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Author Topic: Mach3 Turn tool offsets just don't work  (Read 1903 times)

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Mach3 Turn tool offsets just don't work
« on: June 11, 2017, 11:28:08 AM »
Hi,

You can probably detect my exasperation in the subject line...

I have a Denford Orac, converted to Mach3. I have an automatic toolchanger, which I've written a macro for which works perfectly to change tools. I have a limit / home switch on my x-axis (but not z). According to my indicator, this is very repeatable. I do the following to set my tool offsets:

1. Set x-axis home (causes the x axis to drive to the home switch)
2. Select tool 1 (a turning/facing tool), make a small facing cut, and select home z.
3. With Program Coordinates selected on the manual screen, go to tool offsets, and ensure there's a zero offset in the z-axis 'Part Zeroing Coordinates', then press touch z. Then out of superstition open the tool table editor, select apply and ok.
4. Back in the manual screen, make a small profiling cut. Measure the OD, then go to the Tool Table screen again, type that OD into the x-axis 'Part Zeroing Coordinates', and click touch x. The Axis Coordinates DRO at the top of the screen will show the OD I typed in. Again out of superstition I open the table editor and hit apply, then ok.
5. Select tool 3, a grooving tool.
6. Jog the tool until it's resting against the faced end (using roll-up paper). In the tool table screen, enter 0 in the z-axis Part Zeroing Coordinates DRO, press touch z. The Axis coordinates z value shows zero. Apply and ok in the tool table.
7. Back on the manual screen, make a small profiling cut, then job the tool along the z axis and measure the OD. Then enter this OD in the tool table screen exactly as described above.
8. Repeat steps 5-7 for other tools.
9. Now, to check everything's worked, I go to the manual screen, select different tools, then drive them up against the piece I've turned and check that the Program Coordinates show the right values (zero at the end of the workpiece, and what ever the OD was that I last turned. _Everything seems fine!_

For reasons that will become apparent I make a record of my tool table by going to Config -> ToolTable, and doing a print screen, and saving the image elsewhere.

Now, I go to config->save settings. Then I exit mach3,  which asks me if I want to save tool table values, to which I say yes.

Here's where things go wrong: I load mach3 turn again. I home my x-axis, and choose where I want z zero to be and hit Set Home Z. I type T0101 in to the MDI - the tool changer loads tool 1, mach3 says tool 1 selected. If I now drive the tool tip up to the chucked part, the value displayed in the program coordinates x-axis is totally wrong! E.g. where it should be 22mm, it'll show something miles off, like 40mm. It's the same story with the other tools. Where the offsets appeared to be correct, they're now totally off.

At first I thought the tool table values weren't being saved correctly, but if I compare the values to what I recorded (by doing the print screen as described above), they're correct. What's really strange is that if I go through the whole tool offsetting procedure (as described above), e.g. driving tool 1 up to a known OD (the same OD I had used when going through the whole palaver the first time), entering the OD in the part zeroing x-axis box and hitting touch x, mach3 will load a completely different offset in to the tool table than was there previously!!!

What the hell is going on? I've actually been at this on and off for about a month - I thought I had it licked, but today after another round of this nonsense I just came to the conclusion I have to give up and buy mach4 or go down the linuxcnc route. But before I give in I thought I'd see if anyone out there had any ideas?

Any help is really appreciated!

Thanks,

Luke

Offline RICH

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Re: Mach3 Turn tool offsets just don't work
« Reply #1 on: June 11, 2017, 02:30:14 PM »
Luke,
Turn tool offsets do work. I need  to carefully read your post. There are a number of ways to do tool touch off and they all work.
BTW, I personally made a custom screen set and,  probe all the tools to populate the tool table, use the master tool concept, manipulate the table
via buttons if so desired etc.

Later,
RICH
Re: Mach3 Turn tool offsets just don't work
« Reply #2 on: December 03, 2023, 09:26:31 PM »
yes...yes...yes... the is the exact same issue I am experiencing....2017 omg...I can't for the life of me see how anyone uses mach3 turn with any reliability. I have set up all my tool offsets  a number of times now and verified them just like the original post explained only to have them all way off X center line once again. I haven't narrowed down the event that causes the issue...I've already waisted so much time. My plan was to switch to mach4 as I need threading ability(pokeys57 board), so I'm almost at the point of scrapping mach3. But surely there must be more having the issue, so I thought resurrecting this post might shed a little more light on it. If it matters I'm using version R3.43.066 and F360 CAM.           
Re: Mach3 Turn tool offsets just don't work
« Reply #3 on: December 05, 2023, 03:58:36 PM »
I think I've sorted this out..hopefully.....and I wanted to add this in case someone ends up here with a similar problem. It looks to be related to the X homing configuration, my home switch is at the front so it homes in the X+ direction. I left the auto zero function on setting the Home Off value as X 0.000, I then set the Soft Min at -3.9" and Soft Max at 0.000".
  This set the X travel range from 0" to -3.9" moving front to back, this didn't seem to cause any problem jogging the axis around and in theory it should be perfectly fine. 

Instead I changed the Home Off value to +3.9", and Soft Min to 0 and Soft Max to +3.9". So now the X axis travel range is all positive from 3.9" to 0 moving front to back. Since making this change the X tool offsets have been stable after each machine startup or homing operation. It seems to be a bug of some sort, it just doesn't like the X axis machine coord to be all negative.   
Re: Mach3 Turn tool offsets just don't work
« Reply #4 on: December 18, 2023, 11:15:40 PM »
Turn tool offsets work. I must attentively examine your article. There are many effective tool touch-off methods.
For my custom screen set, I probed all tools to create the tool table, used the master tool idea, then manipulated the table via buttons as needed.
Re: Mach3 Turn tool offsets just don't work
« Reply #5 on: December 25, 2023, 02:42:01 AM »
The turn tool offsets are effective. Your message requires that I read it very attentively. There is more than one method for doing tool touch off, and each of them is effective.
I just wanted to let you know that I personally created a bespoke screen set that allows you to explore all of the tools in order to fill the tool table, use the master tool idea, control the table using buttons if you so wish, and so on.  ;D space bar clicker  ;D