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Author Topic: MR Copy Explodes on the tiller at 100#  (Read 6340 times)

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Offline Del the cat

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MR Copy Explodes on the tiller at 100#
« on: July 11, 2013, 11:46:40 am »
Damn, probably down to pushing it too hard too quick, and an imperfect back*.
The tiller wasn't perfect yet, but I was thinking winch it back to 110# then really clean it all up a get the tiller spot on.
Caught it on video, I had the hard hat and safety glasses on.
http://bowyersdiary.blogspot.co.uk/2013/07/warbow-explodes.html
It was a bit experimental as it was a couple of old odd billets....still the splice was good :laugh:
Enjoy...
Studying the original video I can see the break starts dead centre on the back, probably propagating from the splice. This reinforces my view that a thin sapwood overlay over a splice helps prevent splinters lifting on a full compass bow. You might think I was working the centre too hard, but I was following Mary Rose dimensions and had actually left some extra timber there.
Del
« Last Edit: July 11, 2013, 02:00:31 pm by Del the cat »
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Offline toomanyknots

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Re: MR Copy Explodes on the tiller at 100#
« Reply #1 on: July 11, 2013, 02:39:41 pm »
That sucks so bad.  :'( Dang that thing exploded though, good thing you were wearing protection! Pretty smart idea really! Did you get clobbered with any bow shrapnel! I thought the tiller looked just fine.
« Last Edit: July 11, 2013, 02:42:49 pm by toomanyknots »
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"The way of heaven is like the bending of a bow-
 the upper part is pressed down,
 the lower part is raised up,
 the part that has too much is reduced,
 the part that has too little is increased."

- Tao Te Ching, 77, A new translation by Victor H. Mair

Offline WillS

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Re: MR Copy Explodes on the tiller at 100#
« Reply #2 on: July 11, 2013, 03:29:51 pm »
Man that's a shame, sorry Del! Really encouraging to see that the splice itself stayed solid.  Wish I was able to get to your place as i have piles of prepared billets but never tried splicing before and you clearly know your stuff!
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Offline Del the cat

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Re: MR Copy Explodes on the tiller at 100#
« Reply #3 on: July 11, 2013, 03:48:58 pm »
Cheers guys. I've been playing detective and I think I've spotted the actual culprit, by reassembling the centre section.
A small splinter that lifted by the splice where the sapwood had been rasped down to match either side of the join!
In the video you can see it cartwheeling off right as a faint blur just before it explodes.
Elementary my dear Watson!
Del
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Offline mullet

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Re: MR Copy Explodes on the tiller at 100#
« Reply #4 on: July 11, 2013, 03:53:52 pm »
Man, that does suck. But, if it is gonna break at least make it exciting.
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Lakeland, Florida
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Offline adb

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Re: MR Copy Explodes on the tiller at 100#
« Reply #5 on: July 11, 2013, 10:28:15 pm »
I've had a couple heavy (one 120#) tri-lams explode on the tiller. It's quite an event! No ticks, no creaks... just KABOOMSKI!!!
Sorry for your loss, Del. Do you think a rawhide backing might have helped?
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Offline JW_Halverson

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Re: MR Copy Explodes on the tiller at 100#
« Reply #6 on: July 11, 2013, 10:29:32 pm »
Wow!  What an action shot! 

I like the way you autopsied the remaining corpse to find out what went wrong rather than just having a weinie roast on the way to the next stave.  Great way to make the most of every situation, Del. 

Meet me in Tennessee next year at the Classic, Del, I'll bring my one and only piece of yew (THANK YOU MULLET!!).  You are the only one I want to mentor me thru my first yew bow!
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Offline mullet

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Re: MR Copy Explodes on the tiller at 100#
« Reply #7 on: July 11, 2013, 11:15:15 pm »
I went back and looked at the video again. It looks like when you cranked it back, and I'd have to say,really fast,, it was not bending on the left limb just past the handle grip. The left limb was definitely not keeping up with the right limb.
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Lakeland, Florida
 If you have to pull the trigger, is it really archery?

Offline Del the cat

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Re: MR Copy Explodes on the tiller at 100#
« Reply #8 on: July 12, 2013, 03:16:08 am »
Quote from: mullet on July 11, 2013, 11:15:15 pm
I went back and looked at the video again. It looks like when you cranked it back, and I'd have to say,really fast,, it was not bending on the left limb just past the handle grip. The left limb was definitely not keeping up with the right limb.
Yeah the left limb was definitely stiffer.
I was really just getting to the point where I was going to start tillering.
With cleaner flatter backed billets, I would have matched the backs better and I wouldn't have needed to rasp one down to match the other.
Ironically I glued 'em up to match the heart/sap boundary so it would look good >:( ... in retrospect I should have glued 'em to to match the back surface of the sapwood.
Maybe I'll learn for the next one...  ::)
Del
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Offline Del the cat

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Re: MR Copy Explodes on the tiller at 100#
« Reply #9 on: July 12, 2013, 03:21:25 am »
Quote from: JW_Halverson on July 11, 2013, 10:29:32 pm
Wow!  What an action shot! 

I like the way you autopsied the remaining corpse to find out what went wrong rather than just having a weinie roast on the way to the next stave.  Great way to make the most of every situation, Del. 

Meet me in Tennessee next year at the Classic, Del, I'll bring my one and only piece of yew (THANK YOU MULLET!!).  You are the only one I want to mentor me thru my first yew bow!
Yup, I'm looking forward to that, I won't have to worry about getting that warbow on the plane now ::).
It's been a funny week, the day before it exploded I had an equiry from a TV company researcher about possibly contributing on a forthcoming series 8) (Shhhh... don't tel the others, as I don't supose it will come to anthing) So I was rather 'up' ;D then kabooom  :( but we learn to bounce back pretty quick.
Del
« Last Edit: July 12, 2013, 04:10:08 am by Del the cat »
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blackhawk

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Re: MR Copy Explodes on the tiller at 100#
« Reply #10 on: July 12, 2013, 09:10:02 am »
"There ya go"...lol...nice reaction...usually I say "$&@$" really loud....guess you had to keep censored being on camera ;)

Sucks..but it happens  :-\ ..oh well..you know the routine  ;) ....pick the pieces up n figure what went wrong,and then go start another ;)
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Offline Cameroo

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Re: MR Copy Explodes on the tiller at 100#
« Reply #11 on: July 12, 2013, 03:48:16 pm »
What was even better than witnessing the explosion was your nonchalant reaction to it :) 

Sorry for the loss!
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Offline sonny

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Re: MR Copy Explodes on the tiller at 100#
« Reply #12 on: July 12, 2013, 07:07:33 pm »
.....but take a look at his face right after he says "there ya go"
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Offline toomanyknots

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Re: MR Copy Explodes on the tiller at 100#
« Reply #13 on: July 12, 2013, 10:52:26 pm »
Quote from: Cameroo on July 12, 2013, 03:48:16 pm
What was even better than witnessing the explosion was your nonchalant reaction to it :) 

Sorry for the loss!

I know, haha!
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"The way of heaven is like the bending of a bow-
 the upper part is pressed down,
 the lower part is raised up,
 the part that has too much is reduced,
 the part that has too little is increased."

- Tao Te Ching, 77, A new translation by Victor H. Mair

mikekeswick

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Re: MR Copy Explodes on the tiller at 100#
« Reply #14 on: July 17, 2013, 04:05:22 am »
Ah well......nevermind!
Del - I've3 done exactly the same thing with some yew billets I had a year or so ago. I tried to match the heart/sap boundary......mistake!
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