Messages

7071

FAQs / Re: E-stop not working

« on: October 16, 2010, 07:17:54 AM »

Hi Dan,

If you are using pull-up on your inputs then the e-stop should be connected between 10 and GND. If you are using the n.c. contacts on the e-stop then the function will be 'active high' within Mach. (or 'active low' if you are using the n.o. contacts).

Hope this helps.

Tweakie.

7072

General Mach Discussion / Re: Output voltage problem?

« on: October 16, 2010, 06:57:36 AM »

The SSR you are using should work just fine but there is, perhaps, a better way of driving it.

The LPT parallel port will always sink more current than it will source. Changing the polarity of the drive function (taking the LPT pin low activates the relay) is a much better approach (and kinder to the port). Something similar to this. (change the resistance to suit the SSR drive current - typically less than 10mA).

Tweakie.

7073

Share Your GCode / Re: G Code to set mach into reset at end of program??

« on: October 15, 2010, 11:48:10 AM »

You could try........

Under 'Config / General Config' check the box 'E-Stop the system' on 'Pgm End or M30...'
Then make sure your programs all end with M30 (most do anyway).

Tweakie.

7074

General Mach Discussion / Re: Auto zero tool question

« on: October 15, 2010, 11:27:57 AM »

Hi Rick,

There are probably a number of reasons why the tool is not connected to ground........
Some machines use insulated spindle mountings. Some high speed spindles use ceramic bearings. Some spindles have insulated casings. The list goes on....

My spindle shaft is grounded so I only have one wire and don't need to connect a ground lead to the chuck but a lot of people with wood routers probably use double insulated spindles where the shaft is not grounded.

Tweakie.

7075

General Mach Discussion / Re: Output voltage problem?

« on: October 15, 2010, 04:23:12 AM »

Repeating what has already been said but the computer port was never designed to switch anything more than about 10mA and even then there are conditions attached. You are pretty lucky you got it to work first time round without damaging the port.

One solution is to use an Opto- Coupler, most of these will handle switching currents up to 100mA (which is enough to drive small relays etc.) and I have attached a simple schematic of a typical setup.

Another solution, if you are switching ac loads, is to use a solid state relay as most of these will operate at less than 10mA input and switch ac loads with absolute minimal noise spikes.



Hope this helps.

Tweakie.

7076

*****VIDEOS***** / Re: 4th Axis Fun

« on: October 13, 2010, 02:46:50 AM »

That's great Haik - I can almost smell the steak.

Tweakie.

7077

General Mach Discussion / Re: Starting from scratch.

« on: October 11, 2010, 02:04:54 AM »

Hi Rik,

Good fortune with your project.

You will get plenty of help, if you need it, from the members of this forum.

What sort of things are you considering making with CNC ?

Tweakie.

7078

General Mach Discussion / Re: Still being driven mad by arcs

« on: October 10, 2010, 05:46:34 AM »

I can answer a couple of your questions but not all, sorry.

The servo drive needs the Dir pulse to lead the Step pulse. My problem is that I do not know what that means! I have step set in Mach3 at 3 and Dir as 10. I have tried loads of values but seen no change.

This means that the direction signal has to be established before the step signal is sent and Mach automatically does this.

Is the Dir signal pulsed in the same way as the step or does it only change between 0 and 1 on a direction change?

The direction signal is either low or high (0 or 1) and remains at its last setting until a direction change, for that axis, occurs.

Tweakie.

7079

General Mach Discussion / Re: need general info on steppers and controllers

« on: October 09, 2010, 06:27:02 AM »

Hi Homer,

I have had good results using the cheap single board, multi axis, controllers from China - there are plenty for sale on Ebay. If they go wrong (4 fitted, all different and none have failed so far) then they are throw away items - there is little, if any, after sales or backup support.
I am not recommending a supplier but here are the typical instructions for connecting this type of board. http://www.cooperman.talktalk.net/MDfly.zip

If you can afford to spend more then the Gecko drives are probably the best and have good after sales support etc etc.

Hope this helps,

Tweakie.

7080

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

« on: October 08, 2010, 01:50:08 PM »

Dar303,

Nice to hear you say that this forum has given you new energy. This is a great place to learn and before you know it that project of yours will be completed and you will have little bits of stuff you have made all around the workshop and cluttering up the house etc just like everyone else. 

Tweakie.