Thread: Saw for sliding dovetails (pt 1)

Originally Posted by pmcgee

Another design.

My New Rock And Roll Saw...

I guess that's what you call convergent evolution!

Thanks for bringing that to my attention, Paul - I was feeling a bit silly because my saw was more elaborate than it needed to be, but this one makes mine look very crude!

It's apparent we both set out to solve the same problem, viz., how to saw to a fixed depth on a "blind" cut, and opted for a similar principle. We both opted for a curved blade, but I used a larger diameter curvature, which means mine probably can't work as close to the end of a blind socket as this one should. Mine probably doesn't clear the sawdust as well on a long cut as the 'rock & roll' version, but the flatter blade makes the saw more manageable, for me. I decided it was simpler to make the blade exposure adjustable and let the saw body be the depth stop when it hits the fence, rather than make a separate external fence.

I don't think there would be a huge problem with the rake angle of the teeth, just maintain an angle matched to an approximate tangent to the curve as you form them, but you would certainly have to be careful to keep the curve pretty close to the curve of that fence.

I didn't put quite as much thought into dressing-up my saw, I must say......

Cheers,

Originally Posted by IanW

I don't think there would be a huge problem with the rake angle of the teeth, just maintain an angle matched to an approximate tangent to the curve as you form them, but you would certainly have to be careful to keep the curve pretty close to the curve of that fence.

I didn't put quite as much thought into dressing-up my saw, I must say......

Cheers,

maybe, maybe not, you wouldn't really know until you used it. sometimes these things sound good in theory but don't work so well in practice, if you have ever used curved saws, like a floor saw for instance you would know what i'm talking about, the curve is great (needed) for starting mid way but using the tip of the saw and such it can bite in and make it a bit (sometimes a BIG) of a pita to cut, you preserver of course and you get it to work but using a regular saw is much nicer and if you have that option its the preference, makes a neater cut usually too...its not the same as putting a slight crown on the blade like you have done and using it (mostly) flat, its hard to explain here, but in practice you can tell what i mean straight away using a curved blade when using the tip with the handle up high, especially if the teeth are sharp they bite in and its hard to get the cut going smooth, less teeth per inch the harder too naturally...looking at the pic again (i only looked real quick the other night) it might not be too bad, the blade doesn't look a 'lot' curved, the fence throws me a bit, makes the curve look bigger than it might actually be to my eyes (particularly the other night at a glance) my impression was ,whoe, thats a big curve, perhaps the handle position exaggerates it a bit to me, if the tpi is fine it may work ok but it could still could be a pig to use as well, like i say, you would have to try it, i think i'd much prefer to stick with my way or the traditional way for blind stopped sliding DT, i wouldnt even consider it for through cut sliding DT

IanW

Paul, in the grand scheme of things, I doubt it matters a hoot which way the angled side goes

given the choice its usually better to put the flat side toward the end grain, tad bit stronger that way



cheers
chippy

Originally Posted by ch!ppy

... my impression was ,whoe, thats a big curve, perhaps the handle position exaggerates it a bit to me, if the tpi is fine it may work ok but it could still could be a pig to use as well, like i say, you would have to try it, i think i'd much prefer to stick with my way or the traditional way for blind stopped sliding DT, i wouldnt even consider it for through cut sliding DT....

Hi Chips, that was my first impression, too, & still is! I was actually referring to forming the teeth when I was talking about rake angle not being a problem - the main challenge is laying out the spaces on the curve so that the tpi stays constant. I agree that in use you would need to rotate that curved saw evenly on each stroke to maintain any semblance of a smooth cut - it doesn't look like an easy animal to master to me, either, but as you say, unless you had it in your hands, you couldn't really say. A high tpi would certainly help, but also defeat the purpose to some extent by clogging more & cutting slower.

I can't say I've given my saw a real pounding, yet, but have used it a bit & I like it. It does what I expect of it quite well, & is easy to keep straight & true against a guide. Time will tell how much use it gets, but I expect to do lots more work without burning electrons now that I have the luxury of time....

I do have a couple of curved-blade saws, in fact, but they are the opposite of floor saws, as they are filed to cut on the pull stroke. I use them for forming the 'u' shaped slot in my saw handles. I've never used a floor saw, but have held a couple in my hands & thought they looked like a bit of an ugly thing to have to do any accurate work with, so I'm not surprised at all by your dislike of them....

Cheers,