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Amazing story. I salute you for going through it. Toshiba used to sell CNC milling machines to the Soviets back in the 80's to make very quiet submarine prope

by ww520 16y ago

Amazing story. I salute you for going through it. Toshiba used to sell CNC milling machines to the Soviets back in the 80's to make very quiet submarine propellers. I wonder whether your version were just a smaller scale. If Fred had played his hand right, he could have made out a lot more.

jacquesm 16y ago
The kind of machine you are talking about is called a parametric CNC machine, not all controllers can do it, but those that can are capable of making very complex surfaces. http://www.cncci.com/resources/parametric%20programming.htm http://www.cncci.com/resources/parametric%20programming.htm The work you are referring to requires 5 axis control, something that is fairly common nowadays but back then was extremely rare. The software I wrote was not capable of such complex movements because the machine itself was only a 3-Axis machine, a 5-Axis retrofit would be extremely hard to construct. Basically you'd have to rip apart the main structure of the machine and rebuild it. (see http://www.youtube.com/watch?v=lWCaQ4XvG6Y&feature=related http://www.youtube.com/watch?v=lWCaQ4XvG6Y&feature=relat... from about 3:48) You could conceivably do that if you only worked on one kind of machine but retro-fits tend to be bolted on to whatever is available that still has a rotating spindle and good bearings. The software did have some parametric tricks but not a full suite, mostly related to making different sized versions of the same part. Most CNC machines are programmed in something called 'G-CODE', with a translator step between the CAD and the CAM part. The software that I wrote was much more tightly coupled (cad-cam all in one) so we had the full power of a regular programming language at our disposal to do complex part generation.
- ww520 16y ago
  Pretty amazing video. It's interesting to see how the people disregard safety while the machine is running. They walk so close to the drill. I can see what you meant if there were bugs in the software and the drill arm suddenly swung wildly.
  - jacquesm 16y ago
    There likely is a strike detector on the gantry and the arm the toolbit is attached to, so it is not quite as unsafe as you might think. I agree with you though that they're not practicing proper safety and I've seen numerous examples of millwrights and machinists missing digits, eyes or worse. A toolbit spinning fast enough will throw swarf around over considerable distances and it doesn't take much to take out an eye. In production use normally there would be an enclosure and mandatory goggles. No 'walking around in the machine'. Even the doors normally have interlocks, if they open it counts as an e-stop (emergency stop).

by ww520 16y ago

jacquesm 16y ago

The kind of machine you are talking about is called a parametric CNC machine, not all controllers can do it, but those that can are capable of making very complex surfaces. http://www.cncci.com/resources/parametric%20programming.htm http://www.cncci.com/resources/parametric%20programming.htm The work you are referring to requires 5 axis control, something that is fairly common nowadays but back then was extremely rare. The software I wrote was not capable of such complex movements because the machine itself was only a 3-Axis machine, a 5-Axis retrofit would be extremely hard to construct. Basically you'd have to rip apart the main structure of the machine and rebuild it. (see http://www.youtube.com/watch?v=lWCaQ4XvG6Y&feature=related http://www.youtube.com/watch?v=lWCaQ4XvG6Y&feature=relat... from about 3:48) You could conceivably do that if you only worked on one kind of machine but retro-fits tend to be bolted on to whatever is available that still has a rotating spindle and good bearings. The software did have some parametric tricks but not a full suite, mostly related to making different sized versions of the same part. Most CNC machines are programmed in something called 'G-CODE', with a translator step between the CAD and the CAM part. The software that I wrote was much more tightly coupled (cad-cam all in one) so we had the full power of a regular programming language at our disposal to do complex part generation.

ww520 16y ago
Pretty amazing video. It's interesting to see how the people disregard safety while the machine is running. They walk so close to the drill. I can see what you meant if there were bugs in the software and the drill arm suddenly swung wildly.
- jacquesm 16y ago
  There likely is a strike detector on the gantry and the arm the toolbit is attached to, so it is not quite as unsafe as you might think. I agree with you though that they're not practicing proper safety and I've seen numerous examples of millwrights and machinists missing digits, eyes or worse. A toolbit spinning fast enough will throw swarf around over considerable distances and it doesn't take much to take out an eye. In production use normally there would be an enclosure and mandatory goggles. No 'walking around in the machine'. Even the doors normally have interlocks, if they open it counts as an e-stop (emergency stop).