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Author Topic: Caul Shape  (Read 7364 times)

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Don Case

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Caul Shape
« on: June 24, 2014, 01:07:16 pm »
I'm going to make a caul today. I'm going to be using it mostly to correct deflex and lumpy bumps before tillering. Should it be circular or a little elliptical with more curve toward the end? I am thinking about 3" reflex, is that about right? I will probably be making more as my experience builds but I'm looking for ideas for the first one.
Thanks
Don
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Offline Pat B

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Re: Caul Shape
« Reply #1 on: June 24, 2014, 01:32:49 pm »
Don, 3" to 4"of reflex is perfect IMO. A shallow, circular or elliptical  form will work. I like a back on a form for straightening and removing twists. For reflexed or recurved tips I use separate forms just for that. Look at Pappy's form on the "Life is Good" thread. You will get a good idea from that.
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Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Badger

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Re: Caul Shape
« Reply #2 on: June 24, 2014, 01:43:02 pm »
  Gary Davis gave me a pattern you can copy while I was at the Twin oaks a couple of years ago, I love it. I could print that up some time later today if you like. I could proably explain it easier than draw it.

   If your cawl is 66" long at each end of the cawl mark 1/4 marks until they are 4" high ( 16 marks) Start your first mark even with the back of the bow.
  Now measure out 5" each side of center. You will have 28" of limb to mark. Divide the 28/16=1.75. Ok starting at 5" from center make horizantal lines every 1 3/4" until the end.

   Once you have the lines and dots on your cawl you will start laying out the shape. Hold your yardstick at the bottom of the first line and aim it at your lowest dot. Only draw your line to the next 1 3/4 line even though your ruler is lined up to the end. Next line put your ruler where the first line intersected the second line and line that up to the next 1/4" dot. Only draw this line to the next 1 3/4 mark. Keep doing this till the end, the radius gradually gets tighter as you near the end of the tips. Maybe Pappy can review this but I am pretty sure this is it.
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Don Case

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Re: Caul Shape
« Reply #3 on: June 24, 2014, 01:53:33 pm »
Thanks guys, I think that's all I need. Well that and a 2x6 :D
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Offline PEARL DRUMS

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Re: Caul Shape
« Reply #4 on: June 24, 2014, 02:02:20 pm »
Ive come to like maybe 1/2" of reflex from center out 18-20", then really drop it off mid limb, say 2-3". I noticed my bows took the set they did at the width taper.
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Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline Badger

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Re: Caul Shape
« Reply #5 on: June 24, 2014, 02:07:46 pm »
  Don, I was just going by memory so you might wait till someone reviews it. I refine mine a bit on the belt sander after I get the intitial shape done with the lines.
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Offline Buckeye Guy

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Re: Caul Shape
« Reply #6 on: June 24, 2014, 02:56:42 pm »
Steve is close
I lay out for the Handle  I want then dived it out
I also use 1/8 instead of 1/4  inch marks for a smother transition less sanding
Go from last intersection to next
You will end up with a progressive radius that works very well even if it is hard to describe!
 Guy
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Guy Dasher
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Offline PEARL DRUMS

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Re: Caul Shape
« Reply #7 on: June 24, 2014, 03:04:55 pm »
Use an aluminum yard stick and avoid all those marks and sanding/rasping. It forms and bends, you just trace it out on the wood. Zero clean up off the saw. Keep it simple!
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Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline Will H

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Re: Caul Shape
« Reply #8 on: June 24, 2014, 03:57:19 pm »
I found the Gary Davis more simple and more symmetrical than any other method I've used in the past. I used to do the bent yardstick trick but for me Gary's way was better.
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Don Case

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Re: Caul Shape
« Reply #9 on: June 24, 2014, 04:17:32 pm »
I'll make a bunch of marks and then join them with the yardstick/batten. That'll make everyone happy and I'll get a smooth arc with no rasping. When I'm using this thing and the stave has a big knot on the back I imagine I would have to space the whole stave out. How far apart should the spacers be? I hope you followed that.
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Offline Badger

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Re: Caul Shape
« Reply #10 on: June 24, 2014, 05:10:06 pm »
  Band saws tend to follow smooth arcs anyway. Pretty hard to male a sharp turn with one.
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Offline Buckeye Guy

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Re: Caul Shape
« Reply #11 on: June 24, 2014, 06:21:09 pm »
The sanding is the east part for me
the hard part is remembering where I put the template so I don't have to lay it out again
since I make the caul out of hard Maple they last way longer than my memory!
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Guy Dasher
The Marshall Primitive Archery Rendezvous
Primitive Archery Society
Having  fun
To God be the glory !

Offline Badger

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Re: Caul Shape
« Reply #12 on: June 24, 2014, 07:10:27 pm »
Quote from: Buckeye Guy on June 24, 2014, 06:21:09 pm
The sanding is the east part for me
the hard part is remembering where I put the template so I don't have to lay it out again
since I make the caul out of hard Maple they last way longer than my memory!

   I made mine out of doug fir boards, next time I will use a plywood I think.
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Offline Buckeye Guy

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Re: Caul Shape
« Reply #13 on: June 24, 2014, 08:23:45 pm »
Hard Maple taks the heat better than anything else that I have tried !
anything else is a waist of time in my opinion
plywood may be a bit toxic when it smokes
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Guy Dasher
The Marshall Primitive Archery Rendezvous
Primitive Archery Society
Having  fun
To God be the glory !

Offline Badger

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Re: Caul Shape
« Reply #14 on: June 24, 2014, 08:35:15 pm »
  I will price it out I think maple is about 10.00 bd ft down here.
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