Main Discussion Area > English Warbow
working details for higher poundages
willie:
I am in the process of building a lighter weight 70# "warbow" . this is a sort of trial run for a full size 120??pounder yet to come
As most of the bows I have ever built have been approx 40-45 in the past and I am finding that most everything I have in the past has to be rethought. First I had to rebilld my tiller tree. then I had to rethink what I usually do for string nocks, as I blew a tip, and grooved another with an undersized string loop. Del suggested some glued in reflex in another thread, which is new for me, and with the higher poundages, I find myself like a kid trying to string a mans bow. I going to have to make some adjustments to my methods when I undertake the full size warbow project, for sure, so here is my question
Does anyone have any links or can point to a resource that might be helpful with working at this scale?
Do most use a double block on the tiller tree? and how the heck does one guy string a heavy bow?
willie
Del the cat:
Here are my thoughts:-
Glue on temporary nocks with double grooves that allow you to use a stringer.
Avoid cutting nock grooves into the side of the bow.
Personally I get the middle of the bow moving (having got a rough thickness taper before putting it on the tree) and work outwards, may be less likely to blow a tip that way.
I'm not in favour of reflex on the heavy bows (above 90#).
Make 'em long and leave the tips wide until well past brace height. I narrow them and fit horn nocks when they are drawing about 26"
2:1 on the tiller is a good idea.
Always pull to full target weight, unless there is a visible tiller problem.
The process of tillering a heavy bow is the same as a lighter one... BUT the feel is totally different... it's a pig to get it braced, and once braced you are 80% there!
Most of this is on my blog (Google Bowyers Diary) if you trawl around it, or do a search on the blog for tillering warbow (the search facility works quite well).
All just my opinion of course, terms and conditions apply, contestants must be 18 years or over etc ;)
Del
colin1991:
Hi Willie,
A few questions first.
What are you building the bow from?? Lams or a stave?
If lams, what timbers are you using for them, particularly the belly?
Personally I make quite a few lams over 100lbs using a template I was given from an Aussie bowmaker for ELB's which I have since tinkered with to improve.
I glue my staves in reflex to negate string follow and get better performance and have never had an issue with it.
Bows are always cut with nocks in the sides of the timber for tillering (even across the back of the hickory back lam, but others will disagree with this) and a second nock for stringing when I can get the bow to brace.
I use a long string to get the bow bending to just past brace and then get a short brace with a short string and continue tillering as you would a light bow, upping the brace height to full as you get it bending further. If you have a target weight, don't ever pull it past that weight as it stresses the limbs unnecessarily.
I Always use a stringer to string big bows, its safest for the bow and the shooter and far easier than the step through method.
Hope that helps a bit,
Colin
willie:
Del
I have read your thread some in the past, but will take a closer look now that i see how much you have posted there.
Thanks for the pointers too, as I was just about to booger the tips some more. Temporary double tips seem to be the order for the day.
what do you mean 2;1 on the tiler is a good idea? are you recommending a bow length to draw length ratio? the bow is now 72 long overall and I intend to tiller out to 27"
thanks
willie
Del the cat:
I mean a 2:1 pulley system, as you had mentioned improving your tiller tree... Here:-
http://bowyersdiary.blogspot.co.uk/2013/11/tiller-improvements.html
Bow length to draw length ratio is nearer 2.4 : 1 for a warbow
Del
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