DIY CNC Machines

[woodbob123]

Received latest issue of model engineers workshop today. front cover shows a cnc m/c made using woodworking skills and simple tools. Enjoy
www.model-engineer.co.uk

[mashersmasher]

Notebook in most cases do not have parallel printer port any-more. USB only ev. RS232.

Did you try simple solution as (this one on eBay) USB TO PARALLEL PRINTER ADAPTER CABLE ?

Those are inadvisable. They tend to operate well under the specs of a real port and don't work for most things. You can use a microcontroller such as an arduino mega or you can use one of the bazillion controllers designed for reprap and makerbot which are very cheep and also very good.

[Altra]

WM6,

Its more complex than a level shifter. The usb interface stores g-code commands from the pc and outputs them in a smooth train. It also monitors the limit switches and e stop. There is also an input for manual movement using a control pendant, like a joy stick. The circuit board also serves as a breakout for all the I/O. Even with a parallel cable you still need a breakout board.

[WM6]

Notebook in most cases do not have parallel printer port any-more. USB only ev. RS232.

Did you try simple solution as (this one on eBay) USB TO PARALLEL PRINTER ADAPTER CABLE ?

[Altra]

This something that might interest some of you.

It is a diy usb controller for cnc machines. The catch is you have to buy his software for 69 euro.

Most of the cam programs rely on the parallel printer port to send the step and direction logic signals to the motor controllers. It also receives logic signals from the machine such as limit switches and emergency stop. The Windows operating system is disruptive to smooth machine operation. Apparently its always multi-tasking and can mess up a smooth train of timming pulses.

The program I use, Kcam is very eratic hooked directly to the printer port. The very popular Mach3 runs smooth. The developers of Mach have figured out how to basically disable the polling timers in Windows. But parallel printer ports are or almost obsolete. RS232 are becoming scarce. So the best way to go is a usb interface it has two advantages,first most laptops and pc have usb ports, second the interface buffers the movement commands from the pc and outputs a smooth signal. For kcam I bought an rs232 interface called Maxstepper from Kellyware. It improved the machine greatly.

Now I want to build this usb controller. The software looks really good for the money and will do gerber isolation, dfx, raster, text and nc drill files. Down load the manual from the link below for more details. Also the developer is still active and will answer questions on his forum.

http://www.planet-cnc.com/index.php?page=diy

[Qiaozhi]

Not sure. The file types mentioned above are "raster scan". Gerbers, Dfx, and most cad files are "Vector" files. The goal is to get your file converted to G-code, which is what actually tells the machine what to do. It would be nice to mill boards from published artwork. You would have to manually drill the holes, since no drill file exist.

Try this ->

http://www.imagetogcode.com/

[Qiaozhi]

This is amazing! Yet alarming!

http://www.youtube.com/watch?v=quN37YskoaM

P.S. Turn the sound off its like being at the dentist.

Yes - I've already seen that one. It's really impressive!!

[WM6]

Nice idea, thanks Ap.

[ApBerg]

If we have BW picture (jpg, tiff, giff...) of PCB from say one old electronic magazine, what is the best way to convert it in GERBER file for routing PCB?

Make a bpm scan, put it as background in Sprint Layout, 'overdraw' tracks and pads etc. export as Gerber file...

Yes .... not high tech .. is easy to do..and not much work.

Best regards

Ap

[Altra]

If we have BW picture (jpg, tiff, giff...) of PCB from say one old electronic magazine, what is the best way to convert it in GERBER file for routing PCB?

Not sure. The file types mentioned above are "raster scan". Gerbers, Dfx, and most cad files are "Vector" files. The goal is to get your file converted to G-code, which is what actually tells the machine what to do. It would be nice to mill boards from published artwork. You would have to manually drill the holes, since no drill file exist.

[WM6]

If we have BW picture (jpg, tiff, giff...) of PCB from say one old electronic magazine, what is the best way to convert it in GERBER file for routing PCB?

[WM6]

This is amazing! Yet alarming!

http://www.youtube.com/watch?v=quN37YskoaM

Indeed, for very advanced CNC-enthusiast only.

[Altra]

This is amazing! Yet alarming!

http://www.youtube.com/watch?v=quN37YskoaM

P.S. Turn the sound off its like being at the dentist.

[Altra]

When you make a pcb on cnc. You have three files for a single sided board.

For example you draw your pcb using Dip Trace.

First generate a gerber file for bottom copper layer mirrored.
Second generate a gerber file for board outline.
Third generate an NC drill file.

Next you import your files into a program which can convert these to G-code.
I use Kcam, there are others. Once you are satisfied that everything lines up.
The pcb is secured to the table with clamps, tape or a vacuum. Using manual control you position the spindle near the lower left corner of the pcb. The x and y axis are zeroed in the cam program. This point becomes your "Home" position and everything is referenced to this point.Now you manually move the spindle over the pcb material. The z-axis is lowered until the nose cone is resting on the surface, plus another 0.20" or 5mm. This allows the head to float. The z-axis is set to zero. Now you press the home button. The z-axis raises above the surface, the spindle then returns to home position(0,0).

I generally cut the the isolation for the traces first. When this is done the spindle returns to home. Now change the tool to a drill bit. The drill bit is set so that it extends at least the pcb material thickness below the nose cone. Now you open the g-code file that was created from the nc drill file. Turn on the spindle and start the process. It will drill all the holes and return to home. Next step is replace the drill bit with a carbide router bit and cut the board outline.

The above is a general description and many variations are possible.

[WM6]

Now ... look at this beauty ->

http://www.youtube.com/watch?v=CQzoGTbPrSM&feature=related

It's being used to cut some gantry supports. So it's upgrading itself!
I've never seen such a clean and spotless workshop.

Yes, impressive spindle motor, I wish to have such one.

Do you know good converter from some graphic format as .jpg, .gif etc. to GERBER file?