Compound cuts can be very challenging. The normal procedure for this sort of work was described a couple of years ago in this rather rambling thread. The big problem with using this technique is that once all the cuts have been made on one face, there's nothing to hold that face steady while the other face is cut. Of course, by taping around the block you can add a lot of support, but there's still going to be movement.
A project I've been working on recently calls for very accurate compound cut pieces which stand on a flat base. I considered using the traditional technique but decided to use a different method instead. Working on the principle that inaccuracies are usually due to the piece moving inside the block because there is nothing to support it, I decided to 'nibble' cut the workpiece so that the part of the wood that is being cut is always supported by wood which has yet to be cut. This meant cutting a small section at the top of the piece, rotating it through 90 degrees and cutting the same amount of wood on the adjacent face, then rotating it back and cutting a bit more, gradually working down to the base. I took a photograph of this:
Normally, a scroller would squeal at the sight of so much wood being removed from directly around the area of cut! But there was no movement of the central workpiece because it was still supported - not by the surrounding block of wood but by the wood which had yet to be cut.
The cutting progressed until I had left only the curved section at the base of the block on each face uncut. Then I completed the cut on one face so that it could move freely:
The block was then rotated through 90 degrees again and I held it in a simple clamp made from offcuts of MDF. At this point, the only way the workpiece could move within the block was sideways but putting it in the MDF clamp prevented sideways movement. I didn't clamp it too tightly because I didn't want to compress the wood as I made the two final cuts.
Let's go back to the first photograph. If you look carefully at the base of the block, you'll see that I made some pilot cuts which were just deep enough for me to be able to insert the teeth of my blade. This photograph emphasizes those cuts:
As I tightened the clamp around the block, I positioned a blade in these pilot cuts to ensure alignment. Knowing that the blade could still travel in these cuts despite the block being clamped reassured me that I hadn't over-tightened the clamp.
Then I made the two final cuts with the block clamped in position. When the clamped was removed, my 'creation' emerged, cut more accurately than I could have hoped for using the traditional technique.
Sorry if the pictures aren't too clear. I have difficulty taking photographs when working with such small pieces.
Gill
A project I've been working on recently calls for very accurate compound cut pieces which stand on a flat base. I considered using the traditional technique but decided to use a different method instead. Working on the principle that inaccuracies are usually due to the piece moving inside the block because there is nothing to support it, I decided to 'nibble' cut the workpiece so that the part of the wood that is being cut is always supported by wood which has yet to be cut. This meant cutting a small section at the top of the piece, rotating it through 90 degrees and cutting the same amount of wood on the adjacent face, then rotating it back and cutting a bit more, gradually working down to the base. I took a photograph of this:
Normally, a scroller would squeal at the sight of so much wood being removed from directly around the area of cut! But there was no movement of the central workpiece because it was still supported - not by the surrounding block of wood but by the wood which had yet to be cut.
The cutting progressed until I had left only the curved section at the base of the block on each face uncut. Then I completed the cut on one face so that it could move freely:
The block was then rotated through 90 degrees again and I held it in a simple clamp made from offcuts of MDF. At this point, the only way the workpiece could move within the block was sideways but putting it in the MDF clamp prevented sideways movement. I didn't clamp it too tightly because I didn't want to compress the wood as I made the two final cuts.
Let's go back to the first photograph. If you look carefully at the base of the block, you'll see that I made some pilot cuts which were just deep enough for me to be able to insert the teeth of my blade. This photograph emphasizes those cuts:
As I tightened the clamp around the block, I positioned a blade in these pilot cuts to ensure alignment. Knowing that the blade could still travel in these cuts despite the block being clamped reassured me that I hadn't over-tightened the clamp.
Then I made the two final cuts with the block clamped in position. When the clamped was removed, my 'creation' emerged, cut more accurately than I could have hoped for using the traditional technique.
Sorry if the pictures aren't too clear. I have difficulty taking photographs when working with such small pieces.
Gill
. I've never made one before and often thought it would be nice to have a go.
