Well the ol' Fadal VMC 20 crapped out today. Looks like my Inverter failed. I found a replacement one on eBay - so hopefully it works.
It appears it's complaining about damaged EEPROMs.
Fadal Fixture Plate
Ever since I acquired a 4th axis and a Tool setter, my smaller VMC with a table area of only 20 x 16 started to get small. Once I had mounted the 4th axis and the tool setter - the working area was pretty cramped. I decided to get some sort of fixture plate that would allow me to mount the 4th axis off the table enough to get most of my working area back.
After looking around for a couple of years on eBay, and finding no joy for a used plate (If my mill happened to use Haas spacing - I might have found one). I did happen to see a listing for a new plate from Saunders Machine Works - saundersmachineworks.com. (They also run the NYC CNC website www.nyccnc.com that has lots of great info). It wasn't cheap, but was specific for my machine and was exactly what I wanted.
I had great feedback from NYC CNC about some questions I had re: mounting, cad drawings, etc. and the plate arrived in about a week. It was nicely crated up and very exciting to receive.
One thing that did come up - they sell plugs for all the holes so swarf won't get down in there. I misread the web page and didn't order enough for all the holes. (I asked SMW to clarify the info on the page so it's clearer how many you'll need.)
All in all this is going to be a great upgrade to the mill, giving me many more set up options. Who knows maybe I'll start using dowel pins for alignment?!?!
VH-65 Seal Repair
After rebuilding the VH-65 and mounting it, I kept my eye on the oil level. After a few weeks it fell below the sight glass and I knew I had a leak. I had really fought with the large seal in front and immediately came to the conclusion I had messed it up. Careful observation seemed to show that it was leaking as there was evidence on the front of the rotary.
It's kinda hard to see, but there is some faint staining right below the seal area as shown here.
First up - remove the old seal. Easy - just drill a small hole in the seal and use a slide puller!
My problem the first time was I had no way to evenly pull in the seal. I had tried to gently hammer it in, but I knew at the time I had deformed it. I needed a tool.
When I was scrounging around my local surplus yard, I found a scrap ring of 6.5" ID aluminum. Perfect. For $10 it was mine. All it needed was to a bit of machining to open up the ID a bit and face it. I used the T slots in the face and a couple of scrap plates to rig up a way to pull it down. I carefully tightened each nut so as to install the seal square and even. It went in pretty easy.
I topped it up with oil and I'll keep any eye on it for the next few weeks a see what happens.
When I had purchased the rotary, the Fadal logo plate was missing. One happened to come up on eBay, so I decided - what the hell.
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:
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.
The above layout should work like this:
1) If you want to use the Tool Setter, you send an M65. 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 M64, 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.
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.
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.
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.)
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.