I’ve had my X-Carve for about year now and I like to think i know its in’s & out’s.
But i keep seeing a few posts about ‘Limit Switches’.
In my year with the X-Carve I have never said “Man, i could use me some limit switches right now!”
What am I missing?
Year 7. No limit switches. Totally unnecessary. But - some swear by them.
I’m selling my switches if you want them, just little bit rusty sitting in some shelf, some where.
I have a 3-way touch plate i use if i need precise homing… I only ask because i don’t see why people like/use them.
Limit switches are different from homing switches. Most don’t use hard limit switches because of problems of false single nose. But if you get the single filter capacitors set up it is a nice safety feature.
If you use homing switches you can then use soft limits (max distance from the machine home location.)
A lot depends on your software and workflow.
If you are using single bit cuts on easel, no need.
If you are using UGS or Chillipeppr you want to have homing switches, because they take advantage of multiple coordinate systems. Machine zero, which is different from work zero, which is different from temporary zero, etc. And it effects what happens when you hit the (dreaded) “return to zero” buttons.
It also comes in real handy if something goes wrong and you loose position. Pair it with a fixed bump stop and resetting for a retry becomes really easy.
Actually, there is nothing I can’t do without them. Remember, some of us have been doing this for many years, and have commercial software and control systems. Personally, i would never want to become dependent on something like limit switches of any kind. I do things differently than I did a year ago, which was different that two years, ago, which was … you get the idea. My recommendation would be to evolve without them. But that is just my recommendation.
Before I start ANY carve of any complexity, I create a zero point. I send my ball end mill down into a hole. That hole is zero. I also mark a spot on my work piece outside of the carve and use that to zero z. Works perfectly. See if you can find the five different stops and starts on the “giant cherry 3d carve” I send you. That is five separate carves 1 day apart. I have been programmed to operate this way.
I setup my touch plate for exactly that reason… I had the power go out in the middle of a long job.
It makes bit changes, multi-path jobs and ‘OOPS’ moments a breeze. I can accurately re-home any time no matter what end-mill (including tapered ) i switch to**
Plus, i can place the workpiece anywhere on the machine i want.
For the record, i wasn’t trying to start a fight… I just wanted to know if i was missing something on how they are used.
** You have to do some simple math to find the center/tip of the bit by knowing the diameter of endmill where it touched the plate. I wrote my own program that talks to the grbl controller and sends the g-codes to handle the edge and z calculations.
Y not. Also good for certain ops.
I do it almost same way. Return home, soft limits, hard limits always failed some point. No complex upgrades, no complications. Only upgrade I have is X axis steel bar, dust shoe and Makita. Start working 7 am Xcarve works at least 10 hours a day. Mostly, power goes on and off twice a day here. If I make a mistake jogging it, I kiss my lovely stop button. 
I have to say… I’ve been running my XC without homing switches for 6 months. Mainly because my soldering skills are… well I don’t have any. We’ll leave it at that. I had the kit just sitting around, and when my X-Controller arrived I figured “why not. No soldering required”. And I have to say I already "can’t live without them. Yes I was able to carve just fine with my touch plate from Charlie. (Great product)
The ability to start out with a known X & Y position makes things very fast. And I have to admit I’m one of those guys who will bang his head into everything in the room and my gantry off of every rail known to the CNC world. I’ve probably banged it off the rail of your machine a time or two. With the ability to now use soft limits and G28 ( the greatest thing in the world!) my life just got a whole lot easier.
