spine testers

[cedarshaft]

I tried the search process for posts on building a spine checker and found nothing. I know I have seen posts before, so can anyone out there point me to the articles? I shot four old woods at Denton Hill last week, and fell in love with them again. Bought 2 dz. shafts and will build them this week; but I have a box of 2-3 dz shafts that were given to me and don't know the spine weight.

[xtrema312]

[Marvin M.]

There used to be an article/link over on the how-to forum.  Otherwise, do an internet search and you should find something.

The simplest I've seen was just a way to hang them and adjust to level, then hang a known weight on the end and have the acceptable range for a good arrow marked.  If they fall in that range, they work.

[rraming]

Give them to me and I'll check them and then use them

[Ray_G]

Use Google or another search engine and look for James Hill spine tester.  I think it is the easiest to build and am finishing one now.  The other common tester is 2Jays or something like that.  You may like that one, also.  There are some posts on here.  Just search for tester without the word spine.  Spine will return gobs of posts.  Some of the guys have used mods of the two listed above and it caused me to innovate mine to my liking and materials on hand.

[xtrema312]

2Jays reads like it would be the way to go.  I wish it had some photo's to get the idea.

The problem I have with the James Hill tester is that my dial indicator has a spring.  In testing I did with it, I find it gains spring load as it is depressed.  I put the indicator on the top of a shaft.  I pushed the indicator down on the arrow enough to get it depressed to about what a 400 spine shaft should read.  This caused the shaft to flex some amount in reaction to the indicator spring pressure.  The shaft gets stiffer the more it is flexed.  I wonder how much this affects the readout accuracy.

[Ray_G]

X,

Owning and having used a bunch of dial indicators, not all things are the same across brands.  The indicator that I am using with the James Hill style spine tester has a very light return spring and the indicator shaft moves very, very easily with feather light finger touch.  It should not affect the spine reading when I use it.  It has a 1" travel - not one of the little test indicators.

For stiffer sprung indicator shafts that I used in machining, a little pre-load is required for accurate reading.  One would have to leave it high (using it underneath the shaft), set the shaft on it and lower the weight to to touch the shaft and get a starting point reading and then subtract that start from the ending reading.  A pain and prone to error.  Best to find an indicator with a light return spring.

Here are a couple of links of photos and info on the 2Jays.  There are probably more in the search function here.

 http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=079420#000000

 http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=067504#000000

[xtrema312]

Thanks for the links.  I got some pic's from 2jays also.  I think I will try a version on my wall with rollers.  I have my weight.

I may go out and check out some dial indicators.  Mine is from Harbor Freight, and I used of for working on motorcycles to set timing.  A lighter touch one would make a big difference, but then I am trying to do this on the cheap so don't want to spend a lot on one.

[AkDan]

I have one from Agincourt archery and really love it.  I've tested it against shafts from a few companys and am pleased with the tester.....and sorely dissappointed with some of the shafts I've received as far as what was 5lb spine difference, turned into a 30lb in 2 doz arrows!!!!  So much for premiums!!!

[reddogge]

I made a 2Jays and it works like a charm.  Also it's portable so I loan it to friends.