Stopping router - un-attended

[johnny_s]

Hi folks- was wondering what the easiest and fastest way to stop things like spindle, vacuum, dust collector, etc.- after the program is done cutting. I am not a very good tinkerer, but will try my best to "get it"!

Thanks.

[johnny_s]

okay, found this post, http://www.talkshopbot.com/forum/cgi-bin/discus/show.cgi?tpc=26&post=11362#POST11362
but how does it all work? I understand what you are putting in front of the part file, and at end, but what are the two numbers (such as so4,0) doing? Also, I think I understand that they can control switches, but how to you actually get the something like the router motor turned off and on with the tiny voltage? This part I really do not understand.

[beacon14]

The command SO,4,0 turns switch #4 off. The first # after the "SO," indicates which switch you are referring to, and the second number is either 0 for off or 1 for on.

There is a wiring diagram in the User's Guide (or maybe elsewhere in the manual - I don't have one on hand at the moment), that shows how to create a relay that will use the signal from the output switch as an input, and switch your AC line voltage on or off for your router, dust collector, etc. The parts are inexpensive and available from Radio Shack. You may have to use a secondary relay to handle the size load you want to switch.

(If you have an Alpha machine, the control box already has a relay ready to switch your router (or spindle) on and off.)

Depending on what model control box you have, you will have either 4 or 8 output switches available.
Switch #4 is set by default to operate a warning signal, but can be used to turn a device such as a dust collector on and off, since it has a built-in delay feature which can be set with the SW command.

[johnny_s]

Thanks David. What does a negative number (-1) do?

I have a later model PRT.

So a relay is not a switch, but a series of things that will make a switch - to turn on/off things? A secondary relay is another set of things that needs to be done to handle more load?

If you don't have a delay (as on #4), will all things turn on at once? What does the SW command do?

In my link at top of post, is this person adding "pause" because he is using #4 - or is he not using it at all - I don't understand, because it sounds like he disabled it. Why would this cut his zero plate?

[bill.young]

Hey John,

This is from the SO command section of the help file in the Windows software...

"If switch 4 is set to -1, the switch will come on with the Warning Signal just before movement begins and go off when the warning goes off at the end of the move; if set to -2 it will also go off if the PANIC Bar is hit; if set to -3 it will go off if the PANIC bar is hit or if the tool 'Stalls' (cable drive only); if set to -4 this function will be disabled so that the switch can be used for other purposes. "

Bill

[richards]

John,

All commands are explained by clicking on the Help button in the Shopbot Control Console.

SW sets the warning delay.

SO,4,-1 = the device will turn on just before movement begins and turn off when the warning goes off at the end of the move.

A relay is a switch. It is usually used when a low power/voltage/current source needs to control a high power/voltage/current device. When the coil is energized, the contacts on the relay switch on or off (depending on their prior state). In effect, when you flip a light switch, you are acting as the coil in a relay. More than one relay may be used in series if the coil draws more current than the Shopbot can supply. When you use multiple relays, the first relay's contacts are connected to the next relay's coil. The disadvantage to using relays is the electrical noise generated by the contacts switching on and off. The electrical noise can cause a computer to malfunction. Instead of using a mechanical relay, I use a solid-state-relay. Becuause they are totally electronic with no moving parts, there is not electical noise to worry about. In addition, most of them (at least the AC models) switch state at the zero point of the AC sine wave, which is very gentle on the device being turned on/off. (I once performed an experiment to compare mechanical relays to SS relays. I turned a 100 watt light bulb on/off at one second intervals. Using the mechanical relay, the bulb burned out in a few hours, but the SS relay worked for weeks - until I grew tired of the experiment and shut things down.) One word of caution about SS relays. There is always some leakage current, meaning that you can get shocked even though the SS relay is off. In those cases where leakage can cause problems, I use a mechanical relay or switch to control power going to the SS relays. Turning the mechanical relay or switch off safely cuts all power.

The program that you write to control the outputs will determine when things turn on/off. If the statements to turn things on/off follow each other in your program without pauses or delays, then the things will turn on/off "all at once". As the programmer, you have total control of all delays.

As far as #4 cutting a zero plate, it's all in the programming. If you were to write a program to turn off the router/spindle, move the carriage to a position to check z-zero (perhaps using a zero plate that had been built into the table top) and then perform a z-zero routine, and the router/spindle didn't shut off, the zero plate would be ruined. If the program was written properly and the command to shut the device off did not work as expected, the zero plate would be ruined.

The beauty of a computer is that it can be programed to perform any sequence of steps that you would normally do manually. In my shop, I manually place the material to be cut onto a vacuum mask, manually turn on the vacuum, manually turn on the dust collector, and finally manually turn on the router. A program could easily be written to have the computer do exactly the same series of steps with any delay between steps added as necessary.

Hope this helps,

Mike

[johnny_s]

Wow, thanks guys. I am home trying to get a bunch of files ready to cut, so I don't have my control software with me to check the help file.

Mike, how do you know all of this about the bot, but not do any of it for yourself, as you said your last paragraph?

I still have many questions, but I will wait until I at least look at the manual and help file. If anyone has any sample program strings they can post, that would be appreciated.

