Bridgeport Interact 4 Series 2 to Acorn6 build
Posted: Sun Feb 02, 2025 2:28 pm
Hi all,
I thought I'd start a build thread for my first foray into Centroid. I guess I should start at the beginning! I'm over in Australia doing this and aftermarket CNC stuff, and general CNC and automation knowledge is scarce, and very expensive if you can find it as distances make getting someone to site often prohibitive.
A friend had this Bridgeport Interact 4 Series 2 which "just had an encoder fault on the spindle", he wasn't of the mind to fix it then learn to use it, so if I wanted it, it was free. The only catch, I had to go and get it. A 2000km round trip later and it was in our shed.
It is pretty rough looking and the top shrouds are missing. Looking at the paperwork, wiring diagrams, had written notes, and state of the cabinets, this machine has a long and chequered history of not working! I've rarely seen such a rats nest of an electrical cabinet, it was not looking good from the get-go.
After many hours I got the Heidenhain 155 to fire up, reset all the parameters, sorted the backup power so it kept parameters, and started working though the issues. Here are the ones I found early on:
1. Backup battery had leaked acid onto motherboard and corroded various tracks, home made battery holder was corroded, and no resistor/diode to prevent back-charging of non rechargeable cells
2. Z axis drive would just run off by itself and hit physical limit switch
3. When Y axis drive was turned by hand it would turn off the PLC
4. X axis drive had a dead short on the DC output, but because it was through an isolation transformer it didn't trip main breakers, just burned out the contactor
5. PLC would not output any voltage signals to drives to home machine
6. Z limit switches were wired incorrectly
7. Y axis optical sine/cosine encoder was not sending signals to the PLC
8. Loads of shorted wires, bad connections and power/signal wires together
9. Two of the numbers on the keypad were not working which makes putting parameters in a bit tricky!
The above basically got me to the point of saying that it was not worth fixing, so time to pull all the Heidenhain and DC drives stuff off. I was hoping to use the existing Contraves spindle drive and motor so made a -10 to +10v adjustable circuit, wired that in, but couldn't get the drive to run. Whilst sat looking into the cabinet thinking, the drive decided it was checking out, starting fizzing and all the smoke got out so that too was dead.
This made the decision even easier. The machine itself is a solid lump, good slides and ball screws, but pretty much anything electrical was stuffed. Time to order an Acorn6 and commit to a build.
Another Interact owner had a faulty machine too so I gave him the TNC155 from my machine and wished him luck. He managed to find that one of the EPROM chips was faulty so that was stopping it homing, along with various bad connections and corrosion. Anyway he managed to build one working TNC from the two, so at least some good came of that. I wasn't sorry to see the back of 40 year old electronics so still happy with the call to retrofit.
I thought I'd start a build thread for my first foray into Centroid. I guess I should start at the beginning! I'm over in Australia doing this and aftermarket CNC stuff, and general CNC and automation knowledge is scarce, and very expensive if you can find it as distances make getting someone to site often prohibitive.
A friend had this Bridgeport Interact 4 Series 2 which "just had an encoder fault on the spindle", he wasn't of the mind to fix it then learn to use it, so if I wanted it, it was free. The only catch, I had to go and get it. A 2000km round trip later and it was in our shed.
It is pretty rough looking and the top shrouds are missing. Looking at the paperwork, wiring diagrams, had written notes, and state of the cabinets, this machine has a long and chequered history of not working! I've rarely seen such a rats nest of an electrical cabinet, it was not looking good from the get-go.
After many hours I got the Heidenhain 155 to fire up, reset all the parameters, sorted the backup power so it kept parameters, and started working though the issues. Here are the ones I found early on:
1. Backup battery had leaked acid onto motherboard and corroded various tracks, home made battery holder was corroded, and no resistor/diode to prevent back-charging of non rechargeable cells
2. Z axis drive would just run off by itself and hit physical limit switch
3. When Y axis drive was turned by hand it would turn off the PLC
4. X axis drive had a dead short on the DC output, but because it was through an isolation transformer it didn't trip main breakers, just burned out the contactor
5. PLC would not output any voltage signals to drives to home machine
6. Z limit switches were wired incorrectly
7. Y axis optical sine/cosine encoder was not sending signals to the PLC
8. Loads of shorted wires, bad connections and power/signal wires together
9. Two of the numbers on the keypad were not working which makes putting parameters in a bit tricky!
The above basically got me to the point of saying that it was not worth fixing, so time to pull all the Heidenhain and DC drives stuff off. I was hoping to use the existing Contraves spindle drive and motor so made a -10 to +10v adjustable circuit, wired that in, but couldn't get the drive to run. Whilst sat looking into the cabinet thinking, the drive decided it was checking out, starting fizzing and all the smoke got out so that too was dead.
This made the decision even easier. The machine itself is a solid lump, good slides and ball screws, but pretty much anything electrical was stuffed. Time to order an Acorn6 and commit to a build.
Another Interact owner had a faulty machine too so I gave him the TNC155 from my machine and wished him luck. He managed to find that one of the EPROM chips was faulty so that was stopping it homing, along with various bad connections and corrosion. Anyway he managed to build one working TNC from the two, so at least some good came of that. I wasn't sorry to see the back of 40 year old electronics so still happy with the call to retrofit.