Messages

901

General Mach Discussion / Re: How do match dimensions from Mach to Mill??

« on: April 14, 2009, 09:31:14 AM »

Hood he said 'VistaCNC pendant' as in http://www.vistacnc.com/, NOT Windows Vista.

I have not used the pendant mentioned but have/do use Mach with Vista (and a SmoothStepper) no problems.

902

General Mach Discussion / Re: Moved Mach3 to newer computer, add on parallel card, no go? Need hlep.

« on: April 13, 2009, 03:48:47 PM »

Since computers no longer put parallel ports on computers as a rule I am wondering if I should just go this route? One of the things about my router table is 100ipm is the best I can do and feel good I'll have no issues, loosing steps and so on, would the Smooth Stepper help me gain a little in this area?

Well, personally I think the SmoothStepper is great as it lets the PC do what it is great at (crunching numbers and giving us a nice display) and lets the motion control board so what it is great at (providing a smooth pulse stream). I first bought one last summer for a custom machine that was VERY time critical and I did not want to risk being bogged down with parallel port issues. I had the SS running things in about 15 minutes. (I liked them so much I sell them now.) If you are at the mechanical limits of your drivers/motors and so on then the SmoothStepper won't make it go faster. Some folks have found ,( http://www.machsupport.com/forum/index.php/topic,11108.0.html ), that it has allowed them to tune the machine better as the pulse stream is smoother.

I think the real test is how much time it will take to get a parallel port working on a particular PC, some just work, some are a bear to get going and some just won't work with Mach. The only issue like this with the SmoothStepper I am aware of is with some older USB 1.1 ports. I have an older HP that the built in ports have always been flaky so I just put in a USB/Firewire PCI card.

One thing you will want when using a SmoothStepper is good optical isolation between the SmoothStepper and your I/O and stepper drivers. Any noise in the system that would cause an intermittent 'wired' issue on a parallel port driven machine will likely be very apparent with a USB motion controller. The noise is there either way but the USB will really let you know. I have always recommended optical isolation either way. Drivers like the new G540 even have it built in.

903

General Mach Discussion / Re: Problem with stepper motors (have looked through archives)

« on: April 13, 2009, 11:33:08 AM »

The speed you can drive a stepper motor at is directly proportional to applied voltage. With very slow step rates you can use a lower voltage. As you try to increase in speed the motors inductance prevents quick build up in current needed. The way to over come this is to use a higher driving voltage and then limit the current delivered to the motor once the desired phase current is obtained. This can be done with big resistors which is very inefficient or by current modulation (which is how most newer drives work.)

904

General Mach Discussion / Re: Moved Mach3 to newer computer, add on parallel card, no go? Need hlep.

« on: April 13, 2009, 09:35:58 AM »

Sometimes the chipsets used will have a LPT functionality built in even if they don't bring the pins out to the board. You might also check the documentation on the motherboard to see if they brought the LPT out to a header on the board. I've seen some boards do that with serial ports and PC maker does not advertise the extra onboard ports. Some parallel ports just don't work as well. If you get to the point where Mach will talk with your parallel port here is a good post for more troubleshooting tips: http://www.machsupport.com/forum/index.php/topic,11108.0.html.

905

General Mach Discussion / Re: Problem with stepper motors (have looked through archives)

« on: April 12, 2009, 04:24:43 PM »

I would start from the beginning and check everything.

1) Have ran the driver test? If so what does it look like? If it looks bad have you done the optimization?
2) Double check that you have the correct parallel port selected.
3) Measure the output voltage of the parallel port. Is it 5V? Some breakout boards will not work with newer 3.3V ports.
4) If you have access to an OScope check the pulse stream on each step pin on the parallel port. Some PCs will look OK on the driver test but the parallel port electronics can drive fast enough.

I don't believe that you have mentioned what steppers you are using. Do you have the full specs on them? A 12V supply is pretty low for steppers and will greatly reduce your performance and may not allow the stepper to develop full torque. If you can respond with the stepper specifications someone may be able to offer more advice.

906

SmoothStepper USB / Re: Help ! From Incremental Jog to a runaway !

« on: April 11, 2009, 02:25:37 PM »

Glad it is working out for you!

907

General Mach Discussion / Re: 0-10 volt output for vfd

« on: April 11, 2009, 02:23:54 PM »

You might try an add on PCI->USB card. They are pretty inexpensive...

I just saw you said you were using a SS. I seem to recall that some folks are having an issue with the SS and S/D or PWW spindle control. I would also take a look at the power supply like Peter suggested.

908

General Mach Discussion / Re: 0-10 volt output for vfd

« on: April 11, 2009, 10:10:52 AM »

You could also be seeing some issues with phase jitter from the pulse stream being generated by Mach. Some PCs will do better than others. You didn't say if you were using a Step/Direction signal to drive the VFD or PWM. If you have an O-scope you can take a look at the pulse stream from your LPT. If you don't have an O-Scope listen for small popping sounds as an axis accelerated. In my experience these are caused by phase jitter. If your LPT cable is really long it could cause problems like this too.

You could also have an issue with electrical noise. This could come from how cables are run etc.

909

SmoothStepper USB / Re: SmoothStepper Rocks!

« on: April 09, 2009, 06:20:45 PM »

Whoo Hooo! Glad it is working for you. It is amazing how much the smooth pulse train helps things out...

910

SmoothStepper USB / Re: Help ! From Incremental Jog to a runaway !

« on: April 09, 2009, 05:30:19 PM »

You'll have to remove the shuttle plug-in from the plug-ins folder.