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Main Boards => PowWow => Topic started by: Matt Green on July 11, 2014, 11:22:00 PM

Title: cut "past center" vs. "as close to true ctr"??
Post by: Matt Green on July 11, 2014, 11:22:00 PM
Bob Lee's website claims the riser is cut "as close to true center as possible". I'm sure I could email JJ (and may) but thought I'd see if someone could clarify what that means vs. cut 3/16 or so "past center".  as I've understood it, cutting 'past' center widens the arrow spines the bow would tolerate. However, I've never heard of anyone stating a Bob Lee was more difficult to tune - anyone?
thanks in advance for any input
matt g
Title: Re: cut "past center" vs. "as close to true ctr"??
Post by: Lonehowl on July 11, 2014, 11:43:00 PM
Just bought a Natural recurve. Love it and  it aint hard to tune. Shoots right where I look.
Mark
Title: Re: cut "past center" vs. "as close to true ctr"??
Post by: beaunaro on July 12, 2014, 12:34:00 AM
I always understood it just like you stated it Matt.

Just to add a little more confusion to this topic, a lot of us at his Compton's Seminar, heard Dr. Ed Ashby state that "center shot is not your friend."

I looked thru my seminar notes and didn't write his explanation.

Not to take over your thread here, Matt, but wondering if anyone can remember what Ed meant by that.

I assume he meant that the arrow (with his recommended Extreme Forward Of Center Weight) needs to paradox around the riser and recover, rather than being shot from the center??

Not sure if that is the whole story, or if I got that quite right.
Title: Re: cut "past center" vs. "as close to true ctr"??
Post by: JimB on July 12, 2014, 01:16:00 AM
Just to add a little more confusion to this topic, a lot of us at his Compton's Seminar, heard Dr. Ed Ashby state that "center shot is not your friend."

The farther the side plate is from center,the lighter the spine you can use and still load the front heavy.This helps keep overall arrow weight down,which can be an issue with high FOC arrows.Also,on heavy weight bows,if cut past center,you will need stiffer shafts and you may not even be able get one stiff enough to handle the front end weight that would get you to high FOC.Cut past center works against you,building a high FOC arrow.
Title: Re: cut "past center" vs. "as close to true ctr"??
Post by: Bjorn on July 12, 2014, 08:00:00 PM
Each 1/16" is about 5# coming or going. Jim is correct riser cuts well past center work against EFOC. With so many bowyers cutting 3/16 past, are we going to see a fashion reversal?
Title: Re: cut "past center" vs. "as close to true ctr"??
Post by: ishoot4thrills on July 12, 2014, 09:11:00 PM
If the bow is cut "way past center" it's very easy to just build out the strike plate to the desired cut. Much easier than taking off material from the side plate, I have found.
Title: Re: cut "past center" vs. "as close to true ctr"??
Post by: Orion on July 12, 2014, 09:13:00 PM
Yep.  Jim is correct.  I was at the seminar as well.  I actually find bows cut to center or proud of center easier to tune than bows cut past center.  Fewer correct choices.
Title: Re: cut "past center" vs. "as close to true ctr"??
Post by: Friend on July 12, 2014, 09:48:00 PM
Would suspect that the arrow industry will continue pursueing stiffer lighter shafts.

Not too far in the not so distant past, a 500 spine shaft was an easy find at the local archey shop. Today, many shops don't carry 500's. While the market is supporting faster, the shaft spine trend is up with an emphasis on contiued arrow weight reduction.

My current arrow set-up for 3/16" past center and only a velcro side plate enjoys 30+% EFOC... 350 spine arrows...350 gns up front... at 10.3 gpp.

