this is my first attempt at a recurve tip form.i started out with some leftover birch plywood from a previous project. its is 6 3/16" wide rips following the grain. i used my speed square to make a 20 degree mark from the bottom of the plywood. i also used a coffee can that measures 6 3/16' in diameter.i lined up the can with the top and bottom edges of the rip and slid the can to the 20 degree mark and traced the radius from the mark to the top of the sheet. here are some (http://i602.photobucket.com/albums/tt101/broketooth/100_0504.jpg) pics. i made the cuts with my table say my chop saw and a jig saw. the radius cut with the jigsaw i cut a touch big we will clean this up with a sander. (http://i602.photobucket.com/albums/tt101/broketooth/100_0506.jpg) (http://i602.photobucket.com/albums/tt101/broketooth/100_0505.jpg). i used my table saw because it has a cast iron machined surface to be perfectly flat. i made sure that all machined surfaces where square with a cobination square.
the next step was to fasten all the peices together i used 1 1/4" cource thread sheetrock screws. i counter sunk them to make sure they grabbed alll the material. (http://i602.photobucket.com/albums/tt101/broketooth/100_0509.jpg) (http://i602.photobucket.com/albums/tt101/broketooth/100_0508.jpg). after that i took my speed square and found the apex of the arc and made a 45 degree line intersecting the apex to the meaty prtion of the form. i did this so i could make a notch in the form to accept a c-clamp so i could clamp the peice im bending at the apex of the curve. (http://i602.photobucket.com/albums/tt101/broketooth/100_0513.jpg) (http://i602.photobucket.com/albums/tt101/broketooth/100_0514.jpg)
after that i cleaned up the radius on my benchtop combination sander. (http://i602.photobucket.com/albums/tt101/broketooth/100_0510.jpg) (http://i602.photobucket.com/albums/tt101/broketooth/100_0511.jpg). tomorrow a.m. i will cut the metal strip to protect against splintering a do a test bend on a previous mistake to see if the bend is satisfactory. im hoping that the more experienced bowyers will tell me what they think. mr pat if this form looks farmiliar ive been studying your form i think its a close copy just not as long. ruddy
Thanks Ruddy. I will be making this! I have a few bows in the works and wanted to put some curve in their tips. :thumbsup:
Nice job I really like the looks of that form. Cant wait to see the rest.
Shawn
Thanks Tooth
Sure looks good, way to go.
look good ruddy. I think yall have built a bow building mechine there; gang.
Ruddy, IMO this is an outstanding teutorial, for anyone wanting to build a form like this, that never has done one before. It should be a big help to lots of folks in future. Good pictures, good explanations, and good coverage. Keep up the good work, buddy. I'm looking forward to the rest of the pics, and the trial run of the form. Also to see you use it on the bow you are building for me when the time comes.
Kelly is right, I think, you're becoming a bow building machine, my friend.
well like i said we are getting ready to cut the pressure strip. i laid out a 3' strip of galvinized flashing. (http://i602.photobucket.com/albums/tt101/broketooth/100_0521.jpg). i marked out the thickness of my form on the metal , placed a straight edge on the metal and scored it several times with my utility knife. (http://i602.photobucket.com/albums/tt101/broketooth/100_0522.jpg) (http://i602.photobucket.com/albums/tt101/broketooth/100_0523.jpg) (http://i602.photobucket.com/albums/tt101/broketooth/100_0524.jpg). the last pic is after i cut the strip of metal.
in this pic. (http://i602.photobucket.com/albums/tt101/broketooth/100_0525.jpg). i attached the metal strip 2" in for strength using self tapping metal screws. then i made a bracket from the same metal to act as my first clamp over the metal pressure strip. (http://i602.photobucket.com/albums/tt101/broketooth/100_0526.jpg). at this point im prepped to bend a previous mistake to to do a test bend to see if i need to make any adjustments to my form. (http://i602.photobucket.com/albums/tt101/broketooth/100_0527.jpg) (http://i602.photobucket.com/albums/tt101/broketooth/100_0528.jpg)
ive definatly made a few mistakes.my material to bend is to thick from back to belly. my angle and my radius is to sharp/ dramtic. i need to soften it up a bit. my end result of my first attempt is a flat spot with 2 breaks on the outsid of the radius. (http://i602.photobucket.com/albums/tt101/broketooth/100_0529.jpg). i id soften the rake of the angle to 30 degrees and increased the radius transition to a wider arc. i think im hitting on something here. (http://i602.photobucket.com/albums/tt101/broketooth/100_0530.jpg). just a reminder im using a scrap peice from a previous faliure to practice with. the next attempt will be on the real deal. ruddy. postive and negative comments welcome. ruddy
Ruddy after you scored the flashing did you just bend it over the edge of the table to break it off. Or did you use them tin snips to follow the line?
i just bent it over in half so to speak. ruddy
Cool jig. How thick is your tip? I wouldn't go more than 1/2".
john, i used a previous mistake to do my practice bends to achieve the right angle and propper radius in the transition. i know it was a little thick, 3/4" to be exact. but it wasnt the goal. it was to get the right angle and curve in the radius. i coppied pat brennens curve form to the best of my ability just from seeing the pics from his red elm trade thread. i hope pat doesn't mind. immitation is a form of flattery yes. ruddy
I've never known of Pat minding when anyone learns from or copies anything he posts. He enjoys sharing his knowledge has always been my read on him.
That's some bend, Ruddy - it boggles my mind. Did you have to build a second form or were you able to just modify the curve on the first one?
bernie , i left enough room for adjustment. i had this in mind from the beginning. im real close for sure. thats why i used scrap to test it. i dont want to screw up a perfectly good peice of bow wood. ruddy
Just because it splinters a bit on the belly of the bend it's not ruined. Sand it with a belt sander and laminate a piece of horn on the belly. I did the same on my first static several years ago and I'm still shooting the bow. Plus the horn looks really classy. Good Luck - Tommy
I follow you - so I take it on the second attempt the "test stock" didn't break out even though it is thicker than you would normally have the actual limb tip.
no where near as bad bernie. like pat brennen, and john scrifres have been sayind anywhere from 1/2"- 5/8" thick from back to belly is optimum.i really feel good about it, we shall see. as you know , nothing is a sure thing. ruddy
LOL - you got that right!
Ruddy, You are coming along nicely and picking this stuff up quickly. Half inch thick is about what I like but have bent a bit thicker. More chance of it splintering when thicker. Heat slowly and thoroughly and let the wood get plastic before bending. I always use oil when bending recurves to prevent scorching, deliver the heat more evenly and hold the heat longer. If the wood is thicker or a bit stubbern to bend heat it well and wrap in alum foil for about 5 minutes and heat again to bend. This will give the heat time to go deep into the wood.
Have your metal band as tight as possible before you begin to bend. As you bend the tips the band tightens and adds pressure around the outside of the bend helping to prevent splintering.
Save your test piece. Before you know it you will have enough confidence to tiller it!!! d;^)
Are you heating by steaming the wood or using a heat gun. Just curious. I would think steaming somehow would heat it deeper and be less destructive to the wood fiber but I might be all wrong. I have never done this before.
Sixby, he is using a heat gun. Osage reacts very well to dry heat. Other woods like hickory do better with steam.