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  1. #21
    Registered HuFlungDung's Avatar
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    Rizwan,
    I won't pull any punches, one of the standard proprietory controllers is likely to be more satisfactory right off the bat, because you will get a professional retrofitter in to do the job, and he most likely will know what is going on, and what needs to be done.

    There is nothing stopping a professional from using Camsoft as well, but the interface will be a unique Camsoft interface, and the standard gcodes and threading and turning cycles may not work just like you would expect them to. If you have other people who need training to run the lathe, then you might be better off with standardized factory training materials, such as you would get with one of the proprietory controllers.

    The strength of Camsoft, in my opinion, is that you can implement some nifty ideas that you will never find in any other controller. You can debug, and alter what you don't like. You can service the machine with relatively inexpensive components, from henceforth, without paying a king's ransom for parts.

    But the Camsoft thing is more for those who really want to 'marry themselves' to a machine, or have a special machine that requires custom software anyways. Even having done a Camsoft retro myself, I'd be pretty askance at buying a machine that someone else had retrofitted with Camsoft, because I'd have to wade through their logic to find and fix any issues that I discovered. Even my own still has a few loose ends in it, things that I have partially implemented, or that need outright changing, and stuff like that is very tough to resell unless someone is going to go through and document how you set your controller up. That would take a hundred hours or so (at least) to write up how it all works.

    First you get good, then you get fast. Then grouchiness sets in.

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)


  2. #22
    Community Moderator Al_The_Man's Avatar
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    I know we have covered this before, but hopefully if I get the time in the near future I intend to experiment/work on this threading issues with Gallil using native code.
    Is the problem with using Camsoft the fact that commands are issued one at a time?
    For example, my experience with Galil, is that is is very powerful if a complete program or block of code is downloaded and run, which I believe can simulate the threading as is done on Mitsubishi, Fanuc etc, where essentially the z axis is synced to the marker pulse and then geared to the spindle encoder, so it allows for some variation in spindle speed and the z axis will compensate feed rate accordingly.
    Al.

    Last edited by Al_The_Man; 10-15-2006 at 10:33 PM.
    CNC, Mechatronics Integration and Custom Machine Design

    “Logic will get you from A to B. Imagination will take you everywhere.”
    Albert E.


  3. #23
    Registered HuFlungDung's Avatar
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    Al,
    You are correct in that the Galil is very powerful, and can execute a final part profile chain with excellent smoothness. The lathe is maybe not the prime example of a machine where this quality is needed, but I have actually witnessed toolmarks on a turned part (at the end of each segment), containing about 4 different 'counter-tapers' to try to turn a long, slender surface straight in one pass. As soon as I turn on the Camsoft "SMOOTH" ON, those same marks completely disappear from the surface. The manner in which the SMOOTH command works, appears to me to be the equivalent of feeding a sequence of vectors into the Galil onboard memory, then executing that sequence. It works very well, and I can imagine that it would be really nice on a mill doing 3d contouring.

    But, if there remains any issue with lathe threading, it is not the manner in which Camsoft does it, it is the matter of getting the encoder index signal to do two things:
    1. Start the motion reliably and repeatably after the encoder index is detected.
    2. Detect the encoder index within one revolution.

    Now, the first one I dealt with, trying to find reliable triggering methods from the Galil card. There are a number of ways that you can use Galil's commands to trigger motion, but all of them (except one) have a variable length of time delay between reading the index, and initiating the motion. On a lathe running at a few hundred rpm, there is really no room whatsoever for any 'window width' about when the Z has to start. Its got to start exactly the same after every index, or the tool will not pick up the same path as the previous cut made. I am not saying that it even must be 'super fast' at starting the Z motion, but it must be 'super repeatable' on whatever time delay is built into the hardware, firmware and whatever.

    The second issue, I've heard that guys have built detection devices using 'off-board' high speed I/O to pick up the encoder index. Although I have not added a high speed I/O board into my computer, it does sound like a reasonable explanation for a lot of waiting around for the Galil to detect the encoder, and the faster the encoder is turning, the worse the detection rate using Galil's onboard I/O.

    First you get good, then you get fast. Then grouchiness sets in.

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)


  4. #24
    Community Moderator Al_The_Man's Avatar
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    I was considering using an input with the AL = Arm Latch, this stores the position of the axis within 1µs of going low, so I assume it is a fast interrupt.
    The status of the latch can be read immediately in order to trigger the Z to gear to the spindle encoder.
    Al.

    CNC, Mechatronics Integration and Custom Machine Design

    “Logic will get you from A to B. Imagination will take you everywhere.”
    Albert E.


  5. #25
    Registered HuFlungDung's Avatar
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    Al, should I bias your thinking?

    It's been a few years since I went through all that testing, and I think that was one of the tested methods. But you try it and see what you think. The acid test is running a single pass on the lathe, and then watching the tool rerun exactly the same path (no additional cutting depth) and watch whether or not the tool ever takes another chip on subsequent passes.

    I don't have a clue what the Galil is doing that causes a variable time delay with some of the methods I tried. The speed of response to the high speed latch was not the answer to a consistent restart that was in sync with the encoder position. However, using the AI command to wait for the encoder index seemed to be very consistent and that is what I ended up using.

    First you get good, then you get fast. Then grouchiness sets in.

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)


  6. #26
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    have u listen that some one had made edm machine at home? can u find him



  7. #27
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    Quote Originally Posted by CATCH22 View Post
    HU im curious i just bought a sag12 and the transmission cluthes are slipping. do you know if you are still using the trans or are you just using the motor with a vfd. thanks catch.
    Some-one is selling rebuilt electric clutches. I just don't remember where I saw it. Maybe on The P.M.board
    archie =) =) =)



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