I'm new to bow building and have a question regarding curvature of a riser and how it might affect string follow. I am building my first bow using bamboo flooring slats (2 of them laminated together) with fiberglass for backing. This is a 55 inch straight-limbed longbow for my son and will hopefully be in the neighborhood of 25 pounds at 25 inches.
Anyhow, I laminated the 2 pieces of bamboo and fiberglass together (G3 epoxy) and there is noticable curvature to the resulting blank. Not knowing how to fix that I forged ahead and now have the bow sanded pretty close to final shape and am ready to glue on the riser. In total, I'd say there is between a quarter and a half inch of string follow in the soon to be bow. The riser will be an 11 inch Howard Hill style. My question is, if I put a slight curve in the riser where it meets the bow, could I straighten out the string follow when I glue on the riser...maybe even create a bit of deflex?
Any thoughts would be appreciated. Thank You.
I've never tried anything like that. Usually any reflex or even R/D is glued in with the slats especially with fiberglass .
By being sanded to final shape is that including tiller?
I prefer to put my handles together with 1/8 to 1/4 inch slats and glue them on in layers.
The amount of follow you describe is nothing if not desirable in a straight longbow .
QuoteOriginally posted by macbow:
I've never tried anything like that. Usually any reflex or even R/D is glued in with the slats especially with fiberglass .
By being sanded to final shape is that including tiller?
I prefer to put my handles together with 1/8 to 1/4 inch slats and glue them on in layers.
The amount of follow you describe is nothing if not desirable in a straight longbow .
I have not yet tillered...by sanding to final shape I just meant getting the bow sanded to the lines that I drew onto the back of the bow that represent its approximate fianl shape. Why is it desireable to have string follow in a straight longbow...reduced hand shock?
Thanks for your help.
QuoteOriginally posted by vanillabear?:
You're gonna have glass on the belly too right?
Actually I wasn't planning on it. Not sure if this will ultimately be a mistake. Since this is my first bow, and since the poundage was pretty low, I figured I would try not putting glass on the belly. My reasoning is that I really don't have much of an idea how thick the bow needs to be. With no glass on the belly, I can take the thickness down if the bow comes in over weight, which I suspect it might. I used 2 0.13 bamboo lams and 0.04 fiberglass backing (total 0.30).
Do you think not having glass on the belly is a mistake? I know from others experience that having bamboo flooring as the belly can lead to set, but I figured that having laminated pieces, instead of one thicker piece might help reduce this problem...does that thought hold water?
Thank you for your help.
Have you,made any progress?
On the string follow, I've read that some of the sweetest shooting self bows had some follow , maybe 1 1/2 inches even.
I know many years ago there were bows made with just one piece of fiberglass on the back.
Your demensions sound like a good place to start.
If you wanted some reflex or R/D you would want to glue it in like doing a bamboo backed bow.
Please share how it came out good or bad.