Dovetail Saw Frustrations

[Trevor Walsh]

I'm attempting (On my third handle) to build a Gramercy Dovetail saw. This is odd because I built the carcass saw no sweat on the first attempt, as well as a panel saw from scratch. Even by attaching the plate to a board with screws and moving the handle back and forth I'm still getting a spine/plate crooked in the saw longways. I just can't figure it out. I even scored a line around the handle where the blade was going to go, only the saw seems to have drifted in the cut? Here's a pic, I'm using QS mahogany.

[Jim Koepke]

Are the teeth already set on the saw plate?

My first step would be to make sure the saw plate is solid and parallel to the reference surface.

Then I would try a few practice cuts to see if the saw consistently drifts in one direction or the other.

jtk

[Tom Vanzant]

1+ what Jim said. If the teeth have NOT been set and all else is well with the saw plate, make a spacer 1/2 the thickness of the handle less half the thickness of the plate and clamp the plate and spacer to your workbench or some other known-flat surface. Use a cawl. Cut the saw kerf in the handle by sliding it on the reference surface. The saw kerf should now be centered on the handle and the thickness of the plate. Set the teeth and sharpen... then stone the set as needed to make a straight cut. If the teeth have been set, again 1+ what Jim said. Correct the set to essentially zero and proceed with kerfing the handle. Then re-set the teeth and sharpen. Practice first!

[Jonathan McCullough]

Not sure I'm understanding. The kerf you've made in the saw handle to receive the saw plate and spine, is crooked? If so, one thing you could do is glue in a shim, let it dry, and try cutting again. One trick I saw somewhere on the internet was to secure the saw plate on a block that is perfectly flat, parallel, and half the width of the saw handle. Then put the saw blade on that. Then a block of wood on that and secure it with, say, a holdfast, so you have a blade sticking out of a wood sandwich. Then you lay the handle flat on the bench and run it against the teeth of the saw plate. Since the saw plate is perfectly flat, it should cut a perfectly parallel line half way through the handle, assuming a flat bench and a saw handle with perfectly parallel sides.

[Trevor Walsh]

Jim, Yes there is set to the plate, there was also set in the plate for the carcass saw I made without a sweat. I didn't clamp the blade in a sandwich, but held it down on a piece of scrap that was half the thickness of the handle. I use a piece of offcut ash miter bar, which now that I think about it, may not have been parallel. I'm going to recut the handle and try one more time, with the blade sandwich, before jumping out of my window.

Jim, I may give that a shot, but I'd rather not f-up the nicely set and shiny new sawplate. If this next one doesn't work, I'll peel my butt off the sidewalk and give that a go.

[Joel Moskowitz]

Several questions:
Is the blade and the screwed holder holding the blade really parallel to the surface you are using to register blade and handle when cutting the slot. Even a small amount off could be a problem. THis would be my first suspect.

Is the blade ok? if for some reason the set isn't even the blade will drift. We make thousands of saws the setting is by hand, and after all we are human.

There is also a potential issue that being a very thin blade, stresses in the wood can do weird things to the cut during and after it's cut.

If both of these things check out, of if the blade isn't cutting right, drop an email to Ben C/o : support@toolsforworkingwood.com He will figure out what to do.

joel
(tfww)

[Mark Baldwin III]

I've been having the same issue with the miter saw I'm making. I'm contemplating handle number three because I can't quite figure out where I went out of line on my second attempt. I decided to set the saw aside for a few days and make a new plane before trying to finally tackle the saw once and for all. Lucky for me, if I jump out of my window, I'll just land in the shrub.
Making your own saw helps to explain the price tag on a custom piece like you'd get from Wenzloff or Two Lawyers!

[David Weaver]

trevor, do you have a thin cutting japanese pull saw around anywhere?

I have let in two saws with a ryoba and a third with a no-set dovetail saw.

I'll bet it took me two minutes to make the cut (i.e., I didn't do it in ten seconds, no pressure on the saw and i kept a very close eye on where the plate was tracking) on the small saws, and longer on the big one.

[Trevor Walsh]

Joel, good points, I will recheck all of my setup pieces and change the wood species I'm working with to see if that helps.

Mark, most certainly, and it doesn't hurt that they make sexy saws either.

