Messages

1571

General Mach Discussion / Re: E Stop and my new VFC and Spindle

« on: September 27, 2008, 10:49:18 PM »

Just connect a switch to any available paralllel port input, and configure it as an E-Stop pin.  Mach will turn everything off when that pin is activated.  Usually, a normally open switch would be connected between the PP pin and ground, so when the switch is pressed, the pin is pulled low.

Regards,
Ray L.

1572

General Mach Discussion / Re: Un demanded external e-stop

« on: September 25, 2008, 10:16:39 PM »

Good point Ray. I found with a certain C11 that pin 15 was "Leaking " through the board.
It could not be enabled at all without posing problems.
RC

Yup, and grounding problems can cause all kinds of unpredictable and seemingly random behaviors as well.

Regards,
Ray L.

1573

General Mach Discussion / Re: Un demanded external e-stop

« on: September 25, 2008, 05:52:25 PM »

Hi

With the limit switches disconnected from the breakout board ie with only the stepper motors connected the problem is still there. This almost certainly eliminates the limit switch lines as being a the cause. The only input line still connected is the e-stop and this has a temporary shorting link to eliminate any issues there.

Martin

Not so fast...  The only way to completely rule out the limit switches is to de-configure them in the Ports & Pins configuration.  Otherwise, you still have the PP Cable and breakout board which could be picking up noise.  The way to track down the source is to go to Ports and Pins and disable *everything* that doesn't have to be there to make the machine work, then turn things back on one at a time, and run it long enough to be sure whether the problem is there or not.  You may find it's not just one thing....

Regards,
Ray L.

1574

General Mach Discussion / Re: Heat Sink for Gecko 340 Drives

« on: September 24, 2008, 08:42:28 PM »

Hi Ray

Thanks for the reply. E-bay is out for me as I live in South Africa and as far as I know Paypal does not accept our credit cards something to do with fraud.
I already have a 220v electrical cabinet fan. Would this be enough to keep the drives cool.

Regards

Scott

I ran mine for several weeks with the Geckos bolted to a 3/8" thick aluminum plate.  No forced airflow at all.  They were quite happy like that.  So, bolted to your case, with some airflow, I suspect you'll be just fine.  Get some silicone heat-sink grease, and coat the bottom of the Gecko, so it has good heat transfer to the case.

Regards,
Ray L.

1575

General Mach Discussion / Re: Stepper motors loosing postion.

« on: September 24, 2008, 08:40:02 PM »

I had a similar problem with Z axis couple of months ago. After milling some parts the Z-axis ended up higher then when started. The difference depended on the lenght of the G-code and on it's complexity. I tried everything starting from disassembling the machine (Joe's CNC), checking the HW etc. Finally I localized the problem to be in the SW, i.e. PC, not sure if it was XP or Mach. I tried to minimize the possible area of the problem. One of the last things I did was that I was making single microsteps with Z-Axis motor (jogging). I have realized that when turning 1 step right and then one step left everything was OK, but when turning 1 step left and then 1 step right, the motor actualy made the "right" step to the left and only a second right step turned the motor right. That explained why the Z axis shifted slowly up during the milling. Basically, during each change of rotation from left to right the position shifted by 1 microstep (or actually 2 microsteps, because the second microstep turned it to the previous position). It seemed to be a Mach problem. I checked the Mach setup and tried everything like you playing with an acceleration etc. Finaly, I realised (and I'm sorry I don't remember it exactly because it was couple of months ago) that in Config->Ports&Pins->Motor Output (or Output signals, not sure) I had some pins which I used for the motor control (step, dir) toggled on other positions as well. Those positions were NOT (!) enabled so I thought it doesn't matter, nevertheless removing the pin numbers from these positions fixed the problem. I can't guarantee you've got the same problem but it would be worth to check it.

That is a classic sign of mis-configuation of the direction pin, and/or excessive delays through the BOB.  It for sure ain't a software problem....

Regards,
Ray L.

1576

General Mach Discussion / Re: Heat Sink for Gecko 340 Drives

« on: September 24, 2008, 10:15:22 AM »

Flash,
     I looked on E-Bay, and found inexpensive ($10 each) Pentium/AMD CPU heat sink/fan assemblies.  They keep the Geckos nice and cool, and take up very little space.

Regards,
Ray L.

1577

General Mach Discussion / Re: Restore Desktop Icons

« on: September 21, 2008, 11:37:30 AM »

Ray, this is what I was trying to explain. When you click on the properties to one of these shortcuts on the desktop, the "target" goes to the Loader Icon in the C: directory of Mach 3.

There are no separate icons for each program (Mach Mill, Mach Turn and so on).


Dave

Dave,

    Yes, I believe they all point to the same executable, which then figures out how to behave based on a command line argument.  On mine, the Mach3 Mill icon has this command line:  "C:\Mach3\Mach3.exe /p Mach3Mill"
    I would assume Mach 3 Turn would be the same, except for "Mach3Turn" as the last argument, instead of Mach3Mill.

1578

General Mach Discussion / Re: Restore Desktop Icons

« on: September 21, 2008, 10:46:09 AM »

Can't you just re-create them by finding the executable, right-clicking and selecting "Create Shortcut", then pasting to the desktop?

1579

General Mach Discussion / Knee Mill Coolant Containment

« on: September 19, 2008, 07:46:16 PM »

I'm getting really tired of sweeping/vacuuming up chips several times per day, so I've decided it's time figure out how to enclose my mill table, to contain the mess, and while I'm at it, I'll switch to flood coolant, rather than mist.  So, I'm looking for advice on how to accomplish this cheaply, and effectively.  Here's my current thinking:

Fabricate some sheet metal pans to attach to the saddle.  These will extend outward from the center, with a plexiglas shield 6" or so in front of the table, and another mounted to the machine base in the back.  Chips will then hit one of the plexi shields, fall down into the tray, and be collected there, while coolant will be strained and drop back into a reservoir.  The front Plexi piece will be easily removable, for getting to the table.  I'm thinking the sides will be more like baffles than anything else, and will be attached to the table, perhaps just in the ends of the T-slots.  Perhaps with rubber pieces tying these side shields to the front and rear shields.

One of the complications is I have to be able to accomodate my vice, which hangs 6-8" beyond the front of the table, so simply affixing Plexi to the table itself won't cut it.

I'd be really interested in how other people have done this, and especially in seeing pictures.  I don't want this to turn into a major construction project, and also don't want to spend $$$$ on it.  Fortunately, I'll have access to lots of Plexiglas, as leftovers from a project I'm doing.

Regards,
Ray L.

1580

General Mach Discussion / Re: CSS in spindle without feedback

« on: September 17, 2008, 12:22:21 PM »

OK, dumb question:  What is CSS??