Thursday, 14 November 2013

How to make toy crossbows ...

We've recently been looking at medieval weaponry, and siege warfare, and as a result of that we ended up making a trebuchet and an onager, both of which were used a lot for laying siege to castles and such like many years ago, weapons like these were the most advanced war machines around, on a recent trip to one of museums we were looking at armour, swords and other hand held weapons.

I decided it would be good for the kids to have a crossbow each (non lethal crossbow) this would show them how hand held weapons have changed over the years, and give them an idea of what soldiers would have had in the way of weaponry and what it might be like to use such a weapon.


Here's what we ended up with -


Not historically correct, but fun to play with.

As you can see they are very much toys, but they do show what it might have been like to load,aim and fire a weapon like a crossbow, I've included a video of my daughter using her crossbow in the garden, and I've also worked out how much it cost to make both crossbows, the cost for both of them comes in at a cheap £4.27 (that's for both crossbows) not bad, it will work out cheaper if you already have some spare bits of wood lying about.


Here's everything you'll need to make your own crossbow - 


Doesn't much look like it'll make a crossbow, but it does.

Ingredients list (for 1 bow) - 

  • 2 bits of batten, one at about 40cm and one at about 35cm in length.
  • 1 length of 9mm dowel & 1 length of 6mm dowel.
  • 2 old corks
  • 1 meter of elastic
  • 1 screw (about an inch or inch and a half will do)
  • 1 scrap piece of wood for a trigger.
  • A wooden skewer.
  • A wooden tooth pick.

The basic design is a cross shape, I've used batten for both bows, which can be bought in a pack of 8 x 1.8 meter lengths for £8.42 (from B&Q) I've been using this batten for a while to make things like this, it's cheap and quite versatile, I only used 1 length to make both bows, so if you get a pack you'll have some left over, or you could just buy a single length, which comes in at about £1.56 or there about.

Okay, first thing I did was to get the trigger set up, to do this you'll need to make a slot in the longer piece of batten, first measure in around 8cm from one end of the longer piece of batten and make a line, then measure about 6cm from the first line and make another line, now find the centre of the piece of wood and mark a line between the 2 marks you've already made.


Like this - 

Ready for drilling.

If you've ever made a mortise and tenon joint you'll find this easy, but it's not that hard any way, the next thing to do is drill some holes along the centre line, this makes it easier to slot for the trigger.


Holes drilled - 


Just needs tidying up.

I used my needle rasps (small rasp files) to tidy everything up, and once that was done I used a bit of sand paper to smooth it all.


Trigger slot done - 


Not perfect, but it'll do.

Next you want to mark down the sides of the longer piece of batten, you need to cut a notch out of the wood, this is where the elastic will sit when the bow is loaded.

Lines marked down the side, and notch marked out - 


I used a coping saw to cut it out.

Notch cut out - 


Some adjustment might be needed.


The next thing I did was to make a groove all the way down the longer piece of batten, this acts as a guide for the bolt, and makes it easier for the kids to use, to make the groove I marked a line down the centre and using a small sanding drum in my multi tool I sanded the groove out.


Groove line marked - 


I wasn't too precise.

Here's the sanding drum - 


These come in handy for all sorts of jobs.

Groove done - 


How easy was that ?

If you don't have a multi tool you can always use files and sand paper, it'll just take longer.

Back to the trigger, I cut out a rough shape from my scrap bit of wood (an old bit of tongue and groove) using my coping saw, then I gave it a sand to smooth it off a bit.

Basic trigger shape - 


I drew the shape free hand.

Cut out - 


It's about 8cm in length.

Next I tried it for fit, you want the trigger to be all the way forward, but just below the notch you made, the idea here is that when you pull the trigger it moves up and pushes the elastic out of the notch.


Trigger pin marked - 


Once drilled the 6mm dowel will work as a pivot.

Hole drilled, you can see the trigger is below the notch when fully forward - 


Just drill all the way through, this way the holes will line up.


Trigger pin sorted, just needs tweaking - 


Trigger done, just needs tidying up.

