Alexander Grabovetskiy, woodcarver, School of Woodcarving · Published 2022
How do you carve a matching mirror image of a relief panel by hand?
Quick answer: A pointing machine is a hand tool with a sliding needle that measures one point on a model and repeats that measurement on your block. It removes no wood. For a mirrored pair of panels it hands you every height in the design, so the second one lands exactly where the first one did.
The second panel of a pair is where a carver gets caught. Your eye holds one shape well enough. Across two pieces it drifts, and the drift shows up in the shadow long before anybody can name what went wrong. This old device takes the guessing away by handing you a number instead.
Two panels are going into one room. The first is finished, standing behind me, done about a week ago. Its twin waits on the bench, facing the other way. Same design, reversed. Left wall, right wall.
A client wrote me about a job shaped exactly like that, a whole room of carving with the right side matching the left. He had a suggestion. Carve one side, then run a pantograph or a router over the other one. I wrote him back and told him no. This is not the way I do work, and every piece in this shop is done by hand, with gouges and veiners. So the question was never how to let a machine carve the second panel. The question is how you measure.
Before you start the twin panel
- It measures. No wood comes off it, ever.
- One needle reading gives a height you can repeat anywhere on the block.
- Drill to that depth, then chop until the hole vanishes.
- A reversed design changes nothing. The high spot stays the same height.
- Mine sits on a block of poplar so it references flat on the bench.
- Stone sculptors made it, and the French and the Italians still argue over who was first.
Why does the second panel of a pair never match the first?
Look at one panel and count the places where somebody decided a height. The scroll rises here. A flower sits proud of the ground there. A shell drops away behind it, and a leaf tip crosses over the top of the shell. Every one of those is a number, and on the first panel you made all of them by feel.
Now carve the second. You judge the flower against the scroll you carved yesterday, and yesterday the scroll ran a hair high. So the flower goes high. The shell follows the flower. Keep going and the whole panel has slid, and the ugly part is that nothing looks wrong while you work. It looks wrong later, on the wall, when light from one window crosses both pieces at once.
On a small piece none of this matters much. Put a mark on the wood and you are fine. But sometimes I am working on huge pieces, really big pieces, and then measuring turns into a real problem. Calipers help until they do not: sometimes it is hard to use even calipers, and that is where this old device earns its place.
Can a router or a pantograph carve the reversed side for you?
They can. That is not the argument, and my client was not being lazy. Plenty of good shops work that way.
Years ago another carver asked what I thought of his work. I went to his website and everything there came off a router-based duplicator. No chisels, no nothing, just a router. He told me it was still real carving, and I had to apologize, because he is right. It is. You still carve wood with the router.
Here is what I said to him after that, and I still mean every word. You are not going to see the character, your own character, because you put your heart in every stroke and every movement. And that answer covers the mirrored panel completely. Both sides of the room get my hands or neither one does.
Which is why it matters that a pointing machine is not in the router family at all. Put them side by side and the difference is not accuracy. What separates them is whether the tool ever touches your wood.
| Tool | Removes wood | Left on the bench afterwards |
|---|---|---|
| Pointing machine | No | One honest depth, repeated as often as you ask for it |
| Pantograph | Yes | A traced shape and nothing else |
| Router duplicator | Yes | A machined surface that still wants cleaning afterwards |
| Gouge and mallet | Yes | The carving, with every decision inside it still yours |
Read the middle column again. My tool belongs to the first row, and that is exactly why using it costs me nothing I care about. It tells me where to go, and I still have to walk there myself.
What is a pointing machine, and who invented it?
The name comes from the point on the end of the needle. Do not let the word machine worry you either. No motor lives in it anywhere: a frame, an arm that swings, a steel needle sliding against a stopper, and a base underneath so the whole thing stands flat on its own, no clamps and no screws.
Copying is what it was made for. Call it an ancient form of copy machine, or a dupli carver if you like that better. Think of a three dimensional duplicator sitting in your hands, working on depth. You measure the original, then you translate that to the workpiece.
It did not come from wood. Stone sculptors made it, marble men, and the argument over who exactly is still going. There is a lot of debate about who invented that. French people versus Italians, who did it. Nobody is going to settle that here, and several versions of the design exist anyway.
One thing before somebody asks. I am not promoting anything and I am not selling anything, because I do not have one of these for sale, no matter what. Go looking on Amazon and you will probably come up empty.
Michelangelo said the stone talked to him. Was that true?
Everybody knows the story. Somebody asked Michelangelo how in the world you take a block of marble and carve a beautiful sculpture out of it. He said that when he looks at the stone, he lets the stone talk to him, and then he takes the chisel and the mallet and brings out whatever is already in there.
Really interesting story. Nobody interviewed him, though. Whether Michelangelo himself used one of these, I honestly cannot say. Other Italian sculptors did, and the method is not in doubt.
Two steps came before the stone. They modelled first, in clay, and brought that model to perfection, because clay lets you add on, chop out, put more back, take it away, change the sculpture and change it again. Clay is flexible. Leonardo da Vinci worked the same way. I do it myself, with plastilina rather than hardening clay, and it is not a secret I enjoy admitting.
Then you pick up the stone and it stops being sculpture. Now you are carving, and carving is the art of deduction. You chop away. Chop away too much of the marble and you are finished, which is the same problem sitting on this bench right now.
