Messages

861

Mach4 General Discussion / Re: CNC movements not smooth

« on: August 19, 2016, 04:16:53 PM »

The only M codes that don't break the CV chain are M62 and M63.  M03 and M05 will.  If you think about it, you would never want the look ahead to turn your spindle off (M05) when the machine is actually still 100 lines back in the G code (assuming you have a 100 line look ahead set).  So when the interpreter look ahead runs up to a M05, it simply waits until all of the prior motion is complete (and it will be an exact stop) before turning the spindle off. 

The reason Pedio's code works is because the S word is given just once before a large set of G01 blocks.  CV is in effect for all of those G01 blocks. 

Steve

862

Mach4 General Discussion / Re: Mach4 5-axis

« on: August 19, 2016, 04:07:00 PM »

We do not do kinematics (yet), so a gimble head is not possible.  But 5 axes with a trunion table setup is.

Steve

863

Mach4 General Discussion / Re: CNC movements not smooth

« on: August 19, 2016, 01:37:15 PM »

Just to be clear, the S word separating the G01 moves IS the problem here.  If you take out all of the S words, you will see it run very gracefully in CV mode. 

Steve

864

Mach4 General Discussion / Re: CNC movements not smooth

« on: August 18, 2016, 02:54:18 PM »

It is M62/M63 in Mach 4.  And the motion controller you are using has to support it.  They are special M codes that are an exception to the rule of M codes breaking the CV chain.  I'm not sure if ESS supports them yet or not.    And they also only operate outputs, not some analog value.  So you would have to vary the PWM output based on which output was selected.  maybe 10 outputs to span the range of the PWM?

There is a LUA instance that runs the PLC script.  It basically gets executed at a predefined interval.  That is where I would do any code like what you are talking about. 

Steve

865

Mach4 General Discussion / Re: Modbus and Sim

« on: August 18, 2016, 11:12:10 AM »

No, Brett is not normal at all.  But then again... neither am I.    Anyone that plays with this stuff can't be normal.  Anyway, have fun with the modbus stuff. 

Steve

866

Mach4 General Discussion / Re: CNC movements not smooth

« on: August 18, 2016, 12:12:48 AM »

The issue is all of the G01 lines are separated with S lines.  S breaks the CV chain.  In fact, M, S, and T will all break the CV chain.  In a Fanuc control, they refer to it as MST.

If you think about it, the look ahead would basically set S to the last value it read even when the machine is actually running the FIRST line of G01 code.  So we MUST break the CV chain and WAIT on that G01 line to run before advancing to the next S line.  Then, you will have spindle speed ramp times in there too.  You can probably set them to zero and alleviate that.  But nothing will keep it from going into exact stop mode for the S word.

Steve

867

Mach4 General Discussion / Re: Mach4lathe backlash comp with the pokeys57cnc and encoder

« on: August 18, 2016, 12:02:30 AM »

BL is implemented in the motion controller.  And not all of them do it. 

868

Mach4 General Discussion / Re: Mach4 Tangential

« on: August 17, 2016, 11:57:29 PM »

Brian is working on the tangential stuff right now.  CV is working.  I don't know the status of the rest of it.  But it may do what you need.  Try it out and see.  It should work with Ethernet Smooth Stepper fine.  Or any other motion device that Mach 4 supports.

Steve

869

Mach4 General Discussion / Re: Mach4 5-axis

« on: August 17, 2016, 11:53:29 PM »

ESS and HiCON Integra are two that come to mind. 

Steve

870

Mach4 General Discussion / Re: Mach4 error comp calc failed with current tool radius

« on: August 17, 2016, 11:51:26 PM »

Post up some code that fails.  I was running some cutter comp stuff the other day and all was fine.  So it may just be the way your post processor is outputting the code. 

Steve