Hall Effect (Magnetic) to replace Microswitch - Advice needed.

Hi Everyone,

Has anyone replaced the standard Microswitch Endstop on printers with a Hall effect sensor?

Looking at my board (Geeetech G2S Pro GT2560) the Hall effect sensor will need 5V from somewhere and then the other two connection would connect to where the Micro switch currently does.

Anyone have experience replacing micro switches with Hall effect sensors? What are the steps?

TIA!

Whilst it's more than possible to do this you should consider that the function of stopping the motor will be done through software instead of hardware!

By this I mean that the end of travel limits will be fed into your controller as inputs and it's the function of your program detecting the inputs that will ultimately stop the motor. But consider for one moment that the reason for your motor going over travel is because the program has locked up and is no longer responding, in this scenario your inputs will be ignored and rendered useless.

It is for this reason that hardwired physical contacts are preferred as they are considered fail safe.

A lot of industrial systems will use both, the first set of limits are considered 'soft limits' and will allow the drive to recover without manual intervention. Another set of limits slightly closer to the end of travel are considered 'hard limits' and if triggered usually require manual intervention to reset the drive.

Thanks @RandomCoder - 3D printers rely on Firmware for all the endstops, so regardless of whether its a mechanical switch or an electronic switch, the Firmware is still looking for a H or L state for the switch. The Microswitch is not in line with the power of the servo's. It's all software controlled.

That's ok if the risk of personal injury or mechanical damage is limited, but consider that an electrical fault could happen in which the output becomes stuck on or the motor driver shorts. Then there is no way of stopping the motor if purely software controlled.

It basically boils down to the level of risk and whether or not you need to be certain that the motor can be disconnected in the event of an over travel fault. Maybe the stall current would be sufficient to trip some over current protection and you can rely on this instead?

Out of curiosity, why do you need to replace the micro switches with hall effect switches?

I have a Geeetech G2S Pro Delta printer and over time the M3 screws that are the "Endstop triggers" become loose, so when they home they slowly (over time) turn back (unscrew) and affect the Delta Radius / Homing height.

Removing the screws and going to something that is repeatable all the time / every time saves me having to recalibrate.

I've decided to go with Opto Endstops. I will replace the screws with a static metal rod and tune the Optical end stops to trigger at the same point on all three towers.

I'll put what I did in this thread for future reference in case anyone is interested.

PS - Anyone thinking of getting a 3D Printer?
Stick with the standard Cartesian. Don't bother with Delta's. They look cool as they print (like a stewart platform on 3 axis) but suck at keeping "in tune"

@RandomCoder - You do realise I'm talking about a 3D printer??

@Archie I do now.
For this purpose I'm sure your proposed solution will be more than adequate.