Saturday, January 07, 2012

Updates, Misc., Etc.........

Since just before Christmas when I ended up in the hospital until now there has been so much going on that I've barely had time to live it, let alone blog about it!

Shortly after Black Bunny was crippled by the (expletive) daughter of our (expletive) neighbor, I had a tooth get abscessed. It was a tooth that had been root-canal-ed, but that we hadn't got crowned yet. Unfortunately, it split into two teeth, each with one root. Doctor Bob, my dentist, suggested pulling it out and putting in a titanium stud. After about six months, he'd make a new tooth and mount it to the stud. We'd been talking about doing that for some time, but the abscess meant it was decision time. Regardless, the tooth, both parts, had to come out to resolve the infection. It was already hurting pretty badly, and two hours in the chair getting it completely removed didn't help. The pain was beyond what over the counter stuff would control, so he prescribed some stronger pain pills and sent me home to heal up. The next night another tooth started hurting, even worse than the pain from the extraction. Since I had some pain pills, I keep it to a nearly bearable level until the next day when Doctor Bob arranged to have a look at the second tooth to go nuts in two days. The second tooth had been partially root-canal-ed and crowned maybe eight or ten years ago. Dr. Bob pried off the crown and cleaned out the inside where the infection was cooking away, put in some special stuff to keep it from flaring back up, and put the crown back on as a temporary. Two places going crazy, one on the upper and one on the lower jaw, was generating quite a lot of pain, so I spent a couple of days trying to balance the effects of the pain pills with keeping the pain down to a bearable level. Finally the pain diminished enough that over the counter stuff was strong enough, and now the pain is pretty much gone, although the area where to tooth was pulled is still a little sore.At the same time as all the dental adventures I was also helping a number of liquor store clients with hardware and software tech support.

The wall and the door on the left is new, along with the new sheet rock and insulation on hte other walls and ceiling.

The new controllers are about the size of a PC, but this was state of the art in the early 80's.

Had to figure out a way to keep the heat from going up the stairwell. This seems to work well, and it's actually quite convenient.

I don't have the coolant and tank hooked up, or the shields to keep the coolant contained, but it's not far off now.


 In my spare time (!) I was working to get everything up and running with the new milling machine in the expanded machine shop in the barn. The new wall is fully in, insulated, sheet rocked, taped, sanded, and painted. The other walls are now furred out, sheet rocked, taped, and painted. The same with the ceiling. Two new 220 volt circuits are now wired in, complete with the sockets in and all trimmed out with cover plates, etc. I wired in two separate circuits, one for the spindle motors, and one for the rest of the controller system, so they would be isolated from each other.   Two more 110 volt outlets are also installed. Two doors are now hung, and everything is painted, caulked, and trimmed. The floor now has three coats of epoxy paint. In short, the carpentry part is just about complete.

The CNC milling machine has two main components, the milling machine, and the GE 1050 Controller, which actually runs the milling machine according to the CNC computer file you have loaded into the controller.

 The controller and milling machine are connected together by four huge wire bundles that go from one to the other in an overhead steel raceway. To separate the milling machine from the controller so they could be separately moved, a huge number of wires had to be disconnected from inside the controller and the wire bundles lashed to the milling machine for transport. We documented everything so I could put it all back together once it was in it's new home. It took the better part of a day to get the wire bundles back into the controller and get them all connected. Before I powered it up I triple-checked all the connections, and it all looked perfect. Once I powered it up, though, it didn't want to fully start up. More checking found one pair of wires that, going by the documentation, could be hooked up either of two ways. One wire was black, the other green. Looking really closely with a flashlight, I saw some very faint writing of the letters "GR" behind the connector with the black wire on it. That had to be it! I swapped the wires, and tried it again. This time it started up and all of the display and controls seemed to be working. In checking it out, though, I found that the spindle would go up and down and the table would move in and out, but the table would only move to the left, but not to the right. I theorized that the X Axis (side to side) servo wasn't getting all of it's control signals, so it would only move one way. Each servo has it's own controller circuit board in the controller, so I decided to have a look at the X Axis controller board. To get to the controller board you have to remove a big cooling fan, and then a big aluminum cooling fin assembly. Sure enough, inspecting the board closely with a flashlight revealed three blown resistors on the board. When this board was manufactured they were hand assembled with a soldering iron, so replacing the resistors shouldn't be to tough of a job. I disconnected all of the servo board wiring and put in a spare board. No one locally had any resistors like I needed, so I ordered some, and swapped in the spare board. I can repair the original board  when the resistors arrive next week. This time, when I powered it all up everything worked just like it should!

