If you zero your machine and take note of the values, then do some other stuff and want to go back to your jotted down zeros… can you plug them in and expect the zeros to be physically the same as the time you jotted down? What about after you disconnect from the machine and have to re initialize it?
To add some clarification… I am thinking of making a holding jig that has pockets to hold some smaller parts that I am machining and would like to set up my board, create the holding pockets, put the parts into the holding pockets and do the machining. I will set it up so I can put the board back into the exact same spot so I can add new parts and machine a new batch. If plugging in the zero values takes it to a slightly different spot than the original, then the part machining will be off.
Obviously, the answer I am looking for is YES but figured it is easier to ask the community than figure this out on my own…
Yes, within the physical aspects of the machine motion — one thing which will help is to pull the machine to a consistent point before powering up — front left bottom avoids the switches.
That is enough for me to give it a try! Just to be clear… you are suggesting physically pulling the machine to the front left before powering up? I am curious how this helps with the zeroing (still very new to this).
After you initialize the zero’s are pretty consistent. If you set zero and then reinitialize the zero is persistent in memory but the mechanical position you return to can be a few thousands off. I have proven this to myself several times on projects that once started I stopped because I wanted to fix something or what ever but the machine homed and when I re-ran the job it was off a few thousands. Sometimes it goes to the exact same spot other times no so much.
So as long as you can be off by a few thousands then your jigs should work. But if your tolerances are very tight it may not work. The problem with repeatability is the homing switches. Because they are mechanical there is always a little variance in when the switch is set and sensed. The new inductive switches may work better but most likely you could still be off a few thousands.
It might be — it would be worth performing experiments to determine which is more accurate — I like having the gantry aligned against the endplate though, makes up for not being able to home each end separately as more expensive machines do.
No, I’m saying if you pull to the left front bottom position the machine in theory will in theory have a consistent position when powered up which should make homing more repeatable.
At a minimum it should ensure that the gantry is square to the front endplate which is worth something.
but figured it is easier to ask the community than figure this out on my own…