Primitive Archer
Main Discussion Area => HowTo's and Build-a-longs => Topic started by: Apex Predator on June 04, 2008, 10:34:45 am
-
I've started on my next bow. It will be a 66" Hill style tri-lam. It has a bamboo backing, a cypress center lam, and ipe belly. This cypress was cut locally and used by my Grandfather to build his house back in the 1930s. It had been stored in the loft of his barn for 50 years until his death in 1989. I have only a few good pieces. I plan to have some cut into lams for a fiberglass bow that I plan to build one day soon. Anyway, I pre-tapered the core and ipe leaving a thick 14" center section flat on each piece. This thick portion will serve as my island of wood to glue my handle to. I have had trouble with some of them bending into the handle and making the glue lines bulge. I used my new form for this one. I took out the middle post, and used the two deflex posts to support my rather flat handle section. I glued in 2 1/2" of reflex. I'm hoping it will have 1/2-1" when I am finished. Here is the glue up. If you will notice, I had to add two pieces of square tubing so that I had something for my clamps to grab. They would fit around the whole form.
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Glueup.jpg)
Out of the form it still retained 2" of reflex. This is one stout puppy! I'm gonna have bunches of ipe to remove. Good thing I made the cypress thin. Here she is out of the form. I used plenty of Tite-Bond 3 for the glue up.
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Plentyofglue.jpg)
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Plentyofglue-2.jpg)
Luckily things didn't shift much in the form. I wrap electrical tape around the laminates very tightly in three places before I draw it to the forms profile with clamps. You will have minimal shifting though. You will lose a little width while cleaning up the core. I started with a width of 1 1/4" and am hoping for a finished bow with 1 1/8" wide mid-limbs. She cleaned up nice. The glue lines are superb! They keep getting better.
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Gluelines-1.jpg)
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Gluelines-2.jpg)
I forgot to mention. While the blank was curing in the form for 24 hours, I prepared my riser and tip overlays. I was using a solid ipe block for my riser, but wanted a hickory accent stripe. Here is the ipe and hickory glued up. In the past I have stacked several pieces of handle material, but with this one in wasn't required since my handle section is flat. I glued some pre-prepared elk antler to a thin piece of ipe, for contrast, with CA Gel.
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Riserstart.jpg)
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Tips.jpg)
-
Should be a neat bow. ;D What draw weight are you shooting for? How long is the bow?
-
Here is a dry fit check of the handle section followed by the glue-up.
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Riserdryfit.jpg)
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Riserglueup.jpg)
Here is a dry fit check of the tips followed by the glue-up.
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Dryfittips.jpg)
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Glueuptips.jpg)
Tomorrow I will clean every thing up, rough shape the tips, cut the fades, trap the boo, and put a long string on her.
-
I'm shooting for 55@28, and she will be 66" NTN.
-
the bamboo looks very thick! Good luck with that.
-
My one experience with ipe would leave me to believe that you will have no trouble making weight. ;) I love Hill style bows, and am looking forward to this one. I read and reread Hill's "Hunting the Hard Way" book and it'll be neat to see you build a bow like he did before using fiberglass. Thanks,
Stan
-
guys, what IS a HIll=style bow?
-
Hill style simply means that it is a straight, or nearly straight, longbow of greater length with no deflex. They generally have a narrower, and deeper cross section than a flat bow, and small light-weight riser. That's my definition. I may be off base though.
This piece of boo is has quite a thickness variation between the nodes. I left it a little thicker than normal, but think the ipe can handle it. It measures around 1/8" at the thinnest between nodes.
-
Thanks for the def'n, AP. I have a few trilams leaning in the corner waiting to be tillered. They are all r/d shapes, with maple back, maple core, and yew belly wood rising up over the fades. They are damn thick in section, too: about 5/8! Way too much. Broke one the other day. Had it tillered to 50# at 22", but i wasn't seeing any of the usual shape of r/d bows on stringing...I think I made a mistake and made these bows too thick. But if I reduce the backing thickness by 1/2 what it is now, and go seriously narrow on the width overall, I should be okay.
-
so, how wide are the limbs on a hill style bow? pretty narrow, i guess? If my limbs are 5/8 thick, and tillered into lenticular shape, i guess they should be an inch wide at the most? I'm shooting for 50 lbs or so...66" bow ntn.
-
I think my last one was 1 1/8" wide tapering to about 3/8-7/16" tips.
-
and how thick?
-
I sold my Wesley, but have an Owl on the way. I'll let you know how deep the limbs are when she arrives.
-
Todays update contains some bad news! My belt sander bit the dust. It is a small table top model that I have run the dickens out of. I have probably ran it hard for a couple of hundred hours! I'm gonna tear it apart tonight and hopefully it's just a start capacitor of something. I did get the tips and the riser roughed out before it died. Here are some pics.
