Design to Manufacturing, When to hand over control

Hello All,

Need some help/advice. I have a few projects im working freelance on. Can anyone describe to me in detail the process a design consultancy would take from inception to completion. Say an ipod docking stand, how would this travel from sketching and CAD development. When does the designer hand it off to a engineer, or would a factory who would produce it do the engineering? How would the product be fulfilled, would the internals be fulfilled at the same plant as the injection molder? Do design consultancy usually have relationships with different manufacturing plants? Or do they go to an outside firm to assist in outsourcing this end of production? I would imagine each company is different, but can anyone give a rough estimate of how this would look? I have found manufacturers overseas via and I want to know what they are expecting me to delivery? Should i as a designer be expected to know about gates, snap fits, wall thicknesses, mold flow etc?

Any tips or comments related to manufacturing/ material sourcing are greatly appreciated.

I work in a small design firm associated with a large injection molder. Most of the time I hand over my cad at the point where we are looking at making injection molded parts. Most of the parts at this point have already been seen by our engineers and I will work with them to get it at least close to moldable while maintaining my aesthetics and function before handing over so we both get what we need. From what I’ve seen, prototype molders will give you a few tips but if you are making anything complicated you would definitely want an engineer either generating the CAD or babysitting you and making sure you hit all the requirements. It would also be helpful if you gave us an idea of how many parts you were looking to build. If it is a short run say 100-1000 parts you should look at using a domestic prototype molder who can make you a reasonably priced aluminum tool and will be easy to visit and communicate with. It may be a little more expensive but you will get the support you are looking for. I have seen from toolers in taiwan that they just want the cad and drawings and they will take off from there. If you can get it to that point with a high level of confidence go for it. For now I would recommend talking to an experienced engineer and let them worry about gating, and mold flow etc…
Hope this helps I have only been doing this for a few years so I am sure there are people who can fill in some blanks.

Oh yeah here is our general development path…
designer cad
consumer test
consumer test (repeat last two if necessary)
hand over to engineering
sla of engineered cad
prototype tool (up to I think 50,000 parts max)
refine if necessary
pilot tool (single cavity of soon to be production tool, usually used for test markets and sales samples)
production tool

Hi This rules. Its helpful top see what others are doing and there experience. I have found there is this grey area between front end design and back end engineering and Im doing my best to understand this bridge and exploit it. The projects Im working on will be done most likely in China and will be larger runs 25k and up I would guess. For one project Im designing for either an extrusion or diecasting, how would I go about finding which would be cheaper and easier?

Thanks again so much

Extrusion tools are almost always going to cost less than die casting tools. As in, 3-4x less.

Regardless of quantity? Thanks!

Extrusion tools are inexpensive in the grand scheme of tooling. You generally need a minimum kilo run, 500 kilos for example of a given profile.

Die casting molds are expensive, but you get a finished or near finished part. Extrusions are just long rods of the shape and require cutting and machining in order to arrive at a finished part. Those are the two costs you need to balance. Extrusion makes in general a finer grained part with more strength than a die casting, and allows for different post treatments for alloy character.

Thanks so much for the info, do you have recommendations for extruders in Southern China?