Thanks again.

[richards]

John,

Some things are done more easily manually. For instance, a delay for the vacuum might take three seconds or thirty seconds depending on the material, the amount of bow, or other unforeseen factors. If I were to write a routine for the vacuum, to be on the safe side, I would include a delay for the worst case. For me, it's easier to do some things manually and some things via a program.

There are very few cuts that I make directly from PartWizard without tweaking something. PartWizard does a great job, but it can't read my mind and it doesn't know the all of the characteristics of the wood that I'm cutting, so I modify the programs when necessary. I never run the alpha unattended. To much can happen, quickly. So, in short, I write or modify programs to make the cut exactly how I want it to be, but I flip the switches manually, when I determine that it's safe to make the cut.

[Ryan Patterson]

I do disabled switch #4 when I am not running a part. So that when I move the router with keyboard ,jogging into poistion or Zeroing on my plate the router will not turn on. I will enable the switch to turn on within the part file. I use the pauses so that all will not start at once.

[johnny_s]

Mike, maybe it's good that I have a snail like prt then - I get into less trouble! I cut mainly MDF, plastics and foam, but I know things still happen. Lately though, the files have become very long - like days long. 90% of the time I stop the router with spacebar, my machine gets thrown off, sometimes very badly. I have been leaving the router on over night, which is always scary; luckily I have been cutting soft material at low rpms.

The Fein shopvac has been working well for my hold down, but still, I would like to shut it down when it's job is done.

Hi Ryan, I would have emailed you directly, but that post has you as not existing anymore. So, if I am correct, you somehow set the values so the switch for router motor is always off, then turn it on in your partfile? Can you adjust the timing of each pause?

[Ryan Patterson]

John,

Yes you can, pause 1 will pause for one second and pause 2 will pause for two seconds and so on.
If you use pause with no number following it will pause until you hit enter.

so,3,1 'turn blower on
'press any key to start
PAUSE
so,2,1 'turn dust collector on
PAUSE 3
so,4,1 'turn router on
so,4,-2 'turn router on
PAUSE 1

At the start of the file my blower will come on pause and display press any key to start, until I hit enter (This pause will allow me to check that the parts are being held down). Then the dust collector will come on and will pause for 3 seconds (3 seconds will allow my collector to get up to speed). then the router will turn on and pause for 1 second.

[beacon14]

John,

Try using the "S" key for a ramped stop, instead of the spacebar, which is an emergency stop. You shouldn't lose any accuracy that way.

When a line of a part file consists of only the command "pause", execution of the file will stop until you (or someone) press any key. If you follow the "pause" with a number, i.e. "pause 2", the file will pause execution for that many seconds, then continue.

In addition, you can use comments to remind you to do something. Any characters on a line after a single quote, i.e. ' , are treated as comments and ignored by the software. If the comment is on a line by itself (not following a command), the comment will be displayed on the screen.

So for instance, you could write:

SO,1,1
'press any key when router is on and ready
pause

this would turn on switch #1, display the message, then wait until you press a key before continuing.

or

SO,2,1
pause 3

this would turn switch #2 on, then wait 3 seconds (to give your dust collector time to get up to speed, for instance).

We'll have you programming in no time!

David B.

[johnny_s]

Ahh, this is great. Unfortunately, I will have to cut parts all day, and maybe night on Wednesday, because its due the following day, but this will take priority on my to-do-list after Thursday. My guess is a two days to figure out how to make the relays, and a day to figure out the programming.

Oh, and thanks David, for the tip about the ramped stop, that will save me some frustration!

[johnny_s]

Is Mikes suggestion to use a mechanical switch before solid state switches? Does this add a great deal to my learning curve? Are both available at Radio Shack? Is SS much more expensive than mechanical?

Thanks again.

[Ryan Patterson]

John,
You have mail.

[johnny_s]

I just replied

[richards]

John,

Perhaps I need to clarify my ideas with mechanical relays vs solid state relays.

A mechanical relay acts just like a mechanical switch. For instance, when you toggle a light switch, the contacts either open or close. It seems simple, but the very construction of a mechanical relay's contacts can cause problems. Instead of closing once, a relay's contacts can bounce many times during a period of a few milliseconds. That bouncing can cause arcing and that arcing is the source of "noise", which causes computers to malfunction.

A solid state relay has no moving parts. Usually a low control voltage (3-24VDC) activates a Light Emitting Diode - LED. The light from that LED is sensed by a phototransistor and the phototransistor turns on another solid state electronic component which lets current pass through the solid state relay. Because there is no "bounce", computers and solid state relays get along very well. HOWEVER, a solid state relay has one major fault: it leaks. When it is turned off, it can still pass a small amount of current. That small amount of current can shock.

To be safe, I use a mechanical switch or relay upstream of any solid state relay circuit. That switch or relay can be compared to a circuit breaker. When it is off (open), no current can flow through the SSR. When it is on (closed), current can flow through the SSR. It is simply a safety device that CAN be controlled by the computer, but does not need to be controlled by the computer. As an example, I never change a cutter in the router unless I unplug the router. So far, I've never bumped the on/off switch on the router, but by having the router unplugged, I don't have to worry about bumping the switch. In the same way, a mechanical switch or relay that absolutely disables a SSR circuit is a safety measure to guarantee that you will not be shocked.

