RE: [CAD_CAM_EDM_DRO] Basic CNC set up on Sherline Mill

Contrary to the advice below, this group is dedicated to helping you
learn enough so you don't have to buy an off the shelf package. For
another list member that recently asked about a Sherline the suggestion
was for more of a turn key package. This was because he wanted something
that he could get running as soon as possible with as little learning as
possible. To be honest that is not the typical approach on this list.

> I would like to add,
> that being that you have no experience with this sort of
> thing,I would recommend getting a small complete package that
> includes everything to get you up and going relitively easy,
> until you get the hang of CNC.

I think this is pretty clearly laid out in the subject of this message.
The machine is a Sherline mill. The norm for a Sherline is a NEMA 23
motor with between 150 - 225 in/oz. Some people have done it with less
torque and some with more. If you are in this range you will get great
performance with a Gecko.

> As far as
> what type and torque rating of steppers you need.That all
> depends on your machine.

The below definition is a little off. Yes a 2 phase stepper has 2 sets
of coils. It can be either bipolar or unipolar and how you excite them
has no bearing on them being a 2 phase motor. All the unipolar motors I
have ever seen are 2 phase and virtually all the unipolar motors (6 wire
or 8 wire) can be used as bipolar instead if you just connect them to a
bipolar drive. Basically 2 phase refers to the construction and has
nothing to do with bipolar or unipolar. Bipolar and unipolar has to do
with the drive primarily as most motors (all 2 phase except the 4 and 5
wire units) can be driven in either mode.

> 2 phase steppers,or bipolar , have two sets of coils
> excited at the same time. Which creates much more torque per
> step and they tend to be more accurate. They also require
> more current to drive them compared to a unipolar stepper
> motor.

Just didn't want you to be more confused than necessary as you come up
to speed.

Tim
[Denver CO]