Inserting and Locating a Tool (Otherplan Classic)

This guide refers to Otherplan Classic, OMC’s legacy application for Mac OS X. For the cross-platform version of this guide, please click here.

To insert a tool means to loosen the collet nut halfway and insert a tool with a 1/8" shank all the way into the collet (about ¾"). Then use the wrenches to tighten the collet nut until snug.

To locate a tool means to go through the process of measuring the vertical distance between the tool tip and the collet, so that the machine knows where the tip of the tool is in space.

Since inserting a tool is part of the tool-locating process in Otherplan Classic, we’ll start with locating a tool. If you just need to know how to insert a tool, feel free to skip ahead.

Why is tool locating important?

Once it is homed, the Othermill knows the position of all its built-in parts. It knows the bed position in the x and y dimensions, and it knows the distance between the end of the collet and the bed.

However, Otherplan Classic still needs your help in finding the tip of the tool. Some tools are longer than others, and tools can be inserted into the collet at different depths. Each time a new tool is inserted into the Othermill, Otherplan Classic must measure how far the tool tip extends below the collet.

Skipping this step can result in plans being cut in the air above the surface of the material, or worse, down into the machine bed! You should go through the tool-locating process every time you adjust or change the tool.

How does tool locating work?

For most tools, the fastest and easiest way is by automatic touch-off. The tool is raised until its tip is at a known safe height and then lowered until an electrical connection is made with the bed.

Nonconductive or extremely long tools cannot be located automatically. For those tools, Otherplan Classic also includes a manual locating option.

Step-by-step Walkthrough

The first few steps are the same for both automatic and manual locating:

  • Start the process. In the Setup panel on the right side of the Otherplan Classic, click Set (if no tool is located) or Change (if a tool is located and you’re changing to a new tool).

Setting a tool. Changing a tool.

  • Remove the old tool, if there was one installed, and click Continue.

Remove the tool.

  • Insert a new tool.


  • Make sure the tool is inserted all the way into the collet as shown, and tighten with the wrenches until snug (don’t overtighten).

Inserting a tool

  • If you’re in the middle of a cut operation that requires a certain tool, Otherplan Classic will select it for you. Otherwise, choose your tool from the drop-down menu.

Insert a new tool.

  • Verify the tool position. Otherplan Classic will try to move the tool in the x and y dimensions so that it’s over a clear spot on the bed. Confirm that there are no stray pieces of material, tape, or glue underneath it, and if there are, adjust the tool’s position with the buttons in Otherplan Classic.

  • At this point, the “Locate tool manually” checkbox sets whether the tool will be located automatically or manually. If your tool is not conductive (i.e. a grinding tool or brush wheel), automatic locating will not work, so the checkbox will be checked and greyed out. If your tool is conductive, you’re encouraged to use automatic locating, so the checkbox will be unchecked by default. However, if you wish to manually locate a conductive tool, you may check the box before clicking Continue.

Verify tool position.

Automatic Locating: The Best Choice for Most Tools

  • Move the tool using the buttons in Otherplan Classic until the tool’s tip is within the Safe Zone region highlighted in Otherplan Classic. The tip must be above the lower edge of the x-carriage. This is the trickiest step of the process, so be extra careful! Here are some tips for avoiding common points of confusion:
    • Do not use the blurry tool rendered in Otherplan Classic as a reference for positioning the tool — instead, look at the physical position of the tool in the mill itself.
    • Do not lower the tip of the tool down next to the bed! The goal is not to place it close to the bed but instead to raise it to a known height so that it won’t be rammed into the bed when it’s lowered later.
    • It is safer to position the tool too high rather than too low. If the tool is too high, it will take longer to locate, but if the tool is too low, you run the risk of damaging or even breaking it.

Correct height. Too low.

  • Locate! The tool will move downward rapidly until it is close to the bed and then ease down slowly until an electrical connection is made.

Locate the tool.

Manual Locating: For Long or Non-Conductive Tools

  • Lower the tool until it’s very close to the bed. Set the tool height.

  • Loosen the collet and allow the tool to drop down so that it’s resting on the bed.

  • Then retighten the collet nut and click Set Height to finish!

Finishing Up

After you’ve finished locating the tool, the mill will re-home itself. This will correct for any small changes in position that may have occurred from bumping the carriage while removing and inserting tools. The tool you located will appear in the upper right in the setup panel.

Finishing up.