Does anyone have experience with adding a homing switch to a 4th axis?
I want to pause 4 (and later 5) axis jobs, switch off the machine and home+continue on the next weekend.
I’m thinking about adding an inductive sensor.
I have 2 Y axes which are moving synchronised. Both have homing switch. I’m not sure I understood which was
your question…
@Alex_Paverman how best to make a homing switch on a ROTARY axis.
A, B and C are rotary axes on a CNC.
I don’t have (yet) a rotary but I figure that inductive sensor will be easyer. BUT it’s depending on how many Input ports does your breakout board has. Usually an inductive sensor need one input on board (cannot be cascaded too much) . Mine has not enough. When I built the Y2 axis I was forced to use some mechanical switches because those can be cascaded.
I’m not using a breakout box but a controller board that does all the timing, caches the next few commands and offers lots of relays and inputs. Connected via Ethernet with galvanic isolation.
Parallel port +breakout box and timing on a PC in Software is not my way to go.
So, you won’t have my kind of problems. Good luck!
The same place I got the nice electronics enclosures, sells some very nice CoreTech rotary incremental optical encoders with 2048 CPR. These encoders have an index output at 180 degrees. It might be useful for this type of application. You wouldn’t need the optical encoder itself really, just the index pulse output. I think I pay $20 each or them.
@John_Scherer
I can’t mount that anywhere.
I’m using a 50:1 harmonic drive.
At one end is the stepper.
At the other end is the chuck.
There is no open axis at the chuck-end of the gear box to attach something like this to.
It would work very well on a belt driven 4th axis. However still an index at 180° could be a problem because there are 2 “home” positions. At 180° and at 360° and the machine can’t distinguish between the two.