Author Topic: Update on 120# yew warbow - I don't like to complain, but...  (Read 49320 times)

0 Members and 2 Guests are viewing this topic.

Offline toomanyknots

  • Member
  • Posts: 3,132
Re: Update on 120# yew warbow - tiller opinions needed please!
« Reply #60 on: January 12, 2014, 10:59:41 am »


The trouble is, while common sense (and even the most basic bow making experience) says "stiff limb must become thinner to even out" how far do you let it go? 



As far as the tiller indicates you need to. I can tell you are frustrated with this bow, which anyone would be, especially with the money and time put in. You seem to be thinking about limb thickness too much, the tiller is what matters and determines what thickness the limbs are. Nothing but the tiller at full draw, and actual working tiller when the bow is drawn matters. If the bow looks good at fulldraw, than the braced profile will look fine too, that is my experience. That's the only thing you should be worrying about with this bow or any bow. The tiller is what makes a bow a bow. It sounds to me like your right limb is still too strong, although I can't tell say for sure of course without seeing the tiller. Either way, thank you for sharing this bow. I hope you get it sorted out.
"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

  • Member
  • Posts: 1,905
Re: Update on 120# yew warbow - tiller opinions needed please!
« Reply #61 on: January 12, 2014, 11:18:39 am »
Cheers! Massively appreciate ALL the help and comments, it will get finished and it will be a learning curve and there's nothing wrong with that.  It's just frustrating but that's what happens! If it was easy everyone would do it ;)

Hopefully some other people can learn from my mistakes on here too.

Offline Del the cat

  • Member
  • Posts: 8,322
    • Derek Hutchison Native Wood Self Bows
Re: Update on 120# yew warbow - tiller opinions needed please!
« Reply #62 on: January 12, 2014, 12:27:42 pm »
Regarding the horn nock... maybe the groove was too close to the lower edge of the nock? Horn has grain like wood and can split if there isn't enough material there?
Just a guess as there is no pic.
As for the rest of it, I wouldn't worry too much about how it looks at brace. I've had Robert Hardy tell me one of my bows was upside down, just because I had a naturally deflexed limb as the lower.
Short of sticking strain gauges along each limb and wiring 'em all to a chart recorder, it's down to eye and feel.
Don't be too hard on yourself.
Yesterday at the club 'Taxi Dave' came up to me with 'Dogleg' one of the Yew bows seen on the TV... it had just exploded on him! It was always a tad experimental, and had a belly patch so we weren't too surprized (he needed clean underwear tho'  ;) ). It was made in April last year.
I'll lend him the 100# Elm warbow to see how he gets on with that. Much better making bows for mates than customers who live miles away and don't appreciate the vaguaries of wood.
Del
Health warning, these posts may contain traces of nut.

Offline toomanyknots

  • Member
  • Posts: 3,132
Re: Update on 120# yew warbow - tiller opinions needed please!
« Reply #63 on: January 12, 2014, 01:37:39 pm »

Don't be too hard on yourself.


+ 1! I think when we put our heart and sole into something, and it doesn't come out absolutely perfect, it can be devastating, for me it is usually, especially with bows and all the time and work that goes into just one. Sometimes a bow will not turn out like I had expected, or something will be wrong or quirky with it, so I will throw it in some corner of my house somewhere where I don't have to look at it. It will just eat at me if I think about it, so I won't. Sometimes I will remember it after a couple months, go look at it, and realize it is a really nice bow, and I won't even notice whatever was irking me about it,  :).
"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 meanewood

  • Member
  • Posts: 243
Re: Update on 120# yew warbow - tiller opinions needed please!
« Reply #64 on: January 12, 2014, 05:20:06 pm »
The issue with a re-flexed or deflexed section of a limb is something I have little experience with, so I'm keen to found out what the 'old hands' think.
OK. if you have a section of deflex in a limb, it is already bent in the direction that the rest of the stave is heading. but with no stress imparted to it.

 If you then tiller according to an even looking bend, this section ends up being un touched while the rest of the stave gets reduced to catch up.
Logic tells you, this part is less stressed than the rest and isn't the idea to share the stresses evenly? With a straight stave this is gauged by looking at the bend for evenness and we all seem to focus on the beautiful 'look' of an even looking full draw, but beauty is not the primary goal, especially when dealing with heavy bows that are pushing the stave to it's limits!

I've got 2 Elm staves ready to go with these issues and I hope to get 130-140lbs out of them, so I'm keen to learn from Wills experiences.

Offline WillS

  • Member
  • Posts: 1,905
Re: Update on 120# yew warbow - tiller opinions needed please!
« Reply #65 on: January 12, 2014, 06:04:43 pm »
I'm keen to learn from Wills experiences.

