PVC Youth Bow Build along

[Cuban Missile]

Ok first things first!  We are going to be making a PVC Horse Bow.  The bow that I will be making will be a youth bow so we will need...

4' long 1x4  

3/4" scrap blocks

43" long 3/4" SCH 40 (stands for schedule it will say it on the pipe) pvc tubing.

(2)  3/4" thick  x 9" long x 1 1/4" wide blocks of hard wood for Siyahs

Gloves, towel or oven mitt (to protect your hands against the heat)

Heat gun or stove top for heating up the pipe.


Tapering Jig:
(1) 4 foot long 1x4
    (You wan it to be 1x4 not 2x4 so you can easily flex the board with your weight to taper more mid to outer limb)
(2) 3/4" blocks of wood to glue to the ends of your 1x4

It will look like this at the end with the 2 blocks glued to it.

 

After you have made your jig you will need

(1) 43" long 3/4" diameter SCH (schedule) 40.  It can be longer or shorter to adjust the weight of the bow but I am using 43" long in this build along.

Here is another picture of the jig and the PVC pipe

 

Now you need to layout the PVC.  

#1 Mark the center of the bow.  
#2 Mark two inches on both sides the the center line for you handle.
#3 Now Mark 2 inches in from the tips

It will look something like this...

 

Ok now that ever thing is laid out we need to heat up one of the limbs and have our jig ready to place on top of the soon to be bow.

Put your gloves on and heat up the limb evenly rolling it on a flat surface.  If you are using a stove top you will have to spin the pipe while moving it back and forth over the heat source.  Once it starts heating up it will start to turn limp like a wet noodle.  Try to keep control of it (this is why I roll it on the floor) so that it can be as straight as possible.  You should be able to squeeze the pipe together down the full length of the heated limb.  (with gloves on)

Like so...

 

Now its time to act quick! Line the limb up under jig and smash

 

 

Make sure to put more pressure from the mid limb out like I am doing below.  Now stay put for a couple of minuets.  I like to take my gloves off now and feel under the jig to feel the temperature of the pipe so I can tell when it has cooled enough to hold its shape, but not too cool so that I can not adjust it.

 

Now I sight down the limb and do a line up check, and adjust accordingly.  This is looking good.  
 

Now time to move to the other limb!

[Cuban Missile]

Ok once the first limb has cooled down you can heat up the other limb.   Remember to keep the heat even so you don't burn or blister the pipe.  

Now that the second limb has been heated up hold the first limb flat against the ground and set the jig on the hot limb. ( MAKE SURE TO KEEP THE FIRST LIMB FLAT!!! If you don't the limbs will be twisted and we all know thats no good!)  

 

Now let the bow cool down and sight down it and adjust the limb if necessary.  (keep them lined up!)

Once all is lined up let it cool completely.  It will be about 5 minuets.  

Now heat handle area over lapping your lines and going into the limbs by about 1”

 


Once the handle is pliable squeeze it together to form the handle area while adding around 2"-4" of reflex  2" seem to be the "optimum" amount of reflex.  Any more and you end up taking excessive set.
 
 

 

 

 

Check your tiller if you want but make sure you hold the limbs tight to keep the bow from wanting to roll on you.

 

More to come...

[troutremble]

Ok, done. Waiting on next step

[bjansen]

Very impressed so far.  I have a feeling alot of these are going to be built.

[Trux Turning]

Very cool!! Might have to try one myself- the kids next door would be happy with a couple of those.

[troutremble]

And thanks, these are really cool.I have several nephews who are gonna be pretty happy.

[KellyG]

looking good.

[red hill]

Thanks, Javier. This is great. I've got a couple of neighborhood kids and some scrap pvc.  

[4est trekker]

      Looking forward to the rest!

[troutremble]

[Tron]

Very cool.  I'll definitely be watching this one.  I have a neighbor who is just learning the sport in gym class (sadly using bows with training wheels).  His dad is still a little uncomfortable with how fast a glass bow shoots. But I think he will enjoy this    

[Cuban Missile]

Ok here is that hardwood Block that I was talking about earlier.  We are going to turn this into you Siyah's.  First you need to mark it all out.  Mine are 9 inches total in length.  This will leave 7 inches outside the bow and two inside the PVC.  

#1   To mark it all out divide the whole block in half and put a mark down the center of the block.  In this case 4 1/2 inches.  Then divide that in half (2 1/4) and make a mark on both sides of the center line.  It should now look like the bottom block.  

#2   Now we want to measure 3/4" from top or bottom (in my case I measured from the bottom up) on the ends of the block.
(If you were to use a 1" diameter pipe then you would need to make this 1 inch to fit inside)

#3  Measure 1/2" up on the middle line and mark.

