Quote Originally Posted by Georgehun View Post
However I thinking it's a big job to add on limit switches to the machine? Probably not just a simple job specially need to get the mach3 altered to....
No, it's not a big job, this is one of the things I've supplied and helped others with on these machines. The KK01 breakout board he's fitting as got the spare Inputs.
You will need to make some brackets to mount the switches plus the switches and cables themself. Also, I would advise using switches that work with 24Vdc power, like inductive proximity sw, to lower any chances of electrical interference. In which case you will need a 24Vdc PSU as there is only a 5V PSU in the control box.

Setting up mach3 to use them is very simple.

Quote Originally Posted by Georgehun View Post
Most of the time I use the same program on to the machine so once is set it should be fine but later on I want to use it for different Jobs.
Not really, without Home switches then you won't be able to use the same point because every time you shut down Mach3 it will lose the position and you will have no way to accurately find the WORK ZERO.
This is the function of HOME switches as they provide a FIXED reference point that never changes called MACHINE ZERO, which you can then use to find the WORK ZERO you last used. Or for instance, if you lose position when breaking a tool or hitting E-stop while the machine is moving.


Quote Originally Posted by Georgehun View Post
Only one thing is still worrying.
When the gantry motors not worked properly just one was running so I wonder if they are slightly off-set each other?
How I can get that fixed?
I take some measurements and looks have a few mm different.
This is the other function of HOME switches, On a machine that uses Two motors slaved together you have one switch at each side and they can be used to set the gantry square when HOMING.

To be honest I can't believe they get away without supplying at least LIMIT switches as it's a basic safety feature and the cost is minimal considering the price he's asking and the cheap low-quality components he's fitting to the machine means he's got more than enough profit to do so.
Also, it's very easy to share the switch to do HOME and LIMIT duty's so there is no excuse.

My advice is to fit them ASAP if you want to work accurately and safely.