Minimum dimensions needed to cut a riser to center?

[GentlemanArcher]

Hi All,

So...building 64" R/D bows on bingham's plan.  The first one I made is a hoot.  Very happy with it.  I would like to get the riser cut to center on the next bow.  This will allow a wider range of arrows to be tuned to the bow.

So...how much material do I need in the riser so I can safely cut it to center?  I know there are hundreds of variables here...but I figure there must be some rules of thumb.  The bows are between 35 and 50# at 28 inches.  the riser is 18 inches long, the handle area is about 6 inches long (the space between the glass when looking at the back of the bow). The risers are ending up about 1.3 inches wide. The depth, measured from belly to back at the center of the bow is just shy of 2".

As I write all this down, I'm not even sure this question can be answered.  

Thanks in advance!
GA

[Robertfishes]

I like to add a few pieces of core tuff glass to the riser for stength...i put 26 layers in Helens LB riser and cut shelf past center.

[Johan van Niekerk]

I've cut risers as narrow as 32 mm to center. I think ANY riser can be cut to centre provided you use strong material    
I.e. add a piece or 2 of bow tuff = lots of extra strength, or use bubinga or a similar really strong wood.

[Trux Turning]

I'll echo what's been said- a few pieces of bow tuff or even the cut offs from your glass on the front of the riser will add a bunch of strength to the riser- you can add an accent strip or two in the riser to stiffen it up.

[Glunt]

Pretty normal longbow dimensions.  I wouldn't expect any issues if you have some glass accents, overlays, or an I beam of some sort.  I assume you mean cutting the window to center and not cutting it past center so the arrow would be actually center-shot.

[Robertfishes]

an easy way to add glass to a riser is to start with a good square/flat board, then cut a few pieces of glass and make a wood glass wood sandwich.. for this 1 3/4" wide riser I used 2 inch wide glass and wood and sanded it to 1.75" wide after glue up and cooking..    

[Robertfishes]

I glued this riser up in the bow form, 26 layers of 030 core tuff..it was not fun.. but totally worth the effort. pretty sure I cut it 3/16 past center.  

[Robertfishes]

I used 3 pieces of 030 coretuff in this 46lb @ 28" 64" R/D riser (wood is Shedua) I cut it 1/8" past center, no problems so far. riser is 1.48" wide at top of cut out and 0.66 wide at arrow shelf      

[BigErn]

It is posts like this one,that make this site so good!I keep coming back an reading these posts several times.There is so much information on this site and good people!Thanks to all for sharing all of it!    
                                 Ernie

[Sixby]

I cut longbows 1/8 to 3/16 past center regularly. Key for me is to add a 1/4 in piece of phenolic as an I beam so that the edge of the I beam comes out right on the window cut.  I also surround the entire riser with bow tuff not only for accent but use the top layer as an extension of the fades as a power lam. The bottom layer of bow tuff extends two inches past each end of the riser fades and the top generally three inches past end of fades. It adds a very classy look to the bow and you can adjust length of extensions to change working area of limbs after you get used to using it.

God bless, Steve

[Sixby]

This is an inch and 3/8 wide . There is a 1/4 inch black phenolic I beam and a surround of red Bow tuff glass. Bow window is cut past 3/16 for true centershot. Poundage is 50 lb.
You can see a small part of the black phenolic I beam at the belly side of the sight window.
God bless, Steve

[Wolftrail]

Not on topic here but, Sixby your work is Bow art personified.        
Some people dont understand the Art of Bowyering nor appreciate its complexity.  It should actually be considered a trade.   :cool: