Home build CNC mill/router

[Jesse B]

Very nice looking machines.

[GLynnC]

Originally Posted by eSilviu There are 12mm round rod with associated bronze bushings. I get them from A3 XEROX inkjet printer (don't remember the model). Steppers are from that printer too.

Very interesting , thanks for the reply.

[eSilviu]

Hello,
I've started with the idea of building a PCB mill with 10x16cm working area (Eagle light limitation, more than enough for 90% of my PCB's).
I've ended with a mill with 15x21cm working area, and 7cm of Z travel.
Working good until now: attached a sacrifice MDF, and leveled the working area.
Pictures represent:
- whole mechanical CNC
- nut-spring-nut used for Y axis
- controller + manual jog + bipolar drivers for steppers
(controller = CNCUSBController from Kroko)
- stepper drivers = A3979 based, and are working amazing from a 12V power supply
- RC outrunner used as spindle for milling PCB's (has 3.17mm inner bearing diameter ), well.. milling PCB’s needs only about 15W of power!!!
- 2x12V,2.5A power supply - one for controller and one for spindle
- I intend to put all electronics part on the back of machine
- a small PCB milled just for test (the one with larger isolation tracks was obtained by running the same g-code for about 15 times, just to see what will happen); note: there is no software compensation for backlash!

Merry Christmas to you all!

[Jesse B]

Looks great! Get those electronics organized and you're good to go

[cflas]

Looks great guess I will have to start on one here shortly. Love all these post with very positive results. I have a dremel and a sears 1/4" router and will use those as proto types. if all works good then I would start a search for the famous porter cable 1/2".

[eSilviu]

this is how I've started..
it was the first attempt to do a cnc.
alltrough it wasn't any real use, it helped me to understand all weak points of the design, and to find better solutions.

[jjobezo]

What are you using to control the spindle motor?

[Jesse B]

Seeing as he's using an RC Outrunner motor, I'd assume he's simply using an ESC, and feeding it a PWM signal from some source. I'm sure he'll let us know though

[eSilviu]

Originally Posted by Jesse B Seeing as he's using an RC Outrunner motor, I'd assume he's simply using an ESC, and feeding it a PWM signal from some source. I'm sure he'll let us know though

Cheap RC outrunner + "Mistery" ESC driver (yellow in first picture) + PWM generator build with a PIC microcontroller.
It's working good, since I can set the speed of motor with a small potentiometer.

[jjobezo]

How do you know your speed on the out runner?

[eSilviu]

Originally Posted by jjobezo How do you know your speed on the out runner?

I know Voltage, Kv constant of the motor, and position on the potentiometer. (sometimes, at the begining, I have measured real speed of the motor in diverse circumstances)

[Jesse B]

Originally Posted by jjobezo How do you know your speed on the out runner?

Originally Posted by eSilviu I know Voltage, Kv constant of the motor, and position on the potentiometer. (sometimes, at the begining, I have measured real speed of the motor in diverse circumstances)

kV rating of the motor (provided with 99.9% of all RC brushless motors) multiplied by voltage gives you the approximate RPM, assuming 100% efficiency and no load of course.