[Potatohead908]

I need to buy limit and home switches for my G0704 mill and soon to have G0602 lathe. Are these a good choice? There is 1 NC and 1 NO circuit per unit. There is another on the same site that has 2 NC and 2 NO circuits. These are bigger than I want but trying to move forward without braking the bank!

10 Pcs Adjustale Roller Lever Actuator Limit Switch ME-8108 for CNC Mill Plasma


I bought these thinking they will work but now am in doubt.

Micro Limit switch | Automation Technology Inc

Also I'm thinking it is not best to make some of your limit switches home switches....correct?

[SCzEngrgGroup]

I bought some of those switches, and they are garbage. They are poorly sealed, and have terrible repeatability. They're also quite large.

Regards,
Ray L.

[dracozny]

I have seen a few users build similar switches to these there were some nice anodized ones over on Ebay offered by a Zone user at one point.

[phomann]

Hi,

These Omron switches I sell are sealed, of excellent quality and may suit your needs.

Omron Sealed Mechanical limit/home switch [SW-11]

cheers,

Peter

[Wiggles84]

I'm using These from automation direct.

They are a little big yet, but not as big as the ones you linked to!

No word on how they repeat as I'm still doing my conversion and my electronics are no longer on the test board I was using . Should only need one per axis to act as home and limits.

X



Y



Z



Andrew

[hoss2006]

Also I'm thinking it is not best to make some of your limit switches home switches....correct?

Don't know why you would think that, for years I've used one switch on the x and y axis that work as both a home switch and limits for each end of travel.
Works great.
Makes for a very efficient economical setup and only needs one input on the BOB for the whole shebang.
Home and Limits
Optical Home Switch
Hoss

[library]

I have been pretty happy with these proximity switches from ebay (SN04-P2 DC 3-Wire PNP NC 5mm Detecting Distance Proximity Switch 10-30V) They take 10-30vdc and hook up great to my Mesa 7i76 in LinuxCNC. I've detailed the setup here LinuxCNC G0704 conversion: Limit Switches

I set each switch to it's own input because I have 32 inputs. I use the min limit switch as the home switch on all the axes. It works great.

[LeeWay]

I use the first type on my plasma cutter and they are great in that application. I would not consider putting them on a mill or lathe though. You can tell they aren't water proof and while the accuracy is fine for a plasma table, probably not good enough on a mill.
Some other great recommendations here though.

[vertcnc]

I still have some of these available. Send me a PM if interested. I have them installed on my RF45 and seem to work just fine.

[Potatohead908]

I have been pretty happy with these proximity switches from ebay (SN04-P2 DC 3-Wire PNP NC 5mm Detecting Distance Proximity Switch 10-30V) They take 10-30vdc and hook up great to my Mesa 7i76 in LinuxCNC. I've detailed the setup here LinuxCNC G0704 conversion: Limit Switches

I set each switch to it's own input because I have 32 inputs. I use the min limit switch as the home switch on all the axes. It works great.

Will the PNP work on a C10 or C11 BOB? Also I only have 5 volt off the BOB. Not sure what the PNP means. I looked at your BLOG and it was very informative! Thank you!

[Potatohead908]

vertcnc....those limit switches are nice looking!!

[Potatohead908]

Hi,

These Omron switches I sell are sealed, of excellent quality and may suit your needs.

Omron Sealed Mechanical limit/home switch [SW-11]

cheers,

Peter

Peter, I will be looking into this item!

Power Supply Multiplier with Back EMF Clamp for Double Supply [21C4P7A] - US$45.90 : Homann Designs!, The preferred CNC Component Supplier

[library]

Will the PNP work on a C10 or C11 BOB? Also I only have 5 volt off the BOB. Not sure what the PNP means. I looked at your BLOG and it was very informative! Thank you!

PNP or NPN are the collector types of the transistors that make up the switch. One is current sourcing, the other is sinking. You can read about it on google. I checked the manual for the C10 BOB and it supports either NPN or PNP. You would need to supply 12-24v power and use a couple resistors.

The main benefit to higher voltages on your limit switches is better noise rejection. Running limit switches at 5v can be dicey unless you are very careful to use shielded wire and terminate the shields properly. All commercial machines use 24v for this reason.

[Potatohead908]

PNP or NPN are the collector types of the transistors that make up the switch. One is current sourcing, the other is sinking. You can read about it on google. I checked the manual for the C10 BOB and it supports either NPN or PNP. You would need to supply 12-24v power and use a couple resistors.

The main benefit to higher voltages on your limit switches is better noise rejection. Running limit switches at 5v can be dicey unless you are very careful to use shielded wire and terminate the shields properly. All commercial machines use 24v for this reason.

So if I understand your blog correctly and what you are saying here....I connect these via the BOB, resistors, proximity switch(s), 12-24v power supply positive, 12-24v negative back to the BOB?

[library]

So if I understand your blog correctly and what you are saying here....I connect these via the BOB, resistors, proximity switch(s), 12-24v power supply positive, 12-24v negative back to the BOB?

Looking at the wiring diagram here starting on page 14 (http://cnc4pc.com/Tech_Docs/C10R10_USER_MANUAL_V2.pdf) You connect the signal wire to the BOB with a 10k resistor (if using 12v). The switches have 3 wires, 12v+, 12v-, signal. The +/- get hooked up to the power supply and the signal is connected to the BOB. There's also a section that describes how to hookup NPN switches if you prefer those.

I used 12v power because I had a power supply for it and 12v led switches are a lot easier to find than 24v led switches.

[Potatohead908]

Thanks Library! Yet another wealth of knowledge willing to help a fellow Zoner!

[vertcnc]

Just be careful of the mounting location of the proximity type switches. Metal chips will trip them. That's why i enclosed them.

[phomann]

Peter, I will be looking into this item!

Power Supply Multiplier with Back EMF Clamp for Double Supply [21C4P7A] - US$45.90 : Homann Designs!, The preferred CNC Component Supplier

I sell quite a few of these along with a pair of 24V 14.6A supplies. You end up with a 48V 14.6A supply which covers off a supply for systems using the larger motors (570 oz.in - 1200oz.in)

It usually ends up cheaper than buying a very large supply or an individual supply per driver.

Cheers,

Peter

[Potatohead908]

That makes sense. I will definitely keep that in mind. I can see making them like yours.....only not as purdy as I don't have your talent!

[Potatohead908]

I sell quite a few of these along with a pair of 24V 14.6A supplies. You end up with a 48V 14.6A supply which covers off a supply for systems using the larger motors (570 oz.in - 1200oz.in)

It usually ends up cheaper than buying a very large supply or an individual supply per driver.

Cheers,

Peter

So after reading more about those it doesn't work like I was thinking. I'm trying to think how I can get more voltage just for one driver/motor combo for my Z-axis. Right now it's not an issue as I am moving everything at a slow pace and still learning. However I wasted money in the long run if I can't push more voltage and get a new driver for my 906oz Z axis stepper.