3D Printing is on average less expensive than injection molding up to about 100,000 pieces. If you are making more parts than that in a production run then a mold might be advisable. (Though you should also consider the Just In Time Supply benefits of 3D Printing as well). But that is just an average. So what are ways to optimize a product for mass production with 3D Printing. Here are a few tips
This is by far the most important component, to 3D Printing or any other manufacturing process. Any product design has to be optimized to the 3D Printing process to be made the most cost effectively.
For FDM production 3D Printing the general rule is Fatter, Rounder, Thicker. This is often difficult for designers to adapt to. Injection molding is often the exact opposite (i.e. Thinner, flatter, straighter). But since 3D Printing allows so much control of the properties of a part, volume is irrelevant and the geometry changes often allow the 3D Printed parts to have better performance than a traditionally manufactured part.
Here are more details on design for FDM Production 3D Printing
3D Printing has no MOQ. You can make one piece or millions. And while this seems obvious any increase in volume decreases the per unit cost of production.
We are often asked by clients what are the volume cutoffs for price breaks. At Slant 3D there are none. Basically any increase in quantity decreases the unit cost. It is a curve not a set of stairs. And how steeply that curve drops the prices is entirely dependent on the product.
Since 3D Printing does not have to to produce an entire run of one part at a time the way injection molding does, we instead can produce partial runs of dozens of parts at a time. This not only ensures that a project can launch on time, it will in fact decrease inventory costs on the client side.
This is how it would work. A client might request 10,000 parts for the project. But they only need 1000 per month. Rather than producing all of the pieces in a bulk shipment, Slant 3D would dedicate a smaller amount of capacity to just making 1000 units per month and shipping on a set date. The benefit to Slant 3D is more predictability in production scheduling and the clients has lower inventory carrying costs since they only have 1000 pieces on shelves at any given time not 10,000 collecting dust. Thought sometimes extra shipping charges can offset the cost benefits.
Longer Production Time Using Excess Capacity
Plan ahead. Rushed orders are expensive orders. And while any project will have an expected timeline within the normal production flow, longer lead times can be great cost saving options. And 3D Printing allows these to be achieved much more easily without always delaying a project.
Historically most products have a defined lead time. This is because the client has to be able to plan the launch. And the manufacturer has to produce all the units in one go. 3D Printing is not so stringent. Especially 3D Printing Farms. We have hundreds of machines working on hundreds of projects at any given time. Each machine could be working on any of the active projects. For example, if there is a rush order, most of the capacity could be pointed toward production of that single order, and then the next day switched to the next order in the queue.
But even more common than rushed orders are intermittently used equipment. Since manufacturing is often cyclical some equipment may be unused or kept for overflow purposes. This is called "excess capacity." (Most factories seek to operate at at 85-90% capacity, the extra 10% is for spikes in demand).
If a project has no set lead time then it can be produced on that excess capacity. This allows production capacity to be utilized more effectively and decrease machine down time. The tradeoff is that at any time your project production could be usurped if that capacity has to be utilized for priority clients. So in return for allowing us to utilize our factories more effectively and possibly having a longer lead time, we are able to discount the machine-time component of production.