Messages

251

General Mach Discussion / Re: Lathe tool offsets, tool table, surfeit of splash screens

« on: April 04, 2018, 07:38:55 PM »

John,
Have a look in the Mach Tool Box. I believe you will find what you need to do what you want.

RICH

252

General Mach Discussion / Re: Probing - what would i need?

« on: April 04, 2018, 05:37:43 AM »

Consider or think about this:
The master tool , tool #1, has no tool length or offsets.
Tool 0 has no offfsets and you use this to move about or whatever  and you can't have offsets for it.
All tools relate to the master tool,thus, if the master tool has no length then, all the other tools lengths are
just length values +- from the ref location of zero of the master tool. Machine coordinates can be used
to  measure distances.

Now assumming that tool table is populated, if you were to put any tool other than master in the spindle,
and probe using  the knee to touch off to the tool, the original location used to define the ref of zero
for the master tool is the current tools +- length. So move the knee up down accordingly. Your now
back to the how the tool table was originaly populated.

You can have additional DRO's, buttons, etc  with scripting to do whatever you want to address different
cases.

Again it all depends on how you do work, accuracy is only as accurate as you machines system,
and "all tools ( whatever they actualy are) are related to the master tool and they relate to each other".

Typical repeatable tasks would be:
- Populate the tool table initialy
- Modify the tool table for a new or  replaced  tool, tweak a current tool for machining

Then
- Find where the material is to set a work offset

Sometimes
- measuring, whetever

KISS applies to it all!


FWIW,

RICH

253

General Mach Discussion / Re: Probing - what would i need?

« on: April 03, 2018, 07:47:30 AM »

Dave,
Start somewhere and gradualy add things for probing. You can only fit so much on a screen page so you may
need more than one. The following could be thought of as blocks of a complete probing screen:

Tool setup page - a page to take care of populating the tool table via probing with all that is required to do it.

1. Tool table - be able to manipulate the tool table easily
     - open, save, export, import,reset, back up tool table.
     
2. Probe tools  to populate tool table based on a probe in spindle
    - Probe / set plate for tool touch off
    - Probe direction direction buttons
    - Probe feedrate
   -  probe active
   -  tool number / prev and next for slelection
   - tool offset adjustments for tool table values
   - tool change location

3. Similar to  2 but using the knee, combine with 2,  speperate page..........think about it some

4. Part of screen with jogging control and generic DRO's so no need to jump between pages to accomplish
   whatever task your doing.

Probing routines for different situations. there is no one that satisfies every situation and is done the way you want it to work!
You define what you want and need. There are plenty of examples and there is no right or wrong way
to do it. You are the boss of the machine and not in some enviroment where is needs to be standardied!

Now take it up a notch and add pages or create wizard screen set to take care of  stuff you don't use
every day like the follwoing:

1. The ability to manaully and automaticaly reverse engineer something, so your gathering locations and depending
   on how  the info is gathered you create a drawing of it for use in CAD or CAM.

Sometimes total automation is not the best thing to occur and semi or partialy manual is a much better method.
Different probes, different degrees of accuracy ( quick and ditry has it's place in doing work).
Just depends on how, what, and the end product YOU desire.

I also echo again that:
All tools are related to the master tool but they are related to each other.............
Consider working in Machine Coordinates for any measurement, if you start from a zero location all things are
related to zero!

Must remark that not the sharpest tack in scripting on this end, so , if I can do the above so can you.


Have fun,

RICH
 


   

   

254

Mach4 General Discussion / Re: controlling JP-3163B in 6040T USB CNC with Mach4

« on: April 02, 2018, 07:50:51 AM »

If I was King of the land, which I am not.............

A declaration would be made such that any Chinese junk 60xx controller would be considered contraband and must be destroyed.
Anyone in possession or providing the  contraband item would have only two options, namely,  life imprisonment or death.

Back to dreaming ............. ,

RICH

255

General Mach Discussion / Re: in need of help!!

« on: April 02, 2018, 07:33:37 AM »

cooke86,
You can tell when your missing steps since many times you will hear it or the machine just goes off on in an uncontrollable way.
BUT
You can be missing steps and the above is not true. I can happen gradually, be repeatable, or random.

 I am thinking that for the first set of machining steps  your axis settings are fine BUT they are not appropriate for last machining step.
This can come about from the combination of having too an high acceleration and small moves. You won't hear the missed steps and difficult to even
monitor it.

