My PCB Drilling Setup
The drill stand pic (taken from net) on the left and the original PCB Drilling Rig on the right as I was using it before.
It was junk. The mechanism had a lot of friction (lots of creaking and squeaking noises) and spring tension is too much for a small PCB drill. Moving the handle side to side also moved the drill because there was so much play. After using it for a few years (and breaking a few carbide bits along the way), I realized I needed something better. I took the mechanism off and threw it away. I only reused the base and pillar from the original stand. Here are the new parts I made laid out on the floor.
Here is the bracket attached to the linear bearing (about 1.2" travel).
The linear bearing attached to an aluminum C channel that will hold the drill. A bearing is attached for an aluminum bar to slide on (more on that later).
On the other end, a piece of aluminum angle is mounted as anchor for the pull-up spring.
This second C channel has the hose clamps that will hold the drill to the pillar. The handle rod is
attached to a flat aluminum bar that will ride on the bearing.
The handle rod is shafting from a dismantled copier. The handle is made from four of the paper rollers
superglued and taped so they stay put on the end of the shaft. Wire clamps attach it to the aluminum bar.
The parts assembled together.
Here's another shot of the bearing where the handle rests on. Spring is not yet installed. (Solder lug can also be seen here as the second spring anchor).
A piece of tape stuck between the portion where the handle bar will touch the C channel to prevent metal to metal rubbing.
The handle kept in place with a screw.
The back cover of the speed control box with a magnet attached on the inside and screwed onto the stationary C channel.
A shot of the speed control circuit
A few shots of the complete PCB drill press. The handle can be pulled out or pushed in for different
amounts of leverage. The magnet is used to keep the chuck key in place and stay out of the way while drilling.
Drill on/off switch.
There is absolutely no side to side play. Movement is now smooth and effortless.
Since the rotary tool I'm using is a cheapie I got years ago, the chuck is less than ideal. The bit would have a little to a lot of runout depending on the position of the collet. The chuck itself also isn't balanced so it also causes vibration at high speeds. This was my solution:
After finding the ideal collet position, I cut a 'v' notch on the side of the collet and drilled a 1mm
hole on the side of the chuck and soldered a small piece of wire and trimmed it. That way, the collet would stay in only one position inside the chuck.
I also drilled out a few holes on the heavy side of the chuck to balance it out.
It worked really well. Here, I'm testing it drilling a PCB with a 0.34mm (0.0135" - smallest carbide bit I have) at moderate speed. I have never used it before as I was afraid of breaking it.
All that effort paid off!
17 Jun 2015:
After a prolonged session of drilling, the cheap PCB drill burned out. I had to find a replacement.
I came across these precision motors from Maxon. Ball bearings and smooth running, ideal for a drill.
Motor installed in the drill press.
The collet assembly was re-drilled since the new motor shaft is bigger.
Motor had a cam thing at the back but I did not need it and it was vibrating when running at high speed so I took it off.
Since the motor was smaller diameter than the original drill, the drill bit would hit the base so I added standoffs to move it to the hole.
Since there was no longer a on/off switch on the motor itself, I used a pot with integrated switch.
Turning it fully counter clockwise turns the drill off.
Test drilling to check for runout and alignment.
I think that is enough testing for today.
13 Sep 2016:
I bought this micro chuck made by Dremel for their rotary tools.
Looks like a nice addition to my micro drill press so I wanted to use it there.
I had this machined to mimic the front part of the rotary tool to accept the chuck attachment.
The hole accepts the rod as a lever to hold the shaft when tightening or loosening the chuck.
There is runout either a little or a lot.
Nudging the bit a few times moves it to center and when you hit the sweet spot, it works pretty well.
Page created and copyright R.Quan © 21 Oct 2011.