As to price, a "hockey puck" style SSR from Opto-22, Gordo, and other major suppliers cost anywhere from $25.00 to $50.00 each depending on the current capability of the SSR.

Please note that you must use two SSRs to switch a North American 220-240 single phase circuit, with one SSR controlling each leg of the 220-240 VAC circuit. In addition, both relays must be controlled by the same on/off signal, otherwise you could have an extremely unsafe condition where one leg of a 220-240 line was on while the other leg was off. I always use a double-pole mechanical switch or relay upstream of any 220-240 VAC circuit.

Wheather a SSR is necessary for your use is up to you to decide. They may not be necessary, especially when a device is not switched on/off frequently. As stated above, their main use is to insure that electrical noise is minimized.

[johnny_s]

Okay, Ryan made me some relays, but just as he sent them to me, it just hit me, that I have a Columbo, and you just don't turn it off and on. You power up the controller, then set the rpm and then start. Has anyone figured out how to control this automatically, or done this with a spidle?

I guess I can still power the entire spindle down after the program runs, which is what I need it for.

[bleeth]

John,
I too have the Columbo and find it's entire powering up sequence to be a rather clumsy procedure with the control box as programmed. I am interested in any methods for turning it on more efficiently.

[Brady Watson]

John & Dave,
My understanding is that ShopBot is going to eventually implement RPM control from within the control software. Not sure when this will be, as they have their hands full at the moment with more pressing issues.

There are some instructions in the Delta manual how to program in C a routine to control the VFD from PC through it's RS485/Serial interface. You can also go to the Delta Drive website and download the interface 'toolkit' & tester that tests your application with the VFD.

-Brady

[rjguinn@optonline.net]

Brady,
I believe Morris Dovey (http://www.iedu.com/DeSoto/sbadd.html)has done some spindle communications programming which is available for download.
Jeff

[Brady Watson]

Nice!

Now that you mention it, I remember seeing it on the forum at one time and forgot all about it!

Thanks!
-Brady

Update: I just followed the link and it looks like it is no longer on the server...AND it is designed to run in the DOS version of the control software. Since I've made the leap to SB3, it is of no use to me, but I'll e-mail Morris.

[bleeth]

Brady: the download I found on Delta's site was for a 4 cd communication suite(CVFD Communication Software (Disk 1~4))-Is this what you were referring to?

Dave

[Brady Watson]

Yes, that would be the one. There are 2 programs that you can download...but one of them was missing part3 of 4...So I just got the one.

What you are downloading is essentially a program that lets you communicate with the VFD using a command line. This would be useful for testing your code when developing an application in VB or C. Delta is actually pretty generous in having this utility...most times you are in the dark with poorly written manuals with lots of mistakes in the code...and all you want to do is test communication. There is some C code in the manual listing example routines, but nothing that I found in Basic. You may have better luck than me since I only browsed their site for info.


546

547


-Brady

[johnny_s]

Morris had emailed me a link to a conversation he had with another botter:

<http://www.talkshopbot.com/forum/cgi-bin/discus/show.cgi?tpc=22&post=10188#POST10188>

Unfortunately, this and the stuff above is all beyond my limited comprehension of software and hardware. I guess I will need to wait for SB to come up with a WYSIWYG version - hopefully.

[mrdovey]

I've written some software to control the spindle from within a SBP file; but haven't succeeded in wiring my RS-232/RS-485 converter to the VFD-B. It's been a really frustrating experience.

I just got an e-mail from a Delta distributer in Atlanta that's probably worth posting here:

"The RS232/485 converter that we recommend is by BB Electronics. www.bb-elec.com (http://www.bb-elec.com) or 815-433-5100 the part number of their device which will take power from the computer is 485SD9RJ and sells for $74.95

Your problem is coming from the wiring of the adaptor, we use a different configuration than standard, this is shown in the Delta Instruction manual under parameter 09-04, would give you a page number but every time they change the manual, the page number changes. The pins we use are from right to left being 1 through 6 and we use only 2 for ground, 3 for signal neg, 4 for signal pos and 5 for +5v"

As soon as I can get my hands on a 485SD9RJ (and enough time for thorough testing) I'll be able to provide more info.

[Brady Watson]

Morris,
The converter simply converts RS232 to RS485. It has a jack for the DB9 and output for a 485, plus it requires (in many cases) an external power supply. I had the need to use one of these when I had to interface with a Yokogawa PLC/Temp control at my last job.

-Brady

[mrdovey]

Brady...

Yuppers, that's what I bought; but from reading the manuals, it didn't seem that the two authors lived on the same planet. The darn converter can be configured to operate in a number of different modes; and none of the mode descriptions matched the protocols Delta described.

Since I can't afford to toast either the VFD or the PC, I threw the converter on the shelf and went back to looking for something that I could be sure was compatible.

As I said, it's been a frustrating experience. As usual, it was mostly a matter of finding someone who'd been through the process before me.