I plan on building a 66" R/D LB , 42 @ 28 ( I will be drawing 30.5) . Riser will be 18", 050 glass. I think 4 pr 065 tapers should be in the ballpark. I haven't made any for 15 years and can't find my size chart. Any thoughts?
On my form, .360 with .003 taper,18" riser, and .040 glass would be about 40#, so depending on the taper rate , amount of D/R and width, you should be pretty good. The .050 glass will add a bit, some say up to 10# but I haven't used it in my design.
Let us know! :thumbsup:
Thanks Kenny. My bows are 1.28 at fade outs and .56 at tip overlays. Some of them end up 67" instead of 66".
Kenny I forgot to mention taper rate of .001.
With .004 total I bet you will be close.
Any problem using 15 year old lams and glass if they are cleaned well with acetone? I think they are dry by now!
I would probably scuff the wood lams with a sanding block and blow off. Glass should be good with a bit of cleaning IMO...
won't hurt to lightly sand the glass to freshen it [by hand with a block] then brush clean
Thanks Bamboo! I didn't have 065 lams so I going to use 2 pairs 075's and 2 pairs 060's . Acording to Binghams weight chart it should be right on.
Does Binghams use .004 total taper now? They used to be all .002 total except the TD longbow...
You can clean the glass with acetone. But not the wood. Maybe scratch the wood with a hacksaw blade and blow clean.
Lams were from OMC and 002 taper
Stew, are you saying the 075s and 060s are 002/inch tapered? That would give you 008/inch total taper. You have any parallels? Even if you reverse 2 pair of your tapers you will need parallels to make the .370 stack height.
Robertfishes what size parallels do you think I need? I called Binghams and they said they never send out all tapers with their design. I have my first bow I made from them and the lams are all tapers. I am really confused now!
Big Stew, I'm not feeling good tonight but I'll try to work thru this... Since I dont know what your D/R design is...I don't know what your Total stack height should be..But I'm sure it can be worked out here on TG since there are a lot of guys here with good experiance..So are you using a Binghams design? if so which one? do you have a good dial or digital caliper for measuring lamination thicknesses? It's possible Binghams reverses half of their tapers to make stack "parallel"..
Stew, the only longbow I build is the original 62/64 KennyM design from 2010, but I have built more 66" bows off of my form so I can give you stack heights for that build only..I usually have a limb width of 1.45" at fades. Kennys awesome design uses a total taper of .003/inch so I use one 002/inch taper and one 001/inch taper for a total taper of 003/inch..I use a parallel or parallels as needed to make stack height.
Stew, I am looking at my build log now.. 66" D/R. Riser 18.5",amberboo lams, 24" 030 Powerlam, 002 taper .116, 001 taper.070, parallel 0.048, two .028 zebrawood veneers, two .040 clear glass..total stack 0.370, I do not include the power lam in the stack height. 1.40 wide at end of riser fade, tip 0.60 wide at string groove. 46# @ 28"
Thanks Robert, hope you are feeling better. My form is the 68" longbow from Bingham. I just went and bought another caliper and it is as all over the place as the other one! I think it will be easier calling OMC and ordering new lams and glue.
There is a stack height chart on the Binghams web site. I have a Igaging absolute zero digital caliper that is pretty good.. But I wanted something better.. I bought 2 used dial calipers..both are Japanese made Mitutoyo's and both check out perfect using known standards. I check them every time I use them.
Robertfishes I got an Igaging digital, what a difference! 4 pairs of .075 @ 001 should be .364 with .050 glass subtracting 9 inches for 18" riser. That should be right on for 42 lbs @ 28". Thanks