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Author Topic: Cannot do single point threading. What's wrong?  (Read 5937 times)

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Offline simpson36

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Cannot do single point threading. What's wrong?
« on: November 11, 2008, 11:50:21 AM »
I am evaluating the Mach 3 software on a converted X2 mill. Having seen a YouTube video of this mill doing single point threading using Mach 3 turn, I thought I'd give it a try.

My mach 3 is a demo version, and Mach3 mill seems to be working fairly well now on this mill.

Spindle has an index on it with a single slot. RPMs seem to display correctly in both mill and turn, but the cutter does not repeat in the same groove. It's just all over the place. I've started it as far as 1/4" away from the cut to give plenty of room to accellerate (Z axis driven my 640oz NEMA34 @ 4660 steps per inch).

I tried fiddling with the Z axis accelleration and speed (making it slower) and tried all sorts of different spindle speeds. Mach is not controlling the spindle speed, but I match the speed to what I command in G-code.

So, is the demo version crippled to not do single point, or is there something I have overlooked in getting this set-up to work.



Offline Hood

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Re: Cannot do single point threading. What's wrong?
« Reply #1 on: November 11, 2008, 11:58:12 AM »
Threading  is only available in the licenced version of turn.
Hood

Offline simpson36

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Re: Cannot do single point threading. What's wrong?
« Reply #2 on: November 11, 2008, 12:55:14 PM »
Single point threading is not something I need to do so it would not prevent me from purchasing Mach 3. I am watching with great interest the bugs thread and I have encountered the CV problems described in various places. I have invested a lot of time in Mach3 at this point and I would much prefer to wait for the few issues that do effect me to get resolved rather than start all over looking at other software.


However, to the powers that be . . . what is the logic behind providing an evaluation version that is crippled to the point that it cannot be evaluated.
« Last Edit: November 11, 2008, 12:58:56 PM by simpson36 »
Re: Cannot do single point threading. What's wrong?
« Reply #3 on: November 11, 2008, 01:15:44 PM »
If Mach is not controlling the spindle then how do you expect Mach to syncronize the spindle in order to pick up the thread? The control needs to know the z position as well as rotational position of the spindle to repeat with a single point tool.
Joe
« Last Edit: November 11, 2008, 01:21:28 PM by scudzuki »

Offline Hood

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Re: Cannot do single point threading. What's wrong?
« Reply #4 on: November 11, 2008, 01:43:10 PM »
simson36
 there are only a few things that the unlicenced version of Mach does not do so I wouldn't say it is crippled. Threading in turn is one, max  lines of code (I think 500 in mill and 100 in turn), run from here in both and possibly a few others. Many people run Mach without licencing it and are quite happy, personally with the cost of it being so little for what you are getting I couldnt live with myself if I didnt purchase one.  I have bought 3 licences for the 3 machines I run even though I could have just used the one , its a small price to pay and especially  in comparison to the cost of your machine.

Joe
  You dont need spindle controlled from Mach for lathe threading or even thread milling. The threading in turn just requires Mach to see the index pulse so that it can start the axis moving at the correct time, thread milling doesnt even require that as all that happens is the three axis move in unison and the thread is cut in one pass.

Hood

Offline simpson36

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Re: Cannot do single point threading. What's wrong?
« Reply #5 on: November 11, 2008, 02:29:34 PM »
I will not 'run' Mach3 without buying the license. If I decide to go with Mach3, I will definitely buy it. The cost, as you point out, is minimal . . and it would not matter even if it wasn't. I don't do bootleg software.

Presently I am evaluating it and I have some concerns about the bugs that effect my own objectives and I also want to play with the interesting brain functions before I commit to this particular software.

It just strikes me that crippling single point turning in an evaluation version of a CNC control package is not a smart move. If I wanted Mach3 for a lathe, I would have moved on already. I think a timed eval would make a lot more sense.

As I said, it is not a big deal to me for my purposes, just an observation.

That being said, I will add though that I find it annoying to not have a distinct list in an obvious place of what is crippled so that I do not waste my time trying to get something to work that is intentionally disabled. I had no idea, for example that 'run from here' is crippled until I read your post.  I did notice that it did not work worth a hoot, but I chalked it up to another bug. I cannot seem to find the automatic Z axis feed increments either . . .  so now I wonder if I missed something or if it is intentionally disabled.

Wasting people's time unnecessarily is not a particularly good inducement for them to then spend money on your product . .  just another observation. 
« Last Edit: November 11, 2008, 02:44:21 PM by simpson36 »
Re: Cannot do single point threading. What's wrong?
« Reply #6 on: November 11, 2008, 02:34:11 PM »
Well provided the spindle speed is accurate, I can see where a starting point would be sufficient for single point. I did not get from the OPs post that the controller received angular feedback from the spindle. Spindle speed and angular control obviously has nothing to do with thread milling as this is just helical interpolation using 3 controlled axes, and Mach certainly has control of those.
Joe

Offline simpson36

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Re: Cannot do single point threading. What's wrong?
« Reply #7 on: November 11, 2008, 02:50:44 PM »
Joe,

I don't have 'expectations' at this point. I'm just asking questions because I'm a newbee at this.

But I do my homework first. In my OP, I stated that the mill has an index on the spindle. That is what the software uses to determine the spindle speed and azimuth.

Ultimately, it turns out I was just chasing my tail as the feature is intentionally disabled.


Offline Hood

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Re: Cannot do single point threading. What's wrong?
« Reply #8 on: November 11, 2008, 02:53:07 PM »
Joe
 Mach does not need angular information other than one pulse per revolution. That pulse provides both the feedback that Mach needs to read the speed and also provides an index for starting the threading at the correct point in time. The OP said the following

Spindle has an index on it with a single slot. RPMs seem to display correctly in both mill and turn

That is all that is required by Mach to thread on a lathe (or a mill using it like a lathe ;)  )
Hood
Re: Cannot do single point threading. What's wrong?
« Reply #9 on: November 11, 2008, 03:17:29 PM »
"Slot" is a term I expect to be associated with a toolchanger on a mill. Never heard it used in that context before. Simpson36 stated that Mach is not controlling the spindle speed, and that's what I read. Mach needs to now the angular position of the spindle as well as z axis position to single point thread. If it cannot control but can monitor the spindle speed then it must adjust the axis feedrate to compensate for any mismatch in spindle speed (and the resulting angular mis-positioning). Sorry to muddy the waters.

My use of the work "expect" was related to what appeared to be a misunderstanding of the technology on your part... as it turns out I'm the one who has no idea what I'm talking about.
Joe
« Last Edit: November 11, 2008, 03:23:46 PM by scudzuki »