Proximity switches or limit switches

[chillybo]

Thanks for that information Jazz. My noodle is easily fried. I used a digital calliper and let the gantry push it up against a stop on the rail. Ive unwired it all now because my control enclosure was delivered today. Im going to use the proximity sensors for homing and mechanical switches for limits. I'l position the limit switch so the gantry just touches it without switching when its detected by the proximity sensor. That way if the gantry goes to close the sensor it'l trip the limit before it damages anything.

https://www.youtube.com/watch?v=HZF8jKtbkvo

[JAZZCNC]

Thanks for that information Jazz. My noodle is easily fried. I used a digital calliper and let the gantry push it up against a stop on the rail. Ive unwired it all now because my control enclosure was delivered today. Im going to use the proximity sensors for homing and mechanical switches for limits. I'l position the limit switch so the gantry just touches it without switching when its detected by the proximity sensor. That way if the gantry goes to close the sensor it'l trip the limit before it damages anything.

Your setup is not a good one.? Often when you crash into limits it's not slow like your doing in testing, it's usually at rapid feeds or higher cutting feeds when machine loses position
by missed steps due to things like Sticktion or binding, etc. In cases like these, the gantry doesn't stop instantly and you get over travel which will smash your setup to pieces.

You need to ride over switches, not into them.!

[chillybo]

Point taken I'l change it when I put it back together. If what you say is a possibility of happening then how do we guard against other things getting damaged like BK / BF bearing blocks? Is it therefore wise to leave a good margin of rail / ballscrew for stopping distance?

[JAZZCNC]

Point taken I'l change it when I put it back together. If what you say is a possibility of happening then how do we guard against other things getting damaged like BK / BF bearing blocks? Is it therefore wise to leave a good margin of rail / ballscrew for stopping distance?

Well BK/BF blocks are not easily damaged so wouldn't be too worried about them, stepper motors will stall before doing any damage. However, if you have anything that can be damaged then it's best to fit Sturdy bump stops after the limits. Skateboard wheels work well.!