Homebrew PCBs

Here are some drilling machine ideas.

I have a small high speed drill press that works great with carbide 
drill bits. For simple low volume jobs this drill press can't be 
beat. I think it works much better than the Dremel tool types. This 
drill press was on sale recently at KBC Tools for $130. 

For the more complex jobs I like to use a stylus operated drilling 
system. The machine I use is made by Nawide Machine Tools. It has an 
optical scope for making the master template or for drilling smaller 
quantities. The scope screen has 15 power magnification and a 
clamping system. You line up the pad in the optical screen and push 
the foot switch. The machine pressure foot clamps the stack of boards 
or template, drills the hole from a bottom mounted spindle, retracts 
the drill bit and releases the pressure foot. It is very quick and 
every bit as accurate as the best CNC machine. If you make a template 
and attach the stylus assembly you can drill 60-80 holes per minute 
with precise placement. We usually stack the panels three deep and 
sometimes four deep depending on the smallest drill size when using 
this machine.

Here is the best part. These machines can be purchased for next to 
nothing. The last machine I bought was only $200 and had the optical 
scope and stylus assembly. It is a 1986 vintage Aetna Acrodrill in 
perfect condition. The commercial shops have very little use for 
these machines and will almost give them away. Another machine to 
look for is any of the Excellon Quad Drills. These machines had a 
stylus assembly on a very smooth manual XY movement with four high 
speed spindles. This machine can be made into a CNC version by just 
adding the XY leadscrews and computer. These nmachines are smaller 
than an office desk and have built in casters for easy moving. 

Excellon even made a version of this called a Quadramatic 1255 and 
Quadramatic 1231. The 1255 accepted 12" x 18" panels and the 1231 
took 10" x 12" panels. The XY movement is driven by ball screws. I 
can assure all of you that these machines are excellent for hobby AND 
professional drilling. Take off the old General Electric NC control 
system  and interface with your own PC CNC control system. Very 
little mechanical work would be needed and you would really have 
something to show off. I have personally turned down offers to haul 
these away for free. They are not that big or heavy and will fit in 
any pickup truck. Most of these systems have already hit the dump or 
scrap yard but if you can find one you will not be sorry.

I have owned very large and expensive Excellon drilling and routing 
machines in the past and the only thing they had over the methods 
discussed above was speed and expense. My favorite drill was the 
Excellon EX-200 Driller/Router with CNC-6 controller but even this 
expensive machine was only averaging about 125 holes per minute. I 
can drill the ten boards I need each week in less than 20 minutes 
with a stylus drill. This includes setup time on a 4" x 6" board with 
300 holes.

Save some money and try out some of these ideas. You will be amazed 
with the results.

Tom