Re: green horn alert

Hi Jason,
I'm not sure how big your home CNC system is intended to be (small
like a Sherline or big like a Bridgeport, it can make a difference).

In general (for a simple system) you will need:

1) A PC (that has a parallel port) on which you run CNC software
(CPU speed reqirements depend on actual software platform chosen).
Also a parallel port extesnion cable to bring STEP & DIR signals over
to the work area.

2) The controller software: something that can generate STEP & DIR
pulses out the parallel port is most common for home CNC. Choices
include (but are not limited to): TurboCNC (DOS platform)
registration $20.00, Mach1 (WinXP platform) about $150.00
registration, BDI EMC (brain dead install enahnced machine
controller) (linux platform) Free, or a small fee if you want to get
it on CD.

3) Stepper drivers (or servo drives). With my stepper system
(Xylotex), you can drive 3 axes for $125.00, or 4 axes for $165.00.
The typical running voltage is 24V, and max amps/phase is
2.5A/phase. If you need more voltage/current, check out the specs on
Gecko drives (both stepper & servo drives). The wire thickness (from
the drive to the motor) will vary on the current you are trying
pass. 22ga is adequate for lower amperages going small distances.
Always try to uses stranded wire, as solid wire can break much easier
after repeated movements. A wire that breaks (becomes disconnected)
while the motors are energized can easily destroy the motor drive.

4) A power supply to run the motors with. With my system, a 6 to 8
amp supply at 24V would be adequate for most system that would use my
board. Other systems can use/require higher voltages/amperages.

5) A break-out board if you are not using my system. This is used to
help get STEP & DIR signals from the parallel port to individual
motor drives (like single axis Gecko drives).

6) Your motors. You will need to decide how much torque will be
required for your system. A Sherline type system can get away with
torque in the range of 110 to 200 oz./in. The lower the torque
rating, the lower the speed you will be able to go (generally). You
need to match your motors to the type of drive you get. Stepper
motors require a stepper drive, servo motors require a servo drive.

7) For some smaller systems, home/limit switches may, or may not be
used (user option). These are switches that attach to your CNC
hardware and can be used to stop/warn the controlling software of
eminent end-of-travel crashes. How they are used depends on the
software, and your hardware setup. Larger systems will generally
include these.

8) Transmittion. This could be a simple as a coupling between the
motor and your CNC project, to more complicated things like belts and
gears.

9) Your CNC project hardware itself.

There you go, more stuff to weed through.


Jeff
http://www.xylotex.com



--- In CAD_CAM_EDM_DRO@yahoogroups.com, "zr700fire" <brainstorm@g...>
wrote:

> Hi, Im at the earliest phase of the home cnc project, well long
> story short.
> What the best,user friendly,ok price,and all around good setup I
> should start with, to reduce r+d, should I look for in:
> software,motors, servo, controllers, wire,...blah blah blah.
> I figure if I have enough imput I can weed out any mistakes and

such.

> Hoping for a 3 but wanting a 4 axis setup. And if you could explain
> it like if you were talking to your wife. Some thing are just flat
> new to me.
>
> Thanks guys this is a awesome group site.
>
> Jason