What is Batch Production?

What production methods are available between Rapid Prototyping and large batch production?

• I work for a start-up that is looking to produce hardware products. For small/one off production RP methods are excellent, and if we were to make 1000s then Injection Molding would be cost efficient. What methods are available for intermediate stage of making 10s to 100s?

• Answer:

  3D Printers Some 3D printers, such as the Objet series (http://www.objet.com), print using plastics that can be used in production.  It's probably not the cheapest solution but it's fast and handy. Plastic Resin Casting In this case you are casting 2-part thermoset polymer resins into molds.  There are a few choices (epoxies, urethanes, polyesters, silicones, ...) but polyurethanes are probably your best bet because they are the most flexible: faster cure times, availability of foams and rubbers also. Check http://smooth-on.com , you can find anything you need there. Small-scale Injection Molding Machines There are a number of small, affordable injection molders on the market.  They are hand or pneumatic operated.  Here is one example, http://www.injectionmolder.net/, but there are many other different ones.  Contact me for links to more machines.  These machines will do fine for small parts, in limited quantity, in polypropylene, HDPE, LDPE or polystyrene, all recyclable plastics.  Molds can be machined in aluminium or cast in aluminium-filled epoxy, costs much less but do not last as long as steel. Machining and Laser Cutting Laser cutting is very affordable for flat parts.  PVC and composites (carbon fiber, kevlar) cannot be laser cut but can be waterjet cut. Machining is also a good alternative but plastic parts seldom come out with an acceptable finish.  Finishing them costs extra so it's fine for hidden parts that don't require finishing.    Blow Molding, Vacuum forming, Rotocasting There are affordable machines available for limited production runs.  Outsourcing can also be considered.  The moldmaking part will determine the cost.  That's where you'll need to be creative.  For example,  an aluminium-filled epoxy mold, even one made of MDF, can do many vacuum-formed copies at a fraction of the cost of a metal mold.  Rotocasting using 2-part resins does not require metal molds also.  Metal Parts Getting them machined is the straightforward alternative. Finishing may be required.  Also consider investment or die-casting of zinc alloys.  Costs very little for a minimal, low-quantity setup.  Zinc is easier to cast than aluminium, but aluminium can be cast also. Laser, plasma and waterjet cutting of flat metal parts is easy and affordable. Use of a machine press (for stamping or punching) can be affordable but the dies can be expensive to make so quantities must be bigger to justify. That's all I can think of... As you can see, anything can be done.  Just don't expect it to cost anywhere near large-quantity prices.  Middle-scale production is a balancing act between costs and quantities.  For keeping costs down, my best advice is to keep the parts-count low.  Every part has a setup cost that adds to the final price.