#4  Measure 1/4" up on the two lines located on to either side of the center line.

#5  Now Measure and mark 3/4" above the last three marks.

#6  Conect the marks and and it should look like the top block.

You will need two of these one for each end of the bow.  


 

Make sure it is 3/4” down the length of the arch with will become your Siyah.
 

Now go cut out the arch and sand it so that it is smooth and looks kinda like the bottom of a rocking chair.  You are also going to want to cut the bottom at a 45 degree angle.  It is important that you taper the Siyah slightly so that the bottom is wider than the top.  Especially with the lower 2".  This taper will hold the Siyah into the PVC which you will see further down.

It should look like this.  You can finish the nocks when cutting out and tapering.  I like to drill a hole near the edge of the siyah and cut into the top and bottom 1/4 or the hole so that there is a lip for the string to rest in.  Make sure you round the edges of the wholes and sand the whole thing down smooth.  You can finish it later but its easier when all you have to deal with is a 9" piece of wood.

 

Ok moving right along we are going to heat the last 2-3 inches of the PVC making sure to turn and move the PVC over your eat source.  BE CAREFUL NOT TO BURN THE EDGES!  

Do as I say and not as I do and put your gloves on!

 

Do as I say and not as I do and put your gloves on!

Now that it is heated up it will try to turn back into a tube its ok don't worry just have your siyah ready to slide in.

 

I like to mark the Siyah 2” from the bottom so that I know when to stop sliding the siyah in.  Make sure to slide it in so that the 45 is sitting flat if you have it pressed on the floor.  You also need to be careful not to bend the tip to the side.  (Note! It is not easy to pull the siyah back out of the PVC even when heated. If you need to (because of alignment issues) make sure it is HOT so it can come out easily or else you will stretch the pipe when pulling intern weakening the area.)


 

Ok now that it has slid in and we need to hold the end tight to keep the end of the pvc tight around the wood siyah.  Pay special attention to the very end of the PVC.  Keep it as tight to the wood as possible and hold it there for a minuet or two so that it keeps its form.  

 

Now quickly check to ake sure the tip is straight and not twisting or bending side to side.

 

[Cuban Missile]

Also make sure that you keep your 45° angle!

 

Repeat on the other side and sight down the bow to make sure the limb tips line up nice and strait over the center of the handle.    Also remember to do all your adjusting as soon as your PVC cools enough to keep its intended shape but is still hot enough to tweak.  

Always be patient and let it cool down before you go on to the next step.  Don't go bending it all out of whack because you just want to see its tiller.  This is PVC and requires little patience but being able to whip up a bow this fast will make you want to throw even the little patience needed away.

You should now have a Bow that just needs a little finishing.  

 

Stay tuned...

Next I'll show you how to string it up and check the string alignment.  It might have looked straight but this is the true test to find out to see what adjustments we need to make.

[vanillabear?]

[wood carver 2]

Really cool! I think I might have some pvc in the shed.  :D  
Dave.

[mwosborn]

I am impressed!  Thanks!  Going to have to add this to the list of things to try.    

[troutremble]

I'm on my way home from work to make the siyahs now. Cuban,  I'm guessing the same process could be used on 1" or 1/2" (changing the size of the blocks on jig and making siyahs to fit of course) to get different weight bows? Or do you just change length to adjust poundage?

[Cuban Missile]

Your right about changing blocks and siyahs to match the diameter.  To raise weight you can move up to 3/4" or 1" AND shorten the PVC core of the bow. There are other ways to bring up the weight, like when tapering you can use a stiffer board for tapering like a 2x4 and add a shim on the back end to give it more of a slight taper.  You can also add more reflex and deflex.  The Siyahs don't add any extra weight it just makes it fast. If you use a dense wood like ipe for the tips you can make them pretty thin at the tips.

[Cuban Missile]

Ok here it is strung up.  I had a little tweaking to do to get the tips to line up.   This came out to 20 # @ 23" with is about where I needed to be.

 

I have a positive tiller so it turned out perfect.  

 

I am pleased at how this turned out so I am not going to add any deflex.  If you wanted to you would just have to heat and bend the deflex in.  It is easy to do if you have a 5 gallon bucket or a pot something with a nice rounded edge that you can flatten the area that you determine you want deflex in.  We aren't done yet but it is shootable I put some arrows through it.  It will creek the first couple of pulls but after you shoot it a few times it won't creek anymore.  

more to come...

[b.glass]

I watched the Backyardbowyer video on the recurved youth bow and tried it, twice. Both bows folded about an inch below the handle during stringing. What did I do wrong?

Bona