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One thing that strikes me as odd is 2:48 it says the rollomatic produces 48 pieces per hour, and then at 3:24 a human dominated process for centering the work p

One thing that strikes me as odd is 2:48 it says the rollomatic produces 48 pieces per hour, and then at 3:24 a human dominated process for centering the work piece to have it's drill curve cut "take four to five hours". They surely don't have 200 of these setting jigs. So, are there just lots of blanks made? do they damage that many of the work pieces in the process of setting one up? Are the surplus units used in some other process? I'm curious because that seems like a complicated piece of machinery to only be operating at a few percent of up time.

s1mon 4y ago
That "four to five hours" didn't make any sense to me either. Perhaps they meant that doing this for a batch of bits takes that much time? It also struck me as disappointing that the actual grinding of the flutes was not really shown. I'm sure it would be hard to photograph as it's likely completely bathed in cutting fluid, but perhaps they could have done a run without it just for the video?
- hulke 4y ago
  The "four to five" hours they mention is probably the time required to setup the grinding center, maybe dress the wheels, do some fine adjustments on the grinding process. Once the machine is setup, grinding each drill is just a few minutes. The grinding machines they are using seems to require quite a bit of manual handling, but cnc grinding center where everything is automated also exists. Actually, the grinding of the flutes is shown very briefly around 3:35. Filming this operation on such a small scale is difficult because of the geometry of the system and the grinding process: the drill blank is supported from below to prevent the carbide from snapping under the load, and the wheel grinds from above. The grinding wheel is order of magnitudes larger in diameter than the diameter of the drill it is grinding. Also, everything is flooded with cutting fluid. There are hundred of videos showing the process on youtube if you look for "cnc grinding drill".
mauvehaus 4y ago
They also said that the centerless grinding process is used to reduce the length of the blanks. I'm pretty confident they're doing it to get the finished diameter of the shank. I find the How It's Made segments to be irritatingly shallow and sometimes grossly inaccurate. You could easily do a 22 minute segment on making these things if you went into more depth.
- tejtm 4y ago
  absolutely finishing the diameter not the length, was jarring to hear that
- jcims 4y ago
  >I find the How It's Made segments to be irritatingly shallow and sometimes grossly inaccurate. You could easily do a 22 minute segment on making these things if you went into more depth. It's all well and good until they touch on a process you're very familiar with then 'holy moly, is it always this bad?' Still one of my favorite shows though...it's eye candy for machine dorks like myself.
hulke 4y ago
It really depends on the workflow and scale of operation the cutting tool manufacturer. Some focus mostly on small batches of very specialized tools, and some focus on producing huge volumes of standardized cutting tools. And anything in between of course. Whatever the grinding machine that is used, there is always a necessary setup step before the production run. The setup involves installing some equipment on the cnc machine, heating up to operation temperature, calibration, dry run to check for possible collisions and grinding a few pieces and check that they are within specs. The name of the game is then, given typical customer order or target market, to find the right balance between the utilisation of the different machines, human intervention and automation while optimizing for cost and cutting tool quality. In the video, it look like it is a pretty small manufacturer doing small specialized batches. In this case most of the time is spent doing machine setup and quality control, and the drill value doesn't justify the investment into a more complex or automated system.
dtgriscom 4y ago
I think the "four to five hours" is to set up the process; once set up, it can machine multiple bits.

s1mon 4y ago

That "four to five hours" didn't make any sense to me either. Perhaps they meant that doing this for a batch of bits takes that much time? It also struck me as disappointing that the actual grinding of the flutes was not really shown. I'm sure it would be hard to photograph as it's likely completely bathed in cutting fluid, but perhaps they could have done a run without it just for the video?

hulke 4y ago
The "four to five" hours they mention is probably the time required to setup the grinding center, maybe dress the wheels, do some fine adjustments on the grinding process. Once the machine is setup, grinding each drill is just a few minutes. The grinding machines they are using seems to require quite a bit of manual handling, but cnc grinding center where everything is automated also exists. Actually, the grinding of the flutes is shown very briefly around 3:35. Filming this operation on such a small scale is difficult because of the geometry of the system and the grinding process: the drill blank is supported from below to prevent the carbide from snapping under the load, and the wheel grinds from above. The grinding wheel is order of magnitudes larger in diameter than the diameter of the drill it is grinding. Also, everything is flooded with cutting fluid. There are hundred of videos showing the process on youtube if you look for "cnc grinding drill".

mauvehaus 4y ago

They also said that the centerless grinding process is used to reduce the length of the blanks. I'm pretty confident they're doing it to get the finished diameter of the shank. I find the How It's Made segments to be irritatingly shallow and sometimes grossly inaccurate. You could easily do a 22 minute segment on making these things if you went into more depth.

tejtm 4y ago
absolutely finishing the diameter not the length, was jarring to hear that
jcims 4y ago
>I find the How It's Made segments to be irritatingly shallow and sometimes grossly inaccurate. You could easily do a 22 minute segment on making these things if you went into more depth. It's all well and good until they touch on a process you're very familiar with then 'holy moly, is it always this bad?' Still one of my favorite shows though...it's eye candy for machine dorks like myself.

hulke 4y ago

It really depends on the workflow and scale of operation the cutting tool manufacturer. Some focus mostly on small batches of very specialized tools, and some focus on producing huge volumes of standardized cutting tools. And anything in between of course. Whatever the grinding machine that is used, there is always a necessary setup step before the production run. The setup involves installing some equipment on the cnc machine, heating up to operation temperature, calibration, dry run to check for possible collisions and grinding a few pieces and check that they are within specs. The name of the game is then, given typical customer order or target market, to find the right balance between the utilisation of the different machines, human intervention and automation while optimizing for cost and cutting tool quality. In the video, it look like it is a pretty small manufacturer doing small specialized batches. In this case most of the time is spent doing machine setup and quality control, and the drill value doesn't justify the investment into a more complex or automated system.

dtgriscom 4y ago

I think the "four to five hours" is to set up the process; once set up, it can machine multiple bits.