Messages

5411

General Mach Discussion / Re: Limit Switches and Interference

« on: October 28, 2012, 07:31:09 AM »

Just in general...

The shields of all cables are connected to GND at the controller end only and preferably to one single point or tag.
The machine frame and any other metal parts that you can touch are connected to protective Earth.
Earth and GND should be treated as two entirely separate circuits as far as wiring is concerned.
It is essential that you have no 'Earth loops' or 'GND loops' anywhere within your wiring.

The PC usually has its negative rail (GND) connected to Earth so this should be the only place where they meet.

Often points of conflict exist if the shielding of the LPT parallel cable or PC casing is connected to machine frame (Earth) or the heat-sink of a VFD is connected to the machine frame and also has it's own Earth wiring but there are many other areas where loops can easily be created.

As you have discovered, it is a difficult problem to resolve but unless it is resolved 100% then it may come back to bite you, at some future date - usually 3/4 of the way through a complicated and expensive job.

Tweakie.

5412

General Mach Discussion / Re: Spacely Sprockets or Cosley Coggs ??

« on: October 28, 2012, 05:11:49 AM »

Whilst it is a serious piece of software it still has a fun aspect - I just love it - thanks Art for such a great program.

Tweakie.

5413

Show"N"Tell ( What you have made with your CNC machine.) / Re: Pendant LPT2

« on: October 26, 2012, 11:59:53 AM »

Excellent work Pasquale, my congratulations.

Tweakie.

5414

Show"N"Tell ( What you have made with your CNC machine.) / Re: SkyFall.

« on: October 26, 2012, 10:49:37 AM »

Hi Brett,

It's approx. 35mm diameter and a nice snug fit on the front of my webcam. 

Tweakie.

5415

Show"N"Tell ( What you have made with your CNC machine.) / SkyFall.

« on: October 26, 2012, 05:53:54 AM »

Hi Guys,

I make no claims for originality but as ‘SkyFall’ was released this week it just had to be done. ‘M’ would not be amused. 

Tweakie.

5416

Show"N"Tell ( Your Machines) / Re: My first CNC project

« on: October 25, 2012, 01:43:07 AM »

Excellent work Todd, I look forward to seeing more.

Tweakie.

5417

General Mach Discussion / Re: Motor problem

« on: October 24, 2012, 07:11:46 AM »

Hi Saiz,

I understand what you are asking but you would need 'servo controllers' to drive your motors and 'encoders' to provide the feedback position of their shafts in order to control their movements and this would cost a lot of cash. 

Tweakie.

5418

Show"N"Tell ( What you have made with your CNC machine.) / Re: Motor Encolsure

« on: October 23, 2012, 05:11:39 AM »

Nice work Sam.
It's about time you made something. 

Tweakie.

5419

General Mach Discussion / Re: pc crashes if all 3 axis rapid move simultaneously

« on: October 23, 2012, 03:52:33 AM »

Hi Dave,

My advice would be to try a different PC (Mach3 places a lot of strain on the Windows OS in creating the output pulse train and if the PC cannot cope it will crash). An alternative would be to use an external motion controller such as the Smooth Stepper.

Tweakie.

5420

General Mach Discussion / Re: Mach 3 and Sheetcam under linux?

« on: October 23, 2012, 03:45:19 AM »

Mach3 is a Windows-based machine control system.

Tweakie.