Re: [CAD_CAM_EDM_DRO] Pendant Design, was - Spindle Motor Control?

deanc500 wrote:

>Hi, I have been contemplating a programmable hand held pendant for
>some time now and I am at the point of laying out the keypad to get a
>membrane switch pad manufactured. I will be offering these in small
>volumes at first to test the market.
>

Is this to be a USB device ?? I imagine so....

>I would like to ask the group for
>input on what the most useful functions would be. I agree with Bill on
>his choices of E-stop, on the fly feedrate override, and axis jogging.
>I would add "zero all axes", Home, slow/fast jog.
>

I guess that IF it is a "programmable" device, then "labeling" buttons
could be somewhat limiting.
I like the approach taken by the X-Keys ( or Y-Keys ) by PI engineerings
keyboard in that the keycaps came off in order to place under them
exactly what you want. You can look in the CCED files section and see an
old layout I did for Flashcut V1 in a .pdf file for their double layer
keypad. It does not take very long to do a nice color print of exactly
what one wants for buttons in Corel Draw, cut them out with an exacto
knife, then place them under the clear key caps. THIS is the best option
as it will not limit anyone or any software, but I understand the desire
for a membrane.....

Then again, the membrane on a particular Multicam head I am familiar
with is absolutely shot after 5 years of use......

My complaint with the off the shelf X-Keys was the switch "feedback"...
not a strong enough "click"..

> What else would be
>useful. I am thinking that the pendant will have room for about 12
>functions and Estop.
>

I used to try to get every possible function I could into the X-keys
box, yet now, looking at redoing mine for Flashcut, I'll shoot for only
the necessary items. After all, I found out that the pendant did not end
up in my hand all the time anyhow. It is most used for machine or Job
setup, and the moments right after starting the job. Then it gets set
back in its holder while the job runs.

Homing, Setting Zero, Jogging ( at all available rates), Setting Part
Zero, Move to a reference point ( like machine zero or toolchange
location), Start Job, and finally the "ooops" Feedhold, and Reset option.

The "E-Stop" concept on it is nice, but probably best a "cover" for
liabilities anyhow.

I think it would be a shame if a person "learned" to rely on his
pendants E-Stop" rather than on the ONE Really BIG red Kill button he
SHOULD have ! One might get a little too friendly with the pendant
E-Stop, so that when a real emergency arrives, he is fumbling for a much
less accessable button than he should be. Also, the Real E-Stop should
be cutting power to the drives and spindles, not just halting the
software. So, it has some limitations as a USB E-Stop.

I learned something once about E-Stops.... Do NOT put your ONLY one on
or even too near to the machine. Put an E-Stop by a door exiting the
room, or on a pole 15 feet away in a shop scenario. Let it Disengage a
contactor feeding that machine. I had a fellow start a toolpath, but
forgot to remove his dial indicator and positioning arm from the
spindle. The vibration was unbelievable, and the parts flying off were
deadly. Guess where the E-Stop was ?? NOT where anyone wanted to go to
get it shut down ! As everyone in the whole place was laying flat on the
floor dodging flying parts, I was forced to head for the Main power
panel. Good thing I knew which breaker it was ! I don't need to tell you
that was the "Last Word" from our *Last Word* Indicator.

So, I could do without the E-stop on the pendant... a feedhold is
plenty. E-Stops should be BIG red locking buttons that disconnect Power.
I'll keep my second E-Stop mounted right by the doorway so I can nail
that bugger whan I am headed out in an unexpected hurry.

Chris Luebke
DATA-CUT