Injection molded plastic shells - food for thought

[supertazon]

Having injection molded plastic shells is not as expensive as some might claim: for a GBoy type of shell the costs for a mold vary from $ 5k to $ 12k (shipping excluded).
​

Methodology
I've always wondered how much it would cost to have injection molded plastic shells made. Some emulation consoles like ExperimentalPi's PiBoy DMG, which is not a huge producer like Anbernic or Retroid, have managed to offer kits with injection molded plastic shells. If they could do it, why not us?
Everytime I would ask in a discord server, I would get prices ranging from $ 20k to over $ 60k, which of course seem unreasonable for hobbyist projects like ours. Unsatisfied by the lack of sources for these figures, I set out to ask for quotes from manufacturers directly myself:

• I chose the GBoy, and specifically Curtis' DMGBoy as a starting point: it's an easy and robust build, truly portable and overall my favorite design. This exercise could have been done with the Ashida as well (feel free to do it and let us know how much it would cost!)​
• I converted the STL files into STEP files as most manufacturers cannot work with STL files meant for 3D printing. I followed this tutorial using FreeCAD.​
• I included the following parts: top and bottom shell + START, Z, Trigger, Power buttons​
• I searched for injection molding service providers from China and sent a quote request to 5 providers​

Results
I am attaching the quotes in a ZIP, feel free to check them out to get the details. Here is a breakdown:

• Prices include mold production + test runs and tweaks to the mold + production runs of 500 / 1000 / 2000 pieces
• Prices do not include shipping of the pieces to a warehouse / store
• Most (if not all) providers do not require a MOQ, I do not know how many Gboy kits were sold previously but 500 seems like a good starting point. I could always ask for 200 units, the prices would be lower I guess
• Down payment of 50% when ordering, 50% when the samples are validated by the client

Manufacturer​	Piece​	Mold cost​	Unit production cost​	Total cost for 500 units​	Cost per unit (for 500 units)​
Sositar Mould	Case + buttons	$ 5,200​	$ 0.85​	$ 5,625​	$ 11.25​
LK Mould	Case + buttons	$ 6,906​	$ 1.38​	$ 7,596​	$ 15.19​
FOW Mould	Case + buttons	$ 9,600​	$ 1.53​	$ 10,365​	$ 20.73​
Rilong Mold	Case + buttons	$ 12,800​	$ 1.50​	$ 13,550​	$ 27.10​
Agilian Technology	Case + buttons	$ 12,707​	$ 5.04​	$ 15,227​	$ 30.45​

Is it still too expensive?
Let's say we settle for the middle ground with the FOW Mould at a total cost of $ 10,365 which would make each shell cost $ 20.73. To that we would need to add shipping costs, I am not sure how much that would be but let's say $ 1,000, we thus have a total cost at $ 11,365, and each shell at $ 22.73. It's safe to say that selling these shells at $ 50 would still be more interesting than getting them resin printed + coated (painted or transparent coating) through JLCPCB or PCBWay. At $ 50 each, you would break even at 228 shells, the remaining 272 would be there for profit.
Of course this is a very rough estimate not including taxes and whatnot, still: doesn't sound too crazy to me.

Where do we go from here?
If we were to seriously consider this, here are the next steps I would do:

• Finalize the design:
  • The main pain point of the GBoy is its triggers, something has to be done about them
  • The screen space should accomodate a laminated 3.5" IPS screen (like this one) instead of the regular screen + glass lens
  • The design has to be reworked to be injection molding compatible
• Check the quality of the manufacturer: if possible by contacting trustworthy peers who have dealt with injection molding service providers. For example I would ask ExperimentalPi who he has been working with. Another way would also to ask the manufacturers some ABS samples to test the texture and make sure they can provide something close to a real DMG shell
• Organize a pre-order, as we've seen "only" 228 pre-orders could cover the cost for the whole project, while it does seem like a lot, I feel it might be reachable
  • Considering how building Wii portables is becoming easier with the latest flexes, I wouldn't be surprised we could reach that many clients
  • If we have injection molded plastic shells, I'm sure more and more people would be interested in having commissioned builds

That's all folks! I hope you learned something, I certainly did.

 

[thedrew]

@ohkin86 has done injection molding with the Wii U shell, maybe he might have more information on the process/cost.

 

[ohkin86]

@ohkin86 has done injection molding with the Wii U shell, maybe he might have more information on the process/cost.

You are right. The company I work for is a factory that produces injection molding. I am planning for the injection molded shell of ashida, and g-boy is also a future goal. Although many factories can make molds and produce them, they require a minimum order quantity of 100 or 500 for various colors. The advantage of the factory where I work is that I can freely command technical personnel to help me produce various colors in small batches.

 

[Wesk]

You are right. The company I work for is a factory that produces injection molding. I am planning for the injection molded shell of ashida, and g-boy is also a future goal. Although many factories can make molds and produce them, they require a minimum order quantity of 100 or 500 for various colors. The advantage of the factory where I work is that I can freely command technical personnel to help me produce various colors in small batches.

Proof that it's not what you know but who you know