Messages

6401

General Mach Discussion / Re: System grounding questions

« on: April 12, 2011, 03:14:25 AM »

Ideally the Earth and Ground should be treated as two separate circuits.
For obvious reasons all exposed metal parts must be bonded to Earth and this circuit must be regularly tested under health and safety regulations in industry so it makes sense to regularly test the circuit in home shop installations as well.
The Ground (GND) is the signal common return and as there are many signals then the associated GND's should ideally be connected a at one common point at the controller end only. It is important to avoid GND loops and if you are using the PC parallel port then the LPT screen should only be connected at the PC end and the internal wires 18-20 connected via the breakout board to the common GND point. It may also be prudent to use screened / shielded cable for all external wiring runs just to avoid the possibility of future problems.
In the real world this is not always possible but Earth loops and Ground loops are often the source of unwanted electrical noise so avoid them if you can.

Tweakie.

6402

General Mach Discussion / Re: how to view front,side,back on toolpath display with function key ?

« on: April 12, 2011, 02:49:05 AM »

There is no one replay ?

there is no way to view this ?

As Terry says - hold the left mouse button and drag the image.

If you want to get into programming the function keys with VB and using the screen designer then fine but it is hardly worth all that effort as the mouse system works well.

Tweakie.

6403

Mach SDK plugin questions and answers. / Re: Impact engraving plugin

« on: April 11, 2011, 08:43:08 AM »

I think this is because Mach has a lot to do just to calculate and generate the pulse stream so the PWM speed control comes second.
I really think you should consider the 0 to 5 volt analog or else construct a 'stand alone' PWM generator for the laser maximum current control. (Using a PIC which incorporates the HPWM it is not difficult to do and it will run from 5 volts and need less than 10 or so components to complete).


Tweakie.

6404

Mach SDK plugin questions and answers. / Re: Impact engraving plugin

« on: April 11, 2011, 06:46:27 AM »

Thanks tweakie i will have a look.I am using pwm from mach board,so its little bit tricky to find the voltage and its frequency.

I think that is your problem.
I tried using the Mach PWM and dropped it in favour of 0 to 5 volt analog control for my max laser power.

Tweakie.

6405

Mach SDK plugin questions and answers. / Re: Impact engraving plugin

« on: April 11, 2011, 06:02:47 AM »

Tweakie thanks,
but when i am reducing to 5000mm/min the laser doesnt fire!

Just a thought but it may be worth looking at the electronics train (TTL) to improve the voltage that you get at the laser input. IMO the laser should be triggering OK at 5,000 mm/min (mine triggers down to 3,000 mm/min). If you can get this sorted then I am reasonably confident that the double image problem will be cured and you can return to the 70,000 speed without issue.

Tweakie.

6406

Show"N"Tell ( What you have made with your CNC machine.) / Re: My 1st Design Harley Davidson

« on: April 11, 2011, 05:47:56 AM »

Really nice work Dave - I can't wait to see more.

Tweakie.

6407

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

« on: April 11, 2011, 05:42:05 AM »

Great idea. Did you spring load the marker of just rely on the give in the tip ?

Perhaps a Logo next ? 

Tweakie.

6408

Show"N"Tell ( What you have made with your CNC machine.) / Re: Here's my DIY pendant

« on: April 11, 2011, 05:34:44 AM »

Very nice indeed.

Tweakie.

6409

Show"N"Tell ( Your Machines) / Re: The Laser Project.

« on: April 11, 2011, 05:29:25 AM »

I know that a Permanent Marker would have been just fine but it is these little things that earn me Brownie Points. 

Tweakie.

6410

Mach SDK plugin questions and answers. / Re: Impact engraving plugin

« on: April 11, 2011, 02:16:46 AM »

ntlaser,

Looking at your Micken Mouse, the double image is not linear and this suggests to me that there could be a delay between the Mach digital trigger pulse being sent and the laser actually firing. Maybe that reducing your feedrate to something around 4 to 5 thousand mm/minute may produce different results.

Tweakie.