Adding a Renishaw Probe System to my Fadal VMC

​Since I got my '95 Fadal VMC20 a few years ago, I've always wanted a probing system. Not only does it help you stay accurate and reduce work, but you can insert probing routines in the programming. I wanted it all, a tool setter and an optical probe to use while machining. I hunted on eBay for a couple of years (it takes a while to find good/inexpensive examples) to finally assemble the following Renishaw Parts:

1. MP10 Optical Machine Probe            $156 (with stylus, CAT40 holder and adaptor)
2. OMM Optical Machine Module            $99 (really clean)
3. TS27R Tool Setter                                  $90 (no stylus, from Russia!)
4. MI8-4 Interface                                    $105 (new)
5. MI12 Probe Interface                          $250
6. Misc (PSU, SSRs, Wire)                           $50

                                                            --------------------
                                                             Total   $750

Next I had to figure out the wiring and how I was going physically mount everything. The first step was to create a diagram of how everything needs to be connected.

Bench Testing the Components

The above layout should work like this:
1) If you want to use the Tool Setter, you send an M64. This will cause the MI8-4 to select the Tool Setter as an input and output it's status to the 1060 board. If you send an M65, it will select the Inspection probe (OMM) for the input. 
2) If you select the OMM, then you need to also send an M66 to actually start the probe. In all of the Fadal wiring docs I could find, they never connect the Error and Battery status to the control. If you use them, you can verify the probe started OK is working before you initiate probing. I've written the gcode to test those after a start is issued to verify the probe stated (i.e. go from error to OK) and to make sure the battery isn't failing. If there's a problem the program will loop to try starting again or allow you to abort. 

In order to enable the M64 and M66 gcodes you'll need to populate the 1100 board with 2 SSR's (Solid State Relays)  and 2 fuses. I used a Grayhill 70S2-01-A-03-A and a 1A fuse. Populate K31/F40 and K16/F10 on the 1100 board. These SSR's will be switching power supplied by the 24VDC power supply.

---

SSR

Here's a shot of the SSR's mounted and wired. The red wires are from the 24V PSU. The Green wire is for the M64 signal and the White wire is for the M66 signal.

1100 Detail

In order to detect the Error and Battery status you'll need to create and adaptor for the 1040 board. This has a 26 pin edge connector that you need to interface with. By referencing the Fadal User Manual -> Macros -> Layout of I Macro, you can see that I(3) is pin 19 on J2 and I(4) is pin 20 on J2. You can test is the pin is logic high or low and create logic from there. I assume this card requires TTL voltage levels, so use 5V only!

I decided to mount the MI8-4, the 24VDC PSU, and the connector block to the inside of the electrical cabinet. Luckily there were two 1/4x20 studs sticking out that I could conveniently mount a DIN rail to. I also made up a small connector block out of some perf board to handle wiring up the various components. I 3D printed a couple of DIN rail adaptors for the backside. The  1040 board uses approx. 10K pullup resistors on the input pins. I set things up so an Error or Low Battery are high (active - i.e. the default state) and you need to pull them to GND to indicate a no Error condition. I added some caps to help with AC ripple, as it seemed the power from the Fadal was kinda noisy.

And here's the PSU, Connector Block and MI8-4 mounted and connected. All in all I'm happy with the layout.

Mounted and wired up!

I mounted the TS27R on the back left side of my table and ran the wiring up and over to the cabinet. Initially I was going to mount the OMM on the top left of the cabinet as indicated in the Fadal Maintenance manual, but looking at a bunch of pictures on the internet of HAAS and Fadal OMM installs - it looked like the back of the cabinet would be better. I mounted the MI12 on top of the pendent and ran the wiring under the cover that runs along the top of the cabinet. I had to create a hole to run the wires through on the pendent end.  (The black box to the right of the MI12 is my interface for a programmable coolant nozzle I'm working on - more on that in a future post.)

OMM Mounted

TS27R Mounted

MI12 Wire Routing

MI12 Mounted

I calibrated the TS27R (basically getting the stylus flat) and then determining the fixture offset. After that I tried a tool setting cycle and low and behold - it worked! Can't wait to machine something with my new capabilities.