David, that is a good idea. I could probably saw a line by hand squarer and faster than I could make the jigs. I just have to find a thin enough saw... Time for some searching.

[Klaus Kretschmar]

Trevor,

could it be that the vertical alignment between blade slot and sides of the spine mortise isn't exactly parallel? That would make the blade bowing slightly after the screws are fastened. If that's the case, you can correct the alignment by paring one side of the mortise and glueing in a shim on the other side which will be pared also after it's dried.

There's another way, but it has to be done VERY carefully. Clamp the spine in a vise (only the small part, where it's inserted in the handle) and twist it a little bit by using a binding piece which graps the spine directly above of the vise. Make sure not to impact the spine with the binding piece by using some small pieces of wood between the cheeks of the binding piece and the spine. Then twist it SLIGHTLY clockwise, if the blade is bowed to the left (looking the saw from the top) or counter clockwise if it's bowed to the right.

Klaus

[Steve Branam]

To further follow up on David's suggestion, here's a post I did on using a ryoba with a very simple jig for flat end grain cuts like this:
http://www.closegrain.com/2010/03/ryoba-tenon-cheeks.html. You'll see from the photos that you can get very fine precision with it.

You could even use this method to make your own veneer for filling the cut that went off track.

[Trevor Walsh]

Woohoo, the handle is still in need of shaping, but the slot is straight and the holes are all good. The two things I've messed up over the last 5 goes at this handle. I wound up using the really thin pullsaw technique and did it to layout lines freehand. I'll quit fussing with those blade clamping arraingments.

[Tom Vanzant]

Good for you Trevor. I'm not that confident in sawing to longer lines. Pictures of the finished saw are coming, right?

[Trevor Walsh]

Yes, I used a piece of curly maple, it looks like a dog was chewing on it from the coping saw work, but when it's cleaned up and rounded I'll post some photos.

[David Weaver]

David, that is a good idea. I could probably saw a line by hand squarer and faster than I could make the jigs.

Absolutely, as you've found, this is a cut where you are better off leaving things that get in the way behind, and trusting your eyes and hands. Not only is it easier and ultimately faster, but it feels good to do accurate freehand work.

I know there are lots of tips out there for setups so people who may not do much hand work can cut the saw slot accurately, but I know you've done enough hand work that a lot of that stuff is not necessary and you can just mark it and cut it.

I forgot to mention, I have cut the mortise for the spine before and after the saw slot, and come out the same either way - just cut the mortise undersize (I used a pull saw or a dovetail saw, something that cuts finely) and then float or pare it to a snug fit on the saw spine the same way you might bed an iron on a plane (pare, test fit, pare, test fit, ...). That way, if you do wander to one side or other of the saw line (not off, of course, that'd be bad) a little, you still get a very nice fit on the spine and a result that's pleasing to the eye to look at when you saw.

[Trevor Walsh]

Absolutely, as you've found, this is a cut where you are better off leaving things that get in the way behind, and trusting your eyes and hands. Not only is it easier and ultimately faster, but it feels good to do accurate freehand work.

Thanks, and is does feel great to do accurate work by eyes and hands alone. Not everyone may see it, but in certain cases, someone doing a little forensic carpentry will notice that it was done by skilled hands.

I also took a fine Zona saw to the mortise walls for the spine. I feel much better about this than my past attempts. Now I just have to shape it, ha.

[Chris Vandiver]

1+ what Jim said. If the teeth have NOT been set and all else is well with the saw plate, make a spacer 1/2 the thickness of the handle less half the thickness of the plate and clamp the plate and spacer to your workbench or some other known-flat surface. Use a cawl. Cut the saw kerf in the handle by sliding it on the reference surface. The saw kerf should now be centered on the handle and the thickness of the plate. Set the teeth and sharpen... then stone the set as needed to make a straight cut. If the teeth have been set, again 1+ what Jim said. Correct the set to essentially zero and proceed with kerfing the handle. Then re-set the teeth and sharpen. Practice first!

Trevor, read this quote carefully. It describes the correct sequence to use for kerfing a saw handle. If you carefully do it this way, the results will always be good.

[Trevor Walsh]

The only issue I had with that technique is that the saw plate I'm using comes set and sharpened, which I think accounts for some of my issues.