Messages

8021

Tangent Corner / Re: Welding a motor mount

« on: May 18, 2010, 01:52:06 AM »

I think the rule of buying second hand stuff comes in here. If it's cheap enough then it's worth the chance, If the seller wants proper money then don't take the risk.
(if that was electric welded then some of the current could have gone through the bearings which may prematurely fail as a result. The heat may have compromised the windings insulation or magnetic flux characteristics etc...) But if it's cheap enough - go for it.

Tweakie.

8022

General Mach Discussion / Re: Combining grounds of 12VDC logic and linear unregulated HV

« on: May 18, 2010, 01:40:54 AM »

Like most things, there is always a difference between theory and practice. I think you just have to connect it up, try it and see (common connection at the drive end). From my experience most electrical noise issues have been ground or earth loop related so if you are unlucky enough to get noise problems that would be a good place to start.

Tweakie.

8023

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

« on: May 17, 2010, 12:11:47 PM »

Although my machine is not really fast enough for raster engraving I just had to give it a try.
This image of Jacko is engraved into glass, it is only monochrome so there is no PWM control of the laser at this stage – it is either on or off and controlled by the M11 and M10 commands.
However, when making the laser control circuit I incorporated a spare TTL gate in the trigger path which will allow me to logical AND two control signals – one being the existing on/off trigger (M11 & M10) and the other being a PWM signal derived from the spindle setup (S0 to S100). The PWM will vary the duty cycle of the applied laser pulses from approx 1% to 99% and provided I get the pulse repetition frequency correct should allow for true raster engraving with variable depth. Mach is not quite ready for this type of operation yet but I am sure that if enough people want it the necessary modifications will be made and Mach will become a full blown laser control software.

Tweakie.

8024

Third party software and hardware support forums. / Re: Setting up a PCi Parallel card to work with Mach 3

« on: May 17, 2010, 06:42:15 AM »

It is probably best if you only post your question once.

http://www.machsupport.com/forum/index.php/topic,14910.0.html

Tweakie.

8025

General Mach Discussion / Re: Setting Parallel port address

« on: May 17, 2010, 04:48:17 AM »

It is probably best if you only post your question once.

http://www.machsupport.com/forum/index.php/topic,14910.0.html

Tweakie.

8026

FAQs / Re: Setting Mach 3 Port to PCI parallel port address

« on: May 17, 2010, 04:42:13 AM »

What should be in the box is  0xDCE8
That is your port address.

Tweakie.

8027

General Mach Discussion / Re: PWM Mach Settings

« on: May 16, 2010, 12:55:12 PM »

Hi Dave,

I didn't get reliable results here (just a bench test) with a base frequency of 50 but at 100 I was able to change the mark/space ratio of the PWM signal from around 1% to 99% with the spindle speed slider.

Tweakie.

8028

General Mach Discussion / Re: PWM Mach Settings

« on: May 16, 2010, 12:03:27 PM »

Mach screenshots look OK to me, at least that is exactly what I would do. (have you tried minor tweaking like changing the PWM base to 100 etc.?)

Tweakie.

8029

General Mach Discussion / Re: PWM Mach Settings

« on: May 16, 2010, 11:20:18 AM »

Hi Dave,

If you have the benefit of an oscilloscope you could hook it up to your LPT pin 14 and observe the changing square wave PWM signal as you adjust the spindle speed slider within Mach (don't forget - you need to have a GCode loaded which issues the M3 command !!).
Then observe the 0 - 10 Volt signal at the Gecko pin 8.
If both the above are present then its your wiring (assuming nothing is broke).

Tweakie.

8030

FAQs / Re: Step and Dir signals

« on: May 15, 2010, 01:11:23 AM »

Also, what is the state of the dir pin when the motor is not supposed to turn?

The direction pin retains it's current state until it is changed by the next direction move - so it could be either state.

Tweakie.