# Compound Cutting For Beginners



## Gill (24 Aug 2009)

Compound cutting is fun and can produce items which look striking but are relatively simple to make. The first (and most critical) step of the technique is to check your saw table for squareness against the blade before you begin. If it is not square, you will find cuts which meet up when you follow your pattern do not meet up on the bottom of your wood. I like to use a good, large skip-tooth blade for compound cuts because I find it clears swarf efficiently. However, others suggest a plain blade and it is probably best for a beginner to follow this advice. A number 5 or a number 7 will probably suit most projects but there is no reason why coarser or finer blades cannot be used. Use too fine a blade, though, and the project will take ages to cut; use too coarse a blade and you will not be able to change direction efficiently.

This is what a compound cutting pattern looks like:







(I have doctored the photograph to make it more difficult for anyone to snaffle the pattern – I do not hold the copyright.)

The dotted line down the centre of the pattern is key. The pattern must be folded precisely at 90º along this dotted line so it can be glued to the workpiece with half of the pattern on one face of the block and half on the adjacent block. Your workpiece must be cut perfectly square.






I have lined the workpiece with blue low-tack masking tape because I find this helps to lubricate the blade as it cuts. Unfortunately, I later found it resisted the adhesive I used to glue the pattern to the workpiece; hence the clear sticky tape which appears in subsequent photographs.

Pilot holes were drilled in both faces, one for each of the internal cuts and one for the outside.






Next, all four internal cuts were made. Making the internal cuts first helps to preserve the structural integrity of the workpiece for as long as possible. Some scrollers like to save their offcuts and pack them back in to the workpiece, claiming it helps to maintain the block’s structural integrity. I have never found this to be the case, so I discard them.






Working on one face of the block only and starting from the remaining pilot hole, cut the outside of pattern. This should be cut cleanly with as little deviation from the pattern as possible. However, sometimes it is practically impossible to turn sharply enough to create crisp edges. When this happens, there is no harm in cutting into wastewood to create a turning circle for your blade, as in the photograph below:






Resist any temptation to cut into the workpiece from any starting point other than a pilot hole!

Once you have finished cutting one face in its entirety, the centre of the block will drop out. It should be able to pass through both the bottom and the top of the workpiece; if it cannot, your saw table is not square to your blade.






Re-assemble the workpiece and rotate it through 90º. Of course, you now need to stop the internal block that you have just cut from moving within your workpiece, or you will end up with inaccuracies. There are a number of ways to do this; some scrollers just use sticky tape but I prefer to use a home made clamp instead. Do not clamp the workpiece too tightly; the aim is to stop movement and too much pressure will make it difficult for your blade to cut.






Cut the outside of the pattern and remove the clamp. This is where you get the pleasure of seeing your project emerge from within the workpiece:






Give your project a light sanding and file away any residual excess there might be.






One final thought: if you smell burning at any time, reduce the cutting stroke speed of your saw. Trying to cut too quickly can generate a lot of heat along the blade which not only dulls the blade but also burns the wood.


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## StevieB (25 Aug 2009)

Many thanks Gill, I am always amazed by your skill at compound cutting. I have never managed to cut thick timbers in this manner without blade drift from the vertical. Not sure if its the blades (shouldn't be, use Mikes Flying Dutchman ones) my technique (most likely cause) my speed (also possible) or just my lack of practice (also possible - very little workshop time at all sofar this year). Whichever, thanks for sharing - you give me inspiration to try each time you post something! I still have a chess set to make after you posted your last excellent efforts  

Steve.


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## Gill (25 Aug 2009)

Give it another go, Steve - it's not at all difficult  . Try a softish hardwood next time, something like sycamore or lime.

When you say your blades drift from the vertical, do you mean there is lateral drift? That is normally indicative of a saw table which is not square to the blade. Any other sort of drift is probably attributable to insufficient blade tension.

Something I have noticed when cutting thick hardwood is that the tension slackens after a few minutes. I don't know why this is so but I am speculating that perhaps the blade stretches slightly! Whatever may be the cause, the first sign of it is when the saw starts to cut a little more slowly. I 'ping' the blade and the note is deeper than the note when the tension is set. So I just apply a little more tension and continue along my merry way  .

Gill


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## StevieB (25 Aug 2009)

Thanks for the advice Gill. To be honest, I think I am not running the saw at a high enough speed or alternatively turning too fast. If I tried to cut a circle in thick hardwood for example, I would end up with a cone. The blade is definately square to the table (the make a cut and put the back of the blade into it test is fine) I just need to slow down, use an agressive blade and practice!

Steve.