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Beltsander.jpg)
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Riserprofile.jpg)
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Roughtip-2.jpg)
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Roughtip.jpg)
-
That's too bad about your sander, I hope you can fix it.
How's the bow coming? Bend it yet?
-
I tried, but she is probably 100# right now. I have to remove a lot of wood first.
-
Wish I had more to add, but no progress worth taking photos of. I took the capacitor off my sander and it was blown, but a new one didn't make it work! I guess I need to buy a new sander. I have been working the limbs down with a wood file and scraper. After several hours of sweat, I am about half way to being able to brace it! I figure the belt sander would have got me to the brace stage in less than an hour. It will take about 5 hours with these hand tools. That is the problem with using new designs. I have to leave bunches of wood to start, so that I don't come in under weight. I have a really good taper, so I am working both limbs down evenly. Hopefully, I can get a string on it by tomorrow morning and take some more photos. Stay tuned.
-
Maybe a good lesson for you in using hand tools. I have a sander but I never use it for tillering a bow limb anymore. I did that in the early days until I learned to use my other tools properly. Nothing works as good as a good sharp scraper and a fariers rasp. I can remove material just as quikly with them and I have way more control with them. Good luck and have fun. Ryano
-
Here is a quick update. I haven't had as much time to work on it lately, and the work is going slower without my belt sander. I am almost ready for bracing. The right limb is still a little stiff though.
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Reflexbeforelongstring.jpg)
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/LongString-1.jpg)
Here is a riser shot showing the fades, and another showing the tips a little more finished.
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Riserontree.jpg)
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Smoothertips.jpg)
-
I was able to work on my bow some more this morning. I got the limbs bending 10" past the handle on the long string. Now it's time to cut some string grooves. I start with just a groove on the back to hold the string. After I string her up she may need some side adjustment on the limbs to get the string to line up down the limbs. After I get everything in line I will trace the string on each side of the tip while it's strung to know where I want the grooves cut into the sides. I measure 3/4" from the very tip and mark a line. I find this gives me room for a cup style stringer. I first cut a guide line in with a small trianglular file and then follow it with a tile cutting coping saw. I cut it just deep enough for most of the saw blade to hide in the groove.
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Cuttingstringgroove-1.jpg)
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Cuttingstringgroove-2.jpg)
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Cuttingstringgroove-5.jpg)
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Cuttingstringgroove-3.jpg)
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Cuttingstringgroove-4.jpg)
I strung her up with a brace height of 3-4" and gasped in shock. I had a bad hinge in both limbs just past a node on each end about 12" from the tips. I unstrung her immediately! I still have a good bit of belly wood to work with, and think I can work out the hinges by removing wood else-where. On the long string the limbs were bending some towards the tips, and I should have known they were too thin. As I learn these mistakes I will become a better bowyer! Hopefully some of you can learn from my mistakes! :)
-
i think your long string is a little bit waaaaay too long. it's deceptive.
with the long string, pull til you feel some tension in the limbs, then, if you can draw it the equivalent of a normal brace height (say, 7 inches past where the feeling of limb tension set in), then go to a very slight brace...like 2 inches. You want to brace it as soon as you can, but low. This will show you what the limbs are doing, but in a safe manner. Then you can work out your hinges, and as they disappear, you can gradually increase the brace height to 3", 4", and on up to 7" or whatever.
Looking good so far, man. How thick is it and how wide? Is it a direct taper from the fades to the tips, or do the limbs run parallel partway?
-
1 3/16" or so wide. I'll have to measure the tickness for you. It is a straight taper to the tips.
-
thanks
-
I have been finishing a Hill blank the last few days, and will return to this one in a day or so.
-
Well folks this one died a horrible death this morning. I had worked out the hinges and some limb twist as seen here.
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Lowbrace.jpg)
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Limbtwist.jpg)
I had the bow drawing to 10-12", and was excercising the limbs, when she exploded pretty violently. Luckily, I was standing 12-13' away from my tiller tree. It looks like the cypress just couldn't handle the shear strength. I should have known better! This cypress was pretty, had straight grain, but was feather light.
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Ka-blam.jpg)
(http://i121.photobucket.com/albums/o203/Apex-Predator/Boo-Cypress-Ipe/Ka-blam-2.jpg)
Well, you know what they say. If you ain't breakin, you ain't makin! On to the next one!
-
Good spirit, man! Yeah , i broke one a couple weeks ago myself...choked up mad for about 2 seconds, cuz it was GOING TO BE so pretty and so mega...but then just grabbed another blank from the corner and started cleaning it up.