Lightsaber hilt - Enlarge a tapered hole ?

Twinsen

Sr Member

RPF PREMIUM MEMBER

• Oct 9, 2017

• #1

Hi gang,

I need to slightly enlarge a tapered hole in a (quite expensive) lightsaber hilt made from 2mm thick aluminum. The hole needs to be enlarged from size M3 to M4, which is VERY little, especially considering i'll have to taper the enlarged hole to fit an M4 screw.

Since the diameter of the hole for the M4 tap needs to be 3,25mm, and considering the current diam. of the hole at the top of the threads is 2,5mm, that means I have to remove something like 0,7mm...

I've considered several methods but i'm a bit lost. I'm practicing on a scrap piece of aluminum and one thing's for sure, drilling it out with a larger bit doesn't work as the bit constantly catches the threads because the size difference is so small.

If at all possible i'd like to stay away from power tools for this one as I feel it will give me better control and allow me to be more precise.

I've read about adjustable hand reamers but i'm not even sure what to buy...

Any help much appreciated !!!

 

andrew25rs

Well-Known Member

• Oct 9, 2017

• #2

May not be the best option but something to consider could be a “step drill bit”. The bit isn’t designed like a standard one which could solve your problem of catching the threads. Only issue is you might not be able to get the EXACT mm you need for the m4 tap but with the right one I think you could get close. Other wise maybe something like a correctly sized “end mill bit”?

 

Trooper_trent

Master Member

RPF PREMIUM MEMBER

• Oct 9, 2017

• #3

Can you not just re-tap it with an M4 tap? what size bit is recommended to pilot an M4?

If you're worried about the drill catching the other threads then yeah either go at it high speed with a drill press or very slow with a hand reamer.

 

Twinsen

Sr Member

RPF PREMIUM MEMBER

• Oct 10, 2017

• #4

Mmmmh I've asked around and I can have access to a drill press, that might be a solution. With a fresh and sharp bit, and since aluminum is quite soft, that might just work.

Thanks for the idea!

 

OdiWan72

Master Member

RPF PREMIUM MEMBER

• Oct 10, 2017

• #5

Drill with 3,2mm bit, cut new M4 threads...no biggie

 

Darth Lars

Master Member

• Oct 10, 2017

• #6

Alcohol works as a lubricant when drilling aluminium. Just don't inhale too much of the fumes.

 

OdiWan72

Master Member

RPF PREMIUM MEMBER

• Oct 10, 2017

• #7

Darth Lars said:

...Just don't inhale too much of the fumes....

Click to expand...

WHY NOT Johan???
Prop-building should be fun, right !? :lol

 

Twinsen

Sr Member

RPF PREMIUM MEMBER

• Oct 10, 2017

• #8

Never would have thought of using alcohol as cooling fluid I'll give that a try !

 

propmainiac

Sr Member

RPF PREMIUM MEMBER

• Oct 10, 2017

• #9

I often have a bit of alcohol near me when in my work shop. The drinking kind.

 

R

Ridire Firean

Sr Member

• Oct 10, 2017

• #10

Hey Mr. K ! Any luck? If you still need a last minute suggestion, you could always roll up a piece of 200 grit wet/dry sandpaper and let it uncurl a bit inside the hole. Then just slowly twist it around a time or two.

For what it's worth, I always use cutting oil on metals when I use my drill press.

Good Luck!

 

Last edited by a moderator: Nov 8, 2018

Darth Lars

Master Member

• Oct 10, 2017

• #11

I wasn't referring to using alcohol as a social lubricant

... but as an inexpensive cutting fluid. Isopropyl alcohol, rubbing alcohol or denatured ethanol, not any "good stuff".
I'm not sure what the pro's use, but I got this tip a decade ago and I have subjectively experienced drilling and sawing in aluminium going smoother with it than without.

BTW. Baby oil works for wet-sanding steel with "wet-and-dry" sandpaper.