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The mill’s new brain.

Yea, it’s not working. Locked up on bios. And I had a feeling something like this was going to happen. I don’t know why. It felt weird. The original power supplies 12v rail was at 9v. So maybe that just gave me an uneasy feeling. Or, I just have a 6th sense when it comes to computers. 🤣

Give it to me strait doc, what are the options?

Well, we’ve got two options. Repair or replace. I could repair the computer by swapping out the motherboard, memery, and CPU. Or I could replace the whole control system. Repairing is easier. A lot less work to swap things out then to gut and rebuild.

However, I have basically replaced all my dc drives with ac servo motors. The ac servos have the capability to be controlled more precisely, if the control syestem was upgraded. I also have WAY more experience with modern computers and hardware then the older hardware found in this machine. I mean, I think the computer was considered old tech when it was installed. And I was 5 when it was installed. 😂

If it weren’t obvious, I’m replacing. 😁

With a Centroid oak board. Wait, not that oak board.

That’s better. This is a two part syestem. You have a windows computer that connects to the Oak controller. And then you have the Oak board itself. From what I can tell, the windows computer largely operates as an HMI (human machine interface). The computer tells the Oak controller what to do, but it is the controller itself that performs the operations. Which is good since a windows computer isn’t really the right tool to perform the precise timing that would be required to operate cnc motors.

So, no all that is left is to gut the entire control syestem and replace it. Along with a TON of wire. 😫😫🤣

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VM-16 AC Servo Upgrade update 2- One Step forward, Two steps back.

Well, it lives! And after much trouble too. First, the servo would not stop going. No matter what I did with the configuration. I finally found out that the computer was trying to move the motor, but had the direction backwards. I did think of this and tried to reverse rotation within the drive configuration. But that didn’t have any effect. To make matters worse, the computer would leave the analog signal at 10 volts when it went into emergency stop. The fix was simple, but a bit mind boggling. I had to reverse the polarity of the signal. The software should have sufficed, but this is what it took.

Finally, the X axis homed. But that’s all it would do. It wouldn’t jog, or execute gcode. It took many days of banging my head against a wall till I finally gave Bob McManus a call at electromechtechservices.com After talking over a few things, we found out that the feed rate was at 0. The connection to the feed rate switch was unplugged. Hey man, stop laughing. I’m new to cnc. 😳🤣

Well, it moves, it zigs, one may even say it zags, and it can make a tool change. Let’s calibrate and make some chips. Right?! Well, no. 😥

Z axis limit switches are failing. Given the crappy wiring job at factory, Y is probably right behind it. Y belt is also shot. And the pulleys have seen better days. On top of that, this thing is messy inside. It needs to be properly cleaned out and lubricated before use. The Y motor needs to be pulled to replace the belt, and to cleanout underneath the motor. I already have the driver for the Y axis. I might as well just buy another motor and replace the Y servo as well.

Mmmm, crunchy.
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CNC power Distribution Block

The Milltronics cnc mill needs a power modification. The old X axis DC motor used 120 volt single phase from a transformer in the mill. The new AC servo motor needs 208V 3 phase. Subsequently, I will need to supply the same power to the Y and Z axes when I replace those motors.

Are fuses necessary here since we’re staying inside the equipment box? I don’t think so, but there not a bad idea since we will be using lighter gauge wire then the 30 amp fuse would request. Not to mention, if a servo drive fails catastrophically. Better it blow up at 7 amps then at 30 amps. 😁 But these fuse block holders made by Phoenix Contact offer another benefit. You can bond them together. Meaning one wire can supply power to multiple fuses. It turns a fuse block into a distribution block.

And yet, I still ran jumper wires. But hay, not as many. 😁 The block can handle 10 amps. So how many can a block of fuse holders handle with one feed? I couldn’t find that answer, but I am guessing 10 amps. Though, considering the block could handle 8 gauge wires, plus two 14 gauge wires without an issue…. well, I have to wonder.

Some edge molding protects the wires. Only cause the edge molding was literally in front of me as I was building this. 😂

But where shall such a contraption be placed in such a confined cabinet! Well, removing the old X axis driver card opened up a nice location. It’s not perfect, but it’s a work in progress. I will be replacing a lot of the crap in this compartment because, well, it’s me. It’s what I do. 😎 So this location may change. Then again, it may not. I’m dodgy like that. 😂🤣

But why so many fuses? Well, It’s 3 phase, so we need to fuse each leg, which comes out to 3 blocks. These blocks separated by some grounding terminals. Each block contains 6 fuses. I need 4 fuses for axes, I need one single phase for fans, and one, ok fine. I got a bunch of these fuse blocks cheap on eBay and I fit as many as I could . I would have gone to 7 if I could. 😅