There are quite affordable and available arrows.
Title: Re: cut "past center" vs. "as close to true ctr"??
Post by: Matt Green on July 13, 2014, 08:03:00 AM
Very interesting.  especially on the EFOC info. Why would bowyer's NOT offer OPTIONS on this ?? In other words, cut "to" or "xx/yy past" center just like riser length, draw weight, grip style, etc.
OR do they?  any bowyers want to chime in? maybe i'll post this as a new topic
mg
Title: Re: cut "past center" vs. "as close to true ctr"??
Post by: SL on July 13, 2014, 08:45:00 AM
I see too much value in the site window cut past center. It's so easy to just build out the window for tuning. It's almost like a plunger for tuning. Tuning the bow to the arrow you want to shoot is easier and cheaper than changing arrows every time you try a different weight head or length.
The only reason for not cutting past center is strength of the riser itself. This, of course is only my opinion.     :thumbsup:
Title: Re: cut "past center" vs. "as close to true ctr"??
Post by: McDave on July 13, 2014, 09:13:00 AM
I would imagine that any bowyer who hand machines his risers would be happy to accommodate your wishes to cut the side plate less than 3/16" past center (or whatever his standard cut happens to be).  It might be a little more difficult to reprogram a CNC machine for one riser. I would also imagine that those shooting EFOC are still in the minority, and a bowyer would find that most of his customers prefer 3/16" past center.
Title: Re: cut "past center" vs. "as close to true ctr"??
Post by: kat on July 13, 2014, 09:50:00 AM
QuoteOriginally posted by SL:
I see too much value in the site window cut past center. It's so easy to just build out the window for tuning. It's almost like a plunger for tuning. Tuning the bow to the arrow you want to shoot is easier and cheaper than changing arrows every time you try a different weight head or length.
The only reason for not cutting past center is strength of the riser itself. This, of course is only my opinion.      :thumbsup:  
X2

A little rawhide, or whatever you like under the side plate is an easy adjustment to make. I have also found that 3/16" past center gives me a wide variety of spine selection
Title: Re: cut "past center" vs. "as close to true ctr"??
Post by: AkDan on July 13, 2014, 12:31:00 PM
I also like building my side plate back out so I dislike windows cut short of center.  I like to have that control for tuning purposes..I really don't care what the shoots require.  

I opt to use a tooth pic or sliver of an old shaft under the shelf and sitewindow material.  leather works as well.  Anything to minimize contact.  

I'm not into EFOC...so explain this to me.  If a bow is cut 3/16 past center it hurts guys shooting heavy weight heads?  I'm assuming due to the stiffer spine requirements?
Title: Re: cut "past center" vs. "as close to true ctr"??
Post by: AkDan on July 13, 2014, 12:36:00 PM
got me intrigued...he answer the cut to center question in this.  

http://www.youtube.com/watch?v=7rP8Xantd3Q

I'm gonna have to start reading his stuff finally LOL!
Title: Re: cut "past center" vs. "as close to true ctr"??
Post by: John Havard on July 14, 2014, 10:16:00 AM
If a riser is cut past center you have the flexibility of tuning the bow to your arrows (by building out the side plate).  If the sight window is not cut past center then you have to go through the sometimes frustrating, time-consuming, and sometimes expensive process of finding the perfect arrow spine that works with that precise bow and with that precise draw weight at your draw length.  

I shoot 275-300 grains up front with shafts spined to .280 deflection with a BOP length of 31.25" and my elevated rest is set up so that on the string my arrows are perfectly dead center shot (shaft precisely aligned with the string).  

Intentionally building a sight window that isn't even cut to center on a modern bow with sufficient strengthening through the critical stress areas makes little sense to me.  Cut it past center and build out the side plate.  That way the archer can use a much wider variety of arrow spines by tuning the bow to the available arrows he/she already has.
Title: Re: cut "past center" vs. "as close to true ctr"??
Post by: bigbadjon on July 14, 2014, 02:10:00 PM
While I don't know how true it is I have read old literature about a true center shot arrow is undesirable. The reasoning is that an arrow that was truly centered with the string would half the time want to flex the opposite direction during paradox so no consistent flight pattern could be achieved. I know it is written in the Jack Howard catalogue if anyone has one to verify.