You're a program manager for a big consumer product company. Your team just finished your your complex assembly's design qualification. You've spent tons of money on the development phase of your project and completed your design qualification successfully. You're 2-3 weeks behind schedule, but you've had great results and your prototypes have passed all of your testing requirements with flying colors so you're hoping you can make it up on the back end. You added a month or so of fluff time so you should be alright. You 3D printed 50-100 of each off the plastic parts and they all performed well, so you're not expecting any issues. Prototype tooling for your molded parts was going to take too long and put you over budget so you just upped the quantities from your internal printing department to meet the DQ quantities needed. If the 3D prints were good enough, the injection molded parts should perform much better right? Atleast that's what the design team lead you to believe.
You put together your RFQ package and send it out to your usual go-to's. Some numbers start coming in everything is looking good compared to your initial estimates, so you start the internal process to request the appropriate capitol in anticipation of using the molder you make all your parts at. Your last supplier to submit a bid is taking a bit longer, they say they're still reviewing the parts. They're relatively new for you (and to the industry) so you attribute it to just learning the ways you do things. Doesn't really matter though, because you know you're going with who you always go with. They give you great pricing because of all the volume you do with them and the lead times usually are the best. Your companies have been doing business together for over 20 years now.
You finally get the last supplier's reply, its inline with others, but there's a 10-25 page document for each the parts and is labeled DFM package. You're immediate thought is, well this is great, they really reviewed the parts. Your go-to doesn't usually do that much work until after the PO issued. The comment "we don't provide free engineering work" is usually what they say when you try to get ahead of things. As you start going through the documents you see numerous concerning issues. You see things like "draft needed" on most parts, "too thin will short" or "too thick won't pack out". There's a gate location on the biggest of the parts with a note saying there will be gate vestige, this is on an important/functional surface. There's a note saying "if no gate vestige is needed a hot manifold valve gate system will be needed and it will be 30% more expensive and will take 6-9 weeks longer" below, this is time you didn't have. They also give a cost and time to have them make ALL the changes, its reasonable based on what you've paid for design work but it pushes the timeline out even further. Given the time and cost needed you inform the supplier thank you but they will be significantly higher and you can't afford the added time for all of these issues they are bringing up. You assume your more "experienced supplier" is going to be able to handle this, and they probably already know what is needed to get you the quality of parts they have in the past.
You go with your go-to supplier and cut a PO, it was ready already because you never planned on going with someone new for such a critical project. A few days later you receive an email with a PowerPoint titled "Part concerns". Fast forward months later to T1s:
- The manufacturer brought up most of the same issues as the new guy but they refused to help on the changes. Your engineers were able to do it, but given they don't have that much experience with plastics or mold design, it took three weeks and a lot of back and forth to get it right. The presentation of the concerns wasn't clear, and they kept bringing up new issues as they got through the designs of the mold. Cost and timing to do it internally, was more than double of what the other supplier would have charged.
- On the parts that had surfaces which couldn't be gated on, all but one required hot manifolds. It cost more than the other supplier (they said they use premium manifolds???) and took the full 9 weeks for them arrive because they waited to order them. This is how it should be, but your team took 3 weeks to resolve all the DFM issues. One part was re-designed because nothing worked out. It forced an abridged DQ an you just kicked that one off months later. You will have to rely on 3D printed parts for your first few validation builds, but you've done this before so it should work out.
- Several of the parts had severe sink in one area. The manufacturer brought it up early on, they asked you to accept it if you weren't concerned about the part appearance which you weren't, so you did. Its internal to the assembly and would have only cost more time/money to correct it. However, the manufacturer is now having issues hitting a lot of the dimensions on the part which is coming out VERY small because they can't pack out the part. They gave you a quote to groom the tool to make the thickness changes, you did approve the sink was going to be OK afterall.
OK, so where am I going with this. Due to the amount of time and capital that is spent on developing tooling and manufacturing processes, companies often have one or two suppliers that they have historically used. You have relied solely on the experience of personnel both internally and at the suppliers to get your parts right but recently, people have been retiring or moving on to other companies and taking the "ancient knowledge" with them. I'm not talking a few parts in a box, you have million dollar lines, complex assemblies, secondary finishing, custom packaging and the works. Your internal systems are so intertwined that you even have your out dated ERP systems interconnected. You're STUCK. So what can you do?
