Messages

461

General Mach Discussion / Re: Scripter Compile Errors

« on: December 01, 2011, 11:58:36 AM »

Still getting Scripter Compile Error in M3.mis
Machine ran fine all day no problems, started this morning agin, checked files and everything looks normal but spindle does not turn,Requries mach reboot to fix
Any Ideas??

That, too, is, sadly, consistent with my experience.  I believe something is happening inside Mach3 that causes this, as the same script will throw an error one time, and not the next.  Sometimes editing the script will help, sometimes not.  I've got quite a number of conditions that pop up more or less randomly, that require re-starting Mach3 to restore proper operation.  It is my great frustration with Mach3 - I can go days at a time and everything will function perfectly, then I'll have a day where I have one bizarre problem after another, and I can't get any work done.

Regards,
Ray L.

462

General Mach Discussion / Re: Recent Mach3 Releases and OEMButton(1000)

« on: November 30, 2011, 10:43:30 PM »

Terry,

This issue was introduced about two months ago, in a test build Brian did to address one of my (many!) problems.  It only seems to affect OEMButton calls issued from within the macropump.  The change Brian made had to do with trying to block many/most button calls when a program is running, so my guess is he's not properly tracking the state, and blocking too much.  The macropump exits immediately after issuing the OEMButton call, so adding a while loop will do nothing to return control back to Mach any more than it already is.  Besides, it is a real bug, and NEEDS to be fixed, not just worked around.

Regards,
Ray L.

463

General Mach Discussion / Re: Recent Mach3 Releases and OEMButton(1000)

« on: November 30, 2011, 06:53:30 PM »

DO you have a while Ismoving()  statement after the  OemButton(1000) call?

Try    Button(0) instead

(;-) TP

Terry,

The while loop is unnecessary - this is a fire-and-forget function, activated by a manual button on the pendant, and it's worked perfecly for years, until these last few releases.  The same OEMButton is used for the on-screen CycleStart button (which, inexplicably, still works fine....).

Regards,
Ray L.

464

General Mach Discussion / Recent Mach3 Releases and OEMButton(1000)

« on: November 30, 2011, 12:06:49 PM »

I have a pendant, operated by a macropump driver.  One of the functions is CycleStart, which is actuated by OEMButton(1000).  Starting with v49 (I don't think this was a "public" release), and continuing through v53, each time I hit an M00 or toolchange, I have to send the OEMButton(1000) twice before execution proceeds.  Has anyone else seen this?

Regards,
Ray L.

465

General Mach Discussion / Re: Scripter Compile Errors

« on: November 29, 2011, 07:36:25 PM »

Yup, I get those periodically, and got one today on M3.m1s.  The fix is usually to open the offending file with Notepad, and you should see a few garbage characters at the end of the file.  Delete those, and save it, and the problem should go away.

spindlespeed.m1s does actually have a syntax error in it, in some versions of Mach3, yet it does not always generate an error message.

Regards,
Ray L.

466

General Mach Discussion / Re: Motor Voltage question

« on: November 29, 2011, 06:32:08 PM »

Stepper voltage should be 32 times the square root of the motor inductance (in mH), or as close as our motor drivers allow.  For most steppers, that will be in the 50-75V range.  At 20V, you'll get terrible high-speed performance (i.e. - you won't get high speed at all).  I think 460 oz-in motors will also prove rather small for a BP, unless you have belt reducers on them (which will further cripple your top speed).  I would think you'd want motors with at least 2X that torque.  On my BP clone, I'm running 850 oz-in peak/140 oz-in continuous servos with 2.5:1 belt reducers, and it screams (it will do 400 IPM rapids, and has enough thrust to snap a 1/2" endmill without losing position.

Regards,
Ray L.

467

General Mach Discussion / Re: VFD and vari speed pulleys

« on: November 26, 2011, 09:37:39 AM »

Your numbers are correct.  I would hold out for a sensorless vector drive, otherwise you won't get useful torque at anywhere near 10 Hertz - more like 30-40Hz, before the torque  becomes too little to be of much use without switching to backgear.

Regards,
Ray L.

468

General Mach Discussion / Re: VFD and vari speed pulleys

« on: November 23, 2011, 02:47:24 PM »

I used a Marathon Black Max inverter duty motor, max safe speed 5400 but I never needed to run it over 4500.
It runs at full rated HP down to 30 rpm, the lowest I have needed to run it so far.

"It runs at full rated HP down to 30 rpm" - You mean "...full rated *torque* down to 30 rpm...".  To achieve full rated power would mean the torque was actually *increasing* as you reduced RPM - which would be a good trick.

Regards,
Ray L.

469

General Mach Discussion / Re: VFD and vari speed pulleys

« on: November 23, 2011, 12:32:10 PM »

Ray, that is just what I was looking for.  I figure I am going to keep the back gear so low speeds shouldn’t be an issue and I of course would like the most rpm I can get on the top end without burning up the bearings. 

Thanks!

Like I said, I've been running mine up to 8200 RPM for years with no problems.  The bearings get warm (maybe 120F) after several hours of running.  That will be your first indication of trouble - if the spindle itself starts getting really hot.  Warm is OK, hot is not.  And it's neither difficult, nor terribly expensive, to replace the spindle bearings.

Regards,
Ray L.

470

General Mach Discussion / Re: VFD and vari speed pulleys

« on: November 23, 2011, 11:26:50 AM »

I like the idea of the v belts over timing as one of the things I hope to get out of doing this is to silence the beast.  My step pulley Bridgeport runs smooth and quite and I am hoping for the same on this when I’m done.

What I am having trouble wrapping my head around is the motor is 1725 rpm’s, and max rpm of vari speed is 4000 rpm, what diameter pulleys will I need to get that same ratio?  I know there must be some equation to figure it all out but I don’t know what it is.

Thanks

Speed ratio is determined by pulley diameters.  If you have a 4" motor pulley driving a 2" spindle pulley, the spindle will be running 2X as fast as the motor (4/2).  If you turn that around, and put the 2" pulley on the motor, and the 4" pulley on the spindle, then the spindle will be turning 1/2 the motor speed (2/4).

You need to decide what you want your max spindle RPM to be, and what maximum VFD frequency you will run, and select your pulleys from there.  You will no doubt be using a larger pulley on the motor than on the spindle, so the spindle is spinning faster than the motor.  If using the stock motor (not VFD/inverter-rated), it seems usually safe to run 2X the base frequency.  If using an inverter-rated motor, you can often go even higher.  USe the largest pulleys you can fit into the available space, to get the greatest belt contact area.

So, if your motor is rated 1725 RPM, and you run the VFD up to 120Hz, that will give you 3450 RPM at the motor.  If you want 5000RPM for your max spindle speed, then you need a pulley ratio of 5000/3450 or 1.45:1.  So if your motor pulley is 5" diameter, the spindle pulley must be 5/1.45 or roughly 3.5" diameter.

Finally, make sure your low-end RPM is reasonable.  A good sensorless vector VFD should provide usable torque down to perhaps 10Hz.  For the above example, this would give you 5000 * 10 / 120 = 416 RPM.  Note that, depending on the motor, running extended periods at low RPMs may cause the motor to run hot.

Regards,
Ray L.