Messages

361

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

« on: November 10, 2017, 09:16:01 PM »

Bob,
I have been using SnagIt forever for screen captures so nothing jogs the memory for an alternate and there are ones out there.
Your setups are contained in the xml file. That's why I asked you to copy the original / posted screen and rename it to something different like bobmill0 for original so you have a record. The xml file is saved very time you save settings and you will find them in the xmlbackup directory
under Mach3 folder.

RICH

362

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

« on: November 10, 2017, 12:42:07 PM »

Bob,

To allow for easier playing around with gcode commands suggest you turn off your switch inputs.

- Config>Ports and Pins>Input Signals  un-enable all except for your EStop.

You won't have to worry about having a work offset active and you can change Machine Coordinates to zero easily.
Allows you a simple value to work from.

IE; Jog the 4th axis, Ref All Home and the 4th axis  goes to zero value.
      You can also clear a work offset.
      
Sorry should have mentioned this in lesson#1.

RICH

363

Polls / Re: CAD /CAM Software at a student price

« on: November 10, 2017, 11:53:43 AM »

Having followed Autodesk for over 30 years don't be surprised what could happen in the future.

RICH

364

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

« on: November 10, 2017, 11:48:05 AM »

Gary,

Good point on cutting force. Interesting that there  is research on whats required for machining metal but I have never found anything for exotic woods.

I don't do much woodwork anymore but do machine exotic woods for gun grips, knife handles and some other stuff. Use carbide tooling to machine the stuff. Nothing sucks more than hitting stone which is in ebony. Just need to experiment what feeds, speeds,depth of cuts, tooling work well for intended work.

There is still more to the tuning of the rotary which will be addressed as we progress.

HMM.... this thread will be like,   "round and round it goes where it stops nobody knows"! 

RICH

365

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

« on: November 10, 2017, 11:23:45 AM »

Bob,
Have fun after lesson1 do #2 below.
---------------------------------------------

- It would be nice to have some type of index reference on the chuck so you have a visual of the  A movement.
A number of easy ways to do that ie; marked tape or even mount a plastic circular protractor on the back of the chuck.

- We deliberately set the angular wrong before ( you know what the caculated value was ). So use the axis
calibration feature of Mach  ( read / refer to in Mach3 CNC Controller Software and Installation Configuration
 Section 5.5.2.30) to calibrate the A axis. The input value is in degrees and you need to tell Mach how far it actualy moved so it can calculate the step for you.

You may need to do it more than once but it is an easy way to calibrate both an angular and linear axis.
Note that   1 / steps per    is the theoretical resolution of the rotary. Say it is 400, then 1/400=.15 degrees.

 You now will have a calibrated A axis.

MODIFIED THIS REPLY: Don't do the striked text below.

- Go to the MDI screen, in the Input change current mode from  G90 to G91 by just typing G91.
  To rotate the A 360 degrees input G0 A360.  
   You should know how fast it will rotate at max and different feedrates.
   If you don't have something to measure the rpm then time it over a number of rotations ( measured is  better!).
   I bought a digital tack on ebay for around $12 and it  works great.
  To rotate A for 5 revolutions at a feed rate , type in MDI Input, G1 A1800 F1. Just keep doubling the feedrate  values, note the rpm, and graph the values.

- Looks like your rotary is just driven by timing belt so no gears etc and thus basklash should not be concern.

- Would suggest that you add an index so Mach can display the rpm of the rotary.

-  Click the Mach Coord's button, notice how the DRO changes. Understand the difference between
   using Machine and Work Coordinates.

- Now do some manual commands changing the rotational direction using the minus sign.

-  In both G90 and G91 modes, command  A axis moves with each of the Rotational choices
   that can be selected General Logic Configuration Screen.

----------------------------------------------------------------

Summary so far:
You learned how define, A as angular, tune the angular, calibrate the A axis, get / have  feedrate info for later
use, basic gcode commands, how other settings and modes can affect the turning motion.

Now remember you simply asked can you give a gcode to..........
Don't understand the "other stuff" even a simple command like G0 A 360 is like pressing some magic buttom and not know what will happen!
  
To be continued,

RICH

366

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

« on: November 10, 2017, 08:07:47 AM »

BOB,

I will assume that you  have not changed any of your Mach settings and your still using the xml file that you posted.  Copy the xml to the Mach3 directory and rename the copy it to 4thbobmill.xml. We will  be doing changes to your configuration and will use the "4thbobmill" profile.