Every situation is different and every company has its own situations/partnerships. I think the key take away from this article should be that regardless of the circumstances, there are several steps that you can take to better protect your assets and keep your manufacturer in check. In cases where you have tons of legacy projects, start with the new projects. When you have time, go back and address the older projects if things were missed. Here's a list of things to consider when kicking off new projects:
- Make sure you engage your mold maker/manufacturing team early and often. In our example above, weeks if not months could have been avoided if they sent out their parts for review before they started their DQ phase, rather than after.
- Once you lock in a design, send in your parts for a DFM review. At a bare minimum, it should contain information showing the following items; Parting line location, ejection type and general location, gating strategy recommendation, thickness review and recommendations, draft review and recommendations, and a redline of your drawing. IFFFFFFFF your manufacturer refuses to do this without a PO ask them what it would cost and break it out of the total tooling. Its also a good idea to bring on a 3rd party to consult if the molder doesn't have the personnel.
- Request a detailed timeline and weekly progress updates. This can literally be an email saying the project is on schedule and a few photos here and there. If still a problem, make a weekly phone call and you keep track. If things start to slip, raise the flag and ask what you can do to help.
- If you are making prototype tooling, be sure confirm what exactly is owned by you. If you are only getting core/cavity impressions (A side blocks / B side B blocks) and it will in a shared mold or mud frame, request a standard size is used. DME's MUD frames are a common variety. If things go so bad you need to ship the tooling, this will ensure you can hit the ground running.
- Request a design review before they start cutting steel. This might seem to slow you down, but make your manufacturer explain the plan, show you how the mold components will create your design, and have them run through their mold design checklist. If they don't have one they should. No one knows your part better than you. Regardless of your molding experience, you might find something that will save time and money. Jay W. Carender's "Pocket Injection Mold Engineering Standards" is a fantastic resource and has a good example of a mold checklist. It is available on Amazon and is a great buy if you're in plastics.
- Discuss the quality plan, maintenance plan, and escalation strategy. You want to know how your parts are going to be evaluated/released and your assets (molds, robotic cells, etc) are going to be maintained. As for an escalation plan, you want to know who you need to contact when something goes wrong at each stage of the process and more important, who to escalate to when you're not getting the support you need.
- Request mold files. This can be 3D's, 2D's, but ideally both. Most companies do a 3D design first and for design reviews, a quick 2D of the assembly should be made. This should show the A side of the mold, the B side of the mold, the ejection system, the runner/gating system, the cooling/heating in the tool, and each of the "touches steel" components broken out. You want to see material's and hardness for each components, overall dimensions, and some of the basic molding information. I like to see the molded material and its recommended melt/mold temps, projected surface area, shrink being used, shot size, where the mold will be made, and then basic information of the press it will run in. You might get pushback. If you do, ask what they're willing to give. Any molder should be willing to atleast do a live presentation or even offer to pay for the items, it is worth it. If you still get pushback, and there's not a good reason this should be a red flag.
- Request steel certifications from the material suppliers. If you're being told you are getting high quality steel, this should not be an issue.
- Request to attend first shots. If not feasible, you should ask for a video of the mold running, a process sheet, and samples at every stage (EVEN MORE SO WHEN THERE'S PROBLEMS).
- Request a material cert with each shipment. Most just say the parts conform to the drawing but I would go a step further and have them include any agreed upon dimensions taken as well as the material certs for any lots of material used.
Molding is hard. There are so many moving components that have to come together to make a part successful that its often easier to just let your manufacturer take charge and hope for the best. Be as engaged as you can and get as much information as possible. If you do a lot of parts, you should create purchase specs and universal quality documents to show the standard level of service you expect. If your are a bargain shopping, be sure to be upfront in what you're looking for so you can select items à la cart but know shortcuts have consequences. If you're already STUCK and trying to fix a broken relationship with your manufacturer, find a molding consultant that can both understand the part needs as well as the shop floor and have them mitigate. Feel free to DM if you want to discuss the topic further or need me to point you in the right direction.