Turning Saw

The turning saw is the progenitor of the bandsaw, used to cut curves before the advent of machinery.  I've also heard them referred to as bow saws. Very thin blade material can be used because tension is provided by the wooden frame and a "Spanish windlass".  The handles and blade rotate to allow for cutting stock deeper than the frame, hence the name turning saw .  In addition to cutting curves, they are quite good for cutting dovetails or other joints where a narrow kerf is required.  They can be pushed or pulled for cutting depending on your preference.  I'm making this one with London Pattern handles featured in my previous post.

I have made bowsaws in the past with metal pins inserted into the handle and a slot to hold the blade.  This was unsatisfactory because the pin was epoxied into the handle and eventually worked loose.  I've seen examples of older saws that have wooden pins, but that too seems a weak link for a joint in tension.  A joint that I've seen on European saws is a metal pin with a flat end that keeps the blade with a bolt and wingnut.  I used a hybrid approach, turning the handle and pin as one piece and attaching a flat metal keeper to the wooden pin with brass rivets.  The saw blade is attached with a small stainless steel bolt and a wingnut.

The frame is made from cherry, and the cross member tenon has curved shoulders that correspond to the mortise in the sides. This allows these members to rotate slightly in response to tension or wear.  Chop the mortises and cut the tenons while the members are still squared up. 

Shape the frame elements with a spokeshave, rasp and finish up with sandpaper. Leave the frame full at the handles and joints, but the rest of the frame can be sculpted into graceful slender elements.  The Spanish windlass toggle is also a turned element.  A deep cove accepts the string and once tightened by rotation, the end is inserted into a small round mortise on the top of the cross member to keep it in place. 

The blade is cut to length from a band saw blade.  Several different blades can be made up for this saw depending on the intended operation.  Band saw blades are easily cut with a cold chisel, just remember to use eye protection and leather gloves.  I intend to use this one for dovetails and occasional curve cutting which are mostly rip cuts, so I used a general purpose, 15 tpi bandsaw blade and reduced the set of the teeth by running a sharpening stone down both sides.  If desired, the teeth can be reshaped with saw files and a vise; more on that later.  I use hemp twine for the windlass.  This can usually be found in upholstery supply shops, used to tie springs in furniture.  This is a great weekend project with a result you can use for a lifetime. 

   





London Pattern Handles

There is something really nice about London pattern handles.  The distinctive turned handles with octagonal "flats" are seen on period hand tools from the golden age of hand tools in pre-industrial England.  The sculptural shape is more than embellishment and I suspect that the evolution of this form had a long period of development in European workshops.  Most London pattern handles are seen on chisels and gouges. I've been making a turning saw with LPH's for precisely the same reason that they work so well for edge tools.

When used for chisels or gouges, the octagonal "flats" prevent the tool from rolling off the benchtop, but the other great thing about this handle is the ability to roll the tool between thumb and forefinger for precise control, while locking the "flats" in the palm of your hand.

These are not hard to make and it's a great way to use up small wood scraps and cutoffs. What's shown here is for the turning saw, but the idea is easily adapted for edge tools with the addition of a ferrule. I've started with well seasoned pear wood, one of my favorites, especially for turning. The blank is squared with a jack plane and the flats laid out with a marking gauge.



A sharp low angle block plane is used to cut the "flats". Measure to make sure that the flat truncation equals the remaining portion of the squared blank.  It's ready to go to the lathe when all four truncations have been made.

The lathe work is fairly straight forward, and can be varied to a particular hand size or ferrule for chisels or gouges. Tung oil is a great finish for pear.  It can be applied when the stock is still on the lathe using the heat build up from friction to increase absorption and cure the drying oil.  My next post will show the construction of the turning saw.  Thanks for your interest.