Primitive Archer

Main Discussion Area => Bows => Topic started by: JonW on March 31, 2011, 09:04:10 pm

Title: Caul length question
Post by: JonW on March 31, 2011, 09:04:10 pm
I have a question for you caul experinced guys. I am preparing to make me a caul but I'm not sure on the length. I make bows from 52" - 62" so what do you guys think my length ought to be?
Title: Re: Caul length question
Post by: Pat B on March 31, 2011, 09:42:37 pm
If you want the 62" and the 52" bows to bend the same you will have to make a caul for each...or you can make one longer caul that can be used for both.  The shorter bow won't have as much bend.
Title: Re: Caul length question
Post by: JonW on March 31, 2011, 09:52:22 pm
Pat maybe my question wasn't worded right. My bows are usually 52" up to 62" and everywhere in between. What length would you think would be ideal for bows in that range. I think I have the curve I want for the longer end of my range, but want to be somewhere that will put enough reflex on the shorter end of the range as well.

Thanks
Title: Re: Caul length question
Post by: Dvshunter on March 31, 2011, 10:15:10 pm
I agree with Pat. To get what you are looking for you really need twwo cauls. I use a caul the is really long and only use the part that I want for a certain part of the bow. Like only the very last end for one tip, then flip the bow and use the same part for the other side. Multiple cauls would equal less overall heatings to get the desired results. Hope that was clear.  :-\
Title: Re: Caul length question
Post by: ErictheViking on March 31, 2011, 10:33:50 pm
Jon, What  Pat  said is that if you use the longer size caul on the shorter limbed bows you willl end up with less reflex in them. if you are o.k. with 1/5 or so of less reflex in the shorter ones you will be fine. I just made my own caul this weekend, 68" over all with 3" of reflex. the board was a 2x6 8ft long and cost me $3.50. just make 2, they are actually easy and quick to make.
Title: Re: Caul length question
Post by: Acutus on March 31, 2011, 11:26:41 pm
Caul?? ???
Title: Re: Caul length question
Post by: Lombard on March 31, 2011, 11:53:05 pm
I made this graphic up to help another guy who wanted to make a caul. I have various cauls for different length bows, and varying degrees of reflex. Right or wrong, I tend to make them two or three inches longer than the bow that will be reflexed on them, and account for that in the curve. You can get more or less reflex by adjusting the numbers, kinda self explanatory once you get started. The graphic should give you the general idea though. I went to boat building school about thirty years ago, (holy crap, I'm gonna be fifty this year)  and we used lines like the layout in the graphic to get fair curves on panels in the layout of marine plywood panels. Shame everything went to fiberglass, as I love wooden boats. You might visualize that the curve in the graphic has a hull form to it.  Experiment before you cut, and if you make a mistake, pencil marks are easily sanded away.
Title: Re: Caul length question
Post by: Pat B on April 01, 2011, 01:04:48 am
I use a couple different cauls depending on the bow and the side profile I want. I have one that gives full length(68") reflex, another that works on the inner 2/3 of the bow and a few others for different reflexed or recurved tips. All made from scrap lumber without much thought. My caul for the inner 2/3s also has a backboard for taking out latteral bends and lining up the tips.
  Make your form to accept your longest bow. If you put a smooth even bend in it it should work for your shorter bows also, you just won't get as much reflex in the shorter bow. You could add a block under the handle to make up for the length difference.
Title: Re: Caul length question
Post by: Dvshunter on April 01, 2011, 01:11:05 am
I use a couple different cauls depending on the bow and the side profile I want. I have one that gives full length(68") reflex, another that works on the inner 2/3 of the bow and a few others for different reflexed or recurved tips. All made from scrap lumber without much thought. My caul for the inner 2/3s also has a backboard for taking out latteral bends and lining up the tips.
  Make your form to accept your longest bow. If you put a smooth even bend in it it should work for your shorter bows also, you just won't get as much reflex in the shorter bow. You could add a block under the handle to make up for the length difference.

nailed it.
Title: Re: Caul length question
Post by: Pat B on April 01, 2011, 03:05:46 am
Here are a few of my forms...

2/3 with back board...
(http://i5.photobucket.com/albums/y199/PatBNC/TGtradebow2011004.jpg)

recurve...
(http://i5.photobucket.com/albums/y199/PatBNC/2011TGtradebowelm005-1.jpg)

limb reflexing...
(http://i5.photobucket.com/albums/y199/PatBNC/TGtradebow2011003.jpg)

Title: Re: Caul length question
Post by: Pappy on April 01, 2011, 09:01:55 am
I use the same one for all full length bends,mine have an even tapper from center to the end.I have short ones for flipping or recurving the tips so they will work on any length. I do have several with differen amounts of reflex on them. 3 inches 4 inches and 6 inches.I like the 3 the best. :)
   Pappy
Title: Re: Caul length question
Post by: JonW on April 01, 2011, 11:20:32 am
Thanks for the tips (pun intended) guys!

@ Pat
     I was thinking about using the longest measurement and using shims or spacers to gain reflex on the shorter bows. Thanks for confirming it for me. Sometimes I just need to hear it from someone else...........

@ Pappy
      I put 3 inches in mine as well. Seemed "right".


Jon W.