Proximity switches working infrequently

[mbarinholtz@chdc.org]

Howdy!

Quick question - we understand that high jog or move speeds affect many things - losing steps, poor cut quality, lost sleep, etc. But what about proximity switches? We've had some strange problems with the 'bot grinding beyond the proximity switches when performing a simple xy homing routine, when the move speeds are above 1.5 and the jog speeds exceed 2.75. We may occasionally run MS @ 2 and the JS @ 3.5, but that's really running in the red for us. To put it in simple terms, when the prox switch nears the bolt that sets it off (on either x or y) the light goes on, but the motors just keep on going, grinding, shaking, rattling.

It's not that big of a deal, but it's a pain to have to remember to slow the MS and JS every time we recalibrate (sometimes each morning), and then reset them. Our 'bot is used to teach young woodworkers, is being operated by newbie teachers, and we're wondering how to explain that the strange grinding sound that happens when you run the homing PF at move speeds that are too fast, when they're really not.

Any recommendations?

Thanks!

Matt Barinholtz
Covenant House Washington DC

[rgbrown@itexas.net]

Matt,

I suggest rewriting your "Zero"- ing command to reflect the values you need. After the carriage is in the area, the NEXT line in my "Zero2" file
is a "SS" command.

It is not a bad practice to write ALL files with the first command as a "SS" command for the file. This is ESPECIALLY true with folks who are not familiar with the tool, its' speeds and its' limitations.

Ron

[mbarinholtz@chdc.org]

Thanks, Ron. I will certainly do that. I still am wondering what may be causing these hiccups. Should I re-adjust the height of the target bolts? Is there a way of testing the inputs to see if they are working correctly? Or is this just the way it is?

Matt Barinholtz
Covenant House Washington D.C.

[rgbrown@itexas.net]

I can't answer your questions as my machine is so modified sometimes I don't recognize it. But there are ways to test the "box".

Ron

[dingwall]

How do you turn on input switch #1?

When using the Z_Zero or homing routines, input #1 halts the machine. When running a part file or pretty much at any time else input #1 doesn't do anything. This can be bad.

[ron brown]

Sheldon,

You might want to rethink and rewrite some of your routines. The input switch halts the routine in a "Sub-routine". This allows the same switch to be used for several purposes but at different times.

BUT - to answer the question, the command line is:

SO, 1, 1

(S_witch O_utput), using a comma for a seperator (switch number),(0=off; 1=on)

I hope this explains this. The inputs can be programed to initiate a lot of interesting things. As usual, these are more limited by the mind than the machine - at least in my case they are.

Ron

[bill.young]

Hey Sheldon,

The input switches act in different ways. The #1 and #2 switches ( and #5, 6, 7, and 8 in the new control boxes) are basically just plain on-off switches and have to be programmed to do things when they are turned on or off...you do this with the ON INPUT statement. If you look at the z-zero routine with an editor you'll see the lines...


ON INPUT(1,1) GOSUB CONTACT1
JZ, -5


The first line sets up the action of the switch, telling it to go to the CONTACT1 subroutine when the #1 input switch is turn on. The second line tells it to make a deep (-5) z-axis move. When the part file runs the z-axis will start moving down, and will keep moving until it contacts the plate and turns on the #1 switch. The part file execution will stop ( and the z-axis movement) and the part file will do whatever is in the CONTACT1 subroutine.

The #3 input switch is a special case, and by default acts as a limit switch and stops all movement when it is activated. Your prox switches should be connected to input switch #3, and anything else that you want act as a limit switch.

There's more complete info on using input switches in the help file in the Windows software...type HI and then "limit switches".

Hope this helps,
Bill

[dingwall]

Thanks Ron and Bill,

I don't hit my limit switches often, but I've ruined a piece or two when I have hit them in the middle of a file and they failed to stop the motion of the tool.

I'm using the DOS version. I'll have a look at the Windows version on my laptop at home.