Weekend PVC Bow Project

[Lycosa]

Over the weekend, I decided to make another PVC bow only this time I took what I learned from making my last bows and improvised a few new ideas and made an even better bow. I tillered this one out and it pulled 59.4 lbs @ 28" draw!!! I can't believe I'm getting that much power from nothing more than a 3/4" peice of PVC. Not only that, but this bow will not break after a weekend of playing around with it. Oddly enough, I'll still be shooting this bow 2 years from now. I would have never believed this was possible.

To give credit where credit is due, I learned how to make this bow from watching BackyardBowyer's videos on youtube. He may not have invented PVC bows, but he damn sure refined it. He even wrote a book on it called 'The Impossible Bow'. I think since he's given enough free info on youtube that I've used, the least I can do is buy his book so that's on the Amazon wishlist now.

Anyhow, for anyone that wants to get into archery or just wants to learn how to make a quick and effective weapon, I really suggest you build one of these. It only takes a couple hours to complete and that's with the paintjob.

Here's some pics:


Bow is made from 3/4" schedule 40 PVC. I made a recurve design with 4" of reflex. I actually should have put more reflex into the bow to get the shape I was going for, but that'll be for my next project.


The handle is wrapped in 550 paracord and has an arrowrest made from PVC that I heated, sanded, and formed. I added felt to the side of the bow for a quieter and smoother arrowflight.


The string is made from polypropylene mason line and the string server is made from the nylon insides of 550 cord. I added felt to the knocks to extend the life of the string and a big peice of felt under the string at the end of the limb to quiet any string slap on the recurve.


All in all, I ended up with a very effective and fun bow for about $2 and a couple hours work. Can't beat that.

[Storm Crow]

I would be very curious to see footage of this firing. Looks like you did a dang good job on this.

[White Bear]

OP, that looks great.
His video's are certainly interesting. I really like the idea of this, but I'll wait and see what the collective ZS archery gods have to say.

[Lycosa]

Thanks guys

I finally got a chance to shoot the bow for an hour or so today.

Judging from past experience it definitely feels like a good 50+ pound bow so my tiller scale (standard 'how fat am I?' scale) must have been fairly accurate.

The bow is pretty damn snappy too... meaning that although I haven't had a chance yet to test it with a chrony, it's appears to be a fast bow. A lot of people think that a bow that has a 50 lb draw will fire arrows the same speed regardless of design, but actually the design plays a pretty good part.

FYI.. just in case some of you don't know, when holding an unstrung bow if the limbs are bent in front of the handle away from the archer the limbs are reflexed. If the limbs bend towards the archer they are deflexed.

I forgot to mention it in my title post, but I did add some deflex in the bow too. I pretty much had to so that I could string it and take some of the pressure off the limbs (I broke one earlier in the day attempting to string it that didn't have any deflex). The reflex was about 4" to the edge of where the recurve starts to the top of the handle in the front of the bow and the deflex brought that back down to 2" in a nice curve. I used a simple jig I made out of plywood to wrap the limb around to make sure the deflex was a nice even arc.

My overall plan was to make the bow look just like an medieval horse bow, or in case you don't know what they look like...

Something like this:



Apparently, I needed to add a bit more reflex to get that shape when strung. Beautiful part about it is, I'll spend another $2 and make another one.

My next project will be to make a PVC bow with wooden Siyahs (the end of the limb where the string nock is).

Again, if you have any interest in archery but thought it was too expensive for a hobby you weren't sure of, this is definitely a cheap and fun way to go. I've had a lot of nice wooden bows through the years and these cheap bows work as well as a lot of the commercially made bows.

Downside of PVC bows? The limbs are flattened and the handle becomes crucial to the overall strength of the bow. The handle is formed and slightly flattened perpendicular to the limbs so that the handle beomes oval. If you were to just put a string on a regular unformed length of PVC it would work, but very quickly the bow would deform to the shape of the bow when drawn... because in a stock unformed length of PVC, all of the stress of the bow when drawn is focused to the handle. In a shaped length of PVC as described above, the handle resists the force and the flattened limbs yield causing this force to be distributed along the length of the limbs. However.. PVC bows (and all bows actually) will begin to conform to the shape of the bow when strung. This is called 'string follow' and all bows have this problem over time. With PVC bows, it's a little more dramatic, but honestly it's not so bad that performance drops drastically or anything. On the other hand, if you were to put a string on an unformed length of PVC, it would get 'string follow' quite quickly and the performance would be gone in no time at all.. that's if one of the limbs didn't yield and bend over completely.

