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Main Boards => The Bowyer's Bench => Topic started by: bjansen on April 23, 2012, 09:59:00 PM

Title: trapping jig
Post by: bjansen on April 23, 2012, 09:59:00 PM
I made a very simple but effective trapping jig for my sander this weekend in order to get 10 degrees of trap on my R/D bows.  I used to do this by hand with files but that took a while and had to rely on the feel and angle of the file to get it even on each side.  I also had a hard time trapping from edge to edge...this is much faster and more accurate and thought I would share.  You could certainly make one to fit a Rigid sander as well, but this attachment method worked quite well with that little table that is on the end of the Grizzly.

(http://i492.photobucket.com/albums/rr287/bjjanse/IMG_20120423_192025.jpg)

(http://i492.photobucket.com/albums/rr287/bjjanse/IMG_20120423_192037.jpg)

(http://i492.photobucket.com/albums/rr287/bjjanse/IMG_20120423_192047.jpg)

(http://i492.photobucket.com/albums/rr287/bjjanse/IMG_20120423_192240.jpg)

(http://i492.photobucket.com/albums/rr287/bjjanse/IMG_20120423_192308.jpg)
Title: Re: trapping jig
Post by: Smeans on April 23, 2012, 10:14:00 PM
Very nice!
Title: Re: trapping jig
Post by: White Oak on April 23, 2012, 10:19:00 PM
Great idea Brad! You must be getting a little more time in the shop again.  :thumbsup:
Title: Re: trapping jig
Post by: Big-un08 on April 24, 2012, 12:41:00 AM
Brad that's sweet!!! I like it.
Do you have specific line-up points on your table for mounting the jig or does it even matter?
Title: Re: trapping jig
Post by: Razorbak on April 24, 2012, 01:39:00 AM
looks good and great idea..but looks like it would do one side..do you have another to clamp to do the trap on the other side as im thinking the sanding belt goes in one direction and if you flipped the bow then wouldnt the trap be reversed?
like I said great idea but i was curious
Title: Re: trapping jig
Post by: bjansen on April 24, 2012, 09:09:00 AM
Big un, I do not have specific points.  I set one end and then get the the drum lined up just as shown in that side view pic and then lock the other side in.  


Razor, after I finish trapping one side (pushing it through), I just step on the other side of the table and pull the other side through, thus getting the same trap on both sides.  I initially had a fence on both sides, but that was not as effective as this single fence.
Title: Re: trapping jig
Post by: Greg Szalewski on April 24, 2012, 01:16:00 PM
Good thinking Brad.
Title: Re: trapping jig
Post by: kennym on April 24, 2012, 09:49:00 PM
Cool jig buddy!!
Title: Re: trapping jig
Post by: Razorbak on April 24, 2012, 10:27:00 PM
ok I saw the gap and was wondering if you would get the same depth and such..still a awesome jig..thank you
Title: Re: trapping jig
Post by: David Flanrey on April 27, 2012, 02:57:00 PM
Great idea.  I just trapped a bow this morning with files and sanding blocks.  Like you said, it was slow and I got lots of glass in my fingers.  I'll have to make one myself.  Thanks for sharing.
Title: Re: trapping jig
Post by: Swissbow on April 28, 2012, 11:15:00 AM
That is sleek. I have to get me one of these jigs.

----------
Andy
Title: Re: trapping jig
Post by: wood carver 2 on April 29, 2012, 10:14:00 PM
Great idea! Thanks for the tip.
Dave.
Title: Re: trapping jig
Post by: NYArrow on November 04, 2013, 09:10:00 PM
I'm considering making one of a jig like this....how do you maintain the angle once you hit the riser area? Seems like the fades and riser would raise the bow and throw the angle out of whack. ?
Title: Re: trapping jig
Post by: LittleBen on November 04, 2013, 09:28:00 PM
Good question NY arrow .... I'm also interested. Perhaps some pics or a video are in order.
Title: Re: trapping jig
Post by: chackworth3 on November 04, 2013, 09:44:00 PM
Very cool!
Title: Re: trapping jig
Post by: jsweka on November 04, 2013, 10:22:00 PM
Nice!  That's gotta be much more accurate that free-handing and eyeballing it.
Title: Re: trapping jig
Post by: Dmaxshawn on November 05, 2013, 06:42:00 AM
Cool jig Bud.  Glad to see your back in the shop Brad.  

