Author Topic: tiller for whatever the stave will give  (Read 2461 times)

0 Members and 1 Guest are viewing this topic.

Offline stuckinthemud

  • Member
  • Posts: 2,299
    • avenue woodcarving
tiller for whatever the stave will give
« on: February 19, 2019, 01:17:44 am »
I have been pondering this a lot recently. I think the process works like this: choose your preferred design and get to low brace using a no-set method, slowly tiller to low brace, then to full brace, fit a short string and then instead of chasing a target draw weight back to full draw, keep exercising the bow further and further watching carefully for any signs of set and correcting tiller as you go until perfect tiller at your preferred draw length is reached. How far off am I?

Offline PatM

  • Member
  • Posts: 6,737
Re: tiller for whatever the stave will give
« Reply #1 on: February 19, 2019, 04:42:45 am »
A stave could give you double the draw weight you actually can handle though.  You still need to get it in the right range.

Offline Deerhunter21

  • Member
  • Posts: 2,253
  • What do you despise? By this are you truly known.
Re: tiller for whatever the stave will give
« Reply #2 on: February 19, 2019, 06:12:32 am »
I agree with patm you need to find your draw weight
Life before death. Strength before weakness. Journey before destination.

Offline Badger

  • Member
  • Posts: 8,118
Re: tiller for whatever the stave will give
« Reply #3 on: February 19, 2019, 08:02:11 am »
  The way I do it now is that I try to make sure the entire bow is well about target draw weight once I get done roughing it out. In other words I still floor tiller the bow but it is much stiffer floor tiller that I look for now compared to what I was looking for a few years ago. Once I put it on the tree with a short string I work it up to full target weight after just a few pulls as long as it is fairly even. You can't hurt a bow by being a little uneven if everything is still too strong. I Just continue perfecting the tiller and drawing to full target draw weight at every trip to the tree. If for some reason it starts taking a little set, I reevaluate my target draw weight goal, my design and whether or not I have used enough of the limb for bending and if the wood is dry. If it passes all those I simply drop my target weight by maybe 5# and continue on with the same process. When the bow hits 23" or 24" on the long string I brace it and continue with a braced bow. I find it weighs about the same braced as it does on a long string.

Offline DC

  • Member
  • Posts: 10,396
Re: tiller for whatever the stave will give
« Reply #4 on: February 19, 2019, 09:32:32 am »

If I'm following you and you are trying to get the maximum draw weight out of a given sapling I've tried this a couple of times with 1" dia Ocean Spray sticks. Unfortunately the OS in full round form split lengthwise before I got it halfway tillered(An OS problem). What I tried was just putting the scale away, cutting temp nocks and putting it on the tree. Give a pull and look for stiff spots. The idea is to get it bending evenly as soon as possible. That's the target. The first part is reducing the stump end of the stick to match the top end. You want to take as little wood as possible from the middle of the bow. Just keep drawing it a little further as you remove stiff spots. Like Badger has said in other threads, just keep perfecting the bend. Theoretically, if you were to hit the width and thickness tapers  right away you should just be able to haul it all the way to full draw. I doubt that would ever happen though. Eventually you may reach full draw ;). Then get out the scale and see how you did. The 1" OS thing is still on my "to do" list.

If you are starting with a split stave it's like everyone is saying, you need a target weight of some kind. A 3" stave tillered to maximum would probably support a ton. Kind of a useless bow. You need a limitation of some kind to start.

Offline Badger

  • Member
  • Posts: 8,118
Re: tiller for whatever the stave will give
« Reply #5 on: February 19, 2019, 10:06:14 am »
  DC, I tillered out a 300# white aok board about 7 ft long one time just going for the most I could get. i did what you suggested and built my tapers in from the start. I scaled the thickness up from a 5 ft long bow and made this one extra wide. I think I only got it out to about 24" before it started taking serious set. I used it as a proto type for a bunch of bows I was building for a TV program that had 6 bows mounted on a shooting machine that looked like a squirrel cage that a man walked in to keep it going around

Offline DC

  • Member
  • Posts: 10,396
Re: tiller for whatever the stave will give
« Reply #6 on: February 19, 2019, 10:11:50 am »
It's strange, isn't it, that the best design for a bow seems to be one that fits the average human.

PS Actually I guess 7' is a little short for 300#
« Last Edit: February 19, 2019, 10:15:36 am by DC »

Offline bradsmith2010

  • Member
  • Posts: 5,187
Re: tiller for whatever the stave will give
« Reply #7 on: February 19, 2019, 10:15:49 am »
I have thought about that a lot ,..it is strange
  Ok,,,your limit would be,,,.being able to string it...take it down on long string till you can string it,.,then tiller out evenly till you can draw it,,,,then weigh it and see what u got

Offline Badger

  • Member
  • Posts: 8,118
Re: tiller for whatever the stave will give
« Reply #8 on: February 19, 2019, 10:36:26 am »
  DC, yea it is kind of strange that the nature of wood just seems to work perfectly for humans. It doesn't scale up all that well.

Offline bradsmith2010

  • Member
  • Posts: 5,187
Re: tiller for whatever the stave will give
« Reply #9 on: February 19, 2019, 02:28:17 pm »
really great point, I gonna meditate on that one,, (-S

Offline Woodely

  • Member
  • Posts: 381
Re: tiller for whatever the stave will give
« Reply #10 on: February 19, 2019, 04:02:09 pm »
I have been pondering this a lot recently. I think the process works like this: choose your preferred design and get to low brace using a no-set method, slowly tiller to low brace, then to full brace, fit a short string and then instead of chasing a target draw weight back to full draw, keep exercising the bow further and further watching carefully for any signs of set and correcting tiller as you go until perfect tiller at your preferred draw length is reached. How far off am I?

Not totally sure but practice till you are blue in the face.  Lots of good tips on here.  I have learned by doing and learned by making mistakes.  Heck Henry Ford made thousands of mistakes.  Keep on keeping on.
"Doing bad work is an exercise in futility, but honestly making mistakes is trying your best."

Offline willie

  • Member
  • Posts: 3,164
Re: tiller for whatever the stave will give
« Reply #11 on: February 19, 2019, 04:49:17 pm »
PS Actually I guess 7' is a little short for 300#
scaling works better if you make adjustments for  L ,W, and thickness
a 7' bow pulling 300# would need to be about 5" wide
Quote
keep exercising the bow further and further watching carefully for any signs of set and correcting tiller and dropping the weight goal as you go until perfect tiller at your preferred draw length is reached. How far off am I?

of course this goal reduction "as you go" is an art of its own




Offline Badger

  • Member
  • Posts: 8,118
Re: tiller for whatever the stave will give
« Reply #12 on: February 19, 2019, 06:20:20 pm »
  Willie, I was talking about scaling up like really big like 80 feet or something crazy like that. Kind of like scaling up a flea to the size of a dog. It just doesn't work. Wood seems to work best around human size proportions.

Offline stuckinthemud

  • Member
  • Posts: 2,299
    • avenue woodcarving
Re: tiller for whatever the stave will give
« Reply #13 on: February 20, 2019, 12:26:33 pm »
Thanks guys, I've got a couple of pretty narrow (1.25" diameter at chest height) but otherwise very nice sticks (1 privet and 1 hawrhorn) that will make really nice ELBs.  No idea what draw weight they will end up as, just thought it would be interesting to see what they might yield.