Background:
My daughter (due to Hunger Games) wanted to learn archery last year. When winter rolled around, I thought this was the perfect time to practice muscle memory. I also wanted to teach her to make every shot count (so no hopper/mags). After reading for hours and watching some painstakingly detailed YouTube videos, I started off this project with overly complex designs and ended up with something so simple that I am calling this the SS Bow, for Super Simple Bow - however I doubt I am the only person that came up with something like this.
CREDIT: This bow is like my third or fourth iteration. Thanks to Kane for the aabow design, Carbon for the SNAP-7 design, MAV13 for the answers, and bchamp22795 (from YouTube) for the plunger design. I feel like I took parts of all your designs and combined them into one.
Parts list:
Qty Part BOW 1 1/2" x 50" sch 40 PVC 1 1/2" x 15" sch 40 PVC 1 3/4" cross 3 3/4" to 1/2" reducing bushing 1 1 1/4" x 12 sch 40 PVC 1 1/2" TEE 1 6" PEX 1 5' nylon cord/rope 2 3/8" ID washers Scrap 1/2" PVC for stub bushings PLUNGER HEAD 1 1 1/4" rubber washer 1 1 1/2" rubber washer 1 1 1/4" metal washer 1 1/2" end cap 1 Fender washer
Plunger Assembly
1) Place 1 1/4” rubber washer on top of 1 1/2” rubber washer. Place both on to of 1 1/4” metal washer.
2) Place the three on top of the ½” end cap. Add the fender washer. Secure using whatever means you want. You can screw a machine screw from the top down or drill a hole and secure with a small nut bolt.
3) Connect the plunger head into the ½” x 15” PVC pipe.
4) Slide the 1" to 1/2" bushing onto the plunger rod.
5) Connect the ½” TEE onto the end.
6) Add lube to the plunger head. Insert into 1 ¼” PVC. Plunger assembly is now complete.
Cross Assembly
1) Drill out two of the ¾” to ½” bushings so that ½” PVC will slide completely through. These are for the bow arms.
2) Insert the two drilled out bushings into opposite ends of the cross. If your cross has raised letters on the cross arms, than those cross arms are now the sides the bow arms enter. This is where the drilled out bushings need to go into.
3) Insert normal ¾” to ½” bushing into remain open cross arm. This is the side of the barrel.
4) Slide cross onto ½” x 50” PVC pipe. Again, this is the side with the enlarged bushings. Center as best as you can. Trim down bow arms. A tip to get the cross and bushings onto the bow arms is to use scrap PVC pipe that will fit over the bow arms but not the cross, and hammer down. I'll post a pic when I get home.
a. NOTE: I’ve experimented with different bow arm lengths. 30” to 27” gives the bow a weird curve and is very unbalanced. 26" - 24" is better but range is weak. I chopped it down to about 20" and that seems to be the sweet spot.
5) Connect plunger assembly onto a cross arm. Wrap in electrical tape if a little loose.
6) Use a 5/8” spade bit to drill out the ½” x 6” PVC tube. This doesn’t need to be perfect.
7) Lube up your 6” PEX. I was going to use random garage lube but my daughter doesn’t like the smell so she used girly lotion or something that smells like spring time.
8) Hammer 6” PEX into 6”PVC.
9) Insert new barrel into front of the cross.
10) Drill holes into the end of the bow arms. I chose about an inch from the end. Hole is same diameter as my nylon cord.
11) Insert rope and add a washer. Tie it off.
12) Choose where you want the plunger rod to stop. I did this by pushing the rod forward as far as possible, then pulling off about an inch. Mark it off and drill a hole for the rope to go through. This will allow you to dry fire your bow without damage to your plunger head.
13) String though and tie off on the other end with the washer. I experimented with different lengths. Some say that bow arms at 3/4 of the plunger tube is a good measure. I pulled my daughter’s bow to about that length and it is fine. I pulled mine further and do get more range.
14) Check for fitment. I used some machine screws in random parts like the plunger rod TEE as it came off once and my hand smacked my face. Awesome.
This is my bow which has 3/4" arms:
Edited by Aeromech, 23 November 2015 - 03:18 AM.