Hello Guest it is March 04, 2021, 11:06:50 AM

Author Topic: Tool sensing with ATC  (Read 3679 times)

0 Members and 1 Guest are viewing this topic.

Tool sensing with ATC
« on: February 10, 2015, 06:11:41 PM »
Hello all!

I have a CNC router with a Fischer Precise spindle with ATC capabilities.

I recently set it up as a fully operating ATC system using the macro from the machsupport site and small spring loaded grippers as tool holders. The grippers grab the locating collar on the small end mill tools I use. (pool cue inlay work on this machine)

It was pretty straight forward. I only had to incorporate some of the spindles extra features like "spindle>0" and "RPM Low". It does work very well, and saves a ton of time.

What I want to do now is really more of a problem prevention thing than anything else. I want to pass my current tool through an optical switch to make sure it's not broken before I do the tool change. I'd also like to pass through the gate again to make sure it did release the tool, and I'd like to pass the new tool through the same gate to make sure it picked up the tool as it was supposed to. I don't need to really measure the tool for Z because I use the depth collars on all of the tools. They're all small 1/8" shank tools, and I have a depth ring installer already.

I've looked into the G31 function used with touch probes, but I'm not quite sure how it programs, and I've heard of issues with the smoothstepper. I do use an ESS on this machine.

So, if anyone has any suggestions as to how to program something to work, I'm all ears. I would think that I could create some sort of a "flag" of some kind so that when the tool is passed through the gate any signal would trip the flag. I just don't know how to setup anything like this.

I've also heard of a "high speed skip". I think that's something similar to the G31, but I'm not sure.

Any help would be greatly appreciated.

Thanks

Royce

Offline BR549

*
  •  6,944 6,944
    • View Profile
Re: Tool sensing with ATC
« Reply #1 on: February 10, 2015, 10:03:59 PM »
You would not want to use the G31(high speed skip) Because every time you passed a tool through it  the machine would stop. YOU want the opposite.

So you simply set up a tool slot gate with a very small optical beam  Then position the tool in the centerline of the beam so that it blocks the beam.

So when you are finished with a work segment and want to change tools you simply move the tool to the Tool Check  point and IF the beam is not blocked(tool Missing/broken) then STOP the machine and call for HELP(;-). IF the beam is blocked(tool OK) continue on the to the next tool change position. Pick up a tool and loop through the tool check position on the way back and check IF a tool is picked up.

You can do the same thing for a missing or present tool holder only position it to check the tool holder instead of the tool bit.

Build your gate to be able to check both with one gate. Make it wide enough to pass either through it.

Does your spindle have an output signal to verify the tool holder is present ??

(;-) TP
Re: Tool sensing with ATC
« Reply #2 on: February 10, 2015, 10:28:40 PM »
BR549

I really like your screen name!

I completely understand what you're suggesting. Actually, I've considered doing exactly that. But, and there's always a but isn't there. Some of the tools I use are very small. I'm not confident that the smallest ones would completely block an optical beam. I mean, I'm talking .005" with a tiny depth of cut. For the same reason, I don't really want to come down on top of a touch plate either. They're kind of pricey and the tiniest corners of the bits can break and ruin the cut.

As for the tool holders, I don't really have any holders. The spindle just uses an air powered draw bar attached to the actual collet. My tools, all with 1/8" shanks, are dropped off and picked up by the shanks. Just the collet and the tools, no holders necessary.

In typing this, I realize that if my tool won't block a light sitting still, it might not block it while moving through it either. I guess I need to take a closer look at the optical switches and their specs. I currently use them for homing, and they are extremely accurate. Much more so than mechanical switches. I currently use the Optek OPB941W51Z for the home switches. They do offer a wider version, and the sensor aperture is only .010", so it just might work. It typically only requires about 40 to 50% of the light to be blocked for activation.

I would still like to learn how to turn a flag on and off though if possible. I think it could come in pretty handy at some time or another.

Royce

Offline BR549

*
  •  6,944 6,944
    • View Profile
Re: Tool sensing with ATC
« Reply #3 on: February 10, 2015, 10:39:47 PM »
You can use a simple micro switch with a lever as well. They require very little pressure to work. Just brush it passed the switch lever  an see IF it trips or NOT.

