Messages

1861

General Mach Discussion / Re: PWM output...

« on: March 25, 2016, 11:44:53 AM »

Well, been messing - it all seems relative to the spindle pulley settings.

I set the min as whatever I got after setting a M03 S1 command - this was 1500rpm.

The max was then tried setting above the actual limit - this made things worse.

Then I went below the limit - 20,000 actually did a good job at the 5,000 to 15,000 range and was pretty close BUT it means you cannot command full speed as you have limited it to 20,000 so not good

I am leaving this at present as I am unsure it actually be done without a lot more knowledge and maybe some VFD tweaks too.

1862

General Mach Discussion / Re: PWM output...

« on: March 24, 2016, 03:05:10 PM »

Well, spent an hour messing tonight, i have no doubt it can be done, but its not going to happen by trial and error i think - too many variables and unless you know what effect each one has your'e just pissing in the wind

Pretty certain now that steps/per and acceleration does nothing, this makes sense as we are on PWM so I think that can be taken out of the equation.

That just leaves Min PWM, base frequency, pulley min and pulley max.

Unless there is a setting on the VFD, i guess there might be, might be worth checking that 5v does give 50% speed.

1863

General Mach Discussion / Re: VFD Enable Question

« on: March 23, 2016, 03:27:50 PM »

Yes spot on.

The relay is mapped to an output, that output is mapped in Mach3 ports&pins as the spindle, also in spindle setup i think, the relay normally-open contacts then go to the VFD.

It is possible to direct-connect but i would not, the relay provides excellent isolation between the VFD and in your case the Gecko, there is no drawback to having a relay in this position. To direct connect both signal levels must match or damage will occur.

Usually the VFD has inputs marked FOR, REV & a COM or maybe just numbers - you will need the manual, plus if you are currently using the front panel buttons you may have to alter the VFD parameters to accept remote start/stop - this should all be in the manual is usually easy to do.

1864

General Mach Discussion / Re: PWM output...

« on: March 23, 2016, 02:59:22 PM »

Has anyone achieved this?

I was kindly sent a document written by Art concerning tuning the output but it was written for step/dir VFD not PWM.

I tried it out as far as i could but not only did some of it not make sense, it did not work properly.

It involves tweaking the motor tuning steps per, velocity, spindle pulleys but there is not much that seems to relate to PWM.

What it DID prove was that the answer DOES lie in there somewhere - i set the steps per to 50 as it stated, velocity to max, spindle pulley to 1000 and tried S1000 which gave me 24000 rpm, S1 gave me 1000 so it does make differences.

I also did not have a linearity.dat file which was supposed to be deleted?

Has anyone actually achieved tuning of the PWM output??

1865

General Mach Discussion / Re: VFD Enable Question

« on: March 23, 2016, 11:26:00 AM »

I can't answer the G540 stuff as i have never used one, but stopping a VFD by reducing speed is not a good or safe option for me.

You are correct in that Mach3 should command a Start signal regardless of the speed setting, this is how my mini-mill works. The VFD is triggered by a little relay on the break-out board which in turn is operated by a pin on the outputs from Mach3. This is controlled by the M03 / M05 commands in my G-Code.

The VFD should start then ramp up to the set speed, at switch off it can either ramp-down, coast  to a stop or forcibly slow down using DC-braking.

Does the G540 not have any floating relay outputs?

1866

General Mach Discussion / Re: Chinese 3040T problem - no motor movement

« on: March 23, 2016, 09:29:47 AM »

Why the heck would they lock the button from inside the box?

I really can't fathom the way some of this stuff is shipped from these places - you buy a machine, in good faith that it will work out of the box, in the end its a construction project or rewire job. Yes it's a budget item but it should still perform basic functions surely?

The internet is loaded with stories on all of these models - 3040, 6040, 6090, mostly all in a negative light.

I hope the OP gets it going and it seems wollyacresfarms has a decent bit of knowledge there.

1867

General Mach Discussion / Re: Chinese 3040T problem - no motor movement

« on: March 23, 2016, 09:05:53 AM »

annnnd breathe..........

1868

General Mach Discussion / Re: Physical buttons for plasma

« on: March 22, 2016, 04:47:06 PM »

Some systems ramp the power up and down in the cut, I cut a job tonight where it could have been used apparently - inside square corners on 12mm plate, these usually end up a bit tapered due to the arc-lag in the inside corners. Ramping up the current just in the corner is said to help this, my system is too basic for that feature though.

There is a sweet spot between power density (nozzle size and current), material thickness and speed - get it right and good cuts will follow.

Hand cutting is a mile away from CNC cutting

1869

General Mach Discussion / Re: PWM output...

« on: March 22, 2016, 06:19:25 AM »

Thanks for that, will have a play.

1870

General Mach Discussion / Re: PWM output...

« on: March 22, 2016, 03:11:04 AM »

Anyone?