Sherline 5400 Mill, Mach 3 and soft limits.
Hi.
My name is Ed and I'm new to CNC machining. I own a Sherline 5400 mill (and a long bed Sherline lathe) and have just converted them both to CNC. I have a DeepGrove1, 4 axis controller box with Gecko 540's and 270oz nema 23 motors. I'm running Mach 3 and Mill Wizard. I also have a Soigeneris SSENC-1 Ethernet SmoothStepper System as well.
My question is this. Being new to CNC (translation: I know very little), I've heard that on these smaller mils/Lathes, that you don't need to put Homing Switches on then, but you can use Soft limits to setup your machine coordinates. Is that so? I have my mill's motors on, have gone through doing my "Motor Tuning, and now I'm ready to setup soft limits. Could someone familiar with a Sherline setup like mine, provide me with a little help completing mine? I've read the Mach 3 pdf, and watched a bunch of video's about it, but they don't relate to my setup. I'd really appreciate it.
According to the Sherline Mill's site, my mill's travel spec's are as follow': • X axis Travel: 8.68" • Y axis Travel; 5.00" • Z axis Travel: 6.25
Thank you.
-Ed/emojo5
Re: Sherline 5400 Mill, Mach 3 and soft limits.
from what little i know you can not have soft limits without homing limits enabled..otherwise machine has no idea where to set soft limits
Re: Sherline 5400 Mill, Mach 3 and soft limits.
Yes you can set soft limits without having any physical switches at all fitted.
Pick a point where you want home to be and set soft limits according to that.
The downside is if you have a crash or lost steps you have to re-locate where zero point was by hand (guesstimation).
I have no home or limit switches myself at present. My soft limits warn me if my part will exceed the travel.
I've had to reposition twice by guesswork so far.
Re: Sherline 5400 Mill, Mach 3 and soft limits.
dazp1976 is correct, you can use soft limits in Mach3 without having home switches.
The easiest way is to use the machine's physical limits as your homing points.
Re: Sherline 5400 Mill, Mach 3 and soft limits.
Quote:
Originally Posted by
Shelby5041
How would you set soft limits in mach3.without homing?..would you have to manually set each time you open mach3?..similar to homing sequence?
The "Config - Homing/Limits" menu is pretty self-explanatory.
"Reversed" - leave this unchecked. Not sure what exactly it does, but I have never used it.
"Soft Max" - this is your maximum coordinate value, e.g. 8.68" for the X axis of the Sherline mill from the original post.
"Soft Min" - minimum coordinate value, usually 0.
"Slow Zone" - the distance from the soft limit where the machine will start slowing down during jogging.
"Home Offset" - usually 0, unless your home switch is located somewhere in the middle of the axis.
"Home Negative" - check if your home switch is located at the minimum coordinate. Uncheck if the home switch is at the maximum coordinate.
"Auto Zero" - resets the machine coordinates when you do the homing. Leave it checked.
"Speed %" - the speed during automatic homing.
To home the machine manually, jog it to where you home switches would be and press the "Ref all home" button.
If you don't have any home switches configured in Mach3, the "Ref all home" button will reset the machine coordinates without moving the axes.
Re: Sherline 5400 Mill, Mach 3 and soft limits.
Quote:
Originally Posted by
Shelby5041
And mske sure persistent DRO is checked in gen config.
Now my mach coord soft limits are set and mach3 remembers every time i open n close mach3 ...i dont have to repeat this.
Keep in mind that an axis may inadvertently move while the machine is off.
Also, every time you power down a stepper drive, the microstepping counter resets to 0. So your coordinates may shift as much as a full step after a power cycle. Not enough to matter for jogging safety, but enough to trash a part if you are counting on the machine to remember its position overnight.
Re: Sherline 5400 Mill, Mach 3 and soft limits.
Quote:
Originally Posted by
Shelby5041
How would you set soft limits in mach3.without homing?..would you have to manually set each time you open mach3?..or can it be done once and mach 3 remembers msch coord each time open and close mach3?
I may try it...although soft limits dont prevent most reasons for crashes it can prevent minor booboos like operator error
Get the machine all set up to where you want home to be first off. Once you've done that:
At the end of the days work.
Before you shut it down run a simple gcode program so the machine goes to G28.
This will move the machine to the position you have set up as your homing point.
Next time you start it up the machine wil/should still be in the same position. Just ref home to light it all green and use it.
It's always worked for me so far (barr losing position at a stall on a job).
