# Spine Tester I built for about $75



## b0w_bender (Apr 30, 2006)

Nice work!


----------



## aread (Dec 25, 2009)

Very nice! 

Where did you get your fishing weight? I haven't been able to find a 2# weight.

Allen


----------



## GRIMWALD (Sep 28, 2012)

aread said:


> Very nice!
> 
> Where did you get your fishing weight? I haven't been able to find a 2# weight.
> 
> Allen


Here is one place
https://www.amazon.com/Deep-Drop-We...515784404&sr=8-3&keywords=2+lb+fishing+weight

GRIM


----------



## Hot_Rod51 (Jul 4, 2017)

Is the desired weight 880 grams? I've read conflicting ideas on accurate, industry standard test weight. 



Sent from my SAMSUNG-SM-G930A using Tapatalk


----------



## sportbob (Dec 21, 2012)

I got the lead weight from:
http://www.captharry.com/tackle/lead/stick-lead.html

For the weight of the lead, I trusted in this internet quote I found, which converts to about 880 grams:

"According to the modern standards (ASTM F2031-05) an arrow's official spine deflection is measured by hanging a 1.94 lb. weight in the center of a 28" suspended section of the arrow shaft (not to be confused with the old AMO standard of 2 lb. and 26").


----------



## aread (Dec 25, 2009)

Thanks GRIMWALD & sportbob!

Amazon was a little cheaper so I bought from them.

Allen


----------



## Mackpappy (Apr 9, 2017)

I was just thinking of that. Nice job!


----------



## bentstick2 (Jun 19, 2014)

Nice work and helpful after thoughts on improving it


----------



## PaulME (Jun 11, 2014)

Crowned bearings? If you have access to a metal lathe you could make parts to press on the bearings but it’s not worth it. If you tilt the 608 bearings the arrow will ride on the edge giving you the point contact you are looking for (and not changing the effective length as much as a conical bushing would). Tilting the bearings will require a bit of creativity but will be relatively easy even without access to real machine tools.
Paul


----------



## sportbob (Dec 21, 2012)

Thanks Paul. I was referring to the style of bearings used on the Firenock PAPS, but availability and assumed price have kept me using skateboard bearings.


----------



## escorza88 (Oct 14, 2012)

Well Done! Thanks for sharing your project with us. :set1_applaud:


----------



## sportbob (Dec 21, 2012)

*Version 2 spine tester completed!*

Hi All, I just finished up the version 2 spine tester with some of the improvements I mentioned could be made in my first post. I used square angle aluminum instead of the radius type so that I could push the bearing mount against the back wall while screwing in the thumb screws and be all squared up. This helps keep the arrow in place while spinning so that it doesn't walk left/right, which becomes annoying. This "walking" happens when the bearings are not square from one side of the tester to the other. I found the thumb screws on eBay for $9, used Rustoleum universal satin black paint and JB Weld for the leg components this time to avoid all the nuts and bolts, much cleaner look and still really stable. To eliminate some more nuts and keep the clean look going I made the indicator bracket from the angle aluminum and tapped that as well as the main piece of angle aluminum for the 1/4x20 bolts and cut the thread even with the back end. I also drilled/tapped the main angle aluminum for 4 arrow lengths 28, 27, 26 & 25.25 and you can swap between these lengths with the singe thumb screw on each bearing mount. The thumb screw wasn't enough to keep the indicator really stable on top so I used a socket head allen screw to get some extra torque at the head, but it is mounted with thumb screws so it can be easily removed and clamped elsewhere to check front/back of arrows or components. I used all basic tools; dremel with round metal blade, saw zall and hand hacksaw, a course and fine metal file, drill, tap and sand paper.


----------



## sportbob (Dec 21, 2012)




----------



## trial153 (Nov 27, 2011)

nice job.


----------



## Two Flints (Nov 3, 2006)

*My Arrow Spine Tester*

Hi Bob,

Sent you an Email. Here is my latest attempt at a Spine Tester - all wood, but works OK. Tested it against 2 dozen cedar shafts that have just the nocks and points installed. These cedar shafts had their spine reading marked by the arrow maker. My readings have been pretty close.





FredSG/Two Flints


----------



## bear bows (Oct 26, 2012)

cool think gonna build one myself 


Sent from my iPhone using Tapatalk Pro


----------



## cwegga (Apr 10, 2018)

Nice! Thanks for sharing.


----------



## killerloop (Mar 16, 2008)

What digital gage is that

Sent from my SM-N920V using Tapatalk


----------



## sportbob (Dec 21, 2012)

Mine is a Pittsburgh digital gauge from Harbor Freight. Fred's looks similar but had the name clockwise on it. I just finished up a new weight too and attached a couple pics. Brass was $20 on eBay and used left over angle aluminum for the rest. Glued with JB Weld.


----------



## EC9 (May 9, 2018)

Awesome!


----------



## bear bows (Oct 26, 2012)

cool


Sent from my iPhone using Tapatalk Pro


----------



## Rpri5684 (Jun 1, 2018)

Nice!

Sent from my SM-G920V using Tapatalk


----------



## Tinkertrain (Jul 2, 2018)

Very nice! I'm going to have to try building one now.


----------



## FoggDogg (Jul 9, 2002)

Nice!


----------



## Thumbs (Sep 8, 2013)

Clean and simple 
nice work


----------



## Audible (Feb 9, 2018)

Nice job!


----------



## 2wheelercustoms (Sep 27, 2009)

Hi guys! I have a question: when building the weight that hangs from the arrow are you weighing the weight, bearings and hanger all together to get 2lbs then assembling it all together? Just wondering what your approach is to building this part of it. Thanks in advance!


Sent from my iPhone using Tapatalk


----------



## mcmac (Jun 24, 2012)

Nice! Thanks for sharing!


----------



## Big Pard (Jul 23, 2018)

Good design


----------



## pborowick (Jul 14, 2009)

Looks like I have a new project on my list!


----------



## yvedel65 (May 10, 2019)

Nice work!


----------



## spear0 (May 10, 2018)

nice


----------



## bowpress (Jan 7, 2016)

Looks pretty good, good job


----------

