Small Drill Bits

rocketrider · Post by **rocketrider** » Sun Oct 25, 2009 10:34 pm

I'm working on the Revell Republic Star Destroyer, drilling holes for my fiber optics. I am using a .0160 (#78) drill bit I got in a set from Harbor Freight Tools. I don't think their quality is all that great...

I have purchased about 6 sets of these things because I keep breaking them off. I am using a dremel with a flex line and a speed control, and I am being very careful not to move it around, turning the bit slow so I dont melt the plastic, but it still happens.

Anyway I can no longer afford to pay another $5.50 for a whole set just to get one drill bit.

I have done some internet searching and found Carbon Drill Bits, but before I buy any more stuff I want some opinions. I don't know too much about the different types of bits, is Carbon a strong bit? is there something else I should be looking for?

Thanks for any/all responses

Glen

Andrew Gorman · Post by **Andrew Gorman** » Sun Oct 25, 2009 11:17 pm

Using a #78 bit on styrene in a Dremel is probably your problem. You can easily drill through plastic by hand with a pin vise, with a lot more control and probably never break a bit. And the holes will be nice a and clean when you're done. If you really need to use a power tool, try chucking a straight pin or other piece of fine music wire into the Dremel- it will probably work just as well as a bit.

Kylwell · Post by **Kylwell** » Sun Oct 25, 2009 11:30 pm

You want HSS bits. Carbide bits will break even faster. I get mine from Widget Supply. #78s break a lot, no matter what.

DennisH · Post by **DennisH** » Mon Oct 26, 2009 7:21 am

Hobby shops usually sell sets numbered bits in small packs. You can get a few of the same number that way, without needing to buy a full set of #s 60-80.

I've always found them near the train stuff or behind the counter.

http://www.micromark.com/MICRO-HAND-DRILL,7045.html and Bob's your uncle!

Dennis

rocketrider · Post by **rocketrider** » Thu Oct 29, 2009 3:18 pm

After buying another set of the harbor freight ones (I needed them quick) I got through most of the model only to have that one snap off. I moved to the next size up, and it held up through the rest of the project.

Next time I will order the #78's online

I also took the spring out of the Dremel foot pedal so I could slow the drill way down as not to melt the plastic. The speed control on the Dremel is useless.

Thanks for all the advice

Glen

Tchail · Post by **Tchail** » Wed Nov 11, 2009 1:41 pm

Get a pin vise.

http://www.micromark.com/MICRO-HAND-DRILL,7045.html

It's one of the best $10 I've spent on tools.

-Tchail

DX-SFX · Post by **DX-SFX** » Fri Nov 13, 2009 8:47 pm

Carbon refers to carbon steel. This is cheap and brittle. You want HSS drill bits (High Speed Steel). You should be able to find a tool merchant who will sell you a small pack of ten rather than buying them singularly. Try Dormer as a brand or Hertel.

Stu Pidasso · Post by **Stu Pidasso** » Fri Nov 13, 2009 10:17 pm

PM sent, Rocketrider.

rocketrider · Post by **rocketrider** » Fri Nov 13, 2009 11:09 pm

thanks...

Splatcat · Post by **Splatcat** » Sat Nov 14, 2009 10:16 pm

Small drill bits are extremely difficult to use in powertools. They are easier to use in a pin vise but it takes a little longer. Fortunately styrene cuts rather easily.
Go with HSS drill bits. Carbon steel bits are #@@#$$$ and just aren't worth the hassle. Carbide and cobalt bits are better but a bit to expensive for most modelling projects.