I use this:
(1. HOME SLOT)
(T3 D=3. CR=0. - ZMIN=-17. - FLAT END MILL)
G90 G94 G91.1 G40 G49 G17
G21
G90
(SLOT3)
G28
M30
Re: Sherline 5400 Mill, Mach 3 and soft limits.
Quote:
Originally Posted by
Shelby5041
from what little i know you can not have soft limits without homing limits enabled..otherwise machine has no idea where to set soft limits
Really to make it work correct you need at least ( 1 ) micro switch or a proximity switch per axis or it can not work correctly, it's just a guess each time you set a home for the machine and that can be a problem every time you go to run your machine if you don't use the same place each time
The ( 1 ) switch will work as a Home and a limit from this point you can then set your work area soft limits
Re: Sherline 5400 Mill, Mach 3 and soft limits.
Quote:
Originally Posted by
dazp1976
Get the machine all set up to where you want home to be first off. Once you've done that:
At the end of the days work.
Before you shut it down run a simple gcode program so the machine goes to G28.
This will move the machine to the position you have set up as your homing point.
Next time you start it up the machine wil/should still be in the same position. Just ref home to light it all green and use it.
It's always worked for me so far (barr losing position at a stall on a job).
I use this:
(1. HOME SLOT)
(T3 D=3. CR=0. - ZMIN=-17. - FLAT END MILL)
G90 G94 G91.1 G40 G49 G17
G21
G90
(SLOT3)
G28
M30
Why would you use a program with nothing in it, all that is needed is to input a G28 If it has been setup to do something no more is needed
Re: Sherline 5400 Mill, Mach 3 and soft limits.
Quote:
Originally Posted by
Shelby5041
Hi dream...i didnt see ur post until after i messed eith mach 3 ...but i think i figure it out...i move each axis to max neg travel...i then hit ref all home...then in soft limits i enter +7 for x ...+4 for y ...+6 for z...and put 0 in all - fields.
And mske sure persistent DRO is checked in gen config.
Now my mach coord soft limits are set and mach3 remembers every time i open n close mach3 ...i dont have to repeat this.
I tested it and worked great and will be a good safety feature on my one romaxx cnc that uses v wheels and has no hard stops...this should prevent any user error and having gantry roll off the rail....which would not be a good thing
Thank you for the awesome great info...
No It will never remember where Home is without a referance to home position on start up
Re: Sherline 5400 Mill, Mach 3 and soft limits.
Quote:
Originally Posted by
mactec54
Why would you use a program with nothing in it, all that is needed is to input a G28 If it has been setup to do something no more is needed
Yeah. Actually I forgot I could just do a G28 in the MIDI.
When I first started to newbie dabble in Mach I did it with the program, I didn't realise about the MIDI section for quite a while tbh.
The fake program to G28 home it, just became a force of habit.
You know what novices are like :rolleyes:
Re: Sherline 5400 Mill, Mach 3 and soft limits.
Quote:
Originally Posted by
Shelby5041
Hi dream...i didnt see ur post until after i messed eith mach 3 ...but i think i figure it out...i move each axis to max neg travel...i then hit ref all home...then in soft limits i enter +7 for x ...+4 for y ...+6 for z...and put 0 in all - fields.
And mske sure persistent DRO is checked in gen config.
Now my mach coord soft limits are set and mach3 remembers every time i open n close mach3 ...i dont have to repeat this.
I tested it and worked great and will be a good safety feature on my one romaxx cnc that uses v wheels and has no hard stops...this should prevent any user error and having gantry roll off the rail....which would not be a good thing
Thank you for the awesome great info...
No it is NOT 'safe'. Just doable. User error, missed steps, jams, will screw it up, and need to manually find position again..
If you don't SEND it 'home' at the end of the day and come in next morning and 'ref all home' that will now become your new home.
You have to be careful.
I said it can be done, didn't recommend it should be.
Quote:
Originally Posted by
mactec54
No It will never remember where Home is without a referance to home position on start up
This is why I say the machine should be sent home at the end of the day. It's dead easy to balls this up without having physical switches. It's more of a stop gap whilst building it.
Re: Sherline 5400 Mill, Mach 3 and soft limits.
Quote:
Originally Posted by
dazp1976
No it is NOT 'safe'. Just doable. User error, missed steps, jams, will screw it up, and need to manually find position again..
This is why I say the machine should be sent home at the end of the day. It's dead easy to balls this up without having physical switches. It's more of a stop gap whilst building it.
He is not building this machine it is already built by a company, so he should be doing it correct right from the start, you don't want to crash these wimpy machines or he will damage the screws very easy
