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Author Topic: A-axis rotary lathe question for Mach 3  (Read 7791 times)

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Re: A-axis rotary lathe question for Mach 3
« Reply #80 on: November 21, 2017, 06:34:10 PM »
Ok, thanks...
Re: A-axis rotary lathe question for Mach 3
« Reply #81 on: November 23, 2017, 08:57:46 PM »
Rich,  I think I need to address the following as you suggested:

"- Looks like your rotary is just driven by timing belt so no gears etc and thus basklash should not be concern.

- Would suggest that you add an index so Mach can display the rpm of the rotary. "

Beginner question--what kind of "index" should I buy,  or is it something I should buy... is it a mechanical piece or instrument... since I get stuff off of ebay, what should I avoid... bob


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Re: A-axis rotary lathe question for Mach 3
« Reply #82 on: November 23, 2017, 11:32:01 PM »
Bob,
Will provide some info on the index.

Later,
RICH

 

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Re: A-axis rotary lathe question for Mach 3
« Reply #83 on: November 23, 2017, 11:34:56 PM »
Do you use or have Microsoft Excel?

RICH
Re: A-axis rotary lathe question for Mach 3
« Reply #84 on: November 24, 2017, 12:36:40 AM »
Rich yes, I have Excel
Re: A-axis rotary lathe question for Mach 3
« Reply #85 on: November 24, 2017, 12:37:14 AM »
 oh and thanks for responding on thanksgiving...wasn't expecting that...bob

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Re: A-axis rotary lathe question for Mach 3
« Reply #86 on: November 24, 2017, 08:21:19 AM »
You will find spindel index info in Using Mach3 Turn Manual ( 4.8 page 4-12).
Should also be something in the Mill Manual.

A  CD painted black with ONLY  one ( 1) slot in the disc along with an Optek OPB917B  ( slotted optical switch ), which
needs  a 5v source and 220 Ohm resisotor, will provide everything you need to get a signal to make Mach
so it can read the true RPM.

CNC4pc sells a index pulse board.

The are other optical switches one can use.

I use a Hall Effect  sensor  which generates a pulse each time a magnet ( very small, only one (1) required ) is sensed
by the switch. Easy to mount, especialy in tight places, but is more expensive than the optical switch.

Link to how it works:
https://en.wikipedia.org/wiki/Hall_effect_sensor

You will need to configure the Index in Port & pins.

RICH

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Re: A-axis rotary lathe question for Mach 3
« Reply #87 on: November 25, 2017, 08:21:23 AM »
Lesson 8 attached.

To be continued,

RICH
Re: A-axis rotary lathe question for Mach 3
« Reply #88 on: November 25, 2017, 11:58:02 AM »
I ordered the index pulse card and optical switch.  I will go to the electronics store today for the resistor and hall effect sensors.

Can you give me a short drawing of how the cd and all of this would look in how its attached to the lathe??

I downloaded lesson 8.  Thank you.   bob

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Re: A-axis rotary lathe question for Mach 3
« Reply #89 on: November 25, 2017, 02:41:41 PM »
You will find a pic of a index plate mounted on a shaft along with a slotted type optical switch in the
Using Mach3 Turn Manual on page 4.8. Download the manual as sooner or later you will be reading it.
note that there should only be one (1) slot in the disc. The slot width can be larger than what  4.8
describes.

-------------------------------------------------
Pic of a Hall sensor installed in this link:

CNC CONVERSION - 6" ATLAS LATHE
http://www.machsupport.com/forum/index.php/topic,12484.msg82818.html#msg82818
HCIR#28_1.jpg

Shows  a Hall sensor instead of a slotted disc. Components amount to a rare earth magnet which is was super glued to a gear inside the spindle housing.
The sensor ( SMC D-F7NC ) was mounted onto a steel strip and attached to the casing. The sensor actually has two sensors in it and only one was used. The sensor also has an indicating light to show when it is triggering making for easy alignment and visual confirmation other than using the diagnostics. The sensor components and mounting are shown in HCIR#28_1.jpg .

RICH
« Last Edit: November 25, 2017, 02:53:25 PM by RICH »