Me too ;)

Offline Del the cat

  • Member
  • Posts: 8,322
    • Derek Hutchison Native Wood Self Bows
Re: Update on 120# yew warbow - tiller opinions needed please!
« Reply #66 on: January 12, 2014, 06:12:26 pm »
@ Meanewood... (sorry to hijack the thread, but it's sort of relevant)
If you are working with Elm, it will need heat treating. I'd use the heat treating as an oportunity to equalise the bend in the limbs at the same time. Kill two birds with one stone and make the tillering easier.
The 100# Elm warbow I did recently had issues like that with a nasty kink in one limb.
I corrected it to a degree to even up the limbs and it helped immensely.
If you look at it in this post, it's horrid... follow along the subsequent posts and you can see it finally ends up looking ok.
http://bowyersdiary.blogspot.co.uk/2013/10/busy-weekend.html
Del
Health warning, these posts may contain traces of nut.

Offline meanewood

  • Member
  • Posts: 243
Re: Update on 120# yew warbow - tiller opinions needed please!
« Reply #67 on: January 13, 2014, 01:03:00 am »
Thanks Del
Yes, I have already heat treated one, so I could give it a second session while having the dips clamped to a straight block!

Offline Marc St Louis

  • Administrator
  • Member
  • Posts: 7,877
  • Keep it flexible
    • Marc's Bows and Arrows
Re: Update on 120# yew warbow - tiller opinions needed please!
« Reply #68 on: January 13, 2014, 08:16:37 pm »
You know you can heat-treat Yew.  Just do the lower density/weaker limb and leave the other alone.  I've done that to Elm and Yew before.
Home of heat-treating, Corbeil, On.  Canada

Marc@Ironwoodbowyer.com

Offline WillS

  • Member
  • Posts: 1,905
Re: Update on 120# yew warbow - tiller opinions needed please!
« Reply #69 on: January 13, 2014, 10:28:52 pm »
Yeah I've heat treated every yew bow I've ever made so far.  I was really hoping to avoid it with this one, as the stave was so clean and straight when I started!  I don't think it's necessary just yet with this one, but I'm certainly no stranger to standing for 4 days straight holding a heat gun...

Offline WillS

  • Member
  • Posts: 1,905
Re: Update on 120# yew warbow - tiller opinions needed please!
« Reply #70 on: January 23, 2014, 03:22:23 pm »
She's getting there folks, she's getting there!  I've been given the most amazing help from Ian a very talented bowyer and member of the EWBS.  He's been picking up on stuff I had literally no idea about and it's shown me just how much I have yet to learn - especially when it comes to separating the tiller technique of warbows and normal weight bows. 

This bow is not there yet, there still needs to be a lot more tip movement to really get the true Mary Rose shape, but at least it's looking more like a bow now!  I'm only posting this unfinished tiller pic as a reference point, and hopefully it's interesting to a few of you.  It's also a fair bit over weight still, but as TMK said, the very fact that it's taking this much weight on a broken/repaired limb is a bit of a miracle, and certainly not down to any skill - more a "suck it and see" type thing.

It's taken probably 2" of set now, fairly evenly spread - either a sign of too long on the long string, or due to the fact that my tiller setup is outside, and with the weather we're getting here in the south of England "humidity" is an understatement...


Offline Del the cat

  • Member
  • Posts: 8,322
    • Derek Hutchison Native Wood Self Bows
Re: Update on 120# yew warbow - tiller opinions needed please!
« Reply #71 on: January 23, 2014, 06:20:32 pm »
It looks pretty circular to me. The extreme tips will never move.
Looking good.
If you have the tiller rig up the other way with the bow supported on a fixed block, you can have a rule to measure ditance more readilly.
I'm counting bricks to work out the draw on that pic.
Really please to hear you are making progress. Tillering a warbow is indeed a shift from a target weight bow.
Hope it gets there.
Del
« Last Edit: January 23, 2014, 06:23:35 pm by Del the cat »
Health warning, these posts may contain traces of nut.

Offline WillS

  • Member
  • Posts: 1,905
Re: Update on 120# yew warbow - tiller opinions needed please!
« Reply #72 on: January 23, 2014, 06:47:47 pm »
Thanks Del.

Offline Marc St Louis

  • Administrator
  • Member
  • Posts: 7,877
  • Keep it flexible
    • Marc's Bows and Arrows
Re: Update on 120# yew warbow - tiller opinions needed please!
« Reply #73 on: January 23, 2014, 07:39:24 pm »
Very nice.  The only thing I would do with that bow is get the outer limb to work a bit more, on the right
Home of heat-treating, Corbeil, On.  Canada

Marc@Ironwoodbowyer.com

Offline WillS

  • Member
  • Posts: 1,905
Re: Update on 120# yew warbow - tiller opinions needed please!
« Reply #74 on: January 23, 2014, 07:49:37 pm »
Thanks very much Marc!  Yep, that's the limb with the reflex, it's slowly starting to behave itself but still needs some more work.  I appreciate the help!