This is my first instructable.
I am just a hobbyist who interested making circuits and their pcb's in complete DIY manner.i saw lot of articles of home made PCBs.they were quite good except one step.making holes for mounting components.start from laser printing the PCB layout to mounting the components you can carry out in home except the drilling procedure.you shld have a drilling machine with small drill chuck,which is capable of holding 0.5-1.5 drills.
Then i had in my mind,why not DIY PCB Hand drilling machine.
My goal is to built one from junk which is capable of drilling small holes to mount components.
Remember this is not sort of professional drilling machine.with it u can just make holes small enough to mount electronic components over PCB.
Finishing of the drilled holes will depend up on the type of drill you used.(made)
Below is my PCB hand drill and my PCB making setup.
Step 1: Stuff Needed
1. 24v DC motor (takes from old dot matrix printer)
2. Nylon pulley (from printer only)
3. Mounting screws 3mm (these are used to mount mother board in CPU cabinet)
4. 3mm hardened screws (2-2.5 Inch in length)
5. 24V supply,some basic tools,Grinding machine with Rough and smooth wheels.
Step 2: Procedure
Take 3mm hardened screw and cut off its head.then use a smooth grinding machine to grind it as shown in the below picture.this step require little experience of grinding operation.
In the picture drill 2 is not good.it can make hole but the finishing of the hole will be bad.as its area increased from tip to the end .where as drill 4 has same area from tip to end.so with it u will get exact circular hole.
In the another picture u'll find different types of drills.(sorry for such bad pic i was in hurry so had use MS paint)
drill 1 has circular edge so u have to apply lot of force to drill hole where as its grinding is easy.
drill 2 has square edge.so there will be 4 cutting faces.with it u'll get good hole but its hard to grind.
same with drill 3 but instead of 4 it has 3 cutting edges.
so you have to experiment ,which one is good and suitable to you.
Step 3: Assembly
take the nylon pulley and try to create internal threads.for this u don't need any spl. tools.take 3mm screw and tighten it in to the pulley with little force.as the pulley is made of nylon internal threads will be created by that 3mm screw.now unscrew it and fix the mounting screw firmly.
then fix the previously made drill bit inside the mounting screw.now insert this hole assembly in to the motor shaft.
*If my explanation is not clear please follow the pictures below.
Voilah! your home made drilling machine is ready.before going to drill ur PCB,test it on a waste piece.so that you can confirm which drill is good and with which ur getting good finish.
some points that i want to repeat
1.This is not professional type drilling machine.
2.hole finishing will depend up on ur tool(i prefer square type drill).so make it carefully
3.try to get motor with High RPM and some good torque.
Have a look at the drilling operation sample video
As i said before this is my first instructable,so let me know abt my mistakes.