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Author Topic: A-axis rotary lathe question for Mach 3  (Read 7692 times)

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Re: A-axis rotary lathe question for Mach 3
« Reply #20 on: November 04, 2017, 04:35:14 PM »
Gary thank you for your response.  Let me go over what you have said... I am barely a week into fusion 360.  It will take me a while to get up to speed... but I will consider your suggestions... thanks ;D

Offline dude1

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Re: A-axis rotary lathe question for Mach 3
« Reply #21 on: November 05, 2017, 01:05:31 AM »
You can do that with fusion on 3 axis machines quite easily useing 3D adaptive to rough it out then use morphed spiral or run 2 parallel ops one for the raised bit along the Y axis by setting the direction you can do it with a endmill then do the rest of it with a ball nose along the X axis and setting the direction.
Next month they are planning to add 2 direction to Adaptive, also if you have a look on the fusion forum there are quite a few guitar dudes on there

Offline RICH

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Re: A-axis rotary lathe question for Mach 3
« Reply #22 on: November 05, 2017, 09:38:28 AM »
halfmill,

Reviewed the xml file you posted but need to ask a few questions before commenting.

What version of Mach3 are you using?

Are you slaving an axis for gantry squaring and is it B?
       or asked differently........
Are two motors used on either the X and Y axes?

Are you are using steppers and that the 4th axis ( lathe head) is stepper driven ?

What drives are you using for the motors?

RICH
Re: A-axis rotary lathe question for Mach 3
« Reply #23 on: November 05, 2017, 02:07:30 PM »
Hi Rich,

The Mach3 version is  R3.043.066
running on windows xp

Y axis uses 2 ball screws and thus 2 stepper motors
B is slaved to Y axis for the 2nd motor

The 4th axis lathe head is stepper driver
Stepper driver is MicroStep Driver ST-M5045
The other four stepper motors
have similar stepper drivers

thank you for helping here... bob

Offline RICH

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Re: A-axis rotary lathe question for Mach 3
« Reply #24 on: November 06, 2017, 08:31:19 AM »
GENERAL COMMENTS AND RELATIVE TO THE POSTED XML
------------------------------------------------------------------------------------------------------
- Mach3 version  R3.043.066 is known to be buggy and there are no changes listed as to   what was done from the previous versions. Use version  .062 here thus no experience   with .066 other than what some folks said about it and I took their advice and don't use it!

- With a kernal speed of 25000 HZ, possible ( I didn't say reliable ) pulses would be 25000   pulses / sec  and a  stepper requiring
  200 steps / revolution  you would get 125  rotations  /  sec which happens to be 7500 rpm. FWIW, in theory anyway!
 
- Since B is slaved to Y and both motors used to drive the Y axis, B should be configured      as linear and not angular.  See  Using
  Mach3 Manual ( page 4-11, 4.6.6 )

- Motor tuning for A doesn't look right......ie; 36000 for velocity using a stepper motor.
  From  traditional axis planes and orientations A rotates about X  and C rotates about  Z.
  So  assume that you will be using A as the 4th axis and it is stepper driven.

  Now let me say some things about using a stepper to drive a spindle , 4th axis or as you call it Rotary lathe.

  - Steppers are not a good choice to drive a rotary since as rpm increases the  torque  decreases and you will see that the rpm is not
     linear with an increase in speed.  Fine for indexing and with active mounted tooling while A rotates at a reasonable rate.
 
  - Mach3 does not provide for two spindle operation directly.

  - Stepper controlled 4th axis cannot run continously, it can index, do rotary but not act as     a true spindle. Actually Mach3 can't
     run any axis continuosly.
   
     A can be defined as either angular or linear, thus, gcode commands can make it rotate  a number of revolutions, or, as linear it
     will rotate but in terms of a linear move which relates to the work diameters circumference. Yes, one can command to make a
    " lot " of  rotations or a  long distance, BUT, as said it does not act like a true spindle.
   
  - You can only have one "spindle" configured and running in Mach3.
     As you stated you are manually controlling the spindle. So you can consider the
     your spindle as live tooling mounted on the Z axis. Will expand on the thought, later
     in another reply to this thread.

