How To…. Carve a Mortise and Tenon Campfire Crane

Let me introduce you to what I call the Mortise and Tenon Campfire Crane. This is a crane I made up at the the BCUK Bushmoot this Summer.

The idea came about as usual in a discussion around the fire with my good friends Charlie Brookes and Ian Woodham.

As you can see the arm of the crane can be set high or low (and ranges in between) and if set up correctly the upright can be easily rotated to swing your pot away from the fire.

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Mortise and Tenon Crane

I would classify this one as more Pioneering than my usual constructions as it relies on some string to work. It is one for the long term camp however if you were on an overnighter with a couple of hours spare it would make a good project for an evening.

I will be describing the construction of the crane as I go through the post however I thought it would be helpful to have a completed picture of the crane marked up with the relevant work areas for you. Please refer back to this overview at any stage.

Mortise and Tenon Layout

My tools for the job included my knife, a small saw and and axe but you may find having a pen or pencil to hand will be useful.

I took a rod of Sycamore (fairly well seasoned) and sawed it in two. In the picture you can see I have left the thicker end longer than the thinner end. The thicker pole will become the upright and the thinner pole will become the arm.

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The Makings

Carving the Upright

On the thinner end of the thick pole that was to be the upright I marked out the shape of the Tenon tongue and then cut two stop cuts into the side of the pole.

The stop cuts are put in to so that when I batton the waste wood off the split does not run on down the upright.

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Creating the Tenon Tongue – Stop Cuts

I used my knife to batton off the waste wood (make sure your knife blade is at 90 degrees to your body when you do this).

Once I had the Tenon tongue shape split out I carved one side of it into a curve. This is important to allow the arm of the crane to be raised up and down.

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Creating the Tenon tongue – batton and carve

To finish the upright I axed out a point at the bottom and about half way down it I carved a small wedge-shaped recess. This wedge-shaped recess needs to be on the opposite side of the curve to the Tenon tongue.

The recess does not need to be that deep, just enough to allow some string to catch in it.

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Little extras on the upright

Carving the Arm

About a third of the way along from the thicker end of the arm flatten the wood with your knife on opposite sides. This gives you a decent working surface to carve out your Mortise hole.

In the bottom left picture you can see how I used the top of the upright to help me gauge how big to make the Mortise hole. Mark out your Mortise hole with a pen or pencil (mark out both sides of the arm).

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Flattening the arm and marking out the Mortise hole

I used my knife and a piece of waste wood as a batton to cut out the Mortise hole. I took my time here so I would not split the wood along the length of the arm.

Once I got about half way down the depth of the Mortise hole I started on the other side.

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Creating the Mortise hole – First Side

As I use the tip of my knife for this work I always ensure the work piece is secured on a flat surface. I have seen the after effects of a knife going through someone’s hand and it is not a pretty sight I can assure you.

Soon I had my Mortise hole cut through and tidied up. As I did not want to make the Mortise hole too large I tested out the Tenon tongue in it and trimmed the tongue down slightly so that it would fit in the Mortise hole easily.

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Creating the Mortise hole – Second side

The Tenon tongue when fitted should sit slightly proud. You will probably find you will make lots of little adjustments here as you test the action of your crane at this stage.

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Testing the joint

To finish the arm off I carved a groove near the thick end of the arm (for the string to grip), chamfered the thick end to tidy it up and cut out a groove at the thin end of the arm for attaching a pot handle (I will show this in detail in a further picture).

Finishing the arm
Finishing the arm

The Mortise and Tenon Crane

I spent a long time working out a way of making the arm fully adjustable with just the usual items in my rucksack. After discussing this with Ian and Charlie I opted for a simple system with string and a wooden toggle.

Below you can see that the upright and the arm are connected by string and a toggle on the left hand side.

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In Profile

I tied off some doubled-up string to the arm groove and knotted it along its length with some simple overhand knots. This produced lots of little loops the toggle could fit into.

I attached a toggle to the upright groove and inserted the toggle into one of the loops in the string from the arm. Depending on what loop I put the toggle into I could adjust the height of any pot hanging off the other end of the arm.

The groove for the pot handle I made with a backstop and a slightly angled forward section. This shape allows the pot to remain secure when the arm is either raised or lowered.

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In detail

To insert the upright I had a separate pole to act as a pile driver. I hammered this into the ground first and then inserted the upright into the hole I’d created.

The upright can then be rotated quite easily to move your pot off the fire. I found that I could pour water from the kettle while it was still attached to the arm as the handle sat snugly in the angled section of the pot handle groove.

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In use

I like this crane for the challenges it set me and the fact that I could overcome them with just the kit I would normally carry.

I plan to re-visit the string set up as there must be a simpler method to keep the arm securley attached while giving me the ability to adjust its height.

Feel free to suggest an alternative method for this but remember it needs to be created with what you would normally expect to carry in your rucksack or about your person while out in the woods.

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Up and Down

This will be (for the moment at least) the last How To…. on building campfire cranes however I have really enjoyed exploring this very diverse and little documented area of Bushcraft.

Cheers

George

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