Messages

5071

Newfangled Solutions Mach3 Wizards / Re: tiling - X only very long piece

« on: March 09, 2018, 07:44:47 PM »

Hi,
OK that sounds pretty reasonable.

I don't think that 'ref all' or some modification of it is going to work. When  Mach 'homes' it goes to a particular location and calls that location 0,0,0 Thereafter
all moves and coordinates are relative to that location. That's good for Mach, it knows where it is in relation to the boundaries of the machine but not very
convenient for you and I.

You may have noticed that Mach has a number of Work Offsets. This allows you to manually jog to a location on the material and say this is the orgin of my part.
Thereafter the Gcode will move about that Work zero. If a bit later you wish to shift the cut zone you can do so by calling another work zero. Mach has six work
offsets without a P numbering scheme and up to 256 with such a scheme, plenty enough.

The process would be cut in one area until the parts are all done THEN call G54.1 and run the same file and all the same parts will be cut but displaced from your
original cuts. Would that suffice?

Another possibility is that Mach4 has the concept of a 'head'. Each head is a cutting tool (plasma or spindle or grind head etc) and separated by a head offset.
I've never had call to use it but you could download Mach4 and run the Sim(ulator) plugin for as long as you like to experiment with it.

Craig

5072

General Mach Discussion / Re: ALLEN BRADLEY 2090-UCSR-A300

« on: March 09, 2018, 05:04:15 PM »

Hi,
yeah, these things live at the 'sharp end', if anything is going to go bang its these.

Craig

5073

General Mach Discussion / Re: ALLEN BRADLEY 2090-UCSR-A300

« on: March 09, 2018, 04:30:00 PM »

Hi,
don't think those sound right.

The big (main) braking resistor should be about 36 Ohms.

Resistance measurements are not really effective with a MOSFET/IGBT.
You need to use  diode check on your multimeter, positive drain (center) negative source (right) should be close to open circuit.
Negative  drain (center) to positive source (right) should be the MOSFET body diode, about 450mV.

Would expect drain (center) to gate (left) to be close to open circuit.

Craig

5074

Newfangled Solutions Mach3 Wizards / Re: tiling - X only very long piece

« on: March 09, 2018, 02:55:47 PM »

Hi,

Is there any way for the user to input a measurement which will tell MACH3 that when I do ref all home  its actually at 2400 mm and next time its ref all home its 4800 mm.

Would you expand on this. A home location is just that a home location and is the same time after time, it does not change.
Are you suggesting that you have different home locations dependent on the size of material?

Craig

5075

General Mach Discussion / Re: ALLEN BRADLEY 2090-UCSR-A300

« on: March 09, 2018, 01:27:33 PM »

Hi,
added a couple of diodes, D2 prevents the opto LED of high reverse bias if ACline disappears but DCLink stays up.
D3 prevents massive forward current in the event that ACline is still up when DCLink is down or shorted low.

Craig

5076

General Mach Discussion / Re: Mach3 Pendant

« on: March 09, 2018, 12:58:25 PM »

Hi,
fine if its not hardware then its software, post that.

No one can help what we cant see.

Craig

5077

General Mach Discussion / Re: Servio motor Delta adas b2 Software and electronic gear ratio

« on: March 09, 2018, 12:55:28 PM »

Hi,
by my calculation you don't need any electronic gearing at all.

Denominator=Numerator =1

Would suggest you enter max speed of 800 rpm say.  Keep the max acceleration somewhat less than the absolute theoretical best. The real challenge with
a servo comes when you are decelerating. The motor turns into a generator and energy comes from the servo back into the servo drive and they don't
like it. There may be optional braking resistors for your servo to improve the situation. If you try to decelerate too quickly the drive will fault 'bus overvoltage'
and the servo will coast to a stop. If it coasts right off the end of the axis....to bad....should've been more careful planning the deccel phase.

Modern AC servos are extremely capable, if you can only get 10% of best out of one it will still be amazing. Don't worry about it, get it set it up and
use/experiment with it, you'll be really impressed. The trick is to be a little conservative about accel/deccel, they are so capable that you are inclined to keep
upping the ante only to find that you break your machine.

Craig

5078

General Mach Discussion / Re: ALLEN BRADLEY 2090-UCSR-A300

« on: March 09, 2018, 04:08:26 AM »

Hi,
that very simple idea might have a few weaknesses. What happens if the ACline voltage disappears while the DCLink holds up for a second or two.....
the LED of the opto looks like it could come under severe reverse bias...not a good look for an LED.

Some refinements are definitely in order. I might try making one to see how it pans out in practice.

Craig

5079

General Mach Discussion / Re: ALLEN BRADLEY 2090-UCSR-A300

« on: March 09, 2018, 03:58:36 AM »

Hi,
something like this.

Rectified and smoothed ACline for DCLink reference voltage. If the DCLink+ goes 24V (zener drop) higher then the opto LED conducts turning the shunt
MOSFET on. Cheap and cheerful gate drive powersupply with a little transformer, rectifier and filter cap.

Craig

5080

General Mach Discussion / Re: ALLEN BRADLEY 2090-UCSR-A300

« on: March 09, 2018, 02:26:37 AM »

Hi,
have you considered making one? I think a working unit could be done pretty simply.

Craig