  - For awareness, there is a VB command called Swap Axis, but it only changes the pin #s assigned to an axis. So you can only swap
    similar motors ie; can't swap servo with a  stepper. You can swap axes around and  can be used to make an axis into a spindle
    via  macro's.
   The spindle is not configured so assume that you are manually controlling the router.
   If the router machines spindle is manualy controlled you can still define spindle in motor tuning. So you can swap, say A and
   Spindle, calling the correctly scripted macro at the proper place in the Gcode.

  -  C axis is inhibited ( settings alt 6 screen).  C is defined  angular. Also C is not enabled.     
  -  Jog keys defined for XYZ but not for ABC axis.  Should define keys for A . No reason to define B since
     it is used along with Y for the gantry ( Jog Y and the B gets the same number of pulses...? ).

  - switch pins defined for XYZ and partialy for A . B should also have a switch
    same as Y? One of the router table users should confirm......... I don't use switches!   ;)

   - No tools defined. You will  need to define tools  if you start using CAM programs which generate gcode. Also you will need to use
     a system to touch the tools when changed.
   
 FWIW,
   
 RICH
Re: A-axis rotary lathe question for Mach 3
« Reply #25 on: November 06, 2017, 01:26:18 PM »
Rich,
The problem of Mach 3 being able to run an axis continuously is the whole problem for turn/mill machines. Currently my machine has DL06 plc in it that handles all the I/O like coolant, two different mill spindles and 3d printing extruder, lights, vacuum, heat for 3d printing etc.

I just got a DoMore BRX plc to replace the DL06. AWESOME little PLC!  It has analog inputs and autotune PID to control heaters and such. Analog outputs to control spindle speed for conventional drives that don’t use PWM, and can accept PWM from Mach 3 and translate it. It has high speed inputs for encoders, and high speed outputs to drive servos or steppers  and can do 2 axis coordinated motion on its own. It speaks modbus, USB, Ethernet, serial Rs232 and Rs485.

So I am going to drive my lathe spindle stepper driver through a double pole double throw relay getting pulses for postiong as 4th axis from Mach 3 or as spindle drive from BRX reading Mach 3 PWM spindle output.  It can also generate an index pulse for threading. The analog inputs will read the thermocouple sensors from the 3d extruder and the heated bed and PWM outputs to the heater solid state relays will control temperature. M code inputs from Mach 3  can turn heat on and off and change set points. I am hoping this will end all the crazy work arounds and give me capabilites for othe stuff like an auto tool changer too.
Re: A-axis rotary lathe question for Mach 3
« Reply #26 on: November 06, 2017, 01:29:04 PM »
Rich, thank you for such a detailed set of considerations/recommendations...  I will study this and try to take the right steps.

In a few days I will ask for clarifications.  Basically, if I simply had a small separate wood lathe that would fit under the spindle mill end and where I could vary the speed, then I could do what I need to do for a lot of guitar applications... I will look for a controller to make the current 4th axis lathe independent of  mach 3... just so I can turn things when I need to.  Thanks again, let me go study all of this.

Can I go to Artsoft and download the particular version that you think I should be using?  bob
Re: A-axis rotary lathe question for Mach 3
« Reply #27 on: November 06, 2017, 02:57:07 PM »
Half,
Since I got my BRX plc I have no need for another device I bought. It is a step pulse driver with a potentiometer input. You can have it free. If you hook a double pole double throw relay to be activated by a M code from Mach 3 you could then hook step and direction inputs to the drive to the common terminals and the step and direction output from mach 3 to the normally closed contacts and the pulser step and direction to the normally open. It is a mill with 4th axis when the relay is off and a lathe when it is on.
Re: A-axis rotary lathe question for Mach 3
« Reply #28 on: November 06, 2017, 04:13:08 PM »
Half,
Since I got my BRX plc I have no need for another device I bought. It is a step pulse driver with a potentiometer input. You can have it free. If you hook a double pole double throw relay to be activated by a M code from Mach 3 you could then hook step and direction inputs to the drive to the common terminals and the step and direction output from mach 3 to the normally closed contacts and the pulser step and direction to the normally open. It is a mill with 4th axis when the relay is off and a lathe when it is on.

Gary Hi,  Please translate Brx plc... what does this stand for.

I will show this to my friend who is far more knowledgeable than I and see if we can do what you are suggesting...thanks... bob
Re: A-axis rotary lathe question for Mach 3
« Reply #29 on: November 06, 2017, 04:16:34 PM »
You are offering to send this to me, this device you already have?  bob