What Limit Switches?

[m_c]

Great but 5v and not shielded = Problems

That's actually a bit of a generalisation, as it depends on exactly how you're powering things. I keep meaning to do a post on the why and how the problem can be mitigated to a certain extent.

Regardless, IMO limit switches should always be fail safe I.e. NC, as you want to minimise the risk of a wiring fault causing the switch detection to fail.
Plus, magnetic switches on something that could potentially be machining steel?

[cropwell]

Great but 5v and not shielded = Problems

biggest problem for me is the delivery charge !

[Neale]

I see Hall effect switches mentioned more in US sites than UK. I'm not sure why you would use these rather than the Chinese-sourced proximity switches, unless you are in an environment where there is a lot of metal around and powerful magnet operation is desirable to avoid false triggering. For example, the proximity switches run natively on 24V. Is it really that there is a strong "not from China" feeling in the US rather than any pure technical reason? Just curious - I've a box of proximity switches in the workshop that I am using, so I've already made my design decision

[JAZZCNC]

No Brainer to me Chaz.? . . . .The IP-A gives abilty to Home To Index so use it because will be superior to most SW and very repeatable.
Also means don't need expensive switches for there repeatabilty/reliabilty. Any decent Mechanical SW will work because all you doing is triggering the point Servo searches for the Index pulse.

[Chaz]

No Brainer to me Chaz.? . . . .The IP-A gives abilty to Home To Index so use it because will be superior to most SW and very repeatable.
Also means don't need expensive switches for there repeatabilty/reliabilty. Any decent Mechanical SW will work because all you doing is triggering the point Servo searches for the Index pulse.

Thanks. Ill do some testing on the weekend. Ive not used the Index feature before, so will give it a shot.

[hanermo2]

I am not (yet) homing on servo index w. CSMIO-IP-S-lathe, but ..
based on everything, I expect it to work as well as everything else so far, with some (major) issues sometimes.

I use 1:3 belt drive on the servo spindle.
The CSMIO-IP-S, mach3, lathe, driver cannot understand a transmission, thus will home to next 1:3 limit switch from the encoder.
With "position on spindle" or something similar.
Nothing wrong with it, just makes it impossible to get C axis.

For the time being, fttb,
any overrun is dangerous, potentially really fast (0.05-0.5 secs to crash), so..
For now, I use switches similar to the pics at start of thread.

They look good, are import, and are chinese copies badly made of a somewhat-decent industrial switch from omron (siemens, et al).
My current mechanical switches are not accurate, and don´t repeat well.
Afaik, afai can see, they cannot really fail to "break" on limits, thus they are ok as low-cost limit switches that look good.

My ongoing path will be;..
maintain the mechanical switches, always.
Independent.
They wont catch any crashes, these will come from the servo signals/overload, but usually, I think, with already (some) damage done.
Idea is hw limits prevent system over-run in sw /programming errors.
Both exist.
Imo. Ime.
With Csmio.
With M3.

In very, very, very rare cases it is possible for the cp to move "wrong" - seemingly forever at lowish rate (might be feed, limited feed, just don´t know).
I don´t know why.

Tracking error / load vs commanded path;
Medium-term (3-30 months), I even hope to catch this potential crash-error problem with a tracker system from the servo hw signal in-pos or near-pos.
This means, when running a repeated program, if the load exceeds a given level, or any servo drive has too much (little) load at that point, the program stops.
This would mean perfect "lights-out" running with near zero risk.


Home:
Index from z/ ie encoder, or separate opticals.
Separate opticals are cheap, easy, very very accurate.
Hw optical switches can do 0-1-2 microns, for 20$ or so, plus bits.
But encoder opticals can do 0.4 um, for 0$, and much better reliability.

[A_Camera]

Would you consider using Hall Effect sensors? No moving parts extremely accurate and will outlast mechanical switches. Take a look at these, they run on 5 Volts but I can modify to use higher voltage if needed. They operate in the same manner as a NO switch. However a NC can also be created and will not be expensive.

https://www.tindie.com/products/Kard...ll_prod_search

NO switches are not recommended as limit switch. I would never use them in a mill, maybe a 3D printer, but otherwise your switches look nice.