Messages

5141

General Mach Discussion / Re: unwanted creep in jog mode?

« on: January 16, 2013, 12:06:22 PM »

Can you try a ps/2 keyboard?

Hi Hal,

Unfortunately I don't have PS/2 available on my PC so I can't try that option here - perhaps Tony will have some more information.

Would be interesting to hear if others have seen this weird behaviour also.

Tweakie.

5142

General Mach Discussion / Re: delay in PWM pulse (LaserMode)

« on: January 16, 2013, 11:39:23 AM »

what about the minimum DC in mach config, it has no effect on the outgoing pulse of com, i've set it to 50% and the worse resualt, it doesn't pulse untill to reach 50% of feed rate and at that point starts with 50% DC, so more uncutted path of the shape!

Hi bdn,

Sorry, I can't be of much help with that one as I don't use Mach3 to control my laser output power via the PWM pulse train.

Tweakie.

 

5143

General Mach Discussion / Re: unwanted creep in jog mode?

« on: January 16, 2013, 03:18:29 AM »

Interesting problem this and I wonder what the solution will be.

This creep, very occasionally, happens to me but I have made a few observations…

When opening Mach3 the Reset is flashing – if it can be cancelled using the keyboard  ‘  character then the creep never happens. If the Reset can only be cancelled by clicking on the Reset button then creep can occur. My solution is to close and re-open Mach3 and only run it when the Reset can be cancelled by the keyboard  ‘  character.
I know it is just a work-around but it works for me.
My suspicion is that it is related to the way in which my PC handles USB keyboard etc. communications but I would love to know the definitive answer.

Tweakie.

5144

General Mach Discussion / Re: delay in PWM pulse (LaserMode)

« on: January 16, 2013, 02:20:38 AM »

Hi bdn,

Please ignore what I said about the Spin-Up / Down delays, it will make no difference – My head was still full of another post I had made regarding over-burn with the use of the M3 / M5 command set. 

I think you have identified the cause. My tube requires a minimum of 4mA to fire instantly at it’s first trigger (this would translate to 20% PWM). Thereafter it will fire at 2mA if the next pulse is within approx 100mS of the previous pulse.
The RF tubes have a slightly larger threshold so they overcome this problem by providing the 5kHz ‘tickle pulse’ before and in-between triggers.

I don’t fully understand the physics behind this but it appears that the various gasses within the tube need to be mixed / agitated in order to keep the tube in a state or readiness so you could perhaps try modifying your GCode to include an initial pulse or two (outside the work area) in order to prepare the tube before starting the cut.

Tweakie.

5145

General Mach Discussion / Re: HELP NEEDED URGENT

« on: January 15, 2013, 12:20:32 PM »

Hi Peter,

I appreciate that you are new to the forum but it is not productive, or indeed polite to start more than one thread relating to the same topic.

Tweakie.

5146

General Mach Discussion / Re: Urgent help needed. Setting up MACH 3

« on: January 15, 2013, 11:28:45 AM »

Using a multi-meter on continuity range, unplug one of your motors then identify the A / #A windings and the B / #B windings then check that they connect to the correct pins on your controller.

Using the multi-meter on dc volts range, check the output of your 24 – 30 Volt PSU and also check that it is connected with the correct polarity to your controller / driver cards.

From reading your technical data, it is my understanding that your controller has internal pull-ups and will operate without the charge pump signal.
Therefore;
With your PC switched off and the parallel port cable disconnected from the PC if you switch on your controller the motors should lock.

Tweakie.

5147

General Mach Discussion / Re: Urgent help needed. Setting up MACH 3

« on: January 15, 2013, 08:52:01 AM »

Peter,

I am still not certain if your stepper motors are locking up when you have everything powered on.

Do they lock ??

Tweakie.

5148

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

« on: January 15, 2013, 02:58:01 AM »

Excellent work John.

Wait till Zoltan sees those   

Tweakie.

(Just a note for others that follow - modern mirrors, depending on their origin, are almost always 'Lead-free' but precautions should always be taken to avoid inhaling the dust / fumes produced when working with all mirrors).

5149

General Mach Discussion / Re: delay in PWM pulse (LaserMode)

« on: January 15, 2013, 02:29:29 AM »

Hi bdn,

In Config / Ports & Pins / Spindle Setup - check that your Spin Up / Down Delays are all set to zero.

(I have found a number of problems using the Mach3 generated PWM for laser power control so no longer use it).

Tweakie.

5150

General Mach Discussion / Re: HELP HELP TO GET STARTED ON MOCK3 MILL

« on: January 15, 2013, 02:02:41 AM »

Hi Harry,

In Mach3 - Config / Ports & Pins / Input Signals - enable EStop and reverse the 'Active Low' setting. That should enable you to clear the condition.

Tweakie.