G'Day All - Bit of an Intro
Posted: Tue Feb 11, 2014 6:19 pm
G'Day everyone, joined up here a month or so ago and have been meaning to do an intro thread for a while. The bows have all gone pear-shaped, as they're wont to do, so here's a look at where I went wrong! Before I get going, many thanks to Sam Harper of poorfolkbows who inspired me to give it a shot and see what happens.
Anyway, here's the first shot at a thickness sander jig.
Shortened her up and beefed it a bit since that picture was taken but same concept. I run it on a cheap piece of junk I bought from Super Cheap Auto. Does the job. Sometimes. When the drive belt isn't slipping.
I cut by hand a lot but I do my lams & risers on a little Ryobi 9" bandsaw. It's not bad, really, and the decent blades from the saw place down the road make all the difference. Pretty sure it'll be dying on me soon though, poor little fella. I've pushed him a bit hard, I reckon.
Here's the forms, tack welded & made out of steel. (That's the old fella posing while I got behind the camera)
They've had a couple of coats of grey zinc since, which has made them look tidier. I'm not convinced by them though, especially the R/D/R, shorter form. Too much kink, not enough smooth curves. I'm probably going to flip them and go back to the old way I laid up where I would clamp & bend the bow woods using little blocks to get the lift/bend in it. A picture's worth a thousand words so I guess I'll have to show you all when I get round to it.
Here's some of the (un)finished products.
So the one on the left is your standard R/D style, 70" (68" ntn), 2" R/D, Tassy Oak & Spotted Gun riser with Tassy Oak, Balau & Bubinga overlays. Limbs are all Balau with homemade pretensioned e-glass backing, few little offcuts & goats horn nocks. I've got a bit of a background in composites so I've found it easier to make my own glass lams, rather than buy them. All in the spirit of the hobby, eh? Not finished this bow yet but hoping to have her come in at around 40lb @ 28". Got one .001 taper & one .002 taper in her too, so it should have a nicer (well, more of a) bend to her too.
One in the centre is the first off of the R/D form, so same dimensions as the other fella. Came in at a whopping 10lb @ 28" - I call it 'Stephen', after a certain Mr. Amell. My old archery teacher in Canada is the tech on that show & told us about the 12lb bows they use on set. Nice. Spotted Gum limbs with only a .001 taper, Spotted Gum riser with a Merbau (?) accent strip, same nocks as above. Old piece of hardwood I had knocking about, can't remember what it is really. The glass lam came out well but I didn't grind it down enough so full of bubbles underneath. Ah well. Apart from that, it came up nice for a first hit.
The third bow is my little beaut. Unfinished, and will remain so due to compression cracks on the upper limb near the riser. Note to self - Balau is only for risers from now on. Like the other bows, the design is based on the Golden Ratio, but this time it's 62" (60" ntn) with 2" reflex on limbs, 1.5" reflex on riser. Riser is Tassy Oak, Spotted Gun & Balau with a Merbau (or whatever it is) accent strip. Limbs are a Spotted Gum core with a .002 taper, Balau on the belly, Glass on the back. Nocks are Bubinga & goats horn. Not too sure about the lack of smoothness in the limb curves, but the previous attempts (currently en route from Canada) have a bit of a nicer bend to them and were done without a form as such.
I've learned a lot since making these three, and the other 2 I smashed in frustration which aren't shown. I picked up some Ironbark & Black Bean (seriously, is is really called Black Bean?) today so going to give them a shot in the next couple of weeks. The Balau will be relegated to risers & cores, I think, it doesn't seem to have the rupture coefficient that would be desirable in a compression wood. Can you get Ipe in Australia? I've had a look but no luck as yet.
I've been using epoxy resin as glue, which can get messy, but I get great penetration & adhesion and it's pretty cheap really. I use it for the glass lams so I buy it in enough bulk that it's worth it. In Canada, when making laminate bows, I was using Tightbond III - great stuff, but a bit dear over here in Oz. As you can tell from my timber & tool choices, I'm not exactly flush with funds at present... I used a marine epoxy a few years back and had nothing but trouble with it. What do all you other guys use? Smooth On? I've never been overly impressed by it, personally. For less money I've found much better products, like the epoxy I use now.
