Help calibrating spine tester needed....

[Steve B.]

I have a new spine tester but after some use I know it is measuring spine too weak.

I was hoping to compare some readings on aluminum shafts with what some of you get with the same shafts and then I put a new scale on this thing.

I have 2018, 2020, 2117, and probably some others.  If I can get several people to feedback I will compare those readings and adjust accordingly.

Thanks,
steve

[ryan brodrick]

all of the spine deflection values for aluminums are listed on the eastonarchery page. click on ALLOY and then on MORE INFO and you will see the exact values.

make sure your centers are the same. ie are you using 26 or 28" span?

[moebow]

Steve,  You don't say which spine tester you have, but if it's the "old" standard  of 2# weight on 26" supports  then my 2018s deflect .375" for a spine weight of 69.3#s.  2117s are .300 deflection for 86.7#s.


Why do you think the tester is measuring too weak??  The easy way to tell using the 26"/2# standard is to divide the deflection into 26 to get the spine pound rating AT 28" NOTE 28"!!!

Most of the commercial spine charts recommend way too stiff of a spine.

[Bjorn]

A couple of steel nuts or washers hung on the rod coming out of the weight(assuming that is the type you have)will help you calibrate once you have the readings you want if your readings are weak.

[Steve B.]

I have a Don Adams tester and the span measures 26 1/4".
My 2018's, both Legacy and xx75 measure very close to 60 lbs.+.
My 2117's, both types, are 70 lbs.

I'm using the weight that came with the tester but have not verified it's weight.

I think it spines weak because I have arrows from others who have spine testers and my tester shows 5 lbs. weaker.  I have some hickory and ash arrows that I bought in the 60-70 lbs. range last year and almost all measure in the 50's.
I recently bought some new shafts and once again they showed weaker than advertised.

But thanks for the replies.  sb