Re: 3 axis 9x49 retrofit recomendations.

Dan,

I converted a 9x42 Enco and with 20/20 hindsight should have sold it
and bought a BP.

As other list members have already posted you need to install
ballscrews on at least the X&Y axis and preferably on Z as well, but
that adds additional complications mentioned later. I bought
precision ballscrews from Hiwin at about the same price as rolled
screws from Rockford. Others on the list have successfully installed
screws in different model Enco's, but I found that the yoke on mine
had insufficient wall thickness on the Y axis without making
significant modifications. Rockford handle things differently, you
send them the existing yoke and they make you a new one.

I originally started out with 600 oz/in servos on all 3 axes, but
changed to much larger motors, the latter were obtained from Les
Watts, also on this list. X&Y are reduced 2:1. Unless you change
the Z acme to a ballscrew and add either gas struts or counter-
weights, to stop the knee moving when power is reduced, I would
recommend using a tripple stack NEMA 34 stepper for Z. My reasons
for this recommendation is that unless you use multiple pulleys it is
impracitcal to get the necessary gear reduction to get a servo
sufficiently high into its effective RPM/torque range; steppers
provide the required torque at slow speeds. With the greater mass of
your table the problem will be even worse.

Les's motors require encoders, I mounted mine on the motor mounting
bracket, but you could mount them in place of the existing tach. I
bought the encoders from USDigital, I also found that installing
their EA-D8/EA-R8 differential drivers/receivers virtually eliminated
random stoppages.

To get the most out of the motors Les supplies you need greater
voltage than Geckos can handle and Rutex would probably be your best
choice.

As I didn't want to install and learn a new operating system, I used
Mach1/Mach2 Windows controller. IMO its a great product and Art
provides phenomenal support, check out the Yahoo groups under Master5
(the fore runner to Mach1).

Bernard

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Dan Sergison"
<dsergison@y...> wrote:

> Sorry to ask such a general question, but there is SO much
> information, I'm having trouble processing it all.
>
> I have a plain old 9x49 enco mill. I'd like to retrofit it to 3

axis

> cnc. (maybe 4 w/rotary table)
> I'm perfectly capable of fabricating all the brackets and hardware
> but I'm over my head on the controll system. I believe I'd like to
> have linear positioning feedback from some dro, not rely just on my
> crappy leadscrews. also would need to be able to use the mill
> manually most of the time, and have a dro function.
>
> I'm a solid modeler by trade and fairly handy with computers, I

have

> a few pc's and a hpux workstation, or could set up linux.
>
> what would you recomend for a somewhat economical approach?
>
> thank you very much,
> Dan