Touch Plates

Last Update: 25 May 2020

A touch plate can make it quicker and easier to find your origin point on your material. There are a lot of different types of touch plates, but the vast majority use some sort of metal block that detects when your end mill makes contact with its surface by completing a circuit.

Amongst touch plates, you can find ones that measure just the Z-axis or some that can also find the offset between the X and Y-axes as well. Locating in the X and Y-axes is a nice additional feature, but it doesn’t work for irregularly shaped bits such as v-bits and dado bits due to their inconsistent diameter along their height or radius.

The Sienci Labs Touch Plate is an excellent example of a touch plate that lets you find the corner of your material in all three axes automatically.


Setting up and using the Sienci Labs Touch Plate

This guide will help you set up and use your Sienci Labs Touch Plate with UGSPlatform. If you have a different touch plate, these steps may help you set up yours as well.

Inside the package:

  1. One touch plate
  2. Red and black wire with banana plug and magnet (1.8m)

Step 1: Wiring and plugging in your unit

Your LongMill control board (the LongBoard) comes with a detachable two pin screw terminal on the Probe/GND pins. With a small flathead screwdriver, start by screwing the two bare wires into this terminal. Ensure that the red and black wires are in the correct spot as in the photo.


When properly wired, the red wire will be on the Probe pin and the black wire will be on the GND pin.

Next, plug the banana plug into one of the two holes on the touch plate. Ensure that it is well seated. You can pick the hole you want to use that helps keep your wires out of the way.

Ensure you have an end mill firmly secured in your collet. If you are planning on doing a probe on the X and or Y axis, make sure that you have at least 15 to 20mm of your bit coming out of the collet. For other notes on end mill compatibility, please go to the end of this guide.

Attach the magnet to your end mill. You can also attach it to the collet nut or another part of your router or spindle as long as you have a conductive path through your end mill.

At this step, you are ready to start setting up your touch plate in UGSPlatform!

Step 2: Setting up Probe Module in UGSPlatform

UGSPlatform comes with a simple plugin that allows for your machine to send the commands to your machine to utilize the touch plate for finding the X, Y, and Z-axis.

Start by going to the top of your screen and clicking Window -> Plugin -> Probe Module. You will see a new tab appear on your screen.


Next, we will change a few settings. Click on the “Settings” button on the plugin.

  • Units:  Choose between millimeters and inches. For this guide, we will be using millimeters.
  • End Mill Diameter:  This is the diameter of the end mill you will be using. You can find this diameter based on your manufacturer’s specs, or you can measure it yourself.
  • Fast Find Rate:  This setting adjusts the speed at which the machine will move to touch off the touch plate on the first pass. Set this to 150.
  • Slow Find Rate:  This setting adjusts the speed at which the machine will move to touch off the touch plate on the second pass. Set this to 25.
  • Retract Amount: This setting adjusts how far your end mill moves away from the touch plate on its first touch off. Keep this setting at 1.

Within the left side of the plugin, you’ll also see a few more tabs

  • XYZ: Finds the origin/datum point on the corner of your material in all axes.
  • XY: Finds the origin/datum point in the X and Y direction only.
  • Z: Finds the Z height only.

In these sections, makes sure that these settings are changed. If your section does not have that setting available to change, you can skip it. This means that in the XYZ tab you’ll enter all these settings, in the XY tab you’ll only use the settings pertaining to the x and y-directions, and in the Z tab you’ll only use the settings pertaining to the z-direction.

  • Probe X Distance:  25
  • Probe Y Distance:  25
  • Probe X Offset:  10
  • Probe Y Offset:  10
  • Probe Distance/Direction:  -15 (make sure this value is negative)
  • Touch Plate Thickness:  15

Step 3: Operation of your machine

We’re pretty much ready to go!

If you want to measure XYZ,

  • Move your end mill to the approximate corner of the stock material.
  • Place your touch block on the bottom left corner of your part and attach the magnet to the router collet, being mindful of your fingers when you’re near it. Make sure that both of the insides of the touch plate is contacting the edges of your part.
  • Move your machine to position the end mill 5 to 15mm above the circular logo on the touch plate. Make sure to double-check that your touch plate and magnet are properly connected.
  • Open up the probing window on UGSPlatform and in the XYZ tab press “Measure outside corner”. The LongMill will go through a cycle to home and take its measurements.
  • If the probing function is successful, then the machine should return the bit back to the starting point where you initiated the probing cycle. You should notice that the digital readout (DRO) on UGSPlatform changes to reflect the measurements, the current position being offset a little in the X and Y and quite a bit offset in the Z.
  • You can check that it’s now zeroed on the material corner by first taking the touch plate off the material and removing the magnet from the router collet before pressing “Return to Zero”.
  • If the probing was unsuccessful, then it’ll be indicated by the cutting bit not returning to where you started the probe cycle or the machine will be put into an ‘ALARM’ state. To bring it out of the alarm state, press the “Soft Reset” button followed by the “Unlock” button and that will put the machine back into its ‘IDLE’ state. An unsuccessful probing cycle can result from an incorrectly positioned probe, the magnet not attached to the collet properly, starting too far outside the circular logo, and the probe not being plugged into the controller. Be sure to verify your setup before attempting another probing cycle.

If you want to measure XY only, follow the same steps, but your end mill will have an indeterminate Z height.

To find only the top of your material in the Z direction (Z),

  • Flip your touch plate upside down.
  • Place your touch plate on top of the material that you want to find the top of. Position the machine so that the end mill is above the touch plate.
  • Go to the ‘Z’ tab and press “Initiate Probe”.

Remove your magnet and set your touch plate aside, and you’re done!




You may have some issues with using your touch probe if your end mill is:

  • Irregularly shaped (v bits, dado bits) and the side of the widest point of the bit does not touch off on the side of the touch plate
  • Non-conductive

If you get false detections when using your touch plate, double-check that the polarity of your wiring and the connector are correct.