Countersinking bridge pin holes

[Matt Winfree]

Hi, I'm brand new to the forum and I apologize if this issue has been addressed before. But, I'm having a very difficult time of countersinking bridge pin holes in ebony. I get awful chipout every time. I've tried using a multi-fluted countersink and a drill bit countersink in my drill press with no luck. To minimize chatter, my last idea has been to use a v-shaped router bit and use my plunge router to countersink the pre-drilled holes. No luck there either. I had the router securely attached to my bench and at its fastest speed. Can someone advise?

Thanks,
Matt

[Greg Mirken]

These are what I use. They leave a very smooth hole with no chattering.

http://www.woodcraft.com/family.aspx?familyid=5154

Greg Mirken

[hobocaster]

On the handful of briges i've made, I used a multi fluted countersink.. but instead of chucking it into a drill, I just twist it by hand. It still removes material fairly quick, and I can control the pressure easily, and watch the progress closely. Then a quick clean up with some sandpaper. I've done this with ebony and rosewood.
I imagine some of the more experienced folks here can chime in with further advice..

I'm new myself.. Welcome!

[Ronnie Nichols]

You might also try using a hand-held drill that is variable speed. This will give you a little more control. There are also some diamond tipped dremel-type tools that can be used for the finishing part of the process. The hand drilling that was mentioned is also a good way to control it. The multi fluted countersinks are hard to control unless the speed is just right. The variable speed may help a lot.
Ronnie Nichols

[Jim Bancroft]

I've used a similar tool in a drill press, and haven't had problems. I go with a slow feed at medium to higher speed, slow speed seemed to cause more chatter. Is the countersink in good condition, if not, try a new one.
StewMac probably sells a more proper tool, but I found the hardware store variety satisfactory. Certainly haven't had any chipping.

Jim

[Rev George]

I agree with hobocaster. Use the bit or countersink by hand and go slow! I've been using hand reamers for a while now for various holes in instruments and it may take a little longer, but the work comes out (for me at least) neater and cleaner. Fortunately the instruments I'm making don't require speed in their building. My customers don't mind waiting. They like the slow, hand-built, hand tool idea. Thank god I don't depend on this work for my main income!

Rev George

[Matt Winfree]

Thanks for all the tips! I went and bought a new 1/2" multi-fluted countersink at Lowe's and hand drilled it like hobocaster said and it seemed to work pretty well. The holes were already a bit chipped out so I'm sure it will work much better on a fresh bridge. I like the look of the Woodcraft countersinks that Greg mentioned. Quality blades always help!

Thanks again!