Making a Collapsible Bow Saw

How much wood could a woodchuck chuck

If a woodchuck could chuck wood?

As much wood as a woodchuck could chuck,

If a woodchuck could chuck wood!

Try saying that after a few beers!

On my last foray into the woods, I thought I’d have a go at making a simple collapsible buck saw that I could use whenever I needed to cut large pieces of wood. I originally learnt this technique at the annual May Day meet that’s organised by the good folks at the Bushcraft magazine and I wanted to try making a saw while ‘out in the field’.

This is quite a nice little project to undertake while you’re in the woods our out on a camp so why not give a go for yourself. Here's what I did:

Tools for the job:

• Saw – Yes I know you need a saw to make a saw! This may seem counter-productive, but you can make a much more capable saw that can potentially process bigger bits of wood.
• Knife
• Cordage – I used 550lb paracord
• 21 inch bow saw blade.
• 2x split rings (these are optional)

Stage one – Wood selection

Head out to the woods and look for some nice straight pieces of wood. Hazel is usually your best bet. Ideally you’re looking for something that is roughly the same thickness as your thumb. You’ll need a 4-5ft length of wood to make the saw. Alternatively you can cut two or three shorter sections.

Stage two – Measuring and cutting

Having sourced your wood, the next job is to cut the sections to the appropriate length. The length of the wood that you’ll need to cut will be determined by the length of your saw blade. I used a 21 inch saw blade, but there’s absolutely no reason why you couldn’t opt for a longer or shorter blade.

I cut a piece of cordage to the same length as the blade. This would then help me to measure out the individual sections of the saw frame. You might be wondering why I didn’t just use the saw blade as a guide! I am using string so that I could also measure half and three quarter length sections of wood for the uprights and joints.

First things first then, I cut the long cross section – this needed to be the same length as the saw blade. The two upright sections were next and I used my string to measure three quarters of the length of the saw (or just under 16inches!) and then cut two up rights.

Barney’s top tip: In case you’re wondering how I used the string to measure a ¾ length. I folded it in half and then half again to create four equal lengths, I tied an over hand knot to mark a quarter length and voila!

Stage three – Creating the joints for the blade and framework

The next job is to cut some vertical slots on the end of the uprights to accommodate the saw blade. I tried my very best to cut a nice straight line down the middle of the upright and then repeat this process for the opposite end. I cut the slot to the same depth as the saw blade (just under an inch or so!).

If you have some split rings, now’s a good time to attach them to the end holes on your saw blade (one either end). This will help you fit the saw blade to the frame.

Barney’s top tip: You don’t need to use split rings to secure your blade in the framework.  A simple wooden dowel or wing nut and bolt also work very well indeed.

With the slots cut out, lay out the uprights on the ground and fit the blade in place. The uprights need to be slotted in just in front of the holes that have the split rings. With everything in place, try and ensure that the uprights are at a right angle to the saw blade (just go by eye on this, no need to get the protractor out!).

Using your measuring string mark out  the half way point on the upright and cut a square notch on each upright. Take your time to ensure that you cut these notches in the correct side of the upright as the two notches will need to be facing each other when the frame is assembled. To cut these notches, I used my saw to create a stop-cut on either side of the half way marker and then I carved out the notch with my knife. I ensured that these notches were wide enough to accommodate the cross-section of the frame.

With the notches carved, re-assemble the frame with the saw blade and then see if the cross-section slots into the notches. Ideally the cross-section should fit into place with the uprights maintaining a right angle to the blade. You may need to make some small adjustments here to ensure the fitment is correct. You can do this either by adjusting the length of the cross-section or making the notch a little deeper (don’t go too deep with the notch though as you’ll compromise the strength of the frame).

Stage four – adding the windlass and tensioning cord

Nearly there now! Fist of all the two uprights need a v-shaped notch carved into the outside of the upright and approximately one inch from the top. This notch is simply to house the tensioning cordage and prevent it slipping around on the frame.

The windlass is the piece of wood the you use to twist the cordage and create the tension. To make this, simply cut a piece of wood that is a little over half the length of the upright.

And finally, using your cordage; tie a loop that is big enough to go around the top of the assembled frame. When I tied mine, I used a simple fisherman's knot to create the loop as it enabled me to get the length just right. Cut off any excess cordage from your loop and place your windlass in the centre of the frame and inside the cordage (hopefully my pictures make this point clear as it’s a tricky one to explain in writing!).

You should now be able to use the windlass to twist the cordage and build up the tension that you need to hold the frame together. At first this can be a little bit fiddly, but be careful and once there’s a little bit of tension in place you should be able to pick up the saw without it falling apart.

Keep winding in the tension until things are nice and taught. Be very careful while winding, if you let go of the windlass it will spin around on you as it releases the tension. Don’t say you haven’t been warned!

Stage Five – Testing, adjusting and refining

That’s it, you’ve done it. Top work! All you need to do now is see if it works.

With a bow saw, it’s important to remember that the saw blades are usually quite aggressive. When I use mine I always ensure that I don’t put too much pressure on the blade as it’ll cause the blade to twist and turn. Simply guide the saw through the cut and let the blade do all the hard work.

If you experience any difficulty, then take a moment to see if your frame is square and centred. If not, then you may need to just make some small adjustments to the notches and ensure that the cross-section is seated nice and securely.

If you’re happy with how everything is working then you may wish to play refine the framework a bit more by tidying up the sawn ends or carving in some decoration – that’s entirely up to you.

So there you have it, a nice simple carving project. Hopefully my instructions weren’t too difficult to follow, but feel free to drop me a comment if you have any queries.

As always, thanks for reading. Feel free to comment and/or subscribe to my blog so that you can be notified of future posts.