Messages

121

General Mach Discussion / CAPACITIVE DECOUPLING OF tHE 20KHZ SIGNAL

« on: October 16, 2007, 06:45:13 PM »

Hello all you happy campers! Some people have asked for a circuit, but I cannot upload, the server is blocking me.
I sent the circuit to ART's email, and hopefully he will post it.
I have also noticed that spammers are finding their way in here, so that might be why I can't post pictures.

Regards,
Whacko

122

General Mach Discussion / Re: Serial/Modbus-servo comunication.

« on: October 09, 2007, 01:57:58 PM »

Hi Dan,

It is as Brian said. I know what you want to do, and there are smart drives that except position commands, but then you will need a post processor or macro running to convert the data to your drive's command syntax. You will also have a huge latency between Mach3 and your servo drive controllers.
But technically you will not have a closed loop with Mach3, as the speed and coordinates will be out of Mach3's control. Is this what you mean?

Whacko

123

General Mach Discussion / Re: Serial/Modbus-servo comunication.

« on: October 07, 2007, 02:45:00 PM »

Speed is of absolute essence with encoder loop position feed back. Speed in this case, the communication speed, or "data through put". The modbus will be way too slow for positional closed loop. That is presumed that the question you asked was to exclude the parallel port interface. The Modbus is an industry standard plc serial interface to expand i/o. In some cases it might be possible if the movement of the machine is slow enough, or if cv travel is not essential.
Mach3 can work in positional closed loop mode as it is currently.

Whacko

124

General Mach Discussion / Re: Serial/Modbus-servo comunication.

« on: October 06, 2007, 02:25:00 PM »

Modbus will be too slow for servo loop update. Best check out the TCP version available with the new download.

Whacko for TCP

125

General Mach Discussion / Re: moveing z axis up and down

« on: October 06, 2007, 02:17:05 PM »

Do you want to microstep? A simple step sequence can be implemented with a few components and no computer. "Elaborate", so I can "evaluate" what you want to do, then we take it from there!

Whacko for real

126

General Mach Discussion / Re: A Long Sad Story

« on: October 02, 2007, 01:42:18 PM »

Even better solid edge has a FREE 2D that works also
 klmark

Post a link please

Whacko

127

General Mach Discussion / Re: A Long Sad Story

« on: October 01, 2007, 02:11:22 PM »

There is another way. There is quality cad programs for very good prices. IMSI has a product called TURBOCAD, and you can use the basic version, no need for the proffesional version. You'd most propably be able to get a package at less than a $100. With this cad package, you can do amazing stuff. In your case, scanned image saved as jpg or bmp or a lot of other formats. Import the pic in TURBOCAD and trace the image in the default layer with a polyline. Make sure the polyline is "closed" at the end of the trace, and shazzam, export the dxf.

Whacko for TURBOCAD

128

General Mach Discussion / Re: What is the step/direction pulse width?

« on: September 27, 2007, 06:52:02 PM »

I have opto isolated step pulse and dir very succesfully with the fast schmidt trigger optocoupler from Fairchild. Part no H11L1 in dil06 package. You can buy online from Fairchild.

Whacko

129

General Mach Discussion / Re: how to tell if a stepper is bad

« on: September 27, 2007, 06:39:46 PM »

Have you tried swapping motors on the drive that works? If the one works, and the other don't, then the steppermotor must be faulty. Another way to check motors out of circuit is quite simple. With the motor removed and disconnected, short all the windings out together and physically turn the motor shaft. The motion will be resistive but smooth. If you can feel a ripple effect, chances are one of the windings is open circuit somewhere. You can also measure the windings with a multimeter on ohm setting for consistency of resistance between windings. If you can find the leads that belong to the same winding in the motor, shorting them together and turning the shaft will be resistive and you should feel a ripple effect as the rotor passes the poles which are shorted (static torque). Doing this by alternatively shorting windings should have the same load resistance when you rotate the shaft. If you have an oscilliscope, you can spin the rotor shaft with a drilling machine and observe the sinewave on each winding.

Whacko when all else fails!

130

General Mach Discussion / Re: How to calculate the kerf width for plasma cutting?

« on: September 14, 2007, 10:59:50 AM »

If the program stops there it is most propably an error. That is one of the reasons I don't use the G41 etc codes. I had problems with it, and then worked around it. Maybe Brian or someone else can step in here and give you advice.

Whacko