If you need help, glad to help out.  A simple Mcode(macro) would do the job.    and between checking teh tool OR tool holder is just a matter a Z height using a single switch. Peace of Cake(;-)

NOW of course you will have to reference the machine on startup to the same spot. But you will need that for selecting tools anyway so that Mach3 knows where everything is located.

he code to see the switch is simple. You would have brought the switch wiring to a PIN then assigned it as an input.  Then as part of the tool changer code you park it at the Tool check spot then look at the inout to see IF it is active.

IF not IsActive(input5) then         'If the switch did not trip
      MsgBox("Tool Bit is Broken")   ' Popup message box
      DoButton(3)                         'Stop the program run to allow you to fix the problem         
else
Message" Good To Go "    ' Sends message to status line in Mach3 and continues Program.
End IF
End

If you need help with the Macro coding side just holler, Glad to help




(;-) TP

(;-)TP
« Last Edit: February 10, 2015, 10:53:49 PM by BR549 »
Re: Tool sensing with ATC
« Reply #4 on: February 10, 2015, 11:00:24 PM »
I do reference the machine at start up, so that's not a problem. I'm able pick up a .125" diameter tool with a collet, so I only have a few thou to work with as it is. I have 6 tools that I choose from, and they are all at the other end of the table from the home switches. I don't have any issues with being in the right place

What I'm not familiar with is how to make a move, and watch for a signal while it's moving. That's why I thought of the "flag" concept. I'm not a normal computer guy, so much of the language is new to me.

How do I program a move, in machine coordinates, and during that move, recognize a signal or not? All in a macro, of course. I'm not well versed in VB.


Royce

Offline BR549

*
  •  6,944 6,944
    • View Profile
Re: Tool sensing with ATC
« Reply #5 on: February 11, 2015, 09:24:29 AM »
Actually you would just MOVE to the check position Stop Then look at the input( switch) to see IF it is active or not. It will do it fast enough that you won't notice much lag time.

(;-) TP
Re: Tool sensing with ATC
« Reply #6 on: February 11, 2015, 11:47:24 AM »
BR549

Yes, I knew that I could just stop in the beam and then read the input as to whether it was active or not. I'm sure this is what I'll end up doing. As long as the smallest tools still block enough of the beam I'll be ok.


I guess I just wanted to be fancy and see if I could just pass it through and trip a flag.

I guess I could setup a brain to constantly monitor that input, and when it saw it active, set a variable to a given number, say 10. Then, during the tool change macro, I could just set the variable to 0 before passing through the gate, and then look at it afterwards to see if it's now 10.

I might try that.

I've been very happy with using brains for various things. I have one that monitors all the spindle amplifier's signals. If it sees any faults, it essentially presses the stop button. I have the safe Z turned on, and set above my work. It will actually save a .020" cutter working at 50 ipm if the spindle faults!

Thanks for all your input.


Royce

Offline BR549

*
  •  6,944 6,944
    • View Profile
Re: Tool sensing with ATC
« Reply #7 on: February 11, 2015, 06:41:11 PM »
You are only limited by your imagination (;-) Go for it.

Now keep this in Mind Mach only looks at the inputs 10 times per sec. IF you pass through fast enough considering the very narrow wideth of the beam Mach may NOT see the input. That is WHY I suggested a stop and look approach.

(;-) TP
Re: Tool sensing with ATC
« Reply #8 on: February 11, 2015, 07:33:28 PM »
You are only limited by your imagination (;-) Go for it.

Now keep this in Mind Mach only looks at the inputs 10 times per sec. IF you pass through fast enough considering the very narrow wideth of the beam Mach may NOT see the input. That is WHY I suggested a stop and look approach.

(;-) TP


TP

I'll have to go back and look, but I was pretty sure that brains run very fast. Like 10 times, or even 100 times faster than just the regular Mach stuff like modbus.

It may be a little bit before I get it all setup, but when I do, I'll post about it here.

Here's a link to a video of my current tool change system with the Precise spindle.

I did have one mounted on an inlay machine at one time. I now have 2 NSK's on one machine, and a Fischer Precise on the other. All with ATC. I've got the single Precise working very well right now with fully automated tool changes. Here's a video of it in action. It's really cool.

https://www.youtube.com/watch?v=scZmBhma3fU

Royce

Offline BR549

*
  •  6,944 6,944
    • View Profile
Re: Tool sensing with ATC
« Reply #9 on: February 11, 2015, 08:24:40 PM »
NOPE 10hz is it on input reads, always has been.  NOW on things like limits, homing,probing it reads at kernal speed.

Just a thought, (;-) TP