Lights out manufacturing is the holy grail for machine shops, the thought of machining parts unattended can be daunting and is no easy task. For over a year, Focused on Machining has taken on this challenge, working towards processes and systems that allow us to run lights out so we can increase capacity and reduce costs. We finally achieved that feat in November 2019. It was a combination of hard work on programming, tooling, fixturing, and the right part count that all came together on a customer job.
Here is what we did differently to achieve lights out running from our normal day to day operation.
Programming: We typically program aggressively and achieve max feed and speeds on normal operations. However, to ensure a fail-safe operation without an operator we had to think differently about many things in our program. This is what we did:
Turned down the aggression in our program and reduced our speeds and feeds, not by a lot, but enough to ensure we weren’t going to rip the part out of the vise or risk breaking a tool.
Incorporated our spindle probe and tool probe into our program to check features and distances post machining to verify we’d achieved what we’d hoped.
Used the tool probe to check tool edges to ensure we hadn’t broken a tool during a cycle. These steps we’re performed after each part was machined.
Accounted for chips in the machine. We made tool path updates to ensure the chips would be blown a certain direction and not into a corner of the machine where they would build up and cause issues.
Tooling: We loaded redundant tooling into the machine in case we did lose a tool on an operation. (thankfully this wasn’t needed this time around) We upgraded a couple of tools for this job specifically and used higher quality endmills that would last longer and perform better during operations. This added a bit of cost to the job but was easily recouped by machining lights out.
Fixturing: This was the most challenging part of our task to achieve lights out. The goal was part density, we wanted as many parts in the machine as we could fit to take advantage of the number of hours after our normal shift as we could. We utilized an aluminum tombstone that saved weight and allowed for a greater part density on our pallet. We combined that with a modular rail system from tombstone city that allowed us to hold multiple parts per face of the tombstone.
Right Parts: This was the last piece, and we were happy to receive an order of 100 parts that had an ideal amount of cycle time in the machine. This allowed us to spend the time to develop all the other aspects that we previously covered.
Moving forward, Focused on Machining is making substantial investments into our lights out operation, building upon the current systems and modifying where necessary so we can depend less on “the right part” in order to make lights out a success. Our goal is to achieve lights out operations with as few parts as 3 or 4 parts. Stay tuned!
Justin Quinn, President