G-code provides for sophisticated CAM programs to directly control feed rate for
non-Cartesian motion (rotary axes) by specifying the Time to complete the move
instead of the Feed rate. The code for this mode is G93 and the Rate is specified
as a number equal to 1 divided by the desired time to complete in minutes. This is
called "Inverse Time Mode".

While in G93 mode, every block that contains feed motion must have an F word,
I.E. feed rate is not modal while in G93 mode. For a simple rotary axis this places the
responsibility for compensating for Z radius effects on tool tip travel as the A axis
turns on the CAM program generating the code. It also allows for much more
complicated situations than just a simple rotary axis. The Mach3 software did
have a mode that would work fairly well for a simple rotary axis, but it was not
industry standard and is not implemented in Mach4.

Steve Stallings
PMDX

django013,
I have tested many CAM programs in the past.
I do not know of any CAM program that can output surface speed and the A Axis using the Z Axis as the radius to control the speed.
If you want a controller that can in all conditions you need to speed the $$, HiCON cards can do it all.
Regards,
Mauri.

Newbie question save me some time.

Is Mach4 lathe threading currently 100% functional as described in the manual for the hobby version?

and

What external controllers currently provide 100% functionality for lathe threading at this time?

Thanks,
RICH

Hi,
Mauri and I have had a conversation about how this might work.

My contention is that once a coordinated move is dispatched to the controller it is no longer possible to change the A axis rotation rate, it would break the move.

My suggestion was that the A axis be temporarily assigned as an out of band axis, Mach4 Hobby allows only one out of band axis and it is always the spindle.
Because the A axis is ansynchronous  the speed of rotation can now be changed during a coordinated move of the other axes. In particular if the Z axis is equivelent
to radius then the speed of the A axis can be calculated and repeatedly updated by a short PLC script.

During this time however the main spindle is uncontrolled, it is a shortcoming of Mach4Hobby. Mach4Industrial allows up to six out of band axes.

Craig

Hi,
I have found a possible solution to the A axis rotary speed issue, but have not been able to make it work yet on my files, keep on getting an error.
"Implicit move command given before listing an actual move command (G01/2/3). (Line 4)"
Line 4 = N13G01 Z50.000 F300
The site below has a Jar program that can convert a G94 G-Code file into a G93 G-Code file.
https://www.ganotechnologies.com/cnc/rapidrotary/
If anyone can get it working let us know and provide a G-Code example.
Regards,
Mauri.

Hi,

The Hiconn is not way more expensive.
With the ESS you need to add breakout boards. The Hiconn has them built in.
The ESS and most other motion controllers are 5v I/O. The hiconn is 24V.

When I look at the closed loop option with more than 3 axis - then the Hiconn solution charges about 2k bucks, which is ten times an ESS.
With little knowledge of electronics a bob is not hard to build.

My contention is that once a coordinated move is dispatched to the controller it is no longer possible to change the A axis rotation rate, it would break the move.

Well, that probabely depends on what communication is possible betwenn mach4 and the motion controller - and of cause it depends on the communication refresh rate.

Because the A axis is ansynchronous  the speed of rotation can now be changed during a coordinated move of the other axes. In particular if the Z axis is equivelent
to radius then the speed of the A axis can be calculated and repeatedly updated by a short PLC script.

Well, that requires a fast PLC thread, as well as fast communication between motion controller and mach4.
Don't know the interface speed of other motion controllers. ESS has 40Hz - which is quite slow for such operations.

Reinhard

Mach4 threading support is complete as described in the manual, BUT it is dependent
on the motion controller to implement threading features.

As of 22 January 2018, and as best I know, threading is fully implemented by
Hycon, PMDX SmartBOBs, and PoKeys.

Warp9 (Ethernet Smooth Stepper) is currently working on threading support
but it is not available for test yet.

CS Labs web site reports that they have a Beta release that supports threading.
An add-on option module is required for encoder interface. I am not aware of
any mention on the forum from anyone who has used it.

I thought CNC Drive had released a Mach4 plug-in that was supposed to support
threading, but I can find no mention of threading on their web site nor have
there been any forum mentions from users.

Newbie question save me some time.

Is Mach4 lathe threading currently 100% functional as described in the manual for the hobby version?

and

What external controllers currently provide 100% functionality for lathe threading at this time?

Thanks,
RICH

Newbie question save me some time.

Is Mach4 lathe threading currently 100% functional as described in the manual for the hobby version?

and

What external controllers currently provide 100% functionality for lathe threading at this time?

Thanks,
RICH

Warp9 is expecting Mach4 threading with the ESS to be available soon.

Tweakie.

I thought CNC Drive had released a Mach4 plug-in that was supposed to support
threading, but I can find no mention of threading on their web site nor have
there been any forum mentions from users.

The last I heard, the UC100 plugin did not support threading, but that was a few months ago. And I don't know if the plugins for the various CNC drive devices all have the same functionality. I'd send them an email to find out their current status.

Quote from: Steve Stallings on January 22, 2018, 07:34:39 AM

I thought CNC Drive had released a Mach4 plug-in that was supposed to support
threading, but I can find no mention of threading on their web site nor have
there been any forum mentions from users.

The last I heard, the UC100 plugin did not support threading, but that was a few months ago. And I don't know if the plugins for the various CNC drive devices all have the same functionality. I'd send them an email to find out their current status.

I mailed in an inquiry several days ago.
No reply yet.
Russ

Hi Reinhard,

Quote
My contention is that once a coordinated move is dispatched to the controller it is no longer possible to change the A axis rotation rate, it would break the move.
Well, that probabely depends on what communication is possible betwenn mach4 and the motion controller - and of cause it depends on the communication refresh rate.

I don't think that is the case. The trajectory calculated by Mach and the position/velocity/time data once its dispatched to
the controller cannot be altered. The controller may do so, THC is an obvious example where the controller adds or subtracts pulses
from the Z axis pulse stream. In general though it can't be done...if you attempt to change the pulse rate of one axis say, then
the eventual endpoint of the move will be different than Machs assumed endpoint. Unless the controller can report back to
Mach and Mach can accommodate moves that don't go where they are supposed to then Mach has no chance of controlling
the machine. That requires an out of band axis which can be altered WITHOUT affecting a coordinated move of the remaining
axes.

Craig