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Many moons ago I also spent a fair amount of time in a machine shop, although never more than in an amateur capacity (I'm not sure I'd call what I did even moon

Many moons ago I also spent a fair amount of time in a machine shop, although never more than in an amateur capacity (I'm not sure I'd call what I did even moonlighting, mainly an enthusiast making small stuff), and I was never using really fancy machines as a result. What struck me was how just how little was automated, how stuff that was nominally automated still had quite a bit of manual labor. I had always had in my mind that with CNC machines you just stick the metal in the vise, load the program, hit start, and you're good to go, but there's manual calibration, facing off and the like that needs to be done before every run. For small, simple pieces I would often forgo the CNC automation and just manually make the piece myself, even when I had already made the piece in SolidWorks (and so could easily generate G code). I've heard that for really fancy machines it's truly a push button process (as long as you feed it precision milled blanks), but I've never had a chance to actually use those.

megraf 6y ago
It's all about the tools the shop has. Sapphire probes (edge finders) aid in a lot of the process. Mastercam allows you to simulate the machine process (and you can usually simulate it completely). Every shop is different – the shop I'm at here has a few lathes, robo-drills, 5th axis, and a few older pieces of hardware (which still are able to receive G-Code).
- dwohnitmok 6y ago
  I was definitely using edge finders (it seems like machining in general would be way way way more work without edge finders) and occasionally Mastercam. Definitely never used a 5-axis mill or robodrill though. I guess my main point of comparison was to laser cutters, which really were basically push button automatable in comparison. Granted the problem is a lot easier (purely 2-D cuts) and the cutter loses a lot of precision for thick material, but any time I got to use a laser cutter I was blown away by easy everything is and kept wondering whether a similar process could ultimately take root for machining.
  - phkahler 6y ago
    Machining can be simpler if you've got a couple precision features that can be clamped to with hard fixturing. It's all about positioning the workpiece accurately so the fixed g-code program can do its thing.
  - jononor 6y ago
    The forces involved in CNC machining is a large complicating factor, compared to laser (or 3d-printing). In a laser one can just throw the material onto the bed, and the results will be fine - not so on a CNC. And that one is quite inherent to the paradigm. Other aspects could likely be simplified and automated to a larger degree than today. In many areas solutions exists, but are quite high budget - things like tool changers, material loading and unloading.
extrapickles 6y ago
You can get electronic probes that measure the stock automatically so you don’t need precision blanks. The probe loads in the tool changer so it can be completely automated. Automatic tool setting makes it so operators don’t need to measure new tooling in tool holders, and tooling wear can be monitored automatically. I dabble in running a small machine-shop, and we are able to automate a good chunk of what people still do manually. The stock we use is cheap, straight from the mill stuff as we have the machine measure the stock with an electronic probe. The machines also have 20 pallets, so once the stock is loaded, the operator can leave the machine for 20x the cycle time of a part. The pallets don’t even have to be the same product, so we can queue up replacement of inventory with just the quantity that a customer ordered and offer a bunch of made-to-order parts with reasonable turnaround times. The machines also monitor spindle vibration so they can tell if a tool looses an insert, and the tool-setter is used to check if solid tooling is still intact. The only manual parts are taking raw materials off the suppliers truck, unloading finished parts (next on automation list), final assembly (working on automation for this), occasionally loading new tools as they wear/break and fulfillment.
- dwohnitmok 6y ago
  Wow! That really does sound closer to what I thought CNC meant before I stepped into a machine shop. That's pretty amazing stuff.
  - PragmaticPulp 6y ago
    This rabbit hole goes as deep as your budget allows. If you're curious, search for Renishaw probes on youtube. They make some of the best mainstream tooling in this space.
    - singularity2001 6y ago
      To turn on the probe, type G65 P9832. The CNC software world needs serious disruption / dev UI updates.
- Animats 6y ago
PragmaticPulp 6y ago
> I had always had in my mind that with CNC machines you just stick the metal in the vise, load the program, hit start, and you're good to go, but there's manual calibration, facing off and the like that needs to be done before every run. Much of it depends on the volume. If you're building a million of something, the up-front cost to automate every step of the way makes sense. If you're only building 10 of something once every few months, paying someone to do the manual operations 10 times makes more sense than investing in all of the fixturing, programming, and other tasks. Really though, a lot of smaller machine shops have older CNC machines that are paid for and otherwise sitting idle. Hiring someone for $60/hr to do all the manual steps can keep that machine profitable.
aj7 6y ago
That was before “good” machine shops had probes in every machine.
analog31 6y ago
As I understand it, the economics of machine shops are a bit weird because of the financing cost of keeping up with the latest equipment. If you have old machines, and not money to buy new machines, then you run old machines. The most modern shops are in extremely high demand, expensive, always busy, happy to turn down work. If you can design something in a way that lends itself to conventional techniques, you can get it into a smaller shop that may have some idle capacity, or run on the "tool room" machines in the big shop. The big shops always keep a few old machines around for tooling and jig work, rework, and one-offs. The smaller shops are also willing to take work that's not 100% detailed, even hand drawings. So you don't necessarily even need a CAD operator. "Do things that don't scale." In kind of an odd analogy, my old high school band mate built a recording studio from cast-off obsolete equipment that he bought for pennies on the dollar, and it meant that he couldn't take the biggest jobs, but he was instantly profitable and never in debt. Likewise, I have a very small side business that involves some basic metalworking, and I do all of it with powered hand tools and jigs that I made from plywood and carbide drill bushings. My capital cost was under 100 bucks.