The other problem, well not really a problem but something to consider, is that since the handle is crucial in the overall performance of the bow, you cannot make an arrowrest into the handle to bring the arrow closer to the centerline of the bow. Without getting into too much detail here, since the arrow is farther from center than many modern bows, the bowyer must contend more with the 'archer's paradox'. Simply put, the arrow must flex around the handle and then rebound in order hit the intended target.. so arrow spine weight and distance become a factor and it takes some getting used to (it doesn't take that long to get used to though). Many bows built the same way as a PVC bow have been used throughout history to hunt, wage war, and even just used to target practice with. A lot of traditional archers use bows that must contend with the archer's paradox and find the challenge fun and the eventual skill from having become proficient, more rewarding.

[JesterODX]

Now thats a really nice job. Very cool.

[Dragonblight]

Now THAT's a pvc bow.

Also known as "the $1.50 learning experience"

[Lycosa]

Now THAT's a pvc bow.

Also known as "the $1.50 learning experience"

Very cool. How does it shoot?

Don't worry about it looking all amazing or anything.. the one I posted in this thread certainly wasn't my first. I went through the trouble of making a pretty decent jig for flattening the limbs as BackyardBoyer suggests and that made everything easier. I also grabbed a 3/4" coupler from the hardware store and then sanded the inside out so that it moves smoothly over the 3/4" Pipe. When I measure out my marks to line up the PVC in the jig, I use that coupler so that I can scribe a nice even line around the circumference of the pipe.. it makes lining up everything much easier. I've built 6 of them now and I'm getting better each time I think. Now I'm looking at doing more exotic designs that require a little bit more work, but in the end I think it's worth the effort. Definitely a lot of fun for very little money.

[rednekrampager]

Very fine work y'all. I'm gonna have to try my hand at one of these when i get my shop back together. What arrows were you using in the demo vid?

[Lycosa]

Very fine work y'all. I'm gonna have to try my hand at one of these when i get my shop back together. What arrows were you using in the demo vid?

That demo video is not my own. BackyardBowyer is a guy on youtube who builds these bows and even wrote a book about it. He's the reason I decided to give it a shot after watching his videos. I use 28" fiberglass target arrows and I also make my own. You'll be suprised just how easy it is to make one of these bows and even more suprised at how powerful they are considering it's nothing more than a 3/4" piece of PVC.

[rednekrampager]

I hear ya, I was looking at how deep the arrows were penetrating his target. Good stuff from PVC .

[DarkPhoenix]

Nicely done. My concern with these is how well does the material handle retention? Does it loose any string tension over time?

[Lycosa]

Nicely done. My concern with these is how well does the material handle retention? Does it loose any string tension over time?

They do get some string follow over time. It's not so bad as to really affect the performance of the bow. According to BackyardBowyer, he has some bows that are a couple years old and he still shoots them every day without noticing any real performance issues. They will not hold up as nice as a well made wooden bow, but they also only cost a couple dollars to build and will last quite a long time without failing. These are great for getting into archery on a tight budget or learning how to improvise a quite capable hunting weapon from readily available materials. Not only that, but they are pretty fun to build one and you end up with something that not only looks pretty good, but shoots good too.

[Dragonblight]

Very cool. How does it shoot?

Poorly.

On the other hand,




shoot phenominally. I found backyard boyer's tricks and guide, but didn't use much of it. I used a couple of clamps and a board instead of a jig, and had to do a lot of heat gunning. I used a full 1 inch pipe, too. The thing is crazy. I think i'm getting about 70 pounds of draw on it, but that's just my neighbor's guesstimate.



