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Messages - jimpinder

1071
General Mach Discussion / Re: motors won't move
« on: October 11, 2007, 04:33:25 AM »
Just another thought about the motor reverse - try altering the ports and pins - make the reverse active low - (or high if it is low already) and see if this alters your motor running. ( It shouldn't really, but you never know).

The other thing to do is check the voltage on your CNC board on the reverse pin and see if it alters when you reverse the motor, it should do. You won't see full voltage because they are only pulses, but you should see a change.

If you have a hi/lo/pulse detector for computer work then use this, it gives a lot more reliable information.

1072
General Mach Discussion / Re: motors won't move
« on: October 11, 2007, 04:25:35 AM »
If you are connecting several electrical boards together (speaking generally), although each can have a seperate power supply, +5v, +12v +3.5 volts or whatever, there must be a COMMON connection between all the boards, or the voltage you supply to it does not have a reference. Voltage does not just exist - it is the potential difference between TWO points - this is why birds can perch on 25,000volt overhead wires - they are only touching one wire.

The accepted norm is to connect all the 0v leads together, so that each board then has the same reference for the voltage they are using - so a +5volt signal from your computer will be recognised as a +5 volt signal by your CNC card. If the Common wire is not common to all boards then your CNC board might see a signal from your computer as being ,say,-15v or indeed just not see a voltage at all.

I note you are using a 5 volt power supply from your computer. This is probably fine, but I do not know what power the CNC board needs. Make sure your computer power supply can supply it.

As far as the motor only spinning one way - I do not know what makes your particular motor reverse.
I use stepper motors and my driver cards require two inputs : one is 'step' and the other is 'direction'. A pulse on the step wire moves the motor one step, and the direction is determined by the voltage on the direction wire. This is the method Art has used on the motor outputs from your PC.

If your motor has a driver card, then you will have to look at the details for that. I have heard of Geeko cards and I would have thought these are the same.

Glad you have something running.



1073
General Mach Discussion / Re: motors won't move
« on: October 10, 2007, 12:56:48 PM »
I have had a look at the CNC4PC board and it seems totally misleading and difficult to follow.

1.   You must have a 5 volt supply connected to this board. The standard 25 pin LPT1 output from your computer DOES NOT supply a 5 volt power source. My stepper motor driver boards are 24 volt and derive a 5 volt supply from that - perhaps Geeko are the same and you can use that - I don't know.
2.   Despite what is said - pins 2 to 9 on LPT1 are only OUTPUT pins and cannot be used for inputs. The other output pins are 1,14,16 and 17. The input pins are numbers 10,11,12,13 and 15.
3.   The "common" for pins 2 to 9 and other outputs need to be set to 0 volts. The common for the inputs can be either depending on their use.
4.   Ensure the "Enable" pin on the top right hand corner of the board is jumpered to 5 volts
5.   I must assume that 0 volts on the card is connected to the 0 volts on the printer cable (pins 18 to 25), so therefore the only connections you need to the stepper driver boards are pin 2, pin3 and a common (0v) - the one between pins 2 and 3 will do.
If you find this works, then the second motor will be pin 4 and 5 and a common, and so on.

I suspect that, because you are not getting any indications on the card, this is because a) you did not have a seperate power supply to the board, and b) the enable pin was not jumpered. Connect a power supply, jumper the enable pin, and check again to see if there are any outputs, using the M3 M4 M5 routine. You do not need any input pins connecting at this stage.

1074
General Mach Discussion / Re: motors won't move
« on: October 10, 2007, 06:38:39 AM »
Are you getting ANY output on your breakout board from the computer.

Ignore the motor drivers and set up outputs for say M3 on ANY of the pins 2 to 9 and 1,14,16 and 17.

By running Mach3 then doing M3 followed by M5 you can see if the appropriate pin changes voltage. The voltage should change from 0V or close to it, to either 3.5 volts or about 4.75 volts. If you comfigure Active Low, then these will be reversed. Change the pin allocation and try again. You should be able to check all your output pins in this way. Ensure you have a good signal ground on your connecting cable.

If you are getting voltage changes on all the pins, then Mach3 is fine and you need to look at your drives. If you are not getting any voltage change then your configuration is wrong. I assume you have ticked port 1 as enabled and also put in port 1 on the ports and pins allocation.