megraf 6y ago

It's all about the tools the shop has. Sapphire probes (edge finders) aid in a lot of the process. Mastercam allows you to simulate the machine process (and you can usually simulate it completely). Every shop is different – the shop I'm at here has a few lathes, robo-drills, 5th axis, and a few older pieces of hardware (which still are able to receive G-Code).

dwohnitmok 6y ago
I was definitely using edge finders (it seems like machining in general would be way way way more work without edge finders) and occasionally Mastercam. Definitely never used a 5-axis mill or robodrill though. I guess my main point of comparison was to laser cutters, which really were basically push button automatable in comparison. Granted the problem is a lot easier (purely 2-D cuts) and the cutter loses a lot of precision for thick material, but any time I got to use a laser cutter I was blown away by easy everything is and kept wondering whether a similar process could ultimately take root for machining.
- phkahler 6y ago
  Machining can be simpler if you've got a couple precision features that can be clamped to with hard fixturing. It's all about positioning the workpiece accurately so the fixed g-code program can do its thing.
- jononor 6y ago
  The forces involved in CNC machining is a large complicating factor, compared to laser (or 3d-printing). In a laser one can just throw the material onto the bed, and the results will be fine - not so on a CNC. And that one is quite inherent to the paradigm. Other aspects could likely be simplified and automated to a larger degree than today. In many areas solutions exists, but are quite high budget - things like tool changers, material loading and unloading.

extrapickles 6y ago

You can get electronic probes that measure the stock automatically so you don’t need precision blanks. The probe loads in the tool changer so it can be completely automated. Automatic tool setting makes it so operators don’t need to measure new tooling in tool holders, and tooling wear can be monitored automatically. I dabble in running a small machine-shop, and we are able to automate a good chunk of what people still do manually. The stock we use is cheap, straight from the mill stuff as we have the machine measure the stock with an electronic probe. The machines also have 20 pallets, so once the stock is loaded, the operator can leave the machine for 20x the cycle time of a part. The pallets don’t even have to be the same product, so we can queue up replacement of inventory with just the quantity that a customer ordered and offer a bunch of made-to-order parts with reasonable turnaround times. The machines also monitor spindle vibration so they can tell if a tool looses an insert, and the tool-setter is used to check if solid tooling is still intact. The only manual parts are taking raw materials off the suppliers truck, unloading finished parts (next on automation list), final assembly (working on automation for this), occasionally loading new tools as they wear/break and fulfillment.

dwohnitmok 6y ago
Wow! That really does sound closer to what I thought CNC meant before I stepped into a machine shop. That's pretty amazing stuff.
- PragmaticPulp 6y ago
  This rabbit hole goes as deep as your budget allows. If you're curious, search for Renishaw probes on youtube. They make some of the best mainstream tooling in this space.
  - singularity2001 6y ago
    To turn on the probe, type G65 P9832. The CNC software world needs serious disruption / dev UI updates.
Animats 6y ago

PragmaticPulp 6y ago

> I had always had in my mind that with CNC machines you just stick the metal in the vise, load the program, hit start, and you're good to go, but there's manual calibration, facing off and the like that needs to be done before every run. Much of it depends on the volume. If you're building a million of something, the up-front cost to automate every step of the way makes sense. If you're only building 10 of something once every few months, paying someone to do the manual operations 10 times makes more sense than investing in all of the fixturing, programming, and other tasks. Really though, a lot of smaller machine shops have older CNC machines that are paid for and otherwise sitting idle. Hiring someone for $60/hr to do all the manual steps can keep that machine profitable.

aj7 6y ago

That was before “good” machine shops had probes in every machine.

analog31 6y ago

As I understand it, the economics of machine shops are a bit weird because of the financing cost of keeping up with the latest equipment. If you have old machines, and not money to buy new machines, then you run old machines. The most modern shops are in extremely high demand, expensive, always busy, happy to turn down work. If you can design something in a way that lends itself to conventional techniques, you can get it into a smaller shop that may have some idle capacity, or run on the "tool room" machines in the big shop. The big shops always keep a few old machines around for tooling and jig work, rework, and one-offs. The smaller shops are also willing to take work that's not 100% detailed, even hand drawings. So you don't necessarily even need a CAD operator. "Do things that don't scale." In kind of an odd analogy, my old high school band mate built a recording studio from cast-off obsolete equipment that he bought for pennies on the dollar, and it meant that he couldn't take the biggest jobs, but he was instantly profitable and never in debt. Likewise, I have a very small side business that involves some basic metalworking, and I do all of it with powered hand tools and jigs that I made from plywood and carbide drill bushings. My capital cost was under 100 bucks.