home made crossbow

Considering, or completed a DIY prepper project? Made something using traditional methods? Post it here!
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piglet
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Re: home made crossbow

Post by piglet »

gcp1975 wrote:what about cutting a slice out of another piece and slide it down inside the outer this should make the wall thicker ??? any ideas
Yes I thought that would be a possible idea. I have various types of pipes and some are a very close fit inside others.
I thought you might be able to coat the inner pipe with heat gun glue...let it harden and then slide it into the larger pipe.
Then when the outer pipe is reheated it may bond with the inner pipe?

I was not actually making a bow but I have lots of pvc pipes, and stronger pipes would be useful, so might give the x2 pipe glue idea a try, simply to see if it works.

piglet
ain't settlin'
gcp1975

Re: home made crossbow

Post by gcp1975 »

thought i was onto a winner this morning when i saw some pvc pipe sticking up out of a skip !!!! on closer inspection it was about 12" long with a solvent weld 90 degree bend attatched but the pipe had a wall thickness of about 3mm i asked the guy if he had any more offcuts of said pipe but he said that was what he had ripped out !! bugger
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piglet
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Re: home made crossbow

Post by piglet »

Hello gcp1975

Ok, this wasn’t meant to be, but has turned out to be a bit long..... And it is still a work in progress.

But, I was using some PVC pipe for a small project and thought about your project and the last thing said.

I said.........
I was not actually making a bow but I have lots of pvc pipes, and stronger pipes would be useful, so might give the x2 pipe glue idea a try, simply to see if it works.

piglet
But I thought, why not have a go at making a bow and perhaps help you solve your own problem?

Anyway, I decided on a 4 and half foot length, (purely ‘cos that’s the length it was and I didn’t have any other use for it) of 25 mm outside diameter with a 21mm inner diameter pipe.

Then, after a few experiments with various smaller pipes, (which didn’t end well), I plumped on a piece slightly longer with a 20mm outer diameter and 18 mm inner diameter. This gave me enough space, to add the glue between. Pipes too close in size, and the glue stripped when inserting the smaller into the larger.

So, I first coated the thinner of the 2 pipes with heat gun glue, by holding the glue stick over a paint stripper/heat gun and rubbed it onto the pipe as if it was a crayon. (Took 2 glue sticks)
Then I left it outside to cool off.

The glue had gone on very unevenly and had lots of bumps, so I used the heat gun again to heat a pallet knife and used that to iron the glue smooth, first length ways and then around, by simply twisting the pipe in my fingers.
(I did this as the glue made it a tight fit and so I thought, screwing the inner into the outer would probably be the best way and this might help, if that makes sense?)
In my earlier experiment/test, I tried using the heat gun direct to the glue on the pipe but the pipe had a lower softening point than the glue and distorted)

Now, as I said earlier, the inner pipe was slightly longer than the outer and I made it this way in case the pipe started to get stuck whilst screwing it in....which it did at around three quarters of the way in. (Excess to be trimmed off later)
I used cold water to act as lubricant and it helped a lot.

Anyway, I had to tap the last quarter of the pipe through gently, which worked fine without stripping any of the glue.

So now I have a pipe with an outer diameter of 25mm and an inner diameter of 18mm, so if my maths is good a wall thickness of 3.5 mm. Now I don’t remember if this is the same as schedule 40, but it does seem strong and I could not get more than about a 6 inch bend, from centre, at each end.
I guess that will change once flattened?

I don't know if any of this is any help to you, but it really wasn't that difficult, as it only took about 2 hours and that was whilst I was doing other little jobs at the same time.
All you need is to find pipe suitable for your needs.

So now all I need to do is make some kind of flattening jig and hopefully the 2 pipes will bond during this process.

Then, I will need to learn how to measure and make a bow string and find an arrow or three, from somewhere and see if it actually works.

And yes, I have realised that I don’t actually have a target capable of stopping and trapping an arrow affectively, when I do eventually test it, but I am already working on that. (watch this space)

piglet
ain't settlin'
gcp1975

Re: home made crossbow

Post by gcp1975 »

Wow Piglet thanks for the how to !! will try and look for some pipes that will fit inside each other !!
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piglet
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Re: home made crossbow

Post by piglet »

inner + outer pipes
inner + outer pipes
pipe 002Ra.jpg (70.51 KiB) Viewed 3045 times
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piglet
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Re: home made crossbow

Post by piglet »

I finally got around to completing the bow using the double skinned pipe.
The double skin, being my attempt to make something of similar standard/specifications to the American schedule 40 pipe as used by the Backyard Bower in his videos, as mentioned somewhere earlier in this post.

I followed the method as used by the Backyard Bower to make a simple Re-curve bow, including his plan for the flattening jig and a saucepan for the Re-curves on the ends.
I had to do a couple of minor tweaks as I went along but it really wasn’t that hard.

I found a couple of wooden arrows in a boot sale for pennies.
I didn’t bother to make a fancy string, just used Polypropylene, as I wasn’t quite sure if it would fold in half the moment I tried to pull it.
But no, it worked just fine.
I only tested it over 10metres and it shot pretty straight, obviously at that short range slightly high.
Penetrating about 6" into a 18"high density Styrofoam target.

I know very little about archery but have shot a few bows over the years and would suggest it is not pulling a lot more than around 30lbs tops. So probably ok as a practice bow or youth bow.

But back to the original posters question of whether this method would be useful for making a crossbow prod? ........ Well, probably not, or at least, not without further experimentation to strengthen. And to be honest, although not exactly keeping to the spirit of the DIY project, Crossbow prods can be found pretty cheaply online.

When I get my camera out again, I will try to remember to take a photo to upload, for any that might be interested. Other than that, I think I am done with this experiment/project.
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greyman
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Re: home made crossbow

Post by greyman »

Liking the pvc pipe bow vid.Think this is my new project for the winter.Seems a lot better than the privet hedge bows we used as kids :D
I have got an old slazenger wooden bow in the loft i found once while walking the dog.
strive2survive

Re: home made crossbow

Post by strive2survive »

Great job , how much do you have into this because I bought a 175 lbs crossbow for £100 , wouldn't it be more cost effective if you make one , btw I'm not putting it down because your results are excellent . Thanks
Stasher
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Re: home made crossbow

Post by Stasher »

@ strive2survive

Sometimes it's not about how easy it is to buy, sometimes it's about the journey and the satisfaction of achieving a goal.

I'm really impressed by the dedication and determination here. Fantastic
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junmist
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Re: home made crossbow

Post by junmist »

Have enjoyed this thread and thanks for the info on the back yard bowman spent a couple of hours watching him.
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