1075
General Mach Discussion / Re: moveing z axis up and down
« on: October 08, 2007, 06:31:44 AM »
Brian -

Since Art has done all the work for you, why do you want to build something seperate. All you need is a couple of push buttons connected on the input side of Mach3 and run a Macro. I assume your Z axis is already connected to a stepper (or you wouldn't need a stepper driver).

You can even do it without the push buttons by doing a Macro for the jog, and use the current jog buttons.


1076
General Mach Discussion / Re: Why won't the pins go low?
« on: October 03, 2007, 09:38:08 AM »
The standard printer port address for an IBM PC - which is what PCs are supposed to be - is LPT1 - &H378.  LPT2 if you are lucky enough to have that fitted is address &H278.

The output lines 2 to 9  which Art uses for stepper motor board drivers is address &H378, the 5 input lines - pins (note the order)15,13,12,10,9 are bits  3 to 7 of address &H379, and the 2nd 4 outputs, pins 0,14,16,17 are the first four bits of address &H37A.

If you disconnect your breakout board from the lathe/mill, you should be able to set the correct address, and then test the output at each pin with a voltmeter. You can use Mach3 to address each line individually (on the ports and pins page). Go to the output page and select M3 and allocate it to a pin, starting at 0 and working up the output pin numbers, using M3 and M5 command to turn the pin on and off. See if you have a voltage change on the particular pin.

If you detect the change then you board is OK. Don't forget - most driver cards etc use 0volts as the 'on' command - i.e. that is active low in Mach3.

As an alternative you could peek or poke data to the addresses to test them - but using Mach3 is better.

As far as you machine is concerned, ny computer that I am using now is also full of junk, but I have a copy of Mach3 on it. I had to make sure the driver was functioning - see the tutorial video, and it works OK. I do all my planning and programming on this one, then transfer the GCode on a stick memory to my workshop computer - a Toshiba lap top. All you need do is make sure that as much of the background junk is turned off as possible and it should be able to run Mach3.

1077
General Mach Discussion / Re: Why won't the pins go low?
« on: October 02, 2007, 08:16:13 AM »
Well - at least you saw something move - perhaps not how you intended, but it's a start.

1078
General Mach Discussion / Re: Continuation after tool change
« on: October 02, 2007, 08:11:07 AM »
If you look at the videos, there is one about writing Macros - particularly for a tool change, using M6.

You can write your own macro to move the tool where you like and stop and start etc.

It may be that your macro is a bit fouled up.

1079
General Mach Discussion / Re: where do I start??
« on: October 02, 2007, 08:00:46 AM »
I don't think  you are missing or gaining steps. You seem to have done just about every check in the book, and got everything sorted. Dont worry about the number of steps per inch -  35 in 20,000 is a tiny percentage. I am not sure whether you are talking about a lathe or miller, when you talk about the diameter being 1/10th inch out.

I think your problem, with respect, is that you are just not getting zeroed properly at the start.
With a lathe, I take a facing cut, and zero the Z axis. I then move the tool along the work a little and jog the tool until the tip just touches the work. I then measure the diameter and set the X axis to half of that ( I am in radius mode).

With the miller, touching the work in both axis is fine, but you must then set the axis to the diameter of the tool, not to zero, then bring the tip down and touch the top of the work to set z (usually to 0). If you are using a 1/4 inch cutter this could account for the problem.

Make sure on your tool table that any reference to diameters and lengths are erased and none of the check boxes are checked for tool offsets.

I cannot see that your computer can be at fault, because if everything is OK while the thing is running around, then it is not going to change just because you are cutting something - how does the computer know ???

If you are doing what I have said, then I apologise - and have no idea where the fault lies.

1080
General Mach Discussion / Re: what pc to buy to run mach
« on: September 30, 2007, 05:01:55 AM »
And that is the trouble. Your first problem will be finding one with a printer port - which now seem to have gone in favour of USB. The other is the voltage, and somebody on this forum told me that some of the operating systems "cheat" on the display which sends the timings off.

I was lucky -  I use a Toshiba - about 5 years old, which my daughter bought from PCWorld ( I paid the first months rent on her flat for it) .

It has a LPT1 port and checking the voltages with a volt meter, they are in the 5 volt bracket. It seems very stable and runs Mach3 perfectly.

I think I would go for an older one of better quality, rather than a more modern one.