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Aloha - Getting close to placing an order for 500mm version using my Colt trim router, no waste board, no tool kit. No need or room for the 1000mm. Garage shop is already nearing capacity and I haven’t finished my 18" drum sander.
Not sure about these items:
Limit/Home switches - will these be a big contribution in day to day operation?
Can make my own, or is there is a better option (touch home)?
Stepper motors, 17 vs 23, is bigger better for the 500mm? I am getting the Acme lead screw.
I am planning on adding a laser engraver mod later.
Actually, depending on how you configure your machine, they can be homing switches, limit switches (you would have to add more switches to the far end of the X and Y axes, Z too if you wanted to), and they can be both homing and limit switches.
It’s a very flexible set up.
If you don’t order the limit switch kit with your machine you would need switches, wiring, and the post insertion nuts with bolts (to place the actuators for X and Y) to add the switches later.
To answer your specific question, no you don’t need them. The homing switches are very convenient and they make some operations easier.
The quick answer is that you don’t NEED the switches. I don’t have them and the machine runs fine. Some people really like them and (after lots of tweaking) find them very useful.
I got my machine with limit homing switches and have removed all of them. I suppose they’re useful if you want the machine to automatically go to a machine home location, but I end up always using the jog controls with varying step sizes to move the spindle over to where I want it to go. If you install them per the instructions, they will be ignored during jog operations and only used when you explicity “home” the machine.
I have a 1000mm XC and got the NEMA 23 motors. I like them alot and recommend them.
If you want to be able to repeat setups quickly and accurately, I recommend the homing switches.
That way, if you have a stop set up on your table, you can tell it where X, Y AND Z zero is, and be sure it will exactly there when you tell it to.
This.
I recently did this a few times, and was quite happy to be able to re-home it, then move to last work zero.
I now have one of Charlie’s touch plates, although I haven’t tried it yet, I’m sure it will help a lot.
However in a few of the scenarios where I re-homed and went back to work zero, I had already milled away most of the block, so using the touch plate would have been problematic, since the wasn’t any surface to put it on.
First, let me say that my personal opinion is that soft limits are a better way to go. Using soft limits, out of bounds errors are caught before they are executed. Relying on hard limits is more like the accident has already happened, now let’s see if we can limit the damage.
But, more to your question. You would need to add additional switches and activators on the X and Y axis (some people also do Z, but it is not as useful as doing X and Y).
Once that is done you would wire the two switches on each axis as Normally Closed and in a series configuration, and also in a series circuit with the respective homing switch input on the gShield.
Change $5 to 1 and $21 to 1 in the grbl parameters.
Yeah, funny story (after a while anyway). I was testing a G-code file for someone and I was having some difficulty getting it to run, so as a test I turned off soft limits and ran it again. No more Z axis limit switch.
Won’t be doing that again.
Another advantage of soft limits is that the homing/limit switches are only used during the homing cycle, so once the homing cycle is complete grbl ignores the switches. Eliminates false triggers during your carve.
