Small-diameter plug cutters?

[Mike Kolb]

One of these days (-ha!... them's famous words-) I'll save up and get a little lathe and be done with this issue once & for all. 

In the meantime, does anyone have a source for 3/16"dia (or smaller) plug-cutters?  All the common sets I've seen thus far only go down to 1/4".  Curious.  

[Doc Rathwell]

The Stew Mac "Plug Cutter" from the "Guitar Screw Rescue Kit" can be purchased on its own and it is a 3/16" diameter cutter: http://www.stewmac.com/Luthier_Tools/Types_of_Tools/Routers_and_Bit...

Best Regards,

Doc

[Mike Kolb]

Well, there we go..... many thank's Doc!  

[Paul Breen]

In a pinch, you can make your own plug cutter.

I have made these before using Brass tubing from the hardware store. They sell sizes going up by the thickness of the tubing wall. This lets you both drill a hole and make the correct size plug cutter to fit it.

I just make them rather crudely, by hand with a three sided mill file. I layout the teeth by eye as well, very low tech.

The down side to the Brass is that it is soft and only good for a few holes before the teeth begin to flare out. I haven't bothered yet but may try using stainless steel next time and see if that is more durable. I also have not tried this with a 3/16" or smaller hole.

[Mike Kolb]

Good thinking, as usual Paul.  I've done the brass tubing thing and made a few oddball-sized plugs before, but what I really like about most "official plug-cutters" is the subtle taper they give a plug.  

You raise a good point though, about possibly utilizing stainless tubing to get a few more plugs than brass can give... might have to give that a shot.  Thanks!

[David Farmer]

Mike, this is a pic of a 3/16 tapered plug I make to fill bridge pin holes in tops/plates. that's why it's layered, but the technique works like a champ for small plugs from any wood. Way cleaner than any small cutter I have made from tubing. Chuck a 1/4" dowel in a cordless drill, ca glue a square of wood onto the end and spin it backwards at high speed against a disc sander. just hold real steady and the dowel will help you gauge angle. It's easier than it sounds. try it!

[David Farmer]

[Mike Kolb]

Thanks for sharing that, David.  Definitely worth a shot and I'll try it tomorrow morning... can't wait, actually :)  

Now, if you weren't using a glued square piece, could you get the same results using just the dowel?  Might try that, too just for ducks.

By the way, plugging the top and the plate at the same time is a very cool idea...  thinking outside the box, for sure.  

[David Farmer]

Gluing a piece onto the dowel is just to get a certain grain orientation. even easier if your just making dowels. If you turn a long dowel with an exteamly gentle taper, you can slide your pre-set calipers up the dowel until they stop and that tells you where to cut for a given size.

I didn't mention I have 120grit paper on my disc, which I consider fairly fine. I also use calipers to check size as I go.

I use these in conjunction with a small violin peg reamer that has a very mild taper, but I'm sure a bridge pin reamer would work too. Good luck.

[Paul Breen]

Spinning a bit of wood in a drill or drill press against abrasive or a file does work quite well and it's a fast way to make a plug.

For the application your showing David, I do it a bit differently. I keep some Spruce dowel rod on hand that is sold for making violin sound posts. I'll cut off a 3" piece or so and chuck it in a drill press, spin it, bring a sand paper bock to it and make sure it is reasonably round without loosing much diameter. I prep the Spruce holes to be plugged with a 1:30 (2 degree) tapered reamer, a standard fiddle peg hole reamer. You want the hole at the surface to be same diameter or slightly smaller than the dowel you have prepared. A dip into some hot hide glue and rotate it into the hole. I use the same thin blade Exacto saw that is in your picture but with the blade removed from the frame and trim the dowel nearly flush. I only need to prep one dowel this way and use the same piece for all of the holes.

I can't do the neatly stacked Spruce/ Maple my way though but more often than not, if I am plugging holes, the bridge plate is likely to be off. Thanks for putting the images up though, I enjoy seeing what others come up with and may have an application for your stacked approach cross my bench some time.

[Mike Kolb]

Thanks for the idea  of running the dowel backwards- at slow-speed- with a chunk of spruce (or whatever) glued-on.  It worked much better than I would've thought!

I made it easier on me by first using a 1/4" plug cutter to cut a few oversized round 'blanks', then CA'ing the plug centered to the dowel. Turning it down to 3/16" seemed easier with an already-round blank to start with.

The big benefit was being able to gauge the plug taper at the same time. Kudos!  Great idea and it saved me the $35 or so that StewMac gets for their mini cutter.   Muchas gracias! 

[David Farmer]

I'm glad it worked for you Mike. For me, the key is running the drill at high speed against the rotation of the disc. I used to start from 1/4" plugs as you did but found I could skip this step with the high speed method. Resting the drill on the machine table, even if you need to clamp a piece of wood to it, helps too.

[Mike Kolb]

Thanks David... I'll try it with skipping the 1/4"-dia blank step and see how that works for me. (And, yes... I meant to type "high-speed" but brain-farted!)   You've been a big help and solved a problem. Good stuff.