Endstops, is Hall Effect an Upgrade?

[CodonExe]

Has anyone changed to Hall Effect type endstops? Is it an upgrade? If so, did you use linear or digital type sensor?

[CodonExe]

After more reading my guess is a Hall Effect is an upgrade. So I am going to give it a try.

The stock mechanical end-stops may be a source of troublesome calibration issues I am experiencing. Since it is a direct contact device, vibration/impact may be causing inconsistent homing and from the adjustments I have made, it has induced wear between the cheapskate plastic and metal adjustment screws causing my adjustments to not hold.

Since the Hall-Effect is a non contact device and seems like it would be easier to adjust because I can install a high-turn potentiometer to adjust the trigger distance in very small amounts and never need to induce the metal on plastic wear I am experiencing. I hope my guess is right and it is an upgrade vs a more costly solution that does the same thing as stock. If the trigger remains accurate and the adjustments precise this could be a nice, less then $50 upgrade.

Not sure if linear type hall effect sensors would be better than the digital type hall effect, so I am going to try the digital based hall effect sensor board with high-turn pots installed.

[lordbinky]

I wrote a huge post and the forum imp ate it with pics and all. Short version, Yes they're an upgrade. I have the amico 3144 hall effect sensors installed, just took all three pins straight to the board, nothing fancy. There's a newer version of that sensor, it has a faster response time (is a plus), but I can't attest to it specifically. It's the magnets plus ~$1 per sensor and it's been a great upgrade.

[CodonExe]

I wrote a huge post and the forum imp ate it with pics and all. Short version, Yes they're an upgrade. I have the amico 3144 hall effect sensors installed, just took all three pins straight to the board, nothing fancy. There's a newer version of that sensor, it has a faster response time (is a plus), but I can't attest to it specifically. It's the magnets plus ~$1 per sensor and it's been a great upgrade.

Thanks for the reply! I see you are using the digital types. Did you invert endstops in the firmware or just add a transistor to flip your signal?

[Qdeathstar]

Why is it an upgrade?

[lordbinky]

Ugh, I hate walking away and having my post eaten. For me, homing on the mechanical switches hammered the printer so that it would shift around over time (or it'd take longer than I wanted to home), the switches themselves drift over time with wear, and later while I was testing Z-Probe micro switches, the best working switch for me was a Sanwa arcade button switch that had +/- .003 mm repeatability on it's triggering action (way higher than the specs for the micro switches). That repeatability is important since it doesn't matter if it triggers at 1.48 mm or 1.62 mm, but that it does it consistently at the same point since that's what your basing your settings on. So a little flex in the lever arm or hitting the rounded plunger just a little different, will increase that variation.

Then you have magnetic switches, which as long as you're not heating up the magnets or dropping them, their magnetic fields are going to be quite stable over the range it will trigger the sensor. The sensor itself is not being made contact with so it isn't shifting on the machine or causing the machine to eat the force or homing.

[Eaglezsoar]

Ugh, I hate walking away and having my post eaten. For me, homing on the mechanical switches hammered the printer so that it would shift around over time (or it'd take longer than I wanted to home), the switches themselves drift over time with wear, and later while I was testing Z-Probe micro switches, the best working switch for me was a Sanwa arcade button switch that had +/- .003 mm repeatability on it's triggering action (way higher than the specs for the micro switches). That repeatability is important since it doesn't matter if it triggers at 1.48 mm or 1.62 mm, but that it does it consistently at the same point since that's what your basing your settings on. So a little flex in the lever arm or hitting the rounded plunger just a little different, will increase that variation.

Then you have magnetic switches, which as long as you're not heating up the magnets or dropping them, their magnetic fields are going to be quite stable over the range it will trigger the sensor. The sensor itself is not being made contact with so it isn't shifting on the machine or causing the machine to eat the force or homing.

Have you checked with MHackney, or John Oly to see if it is possible to restore your deleted posts?

[Windshadow]

It has been quite a while since we have seen any posts from Mike Hackney I hope he is just swamped with biz since its fishing season (Or he has gone fishing).

[Qdeathstar]

I see two types of Hall effect sensor boards.
One has a potentiometer and one doesn't.


If i get the one with the potentiometer can I ditch the height adjustment screws and use the potentiometer to adjust trigger height?

[Jetguy]

I would not depend on that. If you even remotely understand magnetic fields, the strength of the field based on distance is both a function of the distance and shape of the magnet. As such, you are adjusting the threshold of sensitivity of the Hall effect device. It's not a linear function.
In other words, for leveling, you need a linear relationship of distance to turns of adjustment. A hall effect without a 15 turn potentiometer and even then, is not going to be the same as a mechanical leveling screw.

You would be shooting yourself in the foot to depend on only that adjustment pot as your "leveling method".

[Qdeathstar]

Well, I think my screws may be vibrating/turning themselves during prints... When I first figuring out hey they worked I think I over tightend the x and y.. As they always seem to work themselves up resilient in the print being high.... Plus I can turn them with my hands..

Wot can I do a about that outside of buying new carriages?

[Nylocke]

You shouldn't be relying on screws, use the software home offsets. Its way more reliable/repeatable. Also it has no problems with nonlinearity of the homing sensors.

[Qdeathstar]

Oh. Why isn't that in the Manuel? Why have screws if you can just forget the screws.

Is is that in the firmware(reflash) or in eeprom?

[Nylocke]

I thought it was in the newer versions but I haven't really checked those parts lately. Its in EEPROM. Something like homing offsets or something similar. Theres one for each tower. I don't even have screws in my carriages, the wood of the carriages just hit the switches. You could either screw the screws in all the way or remove them if the switches will reliably hit in the same spot on yours.

[geneb]

I'm not familiar with the method personally. I suspect trying to lean on that method for neophytes to kit building and 3D printing is asking for it.

If your screws are a bit loose, there's no harm in putting a little bit of blue Locktite on them.

BTW, the kind of hall effect sensor that' s used for end-stops looks like this:

[img]http://reprap.org/mediawiki/images/d/d3/Endstop600.jpg[/img]

The sensor is that little part on the very end - it's an AC1302 hall effect sensor.
It's the same part I used for this project: http://hackaday.com/2012/02/14/improvin ... t-sensors/

g.

[Qdeathstar]

I got some off of eBay that weren't shappee in an arrow or have the adjustment pot. Geneb, what about an appendix similar to the alternate cablibrarion method appendix.