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Main Boards => PowWow => Topic started by: elkshooter on November 29, 2008, 11:47:00 PM

Title: Help building 2Jays spine tester
Post by: elkshooter on November 29, 2008, 11:47:00 PM
Hey all,

I'm working on building a spine tester from plans from 2Jays link here:  http://www.bambooarrow.com/tester.html

I have printed the dial and glued it onto a backing board.  Now I'm ready to follow the directions below, but I'm not following them.

2. Drill two holes opposite one another around the rim. Be sure they are the right size to epoxy your spokes into. Install the spokes into these holes. Don't trim them yet. Be sure not to plug up the axle-hole.
3. Bolt the needle-hub through the hole in "Line A". Make a 90?bend outwards in the short spoke at the other end of "Line A". Be as accurate as possible. THIS LENGTH IS MOST IMPORTANT MEASUREMENT ON THE WHOLE DERN THING!!
3. Remove the hub and put a washer on the machine screw, install the hub to it, another washer, and a self locking nut. Tighten the nut so that the hub spins freely but has a minimum of side-play.
4, Put the axle through the hole in the dial and mark where you want to cut the indicator end of the needle. Cut and shape it to a rounded point.
5. Now locate and make the bend on the other end od the needle assembly. Measure "Line A" on the dial. Whether you enlarged the dial or not, this line establishes the correct ratio. It is important that the length of this line "A" is the distance from the center of the axle-hole to the bend.
6. Then install another washer, the dial, another washer and another self locking nut. Here again, tighten the nut so that the dial spins freely but has a minimum of side-play.

My question is has anyone built this tester that has some pics, I'm thinking that a picture or 2 would help me greatly with this.

Thx.

Elkshooter
Title: Re: Help building 2Jays spine tester
Post by: Hot Hap on November 30, 2008, 05:00:00 PM
My head hurts. Hap
Title: Re: Help building 2Jays spine tester
Post by: ishiwannabe on November 30, 2008, 08:58:00 PM
You are basically needing to drill a straight hole through the hub. Then attach your "needles" One will stay straight, and one will be bent 90 degrees. It will make an "L" on the hub. One needle will point to your diagram, the other will be under the arrow to measure it's flex, thus the importance of making a 90 degree bend, in the right spot. I hope this helps. I know when I made one it hurt my head. Good luck.
Title: Re: Help building 2Jays spine tester
Post by: always89 on November 30, 2008, 09:19:00 PM
Heres Mine

 (http://i30.photobucket.com/albums/c338/tradebow89/DSC03100.jpg)
Title: Re: Help building 2Jays spine tester
Post by: always89 on November 30, 2008, 09:27:00 PM
I sent you an email with some close-up shots of the dial. Hope they help!
Title: Re: Help building 2Jays spine tester
Post by: ChuckC on November 30, 2008, 09:35:00 PM
The ratio between the distance between the hub and the 90 and between the hub and the point of contact with the chart will make or break that chart.

The amount the arrow flexes is not much.  You probably cannot read and make sense of the differences. You need to extend the pointer and broaden the scale.  Heck, if you make the pointer 10 feet long, it will make  huge scale that is much more accurate, or at least more visually different between degrees deflection or computed spine weights.

The concern here is to make the included scale match the equipment you created.

At least... I think so...

ChuckC
Title: Re: Help building 2Jays spine tester
Post by: adeeden on November 30, 2008, 10:05:00 PM
ok I have to ask, always89 just how big is that hershey's bar in the background!
Title: Re: Help building 2Jays spine tester
Post by: always89 on December 01, 2008, 09:28:00 AM
Adeeden,
This, like all of my archery stuff, ended up in my sons room! That is one of the 10 lbs bars! Took a group of about 10 boys well over 4 months to down that bad boy!