Think what that meant for church work before the Reformation. Shop after shop turning out the face of Jesus, the face of Mary, the saints, going into churches across Europe, every one replicated accurately with all the proportions holding. And for me the payoff is not history at all. With a model in front of me and this tool in my hand, the saving was never counted in hours. I saved weeks.
Where does the needle take its reading from?
From the finished piece. Bring the needle onto the model until it touches, lock the stopper, and now that height lives in the tool instead of in your memory.
Carry it across to the new block and a gap opens between the needle and the wood. That distance is the answer. It shows how deep the carving has to go at that one spot, and there are two ways to spend it.
The first way is a drill, and this is where the name comes from. There is a reason that machine is actually called the pointing machine: you drill to the point, and you just put that needle to the height. In the Venice room I was drilling about three quarters of an inch, around 20 millimetres, and the wood then remembered the number for me. One warning from experience. Make sure the bit is wider than the needle, because the needle does not sit exactly 90 degrees down and it needs the room.
When the piece is small you can skip the drill. Lower the machine at the side of the wood and read the height straight off, right there. After that it is repetition. Establish how high one spot is meant to be, then measure all around, every point, anywhere on the panel, and drill the holes all around. Those are my spots. And I do not miss them.
Should you bolt a block of wood under the base?
Mine has one, and it was the only change I made to the tool. These arrive as the upper part only. Just the frame, the arm and the needle, with nothing to stand them on.
So I took a block of poplar. I said maple first on the livestream and corrected myself, which shows you roughly how much thought the base gets compared to the needle. Now the whole tool references flat. I can always place it flat without even mounting anything: the workbench, any flat spot, or the bandsaw table, because I know that is flat too.
Tighten everything before you measure. I had mine a little loose at one of the brass collars on camera, and a loose collar quietly changes the number while you carry the tool across the bench. A bench that does not rock matters here for the same reason, and so does knowing which gouges are going to follow the reading down.
How rough is too rough at the bosting stage?
Rougher than you think. When I turned the camera onto the second panel I had to tell people not to judge it, because that piece was still at the bosting stage and it looked really, really choppy. No final carving anywhere on it.
Bosting is what they call it in England, and it means establishing the overall shape, nothing else. Do not worry if it looks rough. Shaping is all it is at that stage. Production carving is how I make my living, so speed here is not a style choice. All the chopping gets done quick. Then I clean everything up and it looks wonderful.
Drilled holes are what let those two things live together on one panel. Chopping fast and chopping accurately usually fight each other. The holes settle it: I can swing the mallet hard, and the moment a hole disappears, that spot has arrived. Depth stops being a judgement call and becomes something anybody can see.
Does it matter that the design runs the other way?
Not to the tool. It does not matter whether it is a reversed look or the same look. You just replicate it. I put it plainly on the floral panel: I have to do the same detail, but it is going to be flipped, so it is a different direction, and the high spot is going to be the same.
That sentence is the whole lesson. The needle reports one height at one spot, and whether that spot lands on the left wall or mirrored onto the right is a question for your drawing, not for your measuring. Get the design right on paper and the panel becomes a long list of depths that somebody still has to carve out by hand.
That tool is a lifesaver for me, and I have said so on camera more times than I can count. Not a shortcut. This is what let sculptors put the same face into church after church, and what lets me hand a client two panels that agree with each other.
Inside the school it sits with the work it belongs to. The Chamomile and Bow Rosette class is where the machine comes out on the bench and does the job on camera. I call it a lifesaver on the floral and molding panel. Then there is the Venice Room, a whole room of carving of exactly the kind my client was asking about. The tools course covers what stands beside it on the bench, the modern acanthus class shows the bosting stage on its own, and a longer written guide sits in the pointing machine article.
You have a panel that needs a twin, and you have two hands. Access to the school puts the rest of it in front of you.
How it's done
- Tighten the frame before anything else. Slack in a brass collar quietly changes the reading while you carry the tool across the bench. I make sure everything is tight and not moving too much before the needle touches the model at all.
- Stand the base on something flat. The block bolted under mine lets it sit flat on the workbench, or on the bandsaw table, with nothing clamping it down. Flat is the reference the whole reading depends on.
- Take the high spot off the model first. Set the needle against the proudest point of the finished piece and lock the stopper there. Start high, because if you chop away too much you are finished, and wood does not grow back.
- Carry the reading to the new block. Swing the machine over the second piece. The gap you can now see between the needle and the wood tells you how deep to carve right there.
- Drill to the point. Drill a hole as deep as that gap. Use a bit wider than the needle, because the needle does not sit exactly 90 degrees down and it needs the room. In the Venice room that came to about 20 millimetres.
- Walk the points around, then chop. Every flower, every shell, every hollow gets its own reading and its own hole. Then chop fast. Each spot stops the moment its hole disappears.
Frequently asked questions
Is a pointing machine the same thing as a router jig?
No. A router jig removes wood and this removes none. The needle reports a height and you still have to go and take that wood off yourself with a gouge. That one difference is what settled the argument with my client about the mirrored panel, because the machine never touches the carving.
Do you need one for a small carving?
Probably not. On a small piece you can put a mark on the wood and be fine. I reach for it when the piece is big, when the same detail has to repeat, or when calipers cannot get at the spot I need. Sometimes it is hard to use even calipers, and then this is the easy way.
Which wood goes under the base?
Mine is poplar. I said maple on the livestream and corrected myself, and the species really does not matter here. Any stable block does the job, because the base has one duty only: letting the tool stand flat with nothing holding it down.