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Proximity switched for homing

Posted: Mon Apr 05, 2021 1:29 pm
by Joe243672
Can any one give me some good advice on what proximity switches to buy for homing. I have mechancal switches now and really dont like them. Maybe looking for a good optical switch or magnetic switch for homing the y axis and also used for squaring. The mechanical switches i have are pain in ass to make work together. figured optical or magnetic would be easier to adjust. I have the new g5 setup with super z 2. built my table from precision palasma gantry and table design.

Re: Proximity switched for homing

Posted: Tue Apr 06, 2021 8:33 am
by admin13o5
Do you have the FT-02 or the SUperZ II ? Id so there are connection points to pull powered sensors for the XY Homes off od the gantry. You need to consider some things about any type of proximity or none contact swtich: Magnets swithes clog quickly form plasma dust / smke. Proximity swtiches tend to have a sense "zone" that can vary so the trip point is not always predictable . Optical is best but that takes some patience to setup and to make them repeatable . I still use the roller type mechanical switches on our tables taht run 6 - 7 hrs per day here beacuse proximity and optical have to be kept clean. You will find in the FT-02 manual on the website that there are connection diagrams for using 12V powered sensor (prozimity) with the FT-02 that pulls back to the Table I/O 17 on tthe G5 . Also not the power source for the added inputs is separate from the power source for the Ohmic part of the FT-02 . There is 12V for sensors at the Prox inputs of the FT-02.

any sensor you use to sqaure the ganty has to be adjustable The one side can be fized but you have to be able to slide the other side sensor to make it sense and stop the slave side to the right spot. There are all kinds of powered sensors oput there with varying sensitivity , sense range and sense angles. you can't block the sense gap and you have to keep them clean. Most prox sensors are sealed but the sense range varies and theyt are better used for things not requiring precision (limits, breakway sensors, obstruction sensors etc) in the SUperZ II we use both proximity (breakaway sensor) and optical (Z home and over travel) they are slot sensors with a vane on the moving part. They are burried deep in the machine back plate to protect them from debris and dust. The beam detect with separate receiver transmitter othe the "bounce" type that sends and receives a beam are typically not tunable for sensitivyt and some have ranges of up to 15ft so great for detecting an object that is moving or large (like a person) but not very precision.