Messages

1101

General Mach Discussion / Re: Mach3 Jog overide

« on: September 16, 2007, 05:43:32 AM »

Dont press the shift key !!

1102

General Mach Discussion / Re: Problem setting up an xy table onto a Lathe

« on: September 16, 2007, 05:41:03 AM »

Ron - Thanks for that, I didn't think the answer could be catered for so simply (although I have my lathe in XZ) - but I shall bear it in mind for the future if I have problems.

I do agree that Dikkieduk would be better to get it mechanically in line, rather than correct it by software.

I also profile a lot of railway wheels - but in 7 1/4 inch gauge - so I am certainly not in the same league.

Is this by way of business or a hobby/preservation thing.

Jim Pinder

1103

General Mach Discussion / Re: Problem setting up an xy table onto a Lathe

« on: September 15, 2007, 03:24:24 PM »

Are you saying that the bed of your lathe is out of line with the spindle.

If not, I take it that the table is an independent piece of machinery that sits on the original lathe bed, but it is out of square and you cannot correct it. Does this provide vertical movement so you can use your spindle to mill pieces with ??

Either way, I think it would be very difficult for Mach Turn to provide an instant solution "on the move" so to speak. The offset to be provided would depend on the distance travelled, but then if you are applying this on an out of square axis, then another allowance would be needed. If you were turning on an out of square axis, then for every 1 inch of movement on the axis you would get the cosine of the angle movement in the tool.

The only thing I can think of in a simple way is to increase the number of pulses per inch on the stepper motor drivers to compensate for the shortfall. The only problem with this is, you could correct one axis this way, but the tool would also move marginally on the other axis and I cannot think of a way to rectifiy that.

The real alternative that I have just thought of is to write a VB script to put in the compensation automaticall to compensate and this would be relatively easy for say code g0 and g1, but how complicated they would be for g2 and g3 for example, I shudder to think.

1104

General Mach Discussion / Re: Please help me

« on: September 13, 2007, 06:29:52 AM »

It seems to me that you have a computer that uses 3.5v as plus.

Your problem might be that your driver cards cannot tell the difference between 0v (in your case 0.42v) and +v. In my case the outputs are 5v which my card can recognise.

You probably need an interface between the computer and the driver cards. I don't use one, but there are many "break out boards" on the market, usually with their own power supply, which, I would imagine will get over this problem.

You could, if you know what you are doing, put a pull up resistor between a positive supply and the input at your card. If you isolate this with a diode, then the resistor pulls the voltage up, and the 0.42v signal pulls the input down. You must be careful that the resistor is not too low a value as to overload the drivers of your LPT1 port.

You are, in effect building your own break out board, but I imagine this will be cheaper than buying one.

1105

General Mach Discussion / Re: will a video card help?

« on: September 11, 2007, 10:07:28 AM »

Try turning off the onboard video in Task Manager, and see if Mach 3 manages any better then. It will give you some idea.

With 3 Ghz of memory (which is what I assume you are saying) then 10 Mbyte should be no problem. If it is a complex file, it may be just that Mach3 was spending too much time worrying about the job instead of just getting on with it.

1106

General Mach Discussion / Re: Trouble with setup

« on: September 10, 2007, 09:37:05 AM »

In the wiring diagram "KL4030 driver" you are showing pins 2 and 3 wired down to your driver card from the breakout board. You do not have a connection for the signal ground connection (the pin between pins 2 and 3). This ground pin is from the computer and connects it to the rest of your circuit, so should be connected somewhere.

One my cards (Stepmaster) there is a signal ground connection to do this, on the driver card.

1107

General Mach Discussion / Re: Please help me

« on: September 10, 2007, 09:13:53 AM »

I take it you are using a lead from the printer port. I used an old printer cable which I then cut in two. I identified all the pins with each wire and soldered the 25 wires in order 1 - 25 onto a small piece of copper clad strip board.

If you look in Config/Ports and Pins/Motor Output, you can then specify which pins you want the signal to come out of. These are usually 2 and 3, 4 and 5, 6 and 7 for the first three motors. Do not forget to specify Port 1 in the ports column.

You can test if there is any signal on the pins by connecting a TTL/Cmos logic probe to each pin and trying to jog ( without any cards or anything connected). Pins 2,3,4,5,6,7,8, and 9 are the eight outputs used in the stepper motor page. Pins 10,11,12,13 and 15 are inputs. Pins 1,14,16 and 17 are the other four outputs. Pins 18 to 25 are signal ground - and you will need to connect at least one of these to be able to read the port.

You should get a "pulse" reading on the logic probe if a signal is being output.

You can test your cards simply by tapping a positive or negative wire on the "step" input - the motor attached to the driver should react even if it is only a small movement.

If you are getting some signal out on your printer wire, and your cards are giving some signal to the motor, connect up the wired as you have specified in "ports and pins" and it should work.

1108

General Mach Discussion / Re: Mach not completing moves ?

« on: September 07, 2007, 06:16:50 AM »

Read the post on Constant Velocity.

I don't have this problem because my speeds are only 4 inches per minute, and it makes no difference whether I am in constant velocity mode or not - my steppers can accelerate or decelerate almost instantaneously.
If you are in constant velocity mode, at the speeds you are trying to move, the machine will start one move before the last has completed so that it is up to speed for the next move. - hence the rounded corners.

1109

General Mach Discussion / Re: were can i find more I/O pins

« on: September 07, 2007, 05:39:36 AM »

I thought someone was in the stages of developing an input output board specifically for Mach 3. We were asked what features - specifically the number of input and output pins we would like.

Can't be too far down the posts. it was only a couple of weeks ago (or so).

1110

General Mach Discussion / Re: Basic Question

« on: September 05, 2007, 09:07:46 AM »

I have the same problem - having set the lathe up in inches (all the dials are calibrated in inches anyway)

You can just insert g21 before the section you require in metric (mm). This operates the machine in metric dimensions, but seems to use all the offsets etc that you have set up, in inches.

At the end of the section g20 reverts everything back to inches.

The toolpath seems a bit odd - because it just stays the same size. The DRO's revert to mm for metric, but revert to inches when you go back.

Seems to work alright.