R/D compared to straight limbs

PEARL DRUMS · January 21, 2011, 03:35:00 PM

Will an R/D all wood backed bow generate more poundage than a straight limbed bow with equal wood thickness, length and width? I guess what Im asking is will my straight limbed bow recipe generate a higher draw weight if I R/D it? Im trying to figure out how to bend an HBRO that starts with a stack up of .625".

NTD · January 21, 2011, 03:43:00 PM

Yes, when the limbs are relxed it adds weight. I remember reading somewhere an estimate to how many pounds per inch of relfex, I THINK it was something in the area of 5lbs per inch, but don't qoute me on that.

PEARL DRUMS · January 21, 2011, 03:46:00 PM

So maybe I could glue my blank up and run it through my planer to say a 1/2" stack up in order to allow it to bend more in the form? Right now my 5/8 stack up is perfect for straight limbs, but I cant get enough bend to produce a decent R/D at that thickness.

NTD · January 21, 2011, 03:53:00 PM

can't bend it with 5/8" how much reflex are you trying to glue in LOL?

PEARL DRUMS · January 21, 2011, 03:59:00 PM

I dont know how much Im looking for? Never tried it before. Maybe I need to not be afraid of bending it more and just push it down hard and clamp it. Its only $8 worth of red oak and hickory, if it breaks...it breaks. If you have rough recommendations on reflex and deflex, I will try them tonite when I get home. My red oak core is 1/2 thick and my hickory backing is 1/8 thick, 1.5 wide x 68 long.

NTD · January 21, 2011, 06:35:00 PM

With Red Oak and Hickory I don't think I'd want to put too much R/D in, but that's just me. I think that wood combo would do better in the long run with only mild reflexing. Maybe 3" blocks for relfex and a 3/4"-1" block for deflex. But feel free to experiment too, don't let my conservative estimates hold ya back

I don't think you'd want to thin that oak down much though if you are looking for 50# or more. Good luck, look forward to seeing what you turn out.

hova · January 21, 2011, 06:41:00 PM

just clamp it up like one of those horn bows. hickory is impervious to earth's physics.

but seriously , its your money , not mine. i say clamp 3" of deflex and 9" of reflex.

-hov

Ken75 · January 21, 2011, 08:13:00 PM

a little deflex is plenty 1 inch or less. with that combo i would try for more reflex than i intended on keeping. with just two lams some reflex will pull out . not so much if it were three lams.jmo

PEARL DRUMS · January 21, 2011, 09:09:00 PM

I have a 1.625" thick handle section. I will use that as my center height, then try 4" blocks on the tips for this one. Like I said before its $8 worth of wood, I can always try again...and again....and again....thanks for the tips all. One more question. At what mid limb point do I place my "pressure" clamp?

NTD · January 21, 2011, 09:14:00 PM

LOL that depends on what you want from your bow. I've come to prefer midlimb. Dean Torges says in his video that reflex more inner limb is good for shooting light arrows and moving the reflex out towards the tips is better for hunting weight heavy arrows.

PEARL DRUMS · January 23, 2011, 08:54:00 AM

I glued it up with 4.5" of reflex and 2" of deflex. It came off at 2.5" of reflex and about 1.25" deflex. I used a straight grained red oak core and 1/4 sawn hickory backing. Should make a fine bow. I used my work bench as my "jig". I need to build one now. I will post a pic if it holds together!

hova · January 23, 2011, 09:41:00 AM

better get some pics!