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Messages - garyhlucas

201
General Mach Discussion / Re: CNC Router Super Jerky
« on: June 04, 2017, 09:59:48 PM »
I would be concerned that the 3 to 1 reduction which multiplies the motor torque by 3 times also requires that the motor runs 3 times as fast for the same travel speed. Then you may be exceeding the capability to put out steps reliably. Or the motor torque simply falls off so fast that you actually have less torque rather than more, again losing steps.

202
Simple is good if it can be done.  A hardware solution like this is a lot more bulletproof.  No software problem can override the limits.

203
Mach4 General Discussion / Re: How to Emulate a Momentary switch?
« on: June 04, 2017, 10:34:27 AM »
Don't know if it will work here but a trick I havr often used for a toggle button in PLCs is to increment a Word value and the use lowest  bit as the output. Each time you increment that bit changes state and remains that way.

204
I'd connect the VFD fault input using simple isolating relay if your drive has a solid state output instead of a dry contact relay. Then you know your E-stop won't cause you intermittent grief. On my machine I have the limits switches all in series with the mechanicly held E-stop buttons, the Mach 3 E-stop output through a relay and a reset button that closes across all of the E-stop circuit momentarily so Mach 3 can be reset and allow you to jog away from a limit or out of a part while holding the reset button in. The E-stop circuit holds in a power contactor which removes all power from everything on the machine, spindle drives and axis drives.

205
I'm very sure it exists, but likely costs more than your machine and you cam program combined!  You could use your cam program to create code to machine the enclosure shape in a block and continue right on machining the cutouts you need thus simulating your box. Saving the code to machine the box you could then add it to the cam file for future boxes.

206
General Mach Discussion / Re: issues with Machine stalls
« on: May 28, 2017, 01:40:26 PM »
What is your power supply voltage?  Torque falls off as a step motor increases in speed as the back EMF reduces the current that can be supplied. So you want to use the highest voltage the drivers can handle. Acceleration requires more torque too. So if the torque falls off too fast try decreasing acceleration.

207
That is a different form of kinematics than what Mach 3 does, which is linear and rotary by circular interpolation. So I don't believe Mach 3 can do this.  The Linux guys are always bragging on LinuxCNC, maybe it can since the source code is open encouraging someone to add that capability.

208
PoKeys / Re: Pokeys57cnc 10v spindle control only reaches 8.1v
« on: May 25, 2017, 07:45:03 PM »
Simple test. With the vfd disconnected put a 20K resistor across the pokeys output and vary the input across the range of speeds. If you see the voltage drop off same as for VFD then you will be sure the problem is a combination of low output current from pokeys combined with low input impedence of the VFD.  Back before you youngins were playing with this kind of stuff we had to resort to vacuum tube voltmeters so the meter itself wouldn't pull the voltage down!

209
General Mach Discussion / Re: Purposly Making a Weak Spot
« on: May 13, 2017, 01:59:05 PM »
You don't say what servo drive you have but it would be unusual for it not to have overload trips. The best would be if it offered an instantanous trip output at some very high load, and a time delay trip for short term overload that doesn't break things. The best reason for using a drive output is you can E-stop Mach 3 to prevent continuing motion driving the tool when the spindle stops. A mechanical device won't easily do that.

210
Promote and discuss your product / Re: SmartScreens for Mach 3
« on: May 13, 2017, 01:50:51 PM »
Michael,
I have a homebuilt multi-purpose machine as well. It is a vertical and horizontal mill. with a 4th axis, a horizontal and vertical lathe, and a 3d printer. I have air blow off, mist buster coolant, and shop vac connected.

I really like what I see. It is very clean, well organized, and lots of useful functionality. I'd like learn more about your screen set and what your plans are for it.