Scroll Saw Blog

One of the patterns I’ve used a bit is the Scottie pattern from Judy Gale Roberts’ book “Dog Breeds”. This pattern has a log of zig-zag holes to emulate the hair on the Scottie’s face.  These holes are good practice for cutting sharp points and crisp corners.  Below I’ll give you a run-down on how I cut one of these holes, along with some reasoning behind my decisions. Let’s get started!

This is the hole we’re going to cut.  Notice I’ve been cutting holes out from the “nose-hole”.  The idea is to keep as much of the blank as solid as long as I can.  Although on this size of a blank it’s not that big of a deal, when working with tighter holes this can help prevent the blank from splitting on you. You could use a zero-clearance plate to help out here, but I find that threading a blade through that tiny hole in the middle of the plate is too much of a pain.  I rarely use one for that reason.

We’ve now made the first cut.  Here’s a couple of rules-of-thumb we’ll be using :

• Cut into a corner from both sides.  Don’t  spin the blade in the corner.
• Cut into the point going from the point back.  Don’t end a cut at the point.

There’s some modifications to those rules I’ll discuss as we go along. As you can see we’re using the first rule here: cutting into a corner. Then next picture shows us cutting into the next corner:

We put the back of the blade into the kerf of the first corner, and then cut to the next corner.  Why this corner? If you notice, this line is the closest to the already-cut-out holes.  We do this to keep as much strength in the blank as possible.  If we had cut this one after the line on the other side, we would be cutting through a narrow piece of wood–much more fragile and likely to break. Another good rule-of-thumb:

• Keep the blank as solid and intact as long as practical.

We’ve now gone back to the entry hole/first corner, and are now going to cut that point nearest the entry hole. Notice we’re using the second rule-of-thumb: Cut into the point. We’re approaching the point with the blade-note what we do next:

Here’s another rule-of-thumb:

• It’s much easier to start a new cut from a corner than try to vear off a straight cut.

What we’ve done here is approach the point like we’re going down one side, then suddenly change directions so we cut down the other side. This leaves a slight corner which we can use to “catch” the blade and guide it down the second side.  We continue cutting down this first side until we reach the corner: “Cut into a corner from both sides”.

We’ve now positioned the blade to go down the other side of the point.  You can more readily see this in the close-up–along with every little glitch I made cutting that first side!

You can see that the little “corner” we cut catches the blade quite nicely, and sends it properly down the other side of our point. When cutting these little catch-corners, I try to shoot straight down the second side, then turn to point down the first side of the point.

We’ve continued cutting down tha side of the point into the next corner. What I did here was back out to the waste-hole, flip the blade around and put the back of the blade into the corner. Now I can cut out towards the tip of the second point. Note I’m doing the same thing here: aiming initially down the second side, then changing directions to cut down the first side.

We’re now cutting down the side of the second point, and we end up finishing up our first corner–the one we made our first cut into:

Back to the change-of-direction, we now cut down the other side of the second point:

… and continue into the next corner:

Now we could have diverted and started on that last point.  Why not? A couple of reasons:

• It was easier just to continue the cut until a natural stopping place, like the next corner. We needed to cut into the corner anyway.
• We’re separating the lines-to-cut from the already-cut-lines.  This keeps us from cutting narrow fragile areas.

Now if this cut would have continued on a bit further (like several others in this pattern) I would have approached this differently.  I would have cut the same line, but stopped just a bit past where the point is.  I then would have backed the blade up and cut out the point like we did in the previous pictures.  After that, I would go back and continue cutting down the original path.

What are we doing here?! I thought you were supposed to approach the corner from both sides!

No, we didn’t spin the blade; I backed out the blade after the first cut into the corner, turned it around, and backed right into the same corner.  I’ll now cut out of the corner towards the point.  Why? In this case the corner gradually sharpens into an area the thickness of the blade.  You can cut the corner the same way, going into it from both sides.  In fact, this would be quicker, as you don’t have to back out/turn blade/back in.  However, when the corner is this sharp, the blade can slip into the other kerf before you hit the corner.  This leaves a little nub of wood which you really need to grind away for crisp corner.  By backing the blade in first, you can easily guide it down the other side.

I only do this if the corner narrows down to blade-width.   Otherwise you tend to leave a spot in the corner that’s a blade-width wide that suddenly widens into the actual width. The corner will look like you cut into it a little too far!

Note we also seem to be doing the point backwards.  Sometimes you have to approach the point from the rear.  The next picture shows how we handle this situation:

We’ve cut out to the tip of the point, and then made a sudden change of direction.  If you look closely you’ll notice that this new direction is like we came from the rear of the other side of the point:

We continue this cut into the other kerf line, giving us a larger hole we can manuever the blade around in:

The change-of-direction gave us another little “catch-corner” that we can use to guide the blade down the point’s second side.  Note we’re heading to the point from the front.

You can get away with approaching the point from the rear on the first side. But if you try to do it from both sides,the wood fibers are too fragile to support the sawing action and will fray.  This will leave the point jagged.

We’ve now finished cutting that last point, and ended the cut into our last corner.  We’re almost finished with this hole!

What we’re doing here is widening the corner.  We’ve backed up the point’s kerf, then cut into the second side of our corner. The idea here is to approach the corner from both sides.

We’ve now flipped the blade around, and are starting down the final line.  This takes a little practice: We’re using the already-cut side as a guide, and letting the blade gradually bite into the final line. You need enough side pressure to keep the blade from deflecting back into the already-cut area, while not putting too much pressure and causing a barrel cut. It doesn’t take much. Note that some blades will bite more easily on one side of the blade than the other.  I’m using the Pegas “Modified Geometry” blade. This blade doesn’t bit much more on one side than the other. I’d expect “precision-ground” and other similar types to be this way, while the cheaper blades will have the different bites.

We now do our final cut on this hole.  We’re again approaching the corner from both  sides.

We’ve now finished our hole!

I hope you enjoyed this tutorial.  As always, comments are welcome!