Others reviewed and backplotted your code and said the code was good. Here is what I would suggest.
Just run the code for the last machining step and confirm that the problem is repeatable.
- If you have an external DRO display you add a  dwell in the code at strategic line locations in the gcode program and compare Mach's DRO verses
   the external DRO's. Another way is to code in a move to a known physical location and compare to Mach's DRO.
- Change the acceleration and velocity values for the axis. Cut them in half and see affect.

- Another way, in your case, is to change the small Y height moves, and test to see if the problem goes away.

Just do the above in a disciplined / logical way, not quick and dirty, since you want to know the result of each change what the problem really was.

For 3d work high acceleration is desirable for reducing machining time. Simply said, your stepper may not be have the acceleration capability required for the small moves that the controller is instructing. Know your machine and be carefull when using CAM, bad feedrates and impractical machine
tuning cause problems, the gcode generated from CAM and the controller instructions are good, just bad operator CAM input to the program.

Have Fun,

RICH

256

General Mach Discussion / Re: Probing - what would i need?

« on: April 02, 2018, 06:29:14 AM »

What I did was review  many different screen sets and probing suggestions and pick what I thought was the best of the best.
If a purchased screen set satisfies what you want to do then it's worth the couple of bucks to purchase it  since it takes time to do one.
I wanted to do more than just do tool setup and wanted to add practical  functionality from probing data. So more buttons and scripting than the typical probing you find. That said you end up with conditions one needs to address like your last reply.

Suggest you  think about the  big picture of what you want  and what is required for how you work. 

Just some thoughts,

RICH






 

257

General Mach Discussion / Re: Probing - what would i need?

« on: April 01, 2018, 07:32:17 AM »

For probing I would suggest you create a custom probing page or wizard  that works the way you want it to work based on how you work.
Simplisticaly that screen would allow probing of  all the tools and population / manipulation of the tool table . Additionaly you could have it probe
for location, set and create work offsets etc,.....all kinds of things.

Remember that all tools relate to the  master tool but all tools also relate to each other.
If you have use an off machine setter and manualy  populate the tool table that is similar to probing each tool.
The difference is how the info was acquired. Probe each tool  and compare data to what got when manualy done.
Probing tools for my lathe is very accurate and repeatable ( +- 0.0002").

You don't need any fancy probes. For probing locations I use a home made probe with replacable tips and it is very accurate.
It's how the probe is made that is important and used that is important such the probe has no runout. Remember that data from
probing will only be as accurate as YOUR machines system.

So make a custom screen set or custom page to satisfy whatever you want to do and accomplish.

RICH

258

Show"N"Tell ( What you have made with your CNC machine.) / Re: Carved a Colt 1911

« on: March 19, 2018, 05:55:35 AM »

Nice work. Post some info on the process used.

RICH

259

General Mach Discussion / Re: Motor Turning Errors

« on: March 17, 2018, 07:19:24 AM »

I have attached the motor tuning profiles for the X axis and three profiles of the Y axes as you have
 described. Take a close look at the profiles. There will be a difference in how fast the y axis (as
compared to the X axis) will actualy move depending on the distance traveled. The profiles show the
ramp up and down ( accel and decel ) and max velcocity relative to a time frame. Notice that for  a
Y accel of 2 and 10 that the time is different as compared to a vlaue of 5.

The max velocity is the same for all four profiles but notice the time required to reach max velocity.
As accel changes the time increases or decreases to ramp up  / ramp down to / from max velocity.
Now depending on distance the axis is called to move,it  takes time to get to the max velocity, you may
never reach max velocity if the distance is short thus your accelerating only and not achieving a constant
velocity.

A G0 commmand is a rapid move at max velocity and you will not see a diffenrence  for accel of 5.
In a coordinated move the slowest axis defines the velocity. The kernal speed limits how manny
pulses / steps can be sent to the drive.

Make note that acelleration is a change in velocity in time. The profiles show the differences in time
and that relates to distance.

When you jog you can set the jogging rate so be carefull relative to a G0 commnad.

Frankly forget all the above BS and just tune the axes such that the steps per unit are correct and
velocity and accel values are refined for each axis such that the axis movement is reliable and allows for
some head room ( ie; torque required to machine).

RICH

260

General Mach Discussion / Re: Random positioning motion on each operation start.

« on: March 16, 2018, 07:32:00 AM »

I would suggest that you read the Mach3 manual, watch the videos, etc and enhance your understanding of Mach / CNC job creation, machine referencing / homing, work offsets, and some commands,etc. That will cure you problems.

RICH