apparently they also track straighter.
I haven't tried this myself as it sounds rather tedious but might be simplified with a Dremel or equivalent.

I've read that slitting saws can be improved for sticky materials (such as brass or wood) by filing a little off the side of each point so the tip ends up only half the thickness of the saw. This alternates each side and allows a bit more clearance for cut material. Apparently they also track straighter.
I haven't tried this myself as it sounds rather tedious but might be achieved with a Dremel or equivalent.

I use them in my router also. I used to do it in the drill press (see the picture below), but the faster speed of the router works better for me.

I made an arbor for them that leaves only about 1/4" of the blade exposed.




I haven't worked out a better way to do this yet, although I have some ideas. If you are only making one or two handles, I wouldn't bother with the slitting saws.

Because the teeth have no set, they are very finicky to use. They heat up VERY quickly from the friction of cutting, which causes them to warp. The warped blade leaves a kerf that can be twice as wide as it should be. I had hoped that the aluminum arbor I made would act as a heat sink and stabilizer for the blade, but it doesn't.

I use it in a router table. I don't have any guards. I feel comfortable using it that way, but can't speak for others. I haven't noticed much difference in performance between running it slow or fast. I take a couple of passes to get to full depth. Each pass takes just a second or two. You have to keep the handle moving fast so that it doesn't dwell in any one spot, or the aforementioned warping occurs. I have never had the blade catch or try to kick back on me. There really isn't that much force transmitted to the wood.

Originally Posted by hiroller

I've read that slitting saws can be improved for sticky materials (such as brass or wood) by filing a little off the side of each point so the tip ends up only half the thickness of the saw. This alternates each side and allows a bit more clearance for cut material. Apparently they also track straighter.
I haven't tried this myself as it sounds rather tedious but might be achieved with a Dremel or equivalent.

That is interesting, and probably worth trying. I'm guessing the blades are hard enough that a file won't work well. I wonder if removing every other tooth would accomplish the same thing?

Originally Posted by Isaac S

....... I'm guessing the blades are hard enough that a file won't work well. I wonder if removing every other tooth would accomplish the same thing?....

My blades are HSS, and a file won't even mark them - they have to go out to a saw-sharpener when they need attention! Taking a bit off alternate tooth tips seems a bit counter-intuitive to me. Reducing the number of teeth seems a bit more logical, makes it more of a wood-type ripsaw.

I might have run mine too slowly, when I tried cutting wood. The speeds you guys are running them at probably makes more sense, now that I think about it. The shorter the time spent in the wood, the less time there is for heat to transfer to it. There's probably a Goldilocks speed that balances things best.

My other problem is some of the woods I use. She-oak in particular, is one of those woods that chars easily, like Cherry, but worse, it leaves a gummy, charred residue on any blade (or drill bit) that gets a bit over-warm, which doesn't help it to travel freely!

I think handsaws are a much simpler way to go for a few handles, too. For larger numbers, I would definitely be experimenting with mechanised means. The saw manufacturers must have had reliable methods - does anyone know what sorts of blades they used & how they were configured? They did some pretty deep cuts in those saw handles!

Cheers,

Originally Posted by Isaac S

That thing looks hungry - for fingers. I'll stick with my cordless version for now - I can cut blade slots at a much higher rate than I can complete the other steps at this point.

cordless saw kerf cutting machine.jpg

I must admit though that the danger factor is kinda appealing...