First Laminated Warbow - baby steps

[alexw]

Hi All

My first stab at this, here are the results of an afternoon's floor tillering. How are we doing for shape?

35mm x 32mm in the handle, 17.5 x 16 at the tips
Maple, Ipe, Lemonwood.

Unrelated question as I get things ready to make the next one (lighter, 4-lam, Maple/Padauk/Ipe/Lemonwood): how do you taper your laminates? Looking to go from 5mm -> 2.5mm in the tips on the middle two.

Cheers!

[Del the cat]

Can't really see how it's bending yet... you need to be pulling it to full weight to be able to see (Else you'll just end up under weight). I think maybe the ends bending too much, but that could be 'cos I like to tiller by seeing the middle move first.
To taper a laminate, run it through a thicknesser  or thickness sander with it stuck down to a tapered sled. E.g To make a tapering sled... you get two lengths of say 2x3" 4' long and have them hinged together at one end and spaced apart by a couple of mm at the other end, this is your taper (ok it's a bit thick at 4" ! ) if you stick a lam onto it with double sided tape and run the whole assembly through a thicknesser. The lam will come out tapered to exactly match the sled. E.G. The whole assembly comes out constant thickness, but as the sled was tapered the lam is tapered to the equal, but opposite amount (think end of sled is thin end of lam' and vice versa
Out of interest I reckon you need about 1.5 -2mm every 6" of length along the limb of a warbow for the roughing out.
I made a thicknesser from an old powerplane:-
http://bowyersdiary.blogspot.co.uk/2014/10/diy-bowmaking-thicknesser.html
And here's a tapering sled:-
http://bowyersdiary.blogspot.co.uk/2014/11/billet-tapered-on-thicknesser.html
It worked pretty well for tapering billets for a backed bow, but they needed cleaning up on the belt sander.
There is a warbow build along showing the tillering on my youtube channel.
https://www.youtube.com/watch?v=sR28fBBADdY&list=PLBz2tD9476KRkSOSICLsc-zj5ADyPKLZB
Del

[mikekeswick]

As Del says!
I've worked out the perfect taper for an elb is 0.011 inch per running inch. depending on the intended use a short powerlam is a good idea.
For these heavy bows you would be much better to use ipe for your belly.
Lemonwood is just a so so bellywood. It just acts a bit 'soft' for its density and takes more set than I find acceptable. Ipe is a different animal. Also be wary of padauk as a core. It has a tendancy to split along the grain on stressed bows. I had failures with it three times and will not use it again. It fails in sheer.
Your tiller is good but you must be pulling full weight or else you'll come in underweight and don't stay on the long string for too long.

[alexw]

Cheers Del, very helpful especially wrt the tapering.

I too suspect - even at this embryonic stage - that there is way too much poundage in the centre (certainly much more than I can draw, so for that reason if no other we will probably see some gradual reductions there).

I'm waiting for some lime mortar to set in a repointed cellar wall before mounting a tiller-tree proper (temperatures here in Poland are 2 degrees either side of freezing just now, hence the interim measure using my boot and the floor) but once that's in I will start to really put it through its paces.

Mike, just saw your reply coming in - thanks also. I'm fighting shy of ipe as a belly for two reasons this time.

One, this is my first bow and anything that makes the process easier, less harsh on the tools, gets my vote until I've gained a bit more experience; two, my last (bought) ipe-bellied bow exploded after three months' use.

I know, that's as likely down to bad luck with the particular piece of wood than the species as a whole; but I'm hedging my bets for a while yet. Longer term, I'm looking to try cumaru and jatoba as they're both spoken relatively highly of: plus, they're available here, which ipe (barring the bottom-of-the-barrel stuff that gets used for decking) isn't.

Thanks again, A

[mikekeswick]

Your bow broke because of how it was made/used not because it had ipe in it! Any wood can and will break! It's not about luck with bow wood it's about choosing the very best materials to work with. Only a few woods are suitable for a heavy elb belly - I suggested ipe because it will allow to make a few small mistakes without your bow going south, softer woods will chrysal very easily or will take set readily. If you are looking to make this 'easy' then you might want to find another hobby Starting off making a heavy bow is definitely not the easy way to get started but if you have got your plan....you've got your plan.