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Author Topic: Homing switches - optical?  (Read 1214 times)

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Offline Rimmel

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Homing switches - optical?
« on: April 11, 2018, 07:52:22 AM »
I have been using Mach3 a while now and realised that the mechanical homing switches are terrible. I would liike to swap them to a more accurate version, I hear optical is a good option, although they do require and extra wire and perhaps a little circuit?

Has anyone got any insight on this? Does anyone make Opto units complete and ready to go?

thanks
Rim

Offline Davek0974

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Re: Homing switches - optical?
« Reply #1 on: April 11, 2018, 09:22:21 AM »
I would go for inductive proximity sensors myself, pretty accurate if setup right and not so prone to dust/swarf etc as optical
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives.
Plasma table, Mach3 V062, Step motors, C&CNC THC.
Re: Homing switches - optical?
« Reply #2 on: April 11, 2018, 09:34:44 AM »
Hi,
I use roller plunger microswitches for homing and get repeat accuracy of 0.02mm.

http://nz.element14.com/honeywell/bzc-2rq18-a2/switch-basic-top-roller-plunger/dp/1525198

What kind of mechanical switches are you using?

Craig
My wife left with my best friend...
     and I miss him!

Offline Rimmel

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Re: Homing switches - optical?
« Reply #3 on: April 11, 2018, 09:43:31 AM »
Hi,
I use roller plunger microswitches for homing and get repeat accuracy of 0.02mm.

http://nz.element14.com/honeywell/bzc-2rq18-a2/switch-basic-top-roller-plunger/dp/1525198

What kind of mechanical switches are you using?

Craig

I am using roller plunger switches - tried loads and not getting that sort of accuracy.

Rim

Offline Rimmel

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Re: Homing switches - optical?
« Reply #4 on: April 11, 2018, 09:44:14 AM »
I would go for inductive proximity sensors myself, pretty accurate if setup right and not so prone to dust/swarf etc as optical

Sounds good - got a link to any?

thanks

Offline Davek0974

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Re: Homing switches - optical?
« Reply #5 on: April 11, 2018, 09:47:21 AM »
Plenty options - very common

https://www.ebay.co.uk/itm/New-LJ12A3-4-Z-BX-Inductive-Proximity-Sensor-Detection-Switch-NPN-DC6-36V-4mm/122206045078?hash=item1c740c4396:g:hJkAAOSwdzVXuulS

for example.

need to choose NPN, PNP etc as needed.

Is this on a stepper drive machine?
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives.
Plasma table, Mach3 V062, Step motors, C&CNC THC.
Re: Homing switches - optical?
« Reply #6 on: April 11, 2018, 10:44:34 AM »
Not sure where you are located but Automation Direct (USA) sells High Precision Touch and Tool Setter limit switches.  They claim 0.5 micron (┬Ám) repeat accuracy, no movement differential, no temperature drift, and dustproof / water-resistant (IP67).  Not cheap though, $116 USD.  Hope this is helpful.
Tom

Offline Rimmel

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Re: Homing switches - optical?
« Reply #7 on: April 11, 2018, 11:02:03 AM »
Plenty options - very common

https://www.ebay.co.uk/itm/New-LJ12A3-4-Z-BX-Inductive-Proximity-Sensor-Detection-Switch-NPN-DC6-36V-4mm/122206045078?hash=item1c740c4396:g:hJkAAOSwdzVXuulS

for example.

need to choose NPN, PNP etc as needed.

Is this on a stepper drive machine?

The problem being that most mach 3 BoB's are 5v for the limit switches and all the proximity switches start at 6v.

It is a stepper at present.

thanks

Offline Rimmel

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Re: Homing switches - optical?
« Reply #8 on: April 20, 2018, 07:38:09 AM »
For anyone interested I found the same Inductive Prioximity switches in 5v avaiable here: https://www.ebay.co.uk/itm/M12-LJ12A3-4-Z-BX-5V-DC-5V-NPN-NO-300mA-Inductive-Proximity-Sensor-Switch-4mm/352165249518?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Ebay number 352165249518 if the link does not work: Just past number into ebay search box and press enter.

Ordered from China on 13th April and arrived on the 19th April (I am in the UK - land of the liberal idiot) - they work brilliantly and no faffing about with resistors and/or extra power supplies.

Result!
Rim

Offline Davek0974

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Re: Homing switches - optical?
« Reply #9 on: April 20, 2018, 07:54:38 AM »
Nice :)
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives.
Plasma table, Mach3 V062, Step motors, C&CNC THC.