[RogerRetro]

Hi Roger, the hall switches will work on 24v DC supply, but the issue is WHAT are you attaching them to??

If the output of the hall switch must go into a break out board etc then you need to use voltages that are compatible with that.

Please provide more info and I will try to suggest the best way of wiring it.

Hi Roman,
I'm considering using the G540, which I understand can take Limit switch inputs directly... I may be overlooking something here; if so, maybe point me in the right direction?
Thanks,
Roger

[RomanLini]

Hi again Liam, great to hear you got them working well despite putting the resistors in the wrong way around! Just kidding.

Seriously you made a good point that people may not know resistors work just as well either way around, I would add it to the first page of this thread in bold text but the forum won't let me edit those posts as they are too old now.

Maybe a moderator could add a note there?

Liam, how is that mega machine of yours going? I would love to see a photo of the home switches on it, feel free to post photos here if you like. It may help other with sensor mounting ideas.

Roger- The SS441 sensors will work ok, their outputs attached directly to the G540 "general purpose inputs" provided the G540 ground is the same ground as your 24v supply.


The SS441 sensors will work from 24v as their power source. If that is your stepper driver PSU I suggest you put a small cap (0.1uF, greencap etc) right at the SS441 between its +ve and gnd leads. That will suppress noise coming from the 24v power wire.

That setup will work fine but it is not easy to add LEDs to it.

If you really want to have a LED in each sensor block it will be better to run the SS441 sensors and LEDs from a separate supply, like a 5v or 12v supply.

You can make this supply from your 24v supply by purchasing a $1 "3pin voltage regulator" like a 7805 (+5v) or a 7812 (+12v).

[Master of nun]

Hi Romanlini

I'll post some pics here and I really need to update my build thread, I'm up and running in three axis....I completed and had five axis going but found I had unacceptable backlash so a redesign is on the cards.

I'd recommend having the LED's as it does make setup and trouble shooting a breeze.


as for the resistor orientation....yes it's little things like this that yourself wouldn't think need mentioning.



Liam.

[RogerRetro]

Roman,
I'd like to have the LED's for a quick visual check in case of possible future problems, so I could use a 24-5V dc-dc converter that I have, but I'm concerned about noise. Is there likely to be noise problems at 5V when using shielded wire?
Thanks,
Roger

[RomanLini]

Liam- Yes please post photos!

Roger- If your 24v->5v converter is ok there should be little noise caused by it, and with shielded wire the SS441 hall switch output signal should be quite resistant to noise.

You said you are putting the signal from the SS441 into the G540 general purpose inputs? I think they have some noise immunity too.

It should all be fine I think. Just use the resistor values as shown in the first page of this thread, to use the LEDs etc on 5v.

[Master of nun]

Ok heres Mine, 10mm acrylic, m8 capscrews to Tslot, 10 x 10 x 3mm magnets from Jaycar simply superglued to X axis linear slide carriage.
[IMG][/IMG][IMG][/IMG]

[RogerRetro]

Roman,
Yes, I am currently planning on using the G540; what you say about noise sounds good, so I'll do as you suggest with the resistor values and see how that works out and post the results.
Thanks for the guidance.
Regards,
Roger

[RomanLini]

Liam, thanks for photos that's a nice little rounded acrylic mount you machined. And BRIGHT blue LEDs!

Did you fill the mount with clear goo or just a spot of glue to hold the hall sensor in place?

Re supergluing the magnets, I suggest you also put a smear (or a bead) of silicone (silastic etc) around them. Superglue gets brittle with age, and there is a difference in thermal expansion between the magnet ferrite and the machine metal so over enough days and heat cycles they may break the glue. I did lot's of years in appliance repair and machinery troubleshooting etc and magnets glued with superglue commonly break free. A lot of manufacturers use epoxy which will hold a lot better, especially if it is a semi-flexible type. Or use silicone, it will last forever.

