Official Luthiers Forum!
http://www.luthiersforum.com/forum/

countersunk
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=21825		 Page 1 of 1
Author:  Tai Fu [ Tue Apr 07, 2009 3:08 am ]
Post subject:  countersunk
I have been trying to find suitable countersink bits to countersink the bridge properly but I don't want to sink almost 40 dollars on a Stewmac tool that does only that. I ordered a countersink from Enco but I got confused with their countersink angle and it turns out that while 60 degree is great for Fender pickguard it's too steep for bridge holes. The problem is that I needed to jump through a ton of hoop to order from Enco and they insist on shipping it express, so that means 30 dollars shipping for a 5 dollar part. I tried local tool dealers and they don't even know what a countersink is much less provide the correct one so in desperation I bought one of those drill/countersink thing that also turns out to be a 60 degree countersink (and sadly drilled it into a bridge). I tried ordering through McMaster Carr and they said in an email that due to ever complex export regulations (which only consist of filling out one form) they will only deal with a few overseas customers. Caswell plating only accept wire transfer which costs 15 dollars.

So can someone do me a favor? I will order a correct countersink from ENCO or other tool dealers, send it to you then you forward it to me in a first class envelope (which costs like two or three stamps). Or if someone has an extra countersink of the correct size to sell me that would be great too. What degree countersink should I use? 90 or 100 or 120?
Author:  Laurent Brondel [ Tue Apr 07, 2009 8:59 am ]
Post subject:  Re: countersunk
Is this to countersink the bridge pin holes? You can get a carbide burr at a machine shop for much less money.
Author:  Tai Fu [ Tue Apr 07, 2009 9:56 am ]
Post subject:  Re: countersunk
Laurent Brondel wrote:
Is this to countersink the bridge pin holes? You can get a carbide burr at a machine shop for much less money.


I am not sure which carbide burr you're referring to... I tried to find a suitable burr but they were either too steep or too expensive. I thought about using a angle router bit but I think that might chatter a lot. Enco sells most countersink at 5 bucks a piece...
Author:  Laurent Brondel [ Tue Apr 07, 2009 12:52 pm ]
Post subject:  Re: countersunk
A router bit to chamfer your bridge pin holes seems like a bad idea…
Any machine shop should carry a selection of carbide burrs suitable for the job. Otherwise a hardware store/home centre should have countersinks.
Author:  TonyKarol [ Tue Apr 07, 2009 5:56 pm ]
Post subject:  Re: countersunk
The countersink from Lee Valley is awesome ...its about 15 bucks IIRC.
Author:  Shane Neifer [ Tue Apr 07, 2009 6:48 pm ]
Post subject:  Re: countersunk
Hi Tai Fu,

Here is the link to the Lee valley ones:

http://www.leevalley.com/wood/Search.aspx?c=2&action=n

I just bought the larger one on the top row right but have other ones as well that I bought at local industrial stores (for metal working). They are 82 degrees and should be fairly common, even in Taiwan.

Good luck!

Shane
Author:  R W Goodman [ Tue Apr 07, 2009 7:15 pm ]
Post subject:  Re: countersunk
There was a discussion on this awhile back and I believe it was Mario who said he used a rotary tool grinding stone.

Warren.
Author:  Shane Neifer [ Tue Apr 07, 2009 8:25 pm ]
Post subject:  Re: countersunk
R W Goodman wrote:
There was a discussion on this awhile back and I believe it was Mario who said he used a rotary tool grinding stone.

Warren.


Hey Warren,

That particular one looks way too pointy (to get technical!). Also those units are quite soft and the abrasive breaks off quite easily so that would concern me as the strings may rest against that area a bit. But hey, Mario has WAY more experience at that than me...but still there must be other angles that he was referring too.

Shane
Author:  Hank Mauel [ Tue Apr 07, 2009 9:26 pm ]
Post subject:  Re: countersunk
Here is a link to MSC Industrial that will show you what a carbide burr looks like.

http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=1666594&PMT4NO=61622651

I use one to make the countersunk holes on the bridge to accommodate the round heads of the bridge pins. If you want one, I can get them in a day or two from the MSC warehouse in Nevada. Then mail it over to you.

Best used in a drill press for overall stability, but can go in a variable speed hand drill if you're careful.
Author:  Tai Fu [ Tue Apr 07, 2009 9:53 pm ]
Post subject:  Re: countersunk
I think this is what I need:

http://www1.mscdirect.com/CGI/NNSRIT?PM ... O=61623286

I hope the 90 degree angle is correct.
Author:  R W Goodman [ Tue Apr 07, 2009 11:42 pm ]
Post subject:  Re: countersunk
Quote:
Hey Warren,

That particular one looks way too pointy (to get technical!).


I most likely have the wrong bit pictured.

Here's Mario's original post.

Quote:
For bridges, I use a cone-shaped stone in a Dremel. No chance of tearout, and produces a lovely countersink. And the aroma of BRW smoke... ah....

I use the same cone(this Dremel is set aside with this stone in it all the time, I use it so much) for also esing the edges of the tuner holes, for the bushings, for the end pin, and for the bolt holes in the body. Anything that needs a slight chamfer....


Maybe it was this one...
Author:  Daniel Minard [ Tue Apr 07, 2009 11:54 pm ]
Post subject:  Re: countersunk
I have a couple of really good countersinks, but prefer to use a carbide (or high speed steel)
burr. I find the countesinks tend to cause chipping where the cutting edge meets end grain. Sometimes a dull old burr will do a smoother job than an sharp, aggressive one.
Author:  Shane Neifer [ Wed Apr 08, 2009 1:13 am ]
Post subject:  Re: countersunk
Yup, I quite like the look of the burr that Hank linked to. I printed that page off and I will be attending my local Industrial Supply and asking them to get me one and will give that a try. I like that it creates a round hole rather than a chamfered one.

Hey Warren, no worries I was just noting that the angle needed to be shallower. That one looks more like the angle I would like to see.

Shane
Author:  Laurent Brondel [ Wed Apr 08, 2009 5:01 am ]
Post subject:  Re: countersunk
I used to use a Dremel-style stone to do this, but they clog up pretty quickly and burn rather than cut, which I find undesirable.
I use a carbide burr mounted in a hand-powered drill, it will probably last my entire career and some, is very clean and manageable and I even use it to slightly countersink tuner/end pin holes before finishing.
Author:  Todd Rose [ Wed Apr 08, 2009 6:17 am ]
Post subject:  Re: countersunk
http://www.carbidebur.com/shapes/scburs.htm

http://www.carbidebur.com/shapes/skburs.htm
Author:  DannyV [ Wed Apr 08, 2009 8:04 am ]
Post subject:  Re: countersunk
[:Y:] [:Y:] Lee Valley. I've used them for years and would never go back to any other for wood.

Danny
Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/