The next thing I did was to make a notch in the end of the batten opposite to the trigger, this is where the shorter piece of batten will sit, to mark out the notch I just set one piece of batten on top of the other and marked it out with a pencil.


Marking the notch - 


I had already marked the notch out.


Once you've cut the notch out of one piece, slide the other into it and mark out another notch, make sure that there's an equal amount of wood on either side of the notch, once you've cut out both notches you can slide the 2 parts together to check the fit, but don't fix it together yet.


Checking the fit - 


Looks good to me.

Once I was happy with the fit I marked out where I was going to drill a pilot hole for the screw that will hold the crossbow together.


Fixing hole marked - 


Just needs drilling.

Pilot hole and counter sink done - 


I used a bit of glue as well as the screw.

Next it was a case of making things look a little nicer, which basically meant rounding ends of, and giving the trigger a nice shape, I also had to drill out the holes to hold the bolts when the bows isn't in use, and the holes that hold the pegs that control how tight the elastic is.


Trigger shape done - 


I just cut out a half circle.

To round the ends off I drew round a plastic pot, and I used a protractor to mark out the curve for the cross piece.


Rounding ends off -

Anything round will do.
Nice curve.












Making the bow curve - 


Ready to cut out.

To make the bow curve I measured in from each end of the cross piece, then using a protractor I marked out a curve, then I cut it out roughly and smoothed it out using my lathe sander.

I also marked and drilled the holes for the adjuster pegs and the bolt holders, I marked the adjuster peg holes out by measuring down from the line I used to mark out the curve, and then I measured across about 1.5cm.


Adjuster peg holes marked - 


Easy peasy.

Once it was all cut out and sanded the next thing to do was to put it together, and then sort out the peg that holds the trigger in place and the 2 adjuster pegs, this is just a case of cutting a bit of dowel (I used the 6mm dowel) to the right length and then drilling a small hole all the way through it on both sides, then using a bit of skewer pushed into the holes on either side to stop the peg coming out.


Trigger peg sorted - 


This method works well, and looks good.

There's something about using pegs in this way that kind of makes things look older, and generally more aesthetically pleasing.

To make the adjuster pegs it's basically the same method I used for the trigger, but instead of using bits of skewer I used bits of toothpick and only in one end of each peg because the elastic needs to go through the other end of each peg.


Pegs made - 


Pegs done.
Holes drilled.












Next I threaded the elastic through the pegs - 


Loop in one peg.
Knot in the other peg.















I also made a small groove for each adjuster peg to sit in, this will stop them twisting and the elastic unwinding, the basic idea is that by twisting the pegs the elastic twists and gets tighter, this means you can adjust the amount of power in the bow string, the elastic I got for 40p from our local market (20p per metre)


Adjusting the elastic - 


Simple but effective.

Lastly the bolts, these are just lengths of 9mm dowel (about 24cm in length) with a cork stuck on the end, we have plenty of corks about the house because of our wine making exploits, to make the bolts just drill a hole in the end of the cork, make it slightly smaller than the dowel, then put some glue in the hole you drilled in the cork and then stick the dowel in, and that's it, you could also add fletchings (flights) to the bolts for greater range.


The bolts - 


Doesn't get much easier really.


Here's the video of my daughter firing her crossbow - 





Thanks for reading.


3 comments:

  1. Great work, thanks for the info. I'm using this simple trigger style on a larger "adult" crossbow.

    ReplyDelete
    Replies
    1. Thanks for reading, I have been working on a more complex trigger system for a hand held balista type weapon, although wood probably isn't the best material so I'm thinking of making it out of metal.

      Delete
    2. I've been experimenting with the various ways to make triggers. I'm not trying for historical accuracy, just getting the job done. You can see a couple of them on my blog http://palletprojects.blogspot.com/. Notice the thumb trigger made from a spoon on the larger PVC bow. Looks odd but works. I'd also like to make a traditional metal nut mechanism but it's tedious work.

      Delete

Allotment update (part 2)

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