Making a turning saw
Posted: Thu Jun 23, 2022 2:36 am
A couple months ago I decided I wanted to make a turning saw which is a larger version of a coping saw with a tensioned wood frame. Grammercy Tools from NY makes a modern one for $180 US. They also sell the blades for them, which are quite good quality, and they offer a plan and parts if you want to build your own. LV sells the blades and that's where I got mine. Probably the trickiest part are the pins that hold the blade. Like a coping saw they are split and have an angled groove to hold the blade. Grammercy sells a pair for about $40. I decided to try making my own.
I used a Dremel type tool with an abrasive disc to cut the slots and the angled groove for the pins on the blade. The pins are thicker than the blade is so I had to open the angled slot up wider for that. A hacksaw works for either job too. I decided the best way to attach the pins to handles was to thread the pins and the handles. One picture shows threading one of the handles with a standard metal tap. The plan calls for 1/4" pins so I tried using a piece of 1/4" steel rod for one and modified a bolt for the other. I'll stick to using rod next time. There was no advantage to using a bolt. I had to extend the threads anyway.
The pattern for the arms, stretcher, handles, and the toggle that twists the string to tension the blade are a free download from Grammercy. They print actual size on ledger sized paper ( 8.5 by 14 I think that is). There is a test scale on the drawing to make sure it's the right size. Grammercy makes their saw from hickory and I recently bought a piece so I did too. The handles and toggle I turned from Siberian elm. To shape the wood I cut the patterns out and glued them onto my blanks with fish glue. Grammercy uses braided fishing line for the tensioning string. I used some strong colorful cord I bought at LV.
A bow saw/turning saw is a bit superior to a coping saw, not only because it's twice as long but also the twisted string keeps the blade in tension whereas the coping saw relies on the spring it it's frame to keep the blade in tension.
I used a Dremel type tool with an abrasive disc to cut the slots and the angled groove for the pins on the blade. The pins are thicker than the blade is so I had to open the angled slot up wider for that. A hacksaw works for either job too. I decided the best way to attach the pins to handles was to thread the pins and the handles. One picture shows threading one of the handles with a standard metal tap. The plan calls for 1/4" pins so I tried using a piece of 1/4" steel rod for one and modified a bolt for the other. I'll stick to using rod next time. There was no advantage to using a bolt. I had to extend the threads anyway.
The pattern for the arms, stretcher, handles, and the toggle that twists the string to tension the blade are a free download from Grammercy. They print actual size on ledger sized paper ( 8.5 by 14 I think that is). There is a test scale on the drawing to make sure it's the right size. Grammercy makes their saw from hickory and I recently bought a piece so I did too. The handles and toggle I turned from Siberian elm. To shape the wood I cut the patterns out and glued them onto my blanks with fish glue. Grammercy uses braided fishing line for the tensioning string. I used some strong colorful cord I bought at LV.
A bow saw/turning saw is a bit superior to a coping saw, not only because it's twice as long but also the twisted string keeps the blade in tension whereas the coping saw relies on the spring it it's frame to keep the blade in tension.