Primitive Archer

Main Discussion Area => Bows => Topic started by: simk on April 10, 2018, 02:11:16 pm

Title: Hard Learning
Post by: simk on April 10, 2018, 02:11:16 pm
I will build wider limbs...
Title: Re: Hard Learning
Post by: simk on April 10, 2018, 02:17:19 pm
........it was 62 short including the recurves. R.I.P.
Title: Re: Hard Learning
Post by: PEARL DRUMS on April 10, 2018, 02:34:42 pm
Lots of compression fractures in that belly.
Title: Re: Hard Learning
Post by: BowEd on April 10, 2018, 02:36:56 pm
Indeed...See the 3rd pic and the short lines crosswise on the belly below the break.
Title: Re: Hard Learning
Post by: simk on April 10, 2018, 03:13:17 pm
Yes, it was the belly. The collapsed grain looks like cut.
Title: Re: Hard Learning
Post by: PEARL DRUMS on April 10, 2018, 03:14:21 pm
Do you have a picture of the bow bending before it broke?
Title: Re: Hard Learning
Post by: bushboy on April 10, 2018, 04:00:39 pm
I've broken lots,but have never seen a break like that implostion !what type of wood?
Title: Re: Hard Learning
Post by: Springbuck on April 10, 2018, 04:47:31 pm
  What was the wood?  That's a lot like how elm breaks, stubbornly letting go quickly, but splinter by splinter.
Title: Re: Hard Learning
Post by: George Tsoukalas on April 10, 2018, 04:50:25 pm
Wider and longer. Jawge
Title: Re: Hard Learning
Post by: Weylin on April 10, 2018, 10:28:26 pm
Nah, it's fine. Squirt a little super glue in there and clamp her down.  >:D

Title: Re: Hard Learning
Post by: ty_in_ND on April 11, 2018, 12:19:18 am
Nah, it's fine. Squirt a little super glue in there and clamp her down.  >:D

Maybe a rawhide wrap as well, for extra security?  Can't be too safe.  O:)
Title: Re: Hard Learning
Post by: simk on April 11, 2018, 02:23:56 am
After reflecting some time I can tell you what happend:

1. I had finished the tillering-job @ was very pleased with it (but didnt't do pics). Wood is rowan.

2. Then - in a hurry - I reviewed the tiller and found a stiff spot on the lower limb and started scraping again...it's where it finally broke @ FD on the tillering tree...

To my first surprise i didn't broke on one of the problem-spots I occurred while tillering.

3.But: I shouldn't have done this extra tillering in a hurry because the "stiff spot" in fact was a slightly reflexed wave in the limb. This overstressed the wood...BÄMMM...

Now I will go and clamp it with superglue  8)

Cheers
Title: Re: Hard Learning
Post by: BowEd on April 11, 2018, 08:24:13 am
The truth comes out here.Good ananlysis simk.Sorry to see your bow break there but it happens.Those reflexed areas when reduced to go past flat and bend give in and break many times.Tillering those more charcterish bows are a bit different than tillering perfect looking wood.Like leaving knots a bit stiffish too in the bending limb.
Title: Re: Hard Learning
Post by: Badger on April 11, 2018, 08:26:36 am
After reflecting some time I can tell you what happend:

1. I had finished the tillering-job @ was very pleased with it (but didnt't do pics). Wood is rowan.

2. Then - in a hurry - I reviewed the tiller and found a stiff spot on the lower limb and started scraping again...it's where it finally broke @ FD on the tillering tree...

To my first surprise i didn't broke on one of the problem-spots I occurred while tillering.

3.But: I shouldn't have done this extra tillering in a hurry because the "stiff spot" in fact was a slightly reflexed wave in the limb. This overstressed the wood...BÄMMM...

Now I will go and clamp it with superglue  8)

Cheers

  That short reflexed area is a common problem, the more gradual and smoother you can do your reflex in the better it will tiller out. Mark St Louis has always been the master of smooth reflex transitions. Take a look at some of his bows.