Where's your link to your big machine, I haven't seen the thread in a while? People reading this might want to have a proper look at your machine, it's a beauty.

Roger- I'm glad to be of some help. Please post any photos etc when they're done!

[Master of nun]

Thanks for the heads up on the glue.

I used West System epoxy to fill them.

Heres the link, just posted a vid showing your sensors in action....enjoy

http://www.cnczone.com/forums/cnc_wo...tml#post977300

[RomanLini]

Nice one!

[davy182]

I used the a3144 from ebay. They worked great. I wish I would have done this sooner the accuracy is phenominal. X and Y are slide by's and z is coming at the switch. In general about .0005" +/- depending on the speed I home at.

[RomanLini]

Thanks for the sensor info Davy182.

Accuracy like that is pretty typical I think, it gets down to the stepper resolution and things like friction and slop etc, if your machine moves exactly one stepper step distance for each step or if there any bounce, stiction or slop etc in the movement.

[sli21]

hi roman

hope u can help me out. i am building a 3 axis router and was planning to use microswitches as the limits etc until i saw these very sexy switches of yours. Can u explain to me the diff between the SS441 and the ebay A3144's (i think).

I am using a G540. What is the best way to power and wire them up? Do i still need 6 (3 per axis)?

IS ther a circuit diagram somewhere?

I am sure you have posted this elsewhere so maybe you can point me in the right direction.

my build is at http://www.cnczone.com/forums/austra...tml#post982088

many thanks Roman
regards Scott

[RomanLini]

Hi Scott, I saw your build thread in the clubhouse section of the forum, it looks cleverly designed.

As for type, I would recommend the SS441 as this is a device that I know delivers, ie it has the temperature compensation and accuracy etc and Honeywell is a trusted brand. They are not expensive. I have not used the A3144 and can't really judge it as a comparison.

6 hall switches gets you full 3 axis limits, if that is what you want. I just use 2 hall effect "home" switches for X and Y and "soft limits" and have no problems. If it crashes I just reset and re-home the machine which is very accurate.

If you think you might overrun the travels then by all means go for 6 hall switches and use them as limits, and you can also "home" the machine to them as well.

Maybe as your machine has fine leadscrews it should have good torque and not lose steps very often, I think you might get away with just 3 home sensors. Remember if the machine crashes on a job you stop it, and can re-home it at any time (which you still have to do if you have limit switches anyway).

They will connect fine to the G540 general purpose inputs, just power the hall switches from a 5v or 12v supply whichever is easier. The SS441 has an open-drain pull-down output which can connect direct to the G540 inputs.

There are lots of instances of small wiring examples and making mounts etc earlier in this thread, so it's best to take a half hour and have a read through the first few pages.

[Greolt]

Can u explain to me the diff between the SS441 and the ebay A3144's (i think).

Those are the ones I used, working faultlessly.

When you compare the data sheet they are virtually identical in any way that matters.

Greg

[sli21]

Hi Roman and Greg
thanks for the advice. Any suggestions where can i source the SS441's

cheers scott

[bobsch]

[QUOTE=sli21;982377Any suggestions where can i source the SS441's

cheers scott[/QUOTE]

Digikey has them.

Digi-Key - 480-2001-ND (Manufacturer - SS441A)

[ger21]

I got mine at Mouser.

[Greolt]

Scott is in Australia. That does not mean Mouser and Digikey are out, but local is often easier.

RS Components have them. Expect to pay a lot more than the ebay equivalents though. At least that was the case when I looked.

Roman may have a better local source.

As I said I went with the ebay ones because they were inexpensive and available, with the same specs.

Greg

[Streamside]

I bought a dozen at Newark.com for $ 1.23 ea

Manufacturer: HONEYWELL S&C
Newark Part Number: 93F6654
Manufacturer Part No: SS441A

HONEYWELL S&C|SS441A|IC, HALL EFFECT SENSOR, UNIPOLAR | Newark.com