Messages

631

General Mach Discussion / Joy Stick

« on: October 26, 2014, 04:25:52 AM »

http://www.machsupport.com/forum/index.php/topic,12753.0.html


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632

General Mach Discussion / Joy Stick

« on: October 24, 2014, 03:32:02 PM »

There is a plugin that supports a Microsoft game handset which I have.  Gives you two joysticks and sundry other buttons, and wireless.  Works well for me.  Latest version even has vibration feedback!


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633

General Mach Discussion / Feedrate on multi-segment curves

« on: September 22, 2014, 05:46:16 PM »

The cutter accelerates and decelerates for each segment.  The shorter the segment the less time it has to speed up.  You could generate the curve to keep the feed rate constant perhaps?


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634

VB and the development of wizards / Re: Tool zeroing macro help

« on: September 22, 2014, 03:36:20 PM »

Kenneth,  thanks for this - the first time someone has picked up my code and modified it further!  I hope it works for you. 

John.

635

General Mach Discussion / Steps/Inch on Lathe = 75,000; Seems a Tad High

« on: August 31, 2014, 03:00:04 AM »

Well, with microstepping the driver modulates the current to the stepper so as to divide each step into "n".  This means that the motor, from Mach's p.o.v., has 200n steps.  If your z axis was set to 4 micro steps per step, that would account exactly for what you see assuming that the steps per inch should be 6400.  Similarly, if n is set to 16 on the axis.  Try putting the numbers 6400/inch and 80000/inch into Mach and see if that gives the right calibration.  This assumes that the available numbers with the drive are 2, 4, 8, 16 etc which is normal.

Microstepping can give a small improvement in resolution at the expense of accuracy, but is mainly for smoother operation.  Setting it to 16 is a bit high I would have thought, 4 or 8 on each axis is about right.

Hope this helps.

636

General Mach Discussion / Steps/Inch on Lathe = 75,000; Seems a Tad High

« on: August 30, 2014, 06:00:57 PM »

Are your drivers micro stepping types?  If so what are they set to?

637

General Mach Discussion / Notify me when done?

« on: August 23, 2014, 04:35:04 AM »

You could clamp a mobile phone on the table set on SMS with a message to you ready to go, then get the mill to stop its spindle, move over to the send button, and gently press it?

;>))

638

General Mach Discussion / Mill Wizards

« on: August 22, 2014, 05:53:52 PM »

Try Gsimple...

639

General Mach Discussion / Help Please with PWM Spindle Motor Speed

« on: August 22, 2014, 05:49:40 PM »

How are you converting the PWM output to control your motor?  I assume you don't have a spindle speed sensor so the system is open loop. There needs to be a calibration adjustment in hardware between the PWM smoothing and the speed controller.  PWM base frequency is not directly related to spindle speed, it's just the frequency of the pulses whose pulse width is controlled to indicate the desired speed.  Normally you smooth those pulses to generate a voltage, which is scaled for calibration purposes, then applied to the speed controller.

640

General Mach Discussion / Steel Selection

« on: August 12, 2014, 04:52:09 PM »

A simple test is to take a file or hacksaw to it.  If it files reasonably easily and generates filings it's probably machinable too.  If you are going to buy some steel to practice on, I'd suggest (in the UK) some free machining mild steel, or just some CRS.  You can get a cheap/free app for an iPad or iPhone called FSWizard Lite that will give you feeds and speeds for a given material, cutter etc.