Tips and Tricks On this page i show you my experience with problems. 1) Small Cutters.
When you must use a very small cutter tip it’s better to use a HSS cutter instead of a Carbide cutter. This because HSS is more flexible. 2) Copper.
Copper has a difficult property. When you deform it, without heat, it will be hardened.
So when you drill a pcb and you do it to careful , your drill will be breaking. 3) When you engrave Aluminium you must use a fluid like oil or methylated spirit. 4) A conical cutter is many time stronger than a straight cutter. 5) Brass with 5% plumb cut’s very well. 6) If you make a cnc machine, please do not make the ball bearing blocks by your self. Use an old stepper motor. 
This is an old stepper from a 5 1/4 disc drive.
They cost nothing.( i’m a dutch man :-) ) I buy bigger ones by
www.damencnc.com for € 6,- For that price i can not make them. 
You see 2 beautifull ball bearing blocks for your machine. In one of the 2 blocks there is also your mounting threat for your stepper. 7) To remove a gear from an ax. 
This is the problem, how do we remove the gear.
Well simple, make a plate with a groove. 
put it like this in a drill clamp, but do not clamp it.
The motor must hang. Below the motor there is some space. 
With a punch you can remove the grear. | 
