When a designer first starts a new project, he needs to be totally aware of what the final outcome needs to look like. For the designer to be able to visualise the final design he needs to get as much information from you as possible. You need to be aware of the design stages so you can understand the steps to completing your design.
All the information should be asked from your designer to firstly make sure they hit the target costs and secondly make the parts suitable for the final consumer regarding material and strength. If your designer does not ask all the above then you are probably going to end up with an issue when the design is finished.
The biggest thing for you is to make sure you know all the aspects of the final product. You need to do some homework. You do not need to understand manufacturing or engineering processes (this is the designers job) but reading up on this my help you understand the designers restrictions to some details.
The designer should involve you as much as possible during this stage.
A kick off meeting is the first design stage and is basically a meeting between you and the designer where you relay as much information over to him to ensure you get the design how you want it. The reason why I suggest doing a concept in 3D is to ensure that all your dimensions and requirements will be practical. All to often I have started designing something and the parameters don’t look good so I prefer to show the customer and possibly change direction or get them to approve the progression of the design as is. As a designer you dont want to follow a direction of the design and waste time if the customer doesn’t like it.
Once the designer has enough information he will start putting some pencil to paper or just jump into creating some 3D concepts on the computer. The option the designer chooses is irrelevant at this stage of design as they basically just want to get something on paper to show you so they know they are heading in the right direction
After the initial design stages I suggest you and the designer have another meeting to be sure both of you are thinking on the same lines. During the concept phase the designer should have an idea of the manufacturing method chosen so he can steer his design towards that method.
This is pretty normal. The inventor may have visualised his product looking slightly different but to be able to talk around a concept is better than talking around nothing.
After the designer goes away and makes final changes to the concept, sit down and review the design again. This should be the last time you need to look at the design as this concept should look similar to how the final part will look but with a lot less detail.
Approving the concept will allow the designer to go full steam ahead and add all the detail he needs to to ensure the final part can be manufactured.
The final designs should have all the detail designed in the parts to suit its chosen manufacturing method. Special attention should be paid to the material thickness and strengthening features.
The designer is working towards completing the design and eventually will draw the line to how many changes he will allow you to make. At the end of the day the designer will design what you initially decided on so making changes may result in extra costs.
Remember if you are not happy you need to make your changes now as it will cost you more later. When the design is signed off the design stages are completed.
If you choose to get some prototypes made you will need to get some files off the designer which are taken from the final designs. The designer may help you source these quotes for a fee.
If you choose to source the prototypes yourself then ask the prototyping company what 3D file they need. Typically they would ask for STEP, STL or IGES files.
If you are looking to get your product manufactured and need prices you will need to get IGES files off the designer. This should not cost you any more as it should be reflected in the initial design quote.