Worth compromising appearance to save money?

Maybe this could be on the general board, but as it relates to injection molding…

For a injection molded product, mostly funtional but with some aeshtetics , e.g. a stapler or a tape dispenser or cup holder.
Assume example plastic ABS , design change no effect on assembly/packing costs.

I’m currently at the CAD stage have 140gram of plastic , looks very good, could reduce to maybe 100gram but end up with a mediocre-to-average looking product.
OTOH 40g saved is 40g of money gained…

How far is it worth reducing plastic to save cost at the expense of the products appearance?
The cost of plastic fluctuates, I dont actually know how much saving 40g would generate , any approximate idea?
Maybe the answer to the second question will answer the first anyway.(?)

Thanks in advance

Mike

You’ll find the prices for ABS compounds and regranulates online. I only happen to know sources in German. But the prices are the same: ABS is around 1.80 Euro per 1000 gramms. Recycling around 2 /3 of that.

So saving some Matrial will most probably not be worth it. At least if you are looking at more than 2 Euro retail for your product.

mo-i

Depends on the quantity, but usually the money is in the tooling. Maybe this is useful:

Cost is cost.

Price is determined by what the market will bear.

If your design change lowers your price more than it lowers you cost, don’t do it. If your price changes less or none and you increase margin, do it. It is that very margin that pays your salary.

Good product design is always a balance of compromises. There will be a point at which reducing your material (e.g., decreasing the nominal wall, which is the primary driver of part volume) will start to affect the part’s structural integrity as well as its processability and appearance. If you have internal ribs, bosses, etc, those will need to be reduced as well, otherwise you could have sinks, read-through, flow lines, etc. Reducing the nominal wall will also change how the part feels to the user (less solid = lower quality).

This is something that can be difficult to simulate, even with a 3D printed prototype. For a material like ABS, I find using reference parts useful. Over the years I have accumulated a decent library of parts (form my “product autopsies”) that represent a variety of nominal walls, ribbing and boss details, parting line as assembly details, etc. You might be able to find a part sample that is representative of your new design to get a hands-on feel for the amount of flex and surface finish you could end up with.

I think part of our responsibility as designers is to negotiate with the business, marketing, engineering and manufacturing stakeholders to make sure everyone is making informed choices. Sometimes that means advocating for quality over being the lowest cost producer. A “race to the bottom” isn’t always best for the customer.

Best of luck on your project.

w

Warren: This is GOLD.

I should start to call the clutter behind my desk “library”. But perhaps I should get it organized accordingly, then.


Thanks for your input.

mo-i

Similarly, can you demand a premium price for the nicer aesthetic, or conversely does a diminished aesthetic impact your price negatively.