Messages

1

General Mach Discussion / Re: Spindle Index Pulse Problem

« on: November 27, 2012, 11:28:56 AM »

Don't think it's the DigiSpeed board that's causing my trouble. I'm seeing output fluctuations of maybe .001-.002 volts. This shouldn't affect my spindle speed by more than 1rpm, if even that much.

Possibly something with how the drive reacts to analog input commands. I'll be contacting tech support to see if I can work something out there.

I know my drive has a ModBus interface. Is it possible to command VFD speed and direction from Mach via ModBus?

One issue I'm seeing, although slightly unrelated, is the linearity between the S command and Mach's PWM signal. Although I'm sure using a voltmeter to test that signal isn't perfect, at 2Khz base frequency, I should be able to read a fairly clean voltage represented by the PWM signal. And it isn't very linear. Which shows up in the fact that at low RPMS, S actual reads higher than S commanded, and at higher RPMS, S actual reads lower than S actual.

2

General Mach Discussion / Re: Spindle Index Pulse Problem

« on: November 26, 2012, 10:10:00 PM »

Screwed up threading 

I set the speed on the VFD manually, and it stayed steady within 1 or 2 rpm. Gave me much better results on the scribing test. I checked the PWM signal from the SS with my volt meter, and that appeared to stay constant. The analog output voltage from Homann's DigiSpeed board seems to vary up and down a few millivolts  though. Not sure if this is the issue. I need to sit down and do a little math and see if millivolt variations are enough to affect my speed by that much.

3

General Mach Discussion / Re: Spindle Index Pulse Problem

« on: November 24, 2012, 09:44:40 PM »

Did a little more testing. Checked the output from my digispeed DC-05 board...voltage stayed pretty constant during speed fluctuations, so I assume the problem is in my VFD.


Next, I notice that my speed fluctuates slightly less at higher RPMs. Which also means the % fluctuation is quite a bit less due to the higher RPM.  Tried doing some thread testing at 2500rpm and I get much cleaner results than at 500.

I assume the index pulse must be pretty clean if I get decent results at that high speed. Which kinda reinforces to me that my trouble is the speed fluctuation. How does Mach use the index pulse during threading cycles? What kind of speed variation can it compensate for? Does it compensate during the cut or only as it is starting each pass?

Keep in mind I'm only scribing a piece of stock with layout dye on it, not taking actual cuts.

The only problem with threading that fast is that my servos can't decelerate fast enough, so the lead shortens up towards the end of the cut. But I leave plenty of room for accel before staring into the work, and most of the thread comes out with a correct, even lead.

Help!

Kevin

4

General Mach Discussion / Re: Spindle Index Pulse Problem

« on: November 24, 2012, 06:37:15 PM »

Still not having much luck threading. One thing I notice, is that my spindle speed fluctuates quite a bit. Up and down as much as 30-40rpm between passes sometimes. In a recent test, I got 3 good passes before things got out of whack...and I think it's because the spindle speed stayed about the same.

What results do others notice they are getting as far as spindle speed variation? I'm using a 3 phase induction motor driven by a VFD. No speed feedback to the VFD...just open loop.

Thoughts?

Kevin

5

PoKeys / Re: PoKeys 55 and Mach plugin issue

« on: November 23, 2012, 04:47:26 PM »

Also, I have .Net 2.0 and 3.0 SP2, and 3.5 SP1 installed.

6

PoKeys / Re: PoKeys 55 and Mach plugin issue

« on: November 23, 2012, 02:44:37 PM »

Step 5- The error comes up, I close it, it pops up again, close it again, and then I can configure my PoKeys. The configuration seems to stick now. Also, in configuration, if I go from one screen, say the MPG tab, back to the mapping tab, it pops up again.

Pic attached, but I will also email it to you.

7

General Mach Discussion / Re: Help with VB script

« on: November 21, 2012, 06:34:22 PM »

Thanks Hood, I thought of that. Might do it that way. Found that adding a short sleep between the two works:

DoOEMButton(1021)
Sleep 60
Message ("Turret Error, E Stop")


Thanks again guys

8

General Mach Discussion / Re: Help with VB script

« on: November 21, 2012, 06:01:09 PM »

I tried that too. It works if I just use that out of the VB editor, but when it happens within the macro, all I get is the normal "External E Stop Requested"

9

General Mach Discussion / Re: Help with VB script

« on: November 21, 2012, 05:49:59 PM »

This is the final code I ended up using. Works as it should, except that I can't get the message box to display the message I want.

Dim cnt
cnt =0
If GetSelectedTool = 1 Then
ActivateSignal(output7)
cnt =0
Do While IsActive(Input1) And cnt < 500
Sleep 10
cnt = cnt + 10
Loop
If cnt >+ 500 And IsActive(Input1) then
DoOEMButton(1021)
Message ("Turret Error, E Stop")
End IF
Code "G0 A0"
While IsMoving ()
Sleep 10
Wend
Sleep 25
DeActivateSignal(Output7)
cnt =0
Do While Not IsActive(Input1) And cnt < 500
Sleep 10
cnt = cnt + 10
Loop
If cnt >= 500 And IsActive(Input1) THen
DoOEMButton(1021)
Message ("Turret Error, E Stop")
End If
End If

10

PoKeys / Re: PoKeys 55 and Mach plugin issue

« on: November 21, 2012, 02:19:12 AM »

Couldn't find that folder specifically....but I deleted the config file that was in my documents. I still get the error message every time i click on something in the plugin config menu, but it did save the settings and work. After reopening the config menu, the active inputs still show as active, but the buttons they are mapped to don't show up anymore. Still works though. Is there a way to use the PoKeys to trigger a VB button, or execute some VB code?