This particular milling machine has two spindles so you can machine two identical parts at the same time, so it has two separate 3hp. 3 phase 220 volt motors. The controller, the controller circuitry on the milling machine, and the servo motors all run on 220 volt single phase. Since I don't have 3 phase power available, I have to produce it myself. In the old days there were two ways to do it. You could use a converter that was basically a single phase electric motor driving a 3 phase alternator. This worked well ,but it was (and still is) quite expensive. The second way was to use a single phase to 3 phase converter box which "manufactured" a third phase using capacitors and so forth. It worked, but your 3hp. motor would only produce 2hp., so you either had to go to bigger motors, or live with less power. Now there is a much better way to get your 3 phase power, and it borders om magical! There is now a device called a Variable Frequency Drive" or VFD for short. The one I got is about the size of a lunch box, and through digital electronics not only converts single phase to three phase, it also lets you select the output frequency of the three phase power. Standard is 60 cycle (OK, Hertz, if you insist!!), but with a VFD you can select any frequency up to 200 cycles! Since the motor speed is determined by the frequency, the VFD then becomes a motor speed control as well. You can even hook up a potentiometer and a knob and mount it on the front of the machine so you can change motor speed simply by turning the knob. Tonight I powered up the VFD for the first time, and it does exactly what it says. In addition, it also has a built in "Soft Start" feature where it gradually, over a second or so, brings the motor up to speed. This is a lot easier on motors and equipment. All that is left now is to mount the VFD on a heavy duty bracket, and then connect the three phase wiring from the mill to the VFD. That should probably happen tomorrow sometime.

All that remains for the milling machine then will be for me to learn how to program it and start making sight rails and mounts for sale. I've got some good designs I've developed over the last few years, and getting them into production will certainly help to keep food on the table...............

6 Comments:

At Sunday, January 08, 2012 6:23:00 AM, Blogger Gudis said...

Any reason you wouldn't just control the spindle speed with the controller? I know HAAS controllers have a manual override for the spindle and feed speeds, I would imagine yours does too. Not to mention using MDI or changing the G code.

 
At Sunday, January 08, 2012 6:53:00 AM, Anonymous LibertyNews said...

Glad to see you're staying busy :)

 
At Sunday, January 08, 2012 9:55:00 AM, Blogger Mr. Completely said...

The Excello mill uses manually adjustable variable diameter pulleys to vary the spindle speed, and the controller cannot control it. Speed is changed by rotating a crank on the front of the head. If that pulley system ever fails, going to a toothed belt and using the VFD for speed control is a pretty good way to go. It works the way it is, though, so I'm not messing with it until there's a good reason!

Mr. C.

 
At Sunday, January 08, 2012 12:26:00 PM, Blogger Brigid said...

I don't envy ANYONE the dental troubles.

I hadn't planned on blowing my knee out over the holidays but fortunately EJ was off and could ride herd on Barkley and keep me company.

Hope all is well for you in the New Year.

 
At Monday, January 09, 2012 6:54:00 PM, Anonymous Anonymous said...

I read with some concern that "two identical parts could be manufactured at the same time". Mr. C have you forgotten the Heisenburg Principle?

Damiphino

 
At Wednesday, January 11, 2012 2:35:00 PM, Anonymous Anonymous said...

Hey Mike,
Glad to hear you're feeling better!
I have a handful of milling bits and a fly cutter left over from a few years ago, let me know when you're in Edmonds and I'll be happy to gift them to you.
Tim Otway

 

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