Messages

5481

Tangent Corner / Re: SANDY - ONE WITH AN ATTITUDE

« on: October 31, 2012, 06:43:32 AM »

I have been following her progress on the news channel and such devastation has been caused my heart goes out to all those affected.

Tweakie.

5482

Show"N"Tell ( Your Machines) / Re: Home built CNC Router.

« on: October 31, 2012, 03:47:27 AM »

Excellent work on building your machine Marc, that is certainly a machine to be proud of.

Just one suggestion - you may need to replace your limit switch wiring with shielded cable (with the shield connected to GND at the controller end). It does not happen in all instances but 'input' wiring often picks up 'electrical noise' which can cause 'false steps' and lead to inaccuracies in the machine position.

Tweakie.

5483

General Mach Discussion / Re: stepper motor speed

« on: October 30, 2012, 04:19:59 AM »

Hi Garth,

If your motor drive is set for 25,000 steps per revolution and your lead-screw requires 5 turns to progress 1 inch and you want to travel at 40 inches per minute then...

In Mach3 Motor Tuning 25,000 x 5 = 125,000 Steps per unit : Velocity = 40 : Acceleration 18 (or so).

Also check that you have Mach3 configured for Inches and not mm.

Tweakie.

5484

G-Code, CAD, and CAM discussions / Re: Symmetry problem... Is the problem in mach 3 set up?

« on: October 29, 2012, 09:29:45 AM »

Just a pure shot in the dark here…

I am not sure about the MarchantDice machines but some Chinese machines are not fitted with proper, preloaded, thrust races on the ball-screw at the stepper end. They rely on the stepper to take the load which, as we know, usually has a spring washer mounted bearing and thus it’s shaft can move axially under load.
This problem does not show itself as ‘backlash’ because the movement only occurs under reasonably high load – could this be the issue ??

Tweakie.

5485

Mach4 General Discussion / Re: New people welcome !! Come in here and introduce your self!

« on: October 29, 2012, 02:53:13 AM »

Hi Hoges,

Welcome to the forum.

If you post your question as a new topic in the General section I am sure you will receive some useful suggestions on how it can be done.
Personally I would produce a drawing and export it as a .dxf then create the GCode tool-path from that but there are other options.

Tweakie.

"Fabulous Forum it never ceases to amase me how little I know !!!" - You and me both 

5486

Mach4 General Discussion / Re: New people welcome !! Come in here and introduce your self!

« on: October 28, 2012, 11:37:24 AM »

Hi Ottervalley,

Welcome to the forum.

There are many here who would be pleased to help if you get into difficulties with Mach3 and it's settings.

In the meantime, if you make a safe copy of your 'Mach3Mill.xml' (or whatever profile you are using) and the 'Mach1Lic.dat' (both in the Mach3 folder) that should save almost all of your settings and license.

Tweakie.

5487

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.

5488

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.

5489

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.

5490

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.