Re: [CAD_CAM_EDM_DRO] Servo and electronics selection

Sounds like a big machine!
Mine is of similar capability and was also shop made. It
cost a big chunk of money and time for the mechanicals.
There is a link with pictures on my engineering page
in the signature file below.

A commercial control would be the quickest way to get the
machine making chips.

I am using EMC BDI, Copley 412 amps, Servo To Go II
and a K6 pc to run mine with SEM brush dc motors.

I am running with acceleration set at 20 or so in/sec^2
so the 1000 lb gantry zips around like an old plotter
pen. My max rapids are set to 600 in/min. At max
acceleration instantaneous current is 60 amps if all
three axes blast off at once with a load.

I use an external e-stop circuit I designed. A schematic
is on the web page.

I can do a run on my servo sizing program if you will give
me your machine mechanical details (ballscrew size and
type, moving mass, friction estimates, etc). This will tell
you what type and size of motor/amp will work well. I
have lots of extra large servos if you need some but they
may or may not be the right parameters for you- It depends
on what the program says.

Do you have any pictures of your machine?

Les
Leslie Watts
L M Watts Furniture
Tiger, Georgia USA
http://www.rabun.net/~leswatts/wattsfurniturewp.html
engineering page:
http://www.rabun.net/~leswatts/shop.html

----- Original Message -----
From: "kdoney_63021" <kdoney_63021@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Friday, April 05, 2002 9:49 PM
Subject: [CAD_CAM_EDM_DRO] Servo and electronics selection


> I am finally to the stage of selecting my electronics and motors for
> a 3-axis gantry I have been building. I have spend many hours and
> thousands of dollars in the mechanics of this system and although I
> have been researching servos VS. steppers, DC brush and brushless, AC
> with DSP control, even VSRM's, I have no idea what would be the best
> path.
>
> The machine is 8' X 8' X 2' with ground ballscrews and preloaded nuts
> on all axes. The slides are hardened and ground 1" shafts with linear
> bearing. These are attached to 2 - 4' X 8' MIC-6 tooling plates with
> machined fasteners.
>
> I am more interested in precision than speed. Although I have been
> able to buy the items I've needed so far, I don't want to spend any
> more than I have to. I have done my own machining to save money and
> now don't want to just through money at the problem. I want the
> system to be general enough to handle any job thrown at it up to
> milling 1/2" mild steel.
>
> I will be selecting the software later.
>
> Any help or suggestions will be appreciated.
>
>
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