Anyway, there we go. Any feedback/thoughts/criticism/hell raising welcome.
Anyway, here's the first shot at a thickness sander jig.
Shortened her up and beefed it a bit since that picture was taken but same concept. I run it on a cheap piece of junk I bought from Super Cheap Auto. Does the job. Sometimes. When the drive belt isn't slipping.
I cut by hand a lot but I do my lams & risers on a little Ryobi 9" bandsaw. It's not bad, really, and the decent blades from the saw place down the road make all the difference. Pretty sure it'll be dying on me soon though, poor little fella. I've pushed him a bit hard, I reckon.
Here's the forms, tack welded & made out of steel. (That's the old fella posing while I got behind the camera)
They've had a couple of coats of grey zinc since, which has made them look tidier. I'm not convinced by them though, especially the R/D/R, shorter form. Too much kink, not enough smooth curves. I'm probably going to flip them and go back to the old way I laid up where I would clamp & bend the bow woods using little blocks to get the lift/bend in it. A picture's worth a thousand words so I guess I'll have to show you all when I get round to it.
Here's some of the (un)finished products.
So the one on the left is your standard R/D style, 70" (68" ntn), 2" R/D, Tassy Oak & Spotted Gun riser with Tassy Oak, Balau & Bubinga overlays. Limbs are all Balau with homemade pretensioned e-glass backing, few little offcuts & goats horn nocks. I've got a bit of a background in composites so I've found it easier to make my own glass lams, rather than buy them. All in the spirit of the hobby, eh? Not finished this bow yet but hoping to have her come in at around 40lb @ 28". Got one .001 taper & one .002 taper in her too, so it should have a nicer (well, more of a) bend to her too.
One in the centre is the first off of the R/D form, so same dimensions as the other fella. Came in at a whopping 10lb @ 28" - I call it 'Stephen', after a certain Mr. Amell. My old archery teacher in Canada is the tech on that show & told us about the 12lb bows they use on set. Nice. Spotted Gum limbs with only a .001 taper, Spotted Gum riser with a Merbau (?) accent strip, same nocks as above. Old piece of hardwood I had knocking about, can't remember what it is really. The glass lam came out well but I didn't grind it down enough so full of bubbles underneath. Ah well. Apart from that, it came up nice for a first hit.
The third bow is my little beaut. Unfinished, and will remain so due to compression cracks on the upper limb near the riser. Note to self - Balau is only for risers from now on. Like the other bows, the design is based on the Golden Ratio, but this time it's 62" (60" ntn) with 2" reflex on limbs, 1.5" reflex on riser. Riser is Tassy Oak, Spotted Gun & Balau with a Merbau (or whatever it is) accent strip. Limbs are a Spotted Gum core with a .002 taper, Balau on the belly, Glass on the back. Nocks are Bubinga & goats horn. Not too sure about the lack of smoothness in the limb curves, but the previous attempts (currently en route from Canada) have a bit of a nicer bend to them and were done without a form as such.
I've learned a lot since making these three, and the other 2 I smashed in frustration which aren't shown. I picked up some Ironbark & Black Bean (seriously, is is really called Black Bean?) today so going to give them a shot in the next couple of weeks. The Balau will be relegated to risers & cores, I think, it doesn't seem to have the rupture coefficient that would be desirable in a compression wood. Can you get Ipe in Australia? I've had a look but no luck as yet.
I've been using epoxy resin as glue, which can get messy, but I get great penetration & adhesion and it's pretty cheap really. I use it for the glass lams so I buy it in enough bulk that it's worth it. In Canada, when making laminate bows, I was using Tightbond III - great stuff, but a bit dear over here in Oz. As you can tell from my timber & tool choices, I'm not exactly flush with funds at present... I used a marine epoxy a few years back and had nothing but trouble with it. What do all you other guys use? Smooth On? I've never been overly impressed by it, personally. For less money I've found much better products, like the epoxy I use now.
Anyway, there we go. Any feedback/thoughts/criticism/hell raising welcome.