- Per your xml you are using the A for the rotary axis. It is currently defined in Config >General Logic Configuration as linear. Tick the box for A to make it angular and then Save Settings.Now you will need to change your motor tuning. So caluculate the steps per ( the units are degrees for an angular rotary axis ).

Example Calc:
For my rotary using micro stepping and a 72 gear ratio:
200 steps / rev X 1 rev /360 degrees = .5555 steps / deg X 10 micro steps X 72 gear ratio=400 steps per unit
 
- Note the value you calculated but use a value of  50  less than you calculated as an imput for the steps per.
in motor tuning. Use 10 as value for the velocity and 2 as an acceleration value.

- Now define which keys you will use to jog the A axis.
Config>System Hot keys Setup, click the A /U++ box and hit the key you want to use. Do the same for the A/U--. Make sure the keys codes are different than the other axis keys.
 
- Save Axis Settings and also Save Settings under Config.

- Hit the Tab key, and in the flyout set Jog Mode to Cont Jog the rotary to see that it rotates. 
Go back to motor tuning for the A axis and keep changing the velocity value by doubling
the velocity value and jogging the rotary. Do this until the stepper skips.  So 10,20, 40,80,160, 320, etc.
Suppose it skips at 320 then set the velocity  to 160.

- Now start changing the acceleration value with the velocity set at 160 increasing the accel. Do similar as the you did for the velocity increase. So 2,4,6,8,10 etc. for values. Acceleration becomes important in 3d work.
See where the  axis skips. Go back one trial setting of accel, so if skipped at 10 go back to 8.

- You now have found the max velocity and accel settings for your rotary. Note that as the stepper rpm is increased the torque decreases and you need to have adequate torque for machining. Reliability is more important that speed.

Save Settings and exit MACH.

------------------------------------------------------------------------------------------------------------------

- Download the following manuals:
  Using Mach3 Mill
  Mach3 CNC Controller Software and Installation Configuration

- read / refer to in  the Using Mach3 Mill Manual info on:
  - read section 5.5, 6.2.3, 6.2.12,10.1.5 and 10.1.6
  - Gcode commands: G0,G1,G90,G91 then G93,G94,G95 ( You may want to compare Haas command                definition to the Mach3 defintions of the commands)
- read / refer to in Mach3 CNC Controller Software and Installation Configuration
  -  Section 5.5.2.3
  - Page 5-37  about Rotational: settings
  - Page 5-39  about Axis DRO Properties

--------------------------------------------------------------------------------------------------------------------------

To be continued,

RICH

367

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

« on: November 09, 2017, 11:13:36 AM »

Bob,
I will help with the commands.
BUT
It will not be a "type this in the MDI line" kind of thing and you try it out.
Instead you will walk a "learning path", it will start with basics, and progress should be quick.

Just going to be my way of getting you somewhere quickly and having you KNOW what your doing.

So you want to have some fun........?

RICH




 

368

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

« on: November 08, 2017, 07:31:33 AM »

Bob,
Would not it be better to have a clear understanding of various configurations and the affects of some settings before you code?

Anything really important about the next 3 days?

Note that in school your using Haas, yet Smid's book is Fanuc ( Mach 4 is Fanuc based ), Mach3 has a dialect of code which is  say similar but dose not have some of the commands of other controllers. Don't want you to get all screwed up in your head!

RICH

369

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

« on: November 07, 2017, 05:25:42 PM »

Bob,
Not sure what they are use for teaching. There is a Haas Programming Workbook in Members Doc's that you can download. One book I recommend is by Peter Smid
called CNC Programming Handbook. The first 100 pages of it will ground you for most any machine.  You can scan through the lathe info to get a flavor of using the lathe and will just say the lathe has more tool geometry to deal with.

One of the nice things about the Golden Years is that one has choice to do what they want to, whenever they want, at the pace they want,  AND, what they do dosen't have  to make sense to anyone except themselves. Still have a note that my trumpet teacher wrote during a lesson  "Nothing stays still, it either moves forward or regresses withers and dies,
that is fact of nature, get used to it!"

Keep moving forward..............................,

RICH

370

General Mach Discussion / Re: what kind of device do i need

« on: November 07, 2017, 06:45:24 AM »

Bob,
I would suggest just keep posting in the other thread as questions arise relative to your setup and what you want to do. Users following that  thread already have a overall idea of what your doing and you'll get more pointed replies to any question you ask.

RICH