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Setting up Homing and Limits on a Mill

Summary of videoThis 6-minute video is a comprehensive, yet easy-to-follow, tutorial on how to set up homing and limits on a mill using an Apollo I Motion Controller (

 now available).

Video Transcript:

0:07 Today I'm going to be showing you how to setup homing and limits on a mill using an Apollo I and a MachMotion Control. The first thing we're going to do is make sure that all of the axis are moving in the correct direction. So I set my operator panel here to X, and then I jog the positive, and it goes in the positive. Go negative. And it goes in the negative. I move to Y, it goes positive, goes negative. And to Z, and there it's going negative when it should be going positive and vice versa.

0:38 So to reverse an axis on the Apollo I, go to Config and then Homing/Limits. And then check the reversed column on the Z axis. Hit Okay. Now when we hit the Z positive, it goes up, and the Z negative, it goes down. The first thing we can do before we home is to make sure our homing switches are enabled and configured. So if we come to Config Ports and Pins, then Input Signals, and on this machine we have three axis, X, Y, and Z. And so we've got the home on X, Y, and Z all enabled. And they're configured to a port and pin address. And I've checked and all of these do read in correctly, so when I hit the limit switch, it reads in so I know that it will work. 

1:32 Next thing we're going to do is home the system. So we come here to home. And normally, you just hit Home All and that will do all the axis. But since we're setting it up, I'm going to do each one individually. So we'll home the X axis and what I'm watching for on the machine is I'm wanting to make sure it's going in the right spot. In this machine, I want the table to home forward and to the left to put the home position at the back right corner of the table. For the Z axis, I want it to home up. So we're going to be doing each axis here to make sure that they go in the right place. And there the X axis, X changed to green from red so we know that that is homed. Now we're going to home the Y to make sure it's going in the right direction. And there it's homed. 

2:23 Alright, lastly Z. And it's going the correct direction as well. Now that it's homed, you can see all three of these have green letters. If all the directions were already correct, but in the event that they weren't. If say the Z in this case homed down, we could go to Config Homing/Limits. And then here on the Z axis, we would check under the home negative column. I'm not going to actually change that this time because it was correct, but that's where you'd change it. Also, here we have the speed percentage. So that's the percentage of the rapid feed rate that each axis will home at. So you can adjust that to optimize your process and just make it run smoothly and quickly. 

3:07 The last thing we're going to do is setup soft limits. Once your machine homes, you can set up limits in the software that will prevent you from actually hitting limit switches. So, for example, if I jog it right now, so I go to Z axis, and I jog it up. I hit a limit switch. When you hit a limit switch, that e-stops the system so you lose your homing. So you lose your part coordinates, and you have to re-home. So it's disruptive to your process. So setting up soft limits will help you avoid hitting limit switches and let the process run a lot more smoothly. So to set up soft limits, you come to Config Homing/Limits, and then we've got our soft min, soft max, and our slow zone. So the soft min and max values are the machine coordinates that we have from our system. And the slow zone is a ramp down zone so when you jog into it, it automatically slows themachine down to help you recognize that you're near the edge. And it will also actually stop it before it hits the switch. 

4:15 I already know what the limits for this system was. All of the machine coordinates are in negative. So for our soft maxes on all three axis it’s going to be zero. So I'll set all those to zero. I already figured out what the machine coordinates are for the limits on this. So I'm just going to put them in. But you'll have to jog your machine around to figure out what the min and max values are on your machine coordinates to know what to put in here. So now we've got our soft limits in, and I'm going to leave it at slow zone of 1. I hit Okay. So before soft limits will work, you have to home the system. So I'm going to hit Home All. And normally, it's going to home the Z axis first, then the Y, and then the X. 

5:01 So now that our system's homed, I'm going to jog into the middle of the table. And so now same on the X axis here, and I jog it and then it slows down and stops when it hits the soft limit. If I jog the other side, it slows down and stops at the soft limit. I don't get a limit switch, and I get a soft limit system movement aborted. So there's no emergency condition, it just stops. The key point for setting up the soft limits is that the soft limits are set so that you don't hit the limit switch when you're jogging. Now you know how to configure axis, reverse directions, and set up soft limits and homing on your Apollo I system. I hope you found this video helpful. If you want to find more about MachMotion, go to our website MachMotion.com.