Help picking a plan

[Gigman]

Hi,
I am interested in making a CNC machine mostly for PCB work. I would also like to cut out balsa parts and have a relatively large work space for doing things other than PCBs. Also I am on a budget and would like it relatively cheap. I was thinking about the Phoenix from crankorgan.com. Can this machine do PCBs and what is a ballpark price estimate (completed w/ servos and controller)? In addition I have next to no knowledge on stepper drivers, but I’m pretty sure I could build my own, does anyone have or know where to buy plans for one?

Thanks for all your help
-Gigman

[Torchhead]

Drilling and routing PCB's for anything but the crudest of designs (i.e. where runs go between IC pin's) is harder than it sounds. You need a tight and accurate machine that will hold .002 tolerance and the mechanics and electronics to get that level. The bigger you build the machine the harder it is to hold those tolerances. In addition you need to be able to float the cutter using a depth control device (like an adjustable nose piece). You need a high speed spindle for PCB and lower speed with more torque for other operations. Stepper systems are not hard to build if you pick the right drivers.

For an affordable 3 axis Unipolar Chopping drive look at HobbyCNC. 79 bucks for the kit and will spin steppers nicely. Avoid (like the plague) LR drives that use a big resistor for motor current limiting.

If you want assembled and tested boards visit Xylotex.

I know you said you don't have a big budget but the final accuracy of your system will only be a good as the components you put into it.

If you REALLY want a machine that is useful for cutting PCB's then you have to look past draw slides and all-thread. If you just need a project to learn on then you can use just about anything. Load up EMC on Linux (Free) as the control software or spent 65.00 bucks for TurboCNC (DOS based).

Then you need to concern yourself with HOW you cut PCB's Using PCB layout software is the best way but then you need a way to get the drill file (Excellon) and the trace outlines into g-code and make the machine cut it. There is no one-button solution.

Steppers can do a good job on a smaller machine and where slower speeds are needed. I have a stepper based XY table (fixed gantry) that holds .001 easily across it's full 10" X 10" capacity and drills PCB's dead on. It's linear slides and ballscrews. 3 triple stack motors and Gecko drives gives me up to 160 IPM. I cut custom boards all the time but even with the precison componets I have, the first dozen boards were scrap until I firgured out the "secrets".

[Bhima]

the first dozen boards were scrap until I firgured out the "secrets".

What secrets!?

[ydeardorff]

Hello,
Im a professional costumer whit the 501st legion. Im looking at getting into costume and prop making. And in that I am looking for something I can take a3d model set the scale and have it carve it out of stryene, resin, wood, or any toolable material.

These wont be overly complicated items, but will have some details. But are there any plans for a machine like the 3 axis mill plans I have seen but that have more of a depth to them?

Something that either the foam or wood block rotates around, or the dremel to gain access to all sides of the object as it carves it out.

Im looking at objects that would be about the size of a motorcycle helmet or abit larger.

Any help here?

Thanks

Yaughn