Hi all, I'm taking my first tentative steps in bow making. So far I've just made two crossbows (after watching a video - below), a little one not much more than a toy, and another more normal size one, mediaeval style but very rough and ready, and only about 15lbs draw. All just made from scrap timber I found in my garage during lockdown (no chance to source anything else at the time). The best material for the bow (well, the only stuff I found that worked) was some surplus Ikea venetian blind slats! No idea what they're made from but they smell quite fragrant when I sand the white paint off them.
I glued two together for the mini bow stave and 3 for the larger one. This sort of worked but I had a lot of failures: all snapping on the back, until I found the video (below) showing making a backed bow from DIY store wood, using layers of fibreglass scrim tape as a backing. Sounded crazy to me but it worked. The problem is the slat wood is a bit soft; the belly is collapsing a bit and it's taking a set. So now more shops are open I've been to the local B&Queue (!) and got some of the only hardwood they seemed to stock: planed oak.
I got two 90cm long pieces: a 25mm x 11 and a 36 x 11 for crossbow laths, and a 2.4m x 46 x 21mm to have a go at a longbow (not an ELB though, a flat bow style probably). I'll do the crossbow ones first to get more experience at tillering on the cheaper pieces before having a go at the longer one.
My question, probably the first of many, is how to know what dimensions to target? Any rules of thumb?
My mediaeval style crossbow has a power stroke about 8" and a "draw length" if that's the right phrase, of about 10.5". The limbs are about 12.5" long, with a non bending section of about 2" in the middle where it's secured in the stock.
I think the new bow should be a little shorter with (hopefully) stiffer limbs for more speed, but what is a sensible target? Aiming for at least 30lbs from the 25x11mm oak.
Original inspiration for my crossbow build:
Scrim tape and DIY store bow:
I glued two together for the mini bow stave and 3 for the larger one. This sort of worked but I had a lot of failures: all snapping on the back, until I found the video (below) showing making a backed bow from DIY store wood, using layers of fibreglass scrim tape as a backing. Sounded crazy to me but it worked. The problem is the slat wood is a bit soft; the belly is collapsing a bit and it's taking a set. So now more shops are open I've been to the local B&Queue (!) and got some of the only hardwood they seemed to stock: planed oak.
I got two 90cm long pieces: a 25mm x 11 and a 36 x 11 for crossbow laths, and a 2.4m x 46 x 21mm to have a go at a longbow (not an ELB though, a flat bow style probably). I'll do the crossbow ones first to get more experience at tillering on the cheaper pieces before having a go at the longer one.
My question, probably the first of many, is how to know what dimensions to target? Any rules of thumb?
My mediaeval style crossbow has a power stroke about 8" and a "draw length" if that's the right phrase, of about 10.5". The limbs are about 12.5" long, with a non bending section of about 2" in the middle where it's secured in the stock.
I think the new bow should be a little shorter with (hopefully) stiffer limbs for more speed, but what is a sensible target? Aiming for at least 30lbs from the 25x11mm oak.
Original inspiration for my crossbow build:
Scrim tape and DIY store bow: