Author: Paul Van Metre
As Jim and Jason always say on the MakingChips Podcast, “If you’re not making chips, you’re not making money!” We all know it’s true, yet precious few shops have formal systems for increasing uptime. The corollary to that is reducing spindle down-time. An important component to that is to reduce the downtime between jobs – that is when you finish the last part on the job you’re just finishing and when you make your first good part and start running the next job on that same machine. That’s what I want to focus on today. There are a few barebones things that need to happen when you finish a job.
1. Remove the fixtures off the machine, or take out your softjaws, etc. (unless you have modular tooling that will be used on the next job also.)
2. Take any cutting tools out of the machine that you won’t be using on the next job – don’t remove them from their holders unless you absolutely need to.
3. Clean off the bed or table.
4. Download your programs (and save them) or delete them off the machine.
5. Sign off that you’ve finished that operation on paper or in your ERP system. Ideally document your setup somewhere.
6. Wheel the cart or pallet to where it’s going next.
That process is generally fast. If you’re lucky enough to be on a horizontal, you might even be able to change out your fixturing while your other pallet is still running. Or maybe you’ve designed universal tooling so changing over doesn’t require taking out your fixture, or only takes seconds. There has been much study and books written on SMED! Google it if you’re not familiar.
Generally, the next step of the process is getting your next job set up on the machine. This is where most of the savings can be had and where many companies need a lot of help. Here is how it often looks:
1. The machinist goes to find out what is next on the machine and get the paper job traveler.
2. They go and look for material and hopefully find the right stuff.
3. They start collecting some cutting tools and holders from the setup sheet which match the general description of what they are looking for (e.g. ½” EM - but may not be exactly the right tool at all).
4. They try to find the fixtures needed for the job which may be lost, damaged, or misplaced.
5. They bring these things over to the machine.
6. They review some incomplete set-up instructions on an old set-up sheet or they try to remember it from last time.
7. They load tools into the machine, and manually touch off the tools in the machine or with a machine probe.
8. They mount fixtures or vices. (hopefully the fixtures are dialed in with pins or you use zero-point fixtures. If not, then they need to find a dial indicator and dial in the fixtures or vises.)
9. They upload the program into the machine controller.
10. They wander away from the machine several times to go find things they didn’t collect at first.
11. They put some raw stock into the fixture or vise.
12. They turn the feed and rapids down, maybe put it on single block, and show “distance to go” on the controller.
13. They slowly step through the program and prove it out, being careful to not crash until the entire part is machined
14. Go find measuring instruments to check the part.
15. Check the resulting part against a paper drawing which may be dirty, ripped, old-rev, and check a bunch of dimensions to see if they think the part is good.
16. Once they have a part they think is good (which might take several tries), they submit the part to the QC department and wait (sometimes a long time).
17. Once they have received approval from QC, then they can start making parts. This is when the timer stops, and the spindle is “Up” again.
As you can see, this is a lengthy process and can contribute to vast amounts of downtime where you aren’t “MakingChips”! And the description above is still somewhat of an ideal case. Plenty of times the things they are looking for aren’t there, can’t be found, or aren’t ready yet. It can go south quickly, and setups can take many hours or longer! So much lost opportunity for revenue and throughput! There must be a better way!
ProShop ERP can help facilitate and guide shops to dramatically reduce this downtime between jobs. We studied this problem for years ourselves at our own shop. We applied lean principles, concepts from franchise-type businesses, and decades of our own experience and those of our employees. We built the best practices into the software we were developing to run our own shop – ProShop. Here is how the process looks using ProShop – 100% paperless and web-based.
1. Before the last job is finished, ProShop guides the employees through a checklist to ensure all the necessary items required to ensure a fast and repeatable setup have been prepared in advance and are sitting in a queue area, or are digitally prepared and ready to go.
a. The proper cutting tool ID numbers are collected, loaded in the proper holders and extension lengths as defined by the programmer. Offline tool length presets have been measured and stored in ProShop. A G10 offset file has been automatically generated by ProShop and is waiting to be upload into the controller. This tool caddy is loaded on a cart.
b. A well-maintained fixture is pulled from the well-defined storage location and loaded on a cart. (ProShop will show you if it was overbooked)
c. Ancillary items like inspection equipment, packaging materials, deburring equipment, etc. have been specified and collected and loaded on a cart.
d. A proven G-code program which has been stored in a secure file location managed by ProShop
e. The proper material is pulled from a specific storage location defined in ProShop. Traceability is guaranteed to be right.
2. When the prior job finishes, ProShop quickly guides the employee through a breakdown checklist and the machine is ready to go for the new job.
3. They start tracking their time on the new job with ProShop’s fast Time Tracking interface.
4. They load the fixtures, tools (and only the ones that need changing), raw material, tool offset files and G-code programs into the machine, following the digital work instructions with videos, photos, etc.
5. Run the proven code on the first piece.
6. Inspect the first part and record the results in ProShop’s FAI form using the specified instruments and only the dimensions which require checking per the requirements. ProShop will instantly tell them if the part is good or not (And it will format the FAI in the AS9102 if you need it to). If the part is good, then:
7. Check off the “Certified to Run” checkbox (which prompts you to update the setup and cycle times) and log out of “Set-up” and into “Running”.
You have good parts off the machine and the spindle is running again much faster than the first scenario. You’ve increased throughput and have higher revenue on your machine.
The important takeaways are that the setup was highly choreographed, the employee didn’t need to leave the machine, and it took a fraction of the time. It’s also important to note that a less skilled employee (ProShop will manage all their training by the way.) was needed given how much information was available to them. Shift leads, or managers would get automatic notifications if the setup exceeded its time budget, so they can provide support. Also, any out-of-tolerance results that were generated would have prompted an NCR which would also alert managers through our messaging system. Your employees are more supported and successful, increasing engagement and satisfaction.
When you go buy a hamburger at a fast food restaurant, they don’t figure out how to make the burger each time. They follow a very well documented process to make it as fast and repeatably as possible. Producing a highly complex and high precision engineered component is at least two orders of magnitude more complex than a burger. So why would you make your employees do it without a concise and bulletproof plan? It’s because your legacy “one-size-fits-none” ERP system has none of the functionality required to walk employees through the process. You’ve been given a set of tools with a bunch of the tools actually missing. It might be time to upgrade your toolbox. Let us know if you’d like to discuss upgrading your tools.