spine tester, dial indicator

[stinger2]

I'm not real sure about the dial indicator for the spine tester I built. Does anyone know what Beman ICS Bowhunter 500's should spine. My dial indicator reads around .380, with a 2 pound weight. Does that sound about right.  

[beetlebailey1977]

a 500 series shaft should deflect .500" not .380"

[Ray_G]

Stinger2,

Are you using 26" between supports?  That could be why the high reading.  Wood shafts at 26" spacing and 2# weight.  Those carbons need to be done at 28" with a 1.94# weight.  

Using your set up, dividing your .380 by .825 (the conversion) gives you the spine for 26" supports = .4606 spine.

[msamn]

I have found that my dial indicator has a somewhat strong spring and it took about 4 ounces of additional wt to get it to depress .500 inches. When I added that weight to my 2# weight, I got accurate readings.

[stinger2]

Ray_G, I am using a 26" gap with a 2# weight, and that my friend just may be my problem. Does anyone know what beeman ICS bowhunter 500 will spine with a 2# weight at 26"s.

msamn, I will test my dial indicator spring tention tonight.

Thanks guys.

[Rattus58]

I don't use carbons, but a shorter arm will increase spine and that easily could explain your .380 reading.

Much Aloha...  

[calgarychef]

Tell me why a person wouldn't put the dial indicator above the arrow and use the plunger as a "follower" rather than putting it underneath and having to compress the plunger??

the chef

[calgarychef]

Hmmm I might have answered my own question, if it's above then it pushes with the arrow as much as it would push against the arrow from underneath.

[stinger2]

Ray_g, I just noticed your conversion, .460 on my carbon shaft, which means I am .04 off with my dial indicator, that helps alot. correct me if I am wrong but I will need to get .606 out of my wood shafts to equall a .500 carbon shaft?

[Ray_G]

On 26" supports, just use your dial reading for wood shafts or arrows - no conversion.  The James Hill spine tester web site has a decimal to wood spine chart at the bottom of the web page that can be printed.  If you have access to known, spined wood shafts, you could check the accuracy of your indicator.

The conversion is to compensate for the shorter support spacing and extra weight when doing carbons on a tester set up for wood shafts.  You don't convert when using wood on your 26" set up.

The .500 carbon shaft will cover a "range" of spines being dependent on shaft length and point weight for a given bow.  It still only deflects .500 reading on the correct supports for carbon - 28" spacing and 1.94# weight.
 
A .606 is just that - a .606 spine shaft, not a range.  Again, it will depend upon your bow set up and then the arrow components if you are using wood.  There are some good rule of thumb charts for wood shafts on the web but they are only a starting point.  Try a spine range for your bow and one above or below depending upon your arrow setup.  The beauty of the spine tester is it lets you check shafts or arrows after you know what works for you.  You can go through a mess of shafts and pick out the good uns for huntin' and the rest for stumpin or flu flus.

[TomBow]

Bringing this thread back from the dead...
I decided that wood shafts would be my next point of study for my evolving Trad. "career".  Went to see Mr. Knowledge about such things and learned much, shot several woods and received parts for 7 arrows.  I built a arrow spinner (skateboard bearing version), bought a taper tool, and went through the steps to built 7 woods and they fly beautifully.  Now my twisted mind thinks that I need to delve deeper into more wood arrows and put together a spine tester.  I won't spend "half a bow's worth" of money to purchase a pre-made so DIY is now my burden.

Long story short--Where do I get a dial indicator?  Locally or specialty website??  Thanks in advance.

Tom B.

[Sam Harper]

Tom, you can get one at Harbor Freight or just about any hardware store.

[Davesea]

.500" easton deflection equals .410" AMO (26" w/ 2#)

Dave

[Davesea]

Internet auction site has killer deals on dial indicators.

[Grey Taylor]

These two from Harbor Freight are pretty popular:

  Dial Indicator  

and

  Digital Indicator  

Guy

[TomBow]

Thanks Guy.  We have a Harbor Freight here in Duluth so I guess I'm making a Spine Tester!