Redrilling Trustone

[Wct3]

The trustone pen I posted last week wasn't the first blank-- I drilled too far with a brad point drill and blew off about 3/4 inch on the end. Not wishing to waste a blank, I started looking for another 8 mm set to use with a modified blank. I figure I can use some combination of the extra end pieces with some aluminum to make a feature of the pieced blank. Noticeably, however, there aren't a lot of 8 mm pen sets. I'm thinking I need to drill out the hole to a larger size, but boy that sounds risky!

Any suggestions and experience from anyone to help with this project? Thanks...

 

[1080Wayne]

Well , you can`t use a brad point drill to enlarge the hole . The blank needs to be held very firmly so that it can`t flex sideways at all . A former member on this forum who made extremely complex laminations would wrap his blank with several layers of cheesecloth , saturate that with thin CA , wait until it cured and then drill .

 

[MattTheHat]

I re-drilled a blank yesterday, but it wasn't Tru-Stone. In my case I was enlarging a blank drilled with a U bit to 27/64" (.368 - .422"). I drill on my metal lathe, which may have made the task easier since the 3-jaw chuck kind of holds the blank together. Of course, if you drill vertically, a pen-drilling vise would likely provide some support too.

My only advise is to make sure you align the blank very carefully so that the drill bit is making contact with material on all sides. If the bit isn't making contact on all sides, from experience I can say the procedure will likely fail.

I have also used a tiny boring bar on my metal lathe with excellent results. (Also great for when you don't have the correct drill size.)


-Matt

 

[Notscottish]

Instead of cheesecloty, I use dental floss and CA to stabilize my blanks with good results

 

[MattTheHat]

Well , you can`t use a brad point drill to enlarge the hole.

The hole I enlarged yesterday was actually done using a brad point bit. I was quite surprised, but it's all I had in 27/64", so I went ahead and gave it a shot. So, it can be done, but I may have just gotten extremely lucky. As I noted, I made sure there was material on all sides of the drill bit. And I advanced the bit pretty slowly. The lathe was turning approximately 500 RPMs.


-Matt

 

[Charlie_W]

Turn a piece of hardwood scrap wood into a dowel that will fit inside the blank
Glue it in and then drill. I would drill slowly on the lathe.

 

[Bikerdad]

Get a Unibit, or if you're cheap, get the chinese knockoff at Harbor Freight. The step bit will allow you to drill a "starter" accurately centered on your existing hole, either the same size or a smidge larger than the new hole you need.

Personally, methinks that every well equipped DIY'er should have some step bits, they are da bomb for making bigger ones out of not quite big enough ones.