Shawn
Title: Re: trapping jig
Post by: bjansen on November 06, 2013, 08:29:00 AM
Regarding:  How do you maintain the angle once you hit the riser area? Seems like the fades and riser would raise the bow and throw the angle out of whack. ?

The fades and riser will throw it out of wack....when you get to that point I basically stop and finish it up with hand files.
Title: Re: trapping jig
Post by: scars on November 13, 2013, 11:57:00 PM
Is there any reason why you couldn't put the fence on the thick side of the 2 by 4 base, and run the bow face down? That looks like it would eliminate the riser issue. I have never made a glass bow  but from looking at your jig and seeing what you want to accomplish without the riser getting in the way. It might work.
Joe
Title: Re: trapping jig
Post by: Bowjunkie on November 14, 2013, 07:18:00 PM
Ok, I'm a jig guy, I've got stacks of them, but I'll be the odd guy here and say I don't think this type of jig would work well for me. It would set me back. My eventual 'trap shape' varies/evolves from flares to mid limb to outer limb a noticeable amount... better accomlished by hand, eye, and feel, than by jig. Know what I mean?
Title: Re: trapping jig
Post by: bjansen on November 15, 2013, 08:55:00 AM
Scars, if I am thinking about your observation correctly...and maybe I am not:  If you put the fence on the thick side of the 2x4 (i.e. not riding right up against the sanding wheel) you would not be able to adjust how much material the sander would take off.
Title: Re: trapping jig
Post by: scars on November 16, 2013, 04:20:00 PM
No, Mount the fence on the thick side Put the thick side of the 2x4 closest to the drum. Just like you have with the jig now but mirror image it. Your fence would make your trap equal amount of removal. Same principal as a router table. The high side of your table will be against the drum.

The fence would still be against or next to the drum
Title: Re: trapping jig
Post by: Gundog68 on November 20, 2013, 01:01:00 AM
I made an adjustable jig which allows me to use a shelfboard as a rail. This works on a drill press. I made the prototype for a spindle sander but with the drill press it works better. Also a use a crossslide which allows me to adjust in fine details.

  (http://s13.postimg.org/5wg89cec3/Trapping_JIG1.jpg) (http://postimg.org/image/5wg89cec3/)
Title: Re: trapping jig
Post by: bamboo on November 20, 2013, 07:10:00 AM
QuoteOriginally posted by Bowjunkie:
Ok, I'm a jig guy, I've got stacks of them, but I'll be the odd guy here and say I don't think this type of jig would work well for me. It would set me back. My eventual 'trap shape' varies/evolves from flares to mid limb to outer limb a noticeable amount... better accomlished by hand, eye, and feel, than by jig. Know what I mean?
I do know what you mean--not as much trap on the limb butts [fades]as mid limb-as the tips--and I feather out the trap on the tips around the transition to the tip wedges
I found if I layed it out with reference lines--on the belly-say 3/16" in from the rough shape-from fade to tip wedge and grind to that with an eased transition area at both ends of the trapped section--then I finish up with a long block by hand and sanding tape [shoeshine fashion]
they come out pretty consistent
my first thought is always jig too--in this case it was not the answer for me--
Title: Re: trapping jig
Post by: bjansen on November 27, 2013, 08:30:00 PM
Understood Scars...great observation. Simple fix, yet I would never have thought of that.
Title: Re: trapping jig
Post by: scars on November 28, 2013, 08:45:00 PM
:thumbsup: