Tillering question for the bowyers amongst you...

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Spacemonkey

Native
May 8, 2005
1,354
9
52
Llamaville.
www.jasperfforde.com
I've been knocking up (sorry...) a longbow made from ash backing and walnut belly of about 72" which just about reaches my draw of 30" (next one will be longer to make the draw more 'comfortable' for the wood).

Trouble is, that the lower arm is definitely stiffer than the top. The lower arm has, in my opinion, a perfect tiller but the top arm though it looks good, doesn't match, and no amount of scraping seems to be making any changes anymore...

The upper weaker arm has more set when left, but it's only about a centimetre or so. The handle is off centre towards the lower arm, the centre line being about 1" below the top of the handle.

When the bow is strung, I have taken measurements of the bracing height 9" either side of the centre point, and the lower arm gap is 1cm smaller than the upper arm at this point.

The question is, is this a real problem? I'm not doing comps with this bow, it was more a bowmaking experience, but obviously i want to use it informally, preferably without breaking it. I suspect that I might have tillered it too much and too quick causing this problem to occur. I have already appied two coats of linseed oil, so if you think that further scraping is an idea, is this still possible to do??

Any thoughts please...?
 

longshot

Need to contact Admin...
Mar 16, 2006
174
1
57
Newfoundland, Canada
since the handle is off set to the stonger limb what about piking the top limb to increase stiffness and to even out the tiller. i'm only learning to make bows so take it for what its worth. just seems to make since to me.

dean
 

Snufkin

Bushcrafter (boy, I've got a lot to say!)
Oct 13, 2004
2,097
138
53
Norfolk
With a traditional longbow the lower limb should be slightly stiffer by a quarter of an inch so I would say that the difference is acceptable. You could scrape some more off the lower limb if you still have a good draw weight, or pike the upper limb if the bow is a little light. A full draw picture would be helpful.
 

jojo

Need to contact Admin...
Aug 16, 2006
2,630
4
England's most easterly point
I am not the world's expert, but I just looked at the photo of a long bow in the Boyer's bible, and it seem to fit what you describe, ie lower limb slightly shorter and stiffer than the upper limb. Read also that it is possible to "cut off unequal amounts from either end, with more being cut off the weaked limb" but that it is probably better to finish the bow at a lighter weight, and put it down to experience gained. The next one will be a better bow. :D
 

Spacemonkey

Native
May 8, 2005
1,354
9
52
Llamaville.
www.jasperfforde.com
That picture is exactly what it is like (page 277 dia C) but as i said, shaving has not corrected it, so I think unless anyone elese says otherwise very shortly, I'm going to cut the tip off the weaker limb just below the nocks and cut some new nocks in it.

Walnut belly with ash back looks gorgeous when oiled... Now i need to make a grip...
 

stovie

Need to contact Admin...
Oct 12, 2005
1,658
20
59
Balcombes Copse
Spacemonkey said:
.... so I think unless anyone elese says otherwise very shortly, I'm going to cut the tip off the weaker limb just below the nocks and cut some new nocks in it.

...

Go for it. Piking the length can work wonders. But not too much, otherwise you'll suffer with stacking....looking forward to seeing the finished article. As an afterthought have you asked the opinion on paleoplanet...lots of help freely available there.
 

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