Re: Re: Fanuc 6T controller picture posted, hand wheels

> Date: Wed, 13 Feb 2002 10:42:18 -0800
> From: Alan Marconett KM6VV <KM6VV@...>
>Subject: Re: Fanuc 6T controller picture posted, hand wheels

>Are you saying that the pulse generating hand wheels actually have some
>force feedback, or that you can feel the steps (detents?) of the
>encoder? So once zeroed, their scales remain accurate to position, just
>like a manual mill? "Just getting motion" when one turns the handwheel
>is less then desired, I take it? Things just got a little tougher!

Yes, although it is not true feedback (with an open loop stepper system anyway), it is just confirmation that an event has been directed, not that it necessarily happened. The feedback is like a multiposition switch that has a detent at each position. Just getting motion is NOT wanted. This can be accomplished just fine with keyboard arrow keys. What is needed is the reassurance that you have clicked 3 times and the machine has now been commanded to move 3 * (your selected handwheel increment) along the directed axis, either Plus or Minus, depending on the direction of the hand wheel rotation.

Think about the process of using an edge finder. You are setting Zero along the Y axis. You turn on the spindle with the edge finder mounted, jog close to the workpiece (however you want), then turn on the hand wheel in .001 mode. Turn the dial one detent (.0010) at a time until the edge finder clicks contact. Back off -15-20 clicks and come at it again to make sure that it repeats. Now set your Y=0. Pull the spindle above the part, turn the hand wheel on Y and set the gradient to .1 per click. Click it once. Watch it move! OOPS YOU WENT THE WRONG DIRECTION! It's OK, just go 2 clicks the other way and the edgefinder center is now back over the edge of the part. Zero Y and the edge is found. This process gets much more complex when you cannot use the handwheel to quickly move a precise distance per click.

(Since there may be an argument about this method, let me say that no amount of presetting the edgefinder and auto comping for the edgefinder radius works for me. I'm too dumb to automatically add .1 to the reading when I zero it out. This method works for me...always... The other methods, while saving a few steps, I OFTEN go the wrong direction and have to go back and start all over. That may be either before or after I make a scrap part.) :-(

Now if you should happen to be at NAMES this year and stop in to our Vector training class, you might get a chance to feel one of these dials with your own hands. ;-)

Best Regards, Fred Smith- IMService

Listserve Special discounts and offers are at:
http://www.vectorcam.com/cced2.html

We are THE source for low cost Cad Cam