Better way to center holes in T/D risers?

[razorsharptokill]

Is there a better way to precisely locate and drill the holes in the risers and limbs of take down bows than the Binghams jig?

I never have liked the way you have to center the jig using those little thumb screws. not very precise and the screws gouge the side of the riser. How do the big name bowyers do it?

[Curtis Haden]

TTT

[Cupcake]

I recently bought a self-centering dowel jig for about $55.  A week or so ago Rockler had a sale for $27.  It has three different diameter thread-in guide bushings.  None are 27/64 for the threaded insert so I worked out a way to use a smaller diameter as a pilot hole and my drill press.

I had to adjust mine a bit to ensure it is exactly centered, but it was easy.  Search for "self-centering dowel jig" and you will get lots.  Or try Amazon.

[Trux Turning]

I also use a self-centering dowel jig. I just use the 1/4 and 5/16 diameter guides on the jig. I drill the 5/16 first-through the limb and into the riser- then I take the riser to the drill press (square it up)and inlarge the 5/16 hole to 27/64 for the threaded insert. Bolt the limb on-put the dowel jig back on and drill the 1/4 indexing pin hole.Works well for me.

[razorsharptokill]

How do you drill the pin hole with the limb mounted on the riser?

[Trux Turning]

I drill it through the limb and into the riser-the limbs then get an over lay glued on that cover the holes. Since you need the bolt hole or 5/16 one I just flip the limb over and drill through the over lay after it has dried.Here is a picture of the a over lay that covers the pin hole.

[razorsharptokill]

That makes perfect sense now! Why didn't I think of that!

So you drill both holes through the limb into the riser at the same time?

[Trux Turning]

I drill the bolt hole first- once the insert is installed in the riser I put the limbs on and check my center line with a string or laser line-if all is good I then drill the 1/4 pin hole through the limb into the riser-

[razorsharptokill]

Ok that makes sense. That is what I will do on my next one, thanks.

[grizz]

When you bought the self centering doweling jig you should have also recieved a couple extra screw-in bushings. I took the 1/2" one and drilled it out to 27/64" for drilling the hole in the riser. You have to be carefull with this jig because the center block will still move slightly after it is in the clamped position.

[razorsharptokill]

So the Bingham jig could be used the same way. Drill the limbhole and pin hole, take the jig off and drill the hole out to 27/64th in the riser.

[Eastern Hunter 14701]

The bingham jig is used the same way. You drill both sets of holes on the riser first using the end marked "butt riser end", before riser is roughed out. The jig is then turned around to do the limbs. On the limb you are suppose to drill the holes from the belly side. The pin hole is drilled just a 1/4 in. deep so it doesn't show. To keep the jig from gouging the riser you can run a strip of painters masking tape along the edge two deep to protect it. hope this helps

[Bob Sarrels]

I use a jug similar to Binghams but I first drill the 24/67 hole in the riser and the 5'16 in the limb.  Tap and glue in the bushing.  Insert a screw into both threaded screws and heat them with a heat gun to activate epoxy.  Wait 4 hours and screw both limbs onto the riser loosly.  Lay them flat on the bench and tighten them securly.  Reverse my jig on the limb and drill thru both limbs into the riser 1/4 " with the 1/4 ' bit.  Cover hole in limb with limb cap.  Works great.  I really hated Binghams set up.  Expically afler just a few bows.  Holes wallered out and was difficult to get a true cut. New jig has longer guide sleeves made from titanium ( harder than the bits).

[LC]

I basically do what Bob says as for drilling my threaded holes and limb bolt holes simply by measuring. I then have a jig I bolt on the riser for locating the riser index holes. Once those are drilled I put index locater pins in each hole lay my riser and limbs on a perfectly flat board and loosely bolt the limbs up close to the index pin while everything is laying perfectly flat and press the limb base against the index pin. With the limb first covered in masking tape it pin points (pricks a tiny indentation) the exact place to drill the limb pin hole.

I absolutely hated the Binghams Jig thought it was pretty much worthless in my humble opinion.

[gables]

I got a local machinist to make me a 21/64 bushing that fits in my self-centering doweling jig. I have the 1/4, 5/16, and 21/64 bushing loaded in the jig. I also do as trux turning does with the covering plate. I often use glass or phenolic. To me the plate helps spread the pressure much like a fender washer.

[razorsharptokill]

New Bingham jig or did you make one? There is a metal fab shop on my base. I bet they could come up with a jig to do this job consistantly. I'll hit them up at drill this weekend.

[gables]

I use the same self-centering jig shown in Trux Turning's above post. The bushings (jig inserts) are removable. Go to:

http://www.woodzone.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=828625&Category_Code=DBA&Store_Code=Woodworking

The bushing I had manufactured is similar to those shown at the bottom of the photo at this link.