I couldn't find any strings that I felt safe around, so 100lb safe load steel cable from lowes did the trick.

Parts:
1 Inch PVC $3 (Only used half of it, so $1.50)
100 ft. steel cable $9 (only used 1/10 of it, so $1, give or take)
Cable clamps: $.88 ea (4... so about $3 give or take)

Price: $5.50 and a productive afternoon, plus painting time.

36 x 3/8 dowels for about $1 a pop at the hardware store worked great as arrows with some duct tape fletching and a thick saw cut for a nock. The only problem is that they come warped, so you have to bend them straight before you shoot them, but my limited talents that can't pull 70 lbs for shit can make a 4 inch group at about 15 yards.

edit: derp, fix't pix

edit: OH GOD MY STRING IS FALLING APART

[Sckitzo]

Waiting for

EDIT: OH GOD MY FACE!!!

But I hope not, these are all really cool, might have to consider making one once I get a few more projects out of the way.

[Crow]

Noticing dude in the video has a rod recently installed in his left forearm. I am left wondering if it was because of a homemade bow/arrow failure?

[Ad'lan]

You made a Bow, why not make a bowstring? Trust me, it's definitely better than the steel cable, which is much too thick and is only rate 100lb.

Your bowstring needs to have a breaking point of 6 times the draw weight of the bow, so the string needs to have a breaking point of 300lb. So if a single strand of thread, has a breaking weight of 5lb, we'll need 60 strands of it.

Steel isn't that good at making string. This is the first time I've ever seen it done on a bow, and I'm not surprised it fails.

You should be able to get Dacron quite cheap (under $25 I think) and if that's out of your budget, you can use ordinary cotton, or linen thread (or even a synthetic material, but that dosn't take the wax quite as well).

[Dragonblight]

You made a Bow, why not make a bowstring? Trust me, it's definitely better than the steel cable, which is much too thick and is only rate 100lb.

Your bowstring needs to have a breaking point of 6 times the draw weight of the bow, so the string needs to have a breaking point of 300lb. So if a single strand of thread, has a breaking weight of 5lb, we'll need 60 strands of it.

Steel isn't that good at making string. This is the first time I've ever seen it done on a bow, and I'm not surprised it fails.

You should be able to get Dacron quite cheap (under $25 I think) and if that's out of your budget, you can use ordinary cotton, or linen thread (or even a synthetic material, but that dosn't take the wax quite as well).

I read carefully into the steel cable for a string, and I too read the "6 times the draw weight" part. The 'safe working load' of the cable is 100 lbs. the breaking strength, if I remember right, is 5 times the safe working load. That's a breaking strength of 500 lbs, putting it squarely at about 7x the draw of the bow (assuming the draw is in fact 70 lbs)

I was looking into making my own strings, but not gonna lie, always wanted to try the steel cable. It's just a nut that's coming loose on the cable clamps anywho, the cable it's self is just fine so far, and I expect it to stay that way for years, but only time will tell.

so far the only downside it looks is that the cable really bites into the drawing fingers, but hell, that could just be the 70 lbs.

[Ad'lan]

Look out for steel splinters then, are you using a tab or glove or just barefingering it?

[Dragonblight]

Look out for steel splinters then, are you using a tab or glove or just barefingering it?

Barefinger

[sworbeyegib]

My little quicky I made a few weeks ago. I wish I had a heat gun that worked better, other than that, it was a breeze to make.





Backyardbowyer actually lives here in Hawaii, he and a good friend of mine are in the same SCA group. I may have to drop in on one of their sunday meet ups and pick his brain a bit. I can see this becoming a real addicting hobby.

[northernxposure]

PVC is fun to work with, but be aware of the limitations of the medium - it can and will fail at the most inopportune time. I think it's a great exercise in creativity, and can certainly open a door into becoming a bowyer and working with glass and wood, but these are not long term instruments. Bows have been made from everything from aluminum to plastics, and they always come back to one of two things for the sake of stability and reliability - wood and laminates. The others fail spectacularly in the long run.

