Messages

7021

General Mach Discussion / Re: Power Supply +Se amd -Se sigal

« on: January 24, 2011, 12:12:22 PM »

Tweakie,

Thanks for your explanation.  I would assume then this is only useful if a voltage drop is anticipated. If not then one could just jump the +5V with the +Se and the -5V with the -Se terminals.  If this is incorrect please let me know about it.

Jorge

That's exactly what I would do.

Tweakie.

7022

General Mach Discussion / Re: Stepper driver chips

« on: January 24, 2011, 12:10:12 PM »

Hi Tony,

Although they both perform a similar function they are not interchangeable. The 3717 is essentially a single phase device and you would need two chips to drive one bipolar motor. Although they are OK for printers and scanners etc neither are really suitable for CNC use because the drive current is just not sufficient. (Most bipolar stepper motors require a minimum 24 Volts at 2 Amps to provide sufficient torque to drive a CNC). There are better Stepper Motor chips available – take a look at the Alegro range for starters.  http://www.allegromicro.com/en/Products/Categories/ICs/motor.asp

Tweakie.

7023

General Mach Discussion / Re: Power Supply +Se amd -Se sigal

« on: January 24, 2011, 11:43:56 AM »

Jorge,

It is usual on the quality, adjustable, bench power supplies to have Sense (Se) terminals which are link connected to the main terminals to complete the feedback loop for output regulation.

Tweakie.

7024

General Mach Discussion / Re: spindle speed control

« on: January 24, 2011, 06:19:10 AM »

Thanks Larry, I would dearly like to understand quilting machines and their setups. (although I read up as much as I can I think I will probably have to obtain / build a quilting machine before I finally get a grip).

Tweakie.

7025

General Mach Discussion / Re: spindle speed control

« on: January 23, 2011, 12:27:40 PM »

I have read this 10 times Larry and I still don't understand exactly what you are trying to achieve. 

Just as an example machines such as 3D printers often drive the material feed drums but because the material requirement or motion is not constant they use a micro switch or other sensor to check the position of a loop in the material then, when necessary, operate the drum drive a fixed amount then return to standby for the sensor to provide the next signal.
This idea could be made to drive both ways, is this of any use ?

Tweakie.

7026

General Mach Discussion / Re: Enlargement problem

« on: January 23, 2011, 04:55:17 AM »

Lou,

There are a few good tips for correctly setting up the 'steps per' in the 'members docs' area in particular you can download this calculator written by Al Lenz from here http://www.machsupport.com/forum/index.php/topic,16315.0.html.

Hope this helps,

Tweakie.

7027

Show"N"Tell ( Your Machines) / Re: 3rd try is the charm Mach3 Controllable PWM Spindle Motor Controller

« on: January 23, 2011, 04:45:38 AM »

Excellent post Zero Cool, very detailed and informative - don't know how I missed this post before.

If you haven't already seen it, this thread gives some details of pulse feedback which may be of interest to you. http://www.machsupport.com/forum/index.php/topic,995.10.html

Tweakie.

7028

General Mach Discussion / Re: s curve control board

« on: January 23, 2011, 03:39:18 AM »

A lot of work was done on the acceleration curve and slope in the excellent Tempest Trajectory planner which now appears to be an abandoned project. Shame really because it was much faster at 2.5D work and allowed higher accelerations without stall on my router.

From reading other threads I think Bill_O is on to this already.

Tweakie.

7029

General Mach Discussion / Re: cnc screwcutting???

« on: January 22, 2011, 07:16:59 AM »

Dale,

Try setting the 'pull up / pull down' jumper for pin 10 (input configuration) to the opposite of what it currently is.

Tweakie.

7030

Sieg Machines / Re: Help with controlling coolant pump on KX3 w/ Mach 3

« on: January 21, 2011, 01:09:10 PM »

Hi Don,

I think you are absolutely correct on all counts.

Output#1 when selected in the Spindle Setup - Flood Mist Control allows Output#1 in Output Signals to be mapped to the Port and Pin that is subsequently connected to the Flood (M8/M9) relay. If you are switching the lamp on/off then you already have this all configured correctly.

The glitch at machine switch on is bit of a problem area. I assume you have Mach up and running before you switch your machine on ? (this is the way it is supposed to be done) This being the case then even a charge pump circuit will not help as the problem is within the machine control and not Mach. I get a similar glitch with the pump for my vacuum table but this is harmless compared with an unwanted burst of coolant. I certainly don't know of an easy way to solve this perhaps there is someone else who has a suggestion.

Tweakie.