Series I Homing Question

[ranchak]

This might be a dumb question, but here we go. Is there a homing function on the Series I? I want to make some fixtures for parts that I will be making on a regular basis. I want to install a few bullet nose dowel pins and liners installed in the table to position the fixtures. I'm new to cnc and didn't know if there is a way to get the table to always return to a home position. If not I guess I will have to locate a point on each fixture and document it for future use. Also I am running my machine on Mach 3.

[creep_pea]

There is a home switch for the Z axis but none for the X or Y, I've put some more wires into the limit switches so I can reference the X & Y axes. I don't think you can use the original wires as they run at too higher voltage, hence the new wires, there is a spare separate switch under the cover on the limit switch. It's a normally closed switch so if you want to put both axes on the same input on your BOB you will have to wire them in series.

The hillbilly BOB needs 24v inputs, there is a spare 24v terminal and earth on the left side of the main terminal strip, above were the old logic rack used to live.

Hope this helps

Chris

[ranchak]

Thanks for the help Chris.

[Gsparkey]

Hi Ranchak,
If you are still using the original Boss operating system, I suggest temporarily clamping your fixture to the table so that all your programming moves do not fall outside your machines X & Y limits. Once you have determined that your jig is positioned properly you can create a home for your x,y axis, by locating them off of a hole on your fixture. You can jog the axis on the machine by setting the control panel to read other 1.0"; .10" or .01" in whatever axis you need to locate these axis over that locating hole. Once that is done you can create your home position at whatever location from there that you want by move your X & Y plus or minus. Once that is done turn the control knobs labeled X & Y & Z on the lower left side just above the readout to the X & Y position & turn the knob just above that to the zero position, then push the X & Y button the display will set X & Y to zero. So in your program you need to make sure that when all the machining is done you go back to that home position.. The good thing about this is, if you ever have to stop the program in the middle of it. Alls you need to do is turn the X & Y & Z axis knob to the Z axis first, then turn the knob above that to zero & push the Z axis button & Z will home itself, then turn the knob to X & Y axis position & the knob above it to GOTO position & push the X & Y button & the machine will move back to the original 0.00 positions on the display or the home position that you had created at the beginning. As long as you never hit the reset button to reset the display you will always be able to do this.. If you get yourself a copy of the operators manual M-128 all of this is in there plus a lot more. You can get copies of the programming manual also on e-bay for $31.50 each. They are good reference material if you are still using the original Boss operating system. Good Luck

[deanq]

If you're using Mach3, then use your limit switches as homing switches. There are two Z limit switches. I recommend using the ones that give the most travel.
Dean

[ranchak]

deanq: do you mean to always start at maximum -x,-y? I'm not sure if the table drifts when it hits the limit switch, I'll have to give that a try. Thanks, Ron

[ranchak]

I tried using the limit switches as homing switchs. Didn't work, the table didn't stop in the same position, I was afraid of this, but it was worth a try.

[creep_pea]

Have you wired them up into mach? if so what speed are you running up to them as I found mine repeated reasonable well when running fairly slow.

[ranchak]

I don't know what you mean by "wiring them up to mach"? They are wired through my bob, I think maybe my problem is the speed. I was using the arrow keys to run the table to the limit switch.

[creep_pea]

have a look at the pictures on this post it might help http://www.cnczone.com/forums/showpo...8&postcount=64

I've still got my limit switches hard wired to the E stop on the machine as they were originally. I've also got some more wires running from the same limit switch to the BOB so I can reference off them if I lose position for any reason. You have to hold the motor enable switch in while it references to prevent the E Stop tripping.

[Hood]

Originally Posted by ranchak I don't know what you mean by "wiring them up to mach"? They are wired through my bob, I think maybe my problem is the speed. I was using the arrow keys to run the table to the limit switch.

You set them up as Home switches in Machs Ports and Pins and then when you press the RefAll button the axis will start homing. Have the E-Stop button handy just in case you have them set wrong.
If the axis moves the wrong direction you can go to Operator menu then Homing and limits and select Home Negative.
If you just have the one switch that you wish to use for both Home and limits then you just assign the same pin number you have for the limit to the Home.
Hood