CNC Machine R&D

Spindle motor
In the last post I said that I am going to use a brush-less DC motor from an old Airsoft rifle. Here is the reason why. I’m trying to use stuff I already have for one. It is also a very powerful high torque motor that is almost as powerful as a Dremel. Now how will I attach a chuck? Easy, a while back I bought a cheap-o rotary tool from harbor freight. to finish a job since my Dremel decided to die after ten years. It was dirt cheap and the construction isn’t bad but the motor is a small hobby motor. Anyway the chuck on it will fit Dremel bits and small drill bits just fine.
Another thing had come across my mind. The motor can wear out quickly with constant current. To fix this I need a PWM solution. I found a nifty circuit that will use a 556 timer or two 555 timers. This will give me a speed control and even an option to reverse the motor that could come in handy.

Some cool addons
I have an old two megapixel web cam. It would be neat to use it on the machine so I can be in front of the computer monitor watching the CNC software do it’s thing and still keep an eye on the machine cutting the object.

Power Supply
I’m thinking to use an old laptop charger that is rated at 19 volts and 3.16 amps. I can step down the voltage if needed but I might end up building a power supply that can produce 24 volts and 3 amps for the sake of the Stepper motors. Just need a transformer, diodes, couple of mosfets and a LM358N opamp.

Controller case
The case is simple. A box with switches, lights and plugs. What comes to mind is keeping the controller away from the CNC machine. If I build a power supply it will be in the case as well.


Wiring up something is an art per-say. You want it to run the least amount, keep it tidy, well documented if you have to troubleshoot. I plan to put the cabling from the CNC to the controller in some old school fabric wrap. I’m still deciding to use limit switches or not. I just might skip the limit switches. Dunno if I can even add limit switches to my controller board, however I have a schematic.

If I do I can add a spindle control.

There are so many ways to do this but I want it simple as possible so anyone with simple knowledge can build one.


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