Use it to develop a design, then transfer it over to the correct medium. I've had limbs crack/delam and smack me in the noggin before. While it was painful, I'm still here with all my digits and most of my common sense. PVC doesn't crack, it shatters into little, sharp painful pieces.

DB - ditch the steel string. I'd be very surprised if you didn't have severe damage to your limb tips. You can buy a good quality dacron string online for not much more than what you have into that - or just get a spool and roll your own.

Safety first gang.

NXP

[Lycosa]

Waiting for

EDIT: OH GOD MY FACE!!!

But I hope not, these are all really cool, might have to consider making one once I get a few more projects out of the way.

Nah, unless you really overheat the the PVC, breaking isn't an issue. If it fails, it'll bend over at the yield point but is pretty unlikely to break.

[Lycosa]

PVC is fun to work with, but be aware of the limitations of the medium - it can and will fail at the most inopportune time. I think it's a great exercise in creativity, and can certainly open a door into becoming a bowyer and working with glass and wood, but these are not long term instruments. Bows have been made from everything from aluminum to plastics, and they always come back to one of two things for the sake of stability and reliability - wood and laminates. The others fail spectacularly in the long run.

Use it to develop a design, then transfer it over to the correct medium. I've had limbs crack/delam and smack me in the noggin before. While it was painful, I'm still here with all my digits and most of my common sense. PVC doesn't crack, it shatters into little, sharp painful pieces.

DB - ditch the steel string. I'd be very surprised if you didn't have severe damage to your limb tips. You can buy a good quality dacron string online for not much more than what you have into that - or just get a spool and roll your own.

Safety first gang.

NXP

Interesting you should mention that. I've never had that happen at all. Twice now, I've overcooked the PVC with the heatgun and had a limb break on me and it wasn't spectacular at all. In fact, I'd rather take my chances with the PVC than wood. BackyardBowyer has a couple videos where he demonstrates failure because improper construction. More often than not if they are constructed properly, they will bend at the yield point without breaking. If the PVC becomes brittle from being burnt, it'll break, but this is the first time that I have heard or seen someone say it'll shatter. I've shot my bow hundreds of times now and it works as good today as the day I first made it. I don't expect it'll last forever, but for the cost it pays for itself in a couple days. I expect to be using my bows for a long time to come. The idea for the PVC bow is the same as for any wood bow... the limbs need to evenly distribute the forces acting on it in order to function long term. The more accurate the build, the better longevity you can expect. At least that's been my own personal experience so far.

[Lycosa]

PVC is fun to work with, but be aware of the limitations of the medium - it can and will fail at the most inopportune time. I think it's a great exercise in creativity, and can certainly open a door into becoming a bowyer and working with glass and wood, but these are not long term instruments. Bows have been made from everything from aluminum to plastics, and they always come back to one of two things for the sake of stability and reliability - wood and laminates. The others fail spectacularly in the long run.

Use it to develop a design, then transfer it over to the correct medium. I've had limbs crack/delam and smack me in the noggin before. While it was painful, I'm still here with all my digits and most of my common sense. PVC doesn't crack, it shatters into little, sharp painful pieces.

DB - ditch the steel string. I'd be very surprised if you didn't have severe damage to your limb tips. You can buy a good quality dacron string online for not much more than what you have into that - or just get a spool and roll your own.

Safety first gang.

NXP

Interesting you should mention that. I've never had that happen at all. Twice now, I've overcooked the PVC with the heatgun and had a limb break on me and it wasn't spectacular at all. In fact, I'd rather take my chances with the PVC than wood. BackyardBowyer has a couple videos where he demonstrates failure because improper construction. More often than not if they are constructed properly, they will bend at the yield point without breaking. If the PVC becomes brittle from being burnt, it'll break, but this is the first time that I have heard or seen someone say it'll shatter. I've shot my bow hundreds of times now and it works as good today as the day I first made it. I don't expect it'll last forever, but for the cost it pays for itself in a couple days. I expect to be using my bows for a long time to come. The idea for the PVC bow is the same as for any wood bow... the limbs need to evenly distribute the forces acting on it in order to function long term. The more accurate the build, the better longevity you can expect. At least that's been my own personal experience so far.