RE: [CAD_CAM_EDM_DRO] Servo drivers ?

Hi Dave

Well, the dynamics determine the motor type which in turn determines the
driver.

I start with the desired velocity and acceleration and the moving mass.

Velocity required is easy to select.

Acceleration can be thought of as how big the radius will be in a corner
during a continuous move (among other things).

Example: one desires no more than .05" corner radius in a move with a
velocity
of 2 inches per second.

A= V^2/R in the corner
so A= 2^2/.05= 80 in/s^2= 6.7 ft/s^2 = 0.2g

the force required will be the accel times the apparent moving mass, and can
be
converted to torque and rpm. In a cartesian machine both axes will have to
supply
this (if a 2d move).

Then there is friction, gravity, and anything else that might consume or
store
mechanical power.

All this can be conveniently calculated by the free motion design program
from Kollmorgen that I use and periodically post a link to:

http://www.motionvillage.com/motioneering/


Les
Leslie M.Watts
L M Watts Furniture
Tiger Georgia
(706) 212-0242

Main page:
http://www.lmwatts.com
Engineering:
http://www.lmwatts.com/shop.html
Cnc surplus for sale:
http://www.lmwatts.com/forsale.html
Carved signs:
http://www.lmwatts.com/signwp.html


-----Original Message-----
From: turbulatordude [mailto:dave_mucha@...]
Sent: Thursday, December 16, 2004 1:39 PM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] Servo drivers ?




It looks like there are a lot of lower priced DC motors that might be
used with a servo driver, but it also seems these are lower voltage.

The drivers I found so far are Jon's PICO , the Gecko and a Rutex.

IMSERV has a $2,000 package for drivers but that is out of my league.

I'm not sure how to frame the question, but are we just basically
looking for watts for power ?

For a plasma cutter, the gantry will move pretty quickly with both
rapid accel and decel, and have to drag around the hoses.

Is there a rough guideline of which type driver is best for certain
machines ?


Kinda like the Xylotex is great for Sherlines and Geckos can handle
Bridgeports ?


Dave