Messages

371

General Mach Discussion / Re: Need help/advice

« on: November 07, 2017, 06:32:58 AM »

Alex,
Calibrate an axis for the longest move possible and with any backlash removed prior to the calibration move.
That will provide you with most accurate steps per unit for the axis. How accurately the axis will move all along
the axis travel depends on the quality of axis components. Make sure you have tuned your axes.

it will dive into the piece on the last 10,000 ish lines of code,

Different kind of problem and there are a  number of possible reasons.
You will need to do testing to find out why it is happening. Don't be surprised if you get a lot of different suggestions.

RICH

372

General Mach Discussion / Re: A-axis rotary lathe question for Mach 3

« on: November 07, 2017, 06:14:49 AM »

Bob,
 A "loooooooong" time ago I fooled around and used a removable stepper to drive the   spindle on the lathe using  live tooling on the carriage ( high speed manualy driven spindle instead of using a lathe tooling). Intent  was geared towards model making such that I could turn or  mill work without doing another setup on a different machine. So was able to index drill hole patterns on a  face or side of the work post machining  the face and side to size, mill  the  shafts full / partial / circular in or over a partial length or roational over the length, do spiral work, etc.

So the lathe spindle was used in both angular and linear mode with slaving or not slaving
another axis to the spindle. Commands were simple in many cases.
For a lathe / router setup like you show, the routers  Z spindle could be considered  live tooling, use another  axis equivilant to Z on the lathe, or what ever. Note that Mach3 provides for movement of an axis and only knows what you tell it. One just needs to think "out of the box" , code appropriately for some simple individual tasks. One could just create a new profile for when it used and forget about all the VB, Maco's, etc.

Fooling around with this just may satisfy a need,

One could call doing this "The Poor Man's High End CNC"!

RICH

373

General Mach Discussion / Re: A-axis rotary lathe question for Mach 3

« on: November 07, 2017, 05:14:29 AM »

Gary,
May want to start a new thread about use of that PLC for a turn / mill combo.
I assume your are aware of Simpson's work on the matter.
Would make for an interesting topic.

RICH

374

General Mach Discussion / Re: A-axis rotary lathe question for Mach 3

« on: November 07, 2017, 05:06:17 AM »

Bob,
Seems like the gift from Gary will provide an option for you.

I echo what Graig and Gary replied about using CAD / Cam. Have not used Fusion 360
for the mill / router but have used it for the lathe. Have used Meshcam and Cambam to generate code for complex objects also. Like everything, there is a learning curve to using
CAD / CAM,  since you will need to create objects in 3D instead of 2D and understand
how to apply the software to generate code for a part. The software is all similar but some integrate the CAD / CAM much better, and also provide for engineering analysis. So it all depends on  the users needs. Make note that some folks are using industrial software and costs of the software alone are expensive. You would be shocked at the software monthly overhead  cost  ( more than what many folks earn ) paid for me when I was working.

As a hobbiest most will never be able to rationalize big bucks for software.
Remember when AutoCad was rather cheap to use? Do you think Fusion will be provided
free or reduced pricing forever!

You will spend a lot of time learning and if free software is no longer available then where are you? All I am saying is put the cost of things into perspective for intended use and spend for what you want to be able to do. Can have anything you want in the store but once you bring it to checkout ya got to pay for it!

For some simple stuff there is nothing wrong with a little hand coding to do a task and doing multiple tasks. Also there is experience gained in fooling around.

So much for my rant, it's just some thoughts FWIW,

RICH

375

General Mach Discussion / Re: A-axis rotary lathe question for Mach 3

« 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

376

General Mach Discussion / Re: A-axis rotary lathe question for Mach 3

« 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

377

General Mach Discussion / Re: Hall of shame

« on: November 04, 2017, 09:09:04 AM »

Hmm..........

% upfront before starting work and remaining % upon delivery.
90 / 10 sounds like good ratio to me. 

RICH

378

General Mach Discussion / Re: A-axis rotary lathe question for Mach 3

« on: November 04, 2017, 09:02:03 AM »

What is a "Rotary lathe for A-axis"? ie; is it just a Rotary table and how driven?

RICH

379

General Mach Discussion / Re: A-axis rotary lathe question for Mach 3

« on: November 03, 2017, 04:16:41 AM »

Post the xml file that you are using.
You will find the file in the directory where Mach is installed.
Someone will look at the profile  to see how you have Mach3 configured.

RICH

380

G-Code, CAD, and CAM discussions / Re: Simple G Code question

« on: November 02, 2017, 08:57:24 PM »

There are a lot of ways to learn gcode.

 I would suggest that a person wanting to learn how to write gcode purchase the book
"CNC  Programming Handbook" by Peter Smid. It will give you a firm foundation in basics
and it provides an  understanding of gcode. Skip all the other bull,,,, and learn properly
right from the start.

Now on to your question......

Use a different work offset to locate the second circle. IE; G54 for the first circle and G55 for the second. It's just one way of doing it.

RICH