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## Gill (25 Aug 2009)

:?: 

How peculiar! Normally, a cone instead of a disc would be conclusive proof of a table that is out of square, but if (as you say) you can cut into a square block and fit the blade into the cut from behind, then squareness should not be the problem. To be honest, I'm not a fan of that technique for testing squareness. I prefer to cut a small circle out of some waste wood and if the circle doesn't slide out of both the top and the bottom of the block, I know the table is not square. It would be interesting to find out what happened if you were to try my technique for testing for squareness, then tried your technique!

Believe it or not, a Wixey digital angle gauge is also very good when it comes to checking for squareness. If only the battery on my gauge hadn't run out...

The only other possibility to explain your problem that occurs to me is that your blade tension might be too slack and you might be applying sideways pressure as you cut. However, I would be astonished if that was so.

Gill


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## DaveL (25 Aug 2009)

Gill":393prs03 said:


> Pilot holes were drilled in both faces, one for each of the internal cuts and one for the *outside*.
> 
> Snip......
> 
> Resist any temptation to cut into the workpiece from any starting point other than a pilot hole!



Gill,

I now know one of the reasons I had so much trouble when I tried to do these, might even have another go armed with this extra info. :roll:


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## StevieB (25 Aug 2009)

Well I hesitate to post this first image given that it is so awful, and the camera makes it seem worse! But you did ask...






The chess pieces were my first attempt at compound cutting some months ago and are clearly not square. Since there are no real curves its difficult to see properly what I mean but as a further example, this puzzle will only go together one way






Now this could be because of a non square table, and according to your test Gill it is definitely a non-square table since this is exactly the problem you describe if a table is non square! When I have time I will play with the tension of the blade, alter blade grade and practice some more, but my workshop time is severly limited at the moment and likely to be non existant soon as my wife gives birth within the next two weeks.

Cheers for the advice!

Steve.


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## Gill (25 Aug 2009)

Steve - judging from the photograph of your chess pieces, your table is definitely not square to the blade. Apart from that... nice work; there's nothing at all wrong with your technique  .

Fingers crossed for your forthcoming happy event. That's going to be one lucky baby with a daddy who can make lovely toys. I really like your fish jigsaw. Did you cut it out of one board and then stain the two little fish? It's worked a treat.


Dave - :lol: . At least now you know where you went wrong! I'm really pleased that you're thinking of having another go - it makes the work I put into this thread all worthwhile  .

Gill


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## StevieB (26 Aug 2009)

Thanks Gill  The fish puzzle is from a Richard Greenslade pattern - I have a couple of other patterns apart from this one (pelican and another bird from memory) but they are difficult to find. Wish he would publish a book! He did do a piece in SSW a year or so ago and I really like his work. 

The fish in the picture is 25mm Maple with the two fish in the middle cut in black walnut to fit. The whole piece needs finishing and has been sitting on my shelf for about a year waiting  Still, a plasterer friend did a bit of patching in return for one from oak and maple so it was worth doing!

Regaarding the squareness of the table, thanks for the advice. One quick query though - you mentioned too much pressure on the blade, causing it to bend. I do get a hole appearing in my zero clearance inserts after a while from lateral blade movement, perhaps I do need to tension my blades better. With the Axminster AWFS18 however there are guides for aligning the blocks to the side of the table and a tensioning lever so I always assumed this was the correct blade length/tension. Might try and shorten the blade a fraction between the blocks and see if that makes a significant difference. Got a deck and pergola to build over the bank holiday but am now inspired to at least try if I can fit half an hour in the workshop too!.

Steve.


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## Gill (26 Aug 2009)

StevieB":19076tlg said:


> ...The fish puzzle is from a Richard Greenslade pattern - I have a couple of other patterns apart from this one (pelican and another bird from memory) but they are difficult to find...



I'm not familiar with Richard Greenslade's work, and an internet search against his name has failed to produce anything worthwhile. I will keep my eyes open for him in future and let you know if I come up with anything.



StevieB":19076tlg said:


> The fish in the picture is 25mm Maple with the two fish in the middle cut in black walnut to fit.



 Shades of intarsia! That's not a technique I've ever had any success with. It makes your fish all the more mpressive.

Gill


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## StevieB (26 Aug 2009)

doh, you beat me too it. Russell, not Richard  

Steve


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## Gill (26 Aug 2009)

By the strangest serendipity, Steve Good's latest project is a 3D decorative candlestick. Just scroll down the page and you'll find the downloadable free pattern.

There are also a couple of videos in which he demonstrates compound cutting:

http://www.youtube.com/watch?v=Q1_TgDNa228

http://www.youtube.com/watch?v=2HzGSNZj66g


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## Blacklabradorman (28 Aug 2009)

That was really useful Gill - Thank You. I'm especially grateful for the tip about not cutting from the outside - I would have just started in to have it all fall away in pieces...  

Sean


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