Paper testing

[DC]

In my shop I can get a sheet of paper set up about 8' from the bow. Is this far enough to tell me much about release and flight?

And is paper testing a decent option in liu of spine testing? If it's not cutting a great slash across the paper it must have come around the bow properly, right?

[Badger]

  A good paper test would trump a spine calculation. Can't help you on the distance but I think about 8ft would be pretty good. Allen does a lot of paper testing I am pretty sure he will chime in.

[DC]

I tried a couple of shots that showed the arrow was going sideways but I was using newspaper and it has a grain. Maybe I should use different paper?

[Badger]

   A good starting point for spine on a 50# bow. Test your arrow on 22" centers instead of 26". You are looking for 1" deflection with a 2# weight. Very little spine is needed with no weight up front and light arrows.

[DC]

Oh, very light, I'll try that. The paper training is saying that I need a stiffer arrow I think. I'm getting a 3" tear to the left. Since the bow is held horizontally in my machine left is actually up. I put the top to the right. Having the bow horizontal shouldn't have a big effect on this should it? I'm not sure what gravity would do in this case.

[DC]

   A good starting point for spine on a 50# bow. Test your arrow on 22" centers instead of 26". You are looking for 1" deflection with a 2# weight. Very little spine is needed with no weight up front and light arrows.

Yikes,, I have to double check this. I don't have any boo this light. A regular 30# spine arrow(from my grandson's quiver) shows .5" (1/2") this way. What length arrows would be spined this way or does it matter? I think I'll put a longer pull rope on my shooting machine

[willie]

What length arrows would be spined this way?

@22 in centers, 1" deflection with 2#?

[DC]

I must be doing something wrong. I'm a coward so I'm using my 35#@25" bow and I'm drawing it to 20" where it's about 20#. If I use a 50-60#(26" centers)arrow it makes a 1" vertical tear. If I use the 1" deflection@22" (no fletching) it cuts the paper in half(8" tear) to the left. Could that be something to do with my machine. I'm reporting the direction if the tear as if the bow was vertical. Make it easier to think about. The paper is 7' from the bow.

[Badger]

I must be doing something wrong. I'm a coward so I'm using my 35#@25" bow and I'm drawing it to 20" where it's about 20#. If I use a 50-60#(26" centers)arrow it makes a 1" vertical tear. If I use the 1" deflection@22" (no fletching) it cuts the paper in half(8" tear) to the left. Could that be something to do with my machine. I'm reporting the direction if the tear as if the bow was vertical. Make it easier to think about. The paper is 7' from the bow.

  I was going by what Ivar Mald had told me at the flight shoots, 24" arrow that weighs about 160 grains, no point weight and tapered tip. If you have any weight at all up front it would change that formula drastically. Ivar had tremendous success with his arrows. 

[DC]

I tried it once with no weight but it was 28" or better long. I'll try again at 24" no weight. Thanks

[Badger]

I tried it once with no weight but it was 28" or better long. I'll try again at 24" no weight. Thanks

You will also need to taper the front 2" to get some more weight off the front

[DC]

Not a lot better but I did get 204fps from a 20#@20" bow .  The arrow is 170 grains. I'm just throwing these arrows together so there may be a problem there but I think it's because I'm so close to the bow. I don't think the arrow can straighten out in 7'. I think I'll have to build a bigger paper frame that I can try outside.

[willie]

I don't think the arrow can straighten out in 7'

are you working on what it takes to straighten the arrow flight, or to see how straight it can leave the bow?

Perhaps a release from the string as close to a good finger shot as you can duplicate would be something to establish first.

[DC]

I have a rolling block release. I can't think of anything except maybe a spring to add some resistance to the release and I'm having trouble finding room or attachment points for that. I have a stop on the rolling block so that it doesn't flatten right out but leaves the "fingers" up slightly. Actually all the shooting machine releases I've seen(not many) have a compound bow type release which doesn't supply any sideways kick.

PS I just went and looked at Del's release and it's very much like mine.

[willie]

guess thats as close as it comes,

it would be nice to see some trend, ie the softer the spine, the further (or lesser) an arrow seems be knock left. I wonder if you are changing too many variables at once, only drawing 20"