Creating a model or prototype can help you get the best method to manufacture the device you have invented. It may be useful for all sorts of things like figuring out where you should put labels, what are the shipping weight is going to be, the best way to package it, what it may cost to fabricate it, also to get feedback from test users. It's a valuable tool for you to use.
If you are intending to try to raise money to fabricate the newest product yourself, or if perhaps you're demonstrating it to a potential consumer to get a big order, you will require the prototype if you don't already have a production unit to demonstrate or demonstrate.
People just don't have much imagination. You're an inventor, and that means you will have an imagination. One which just invent something you have to have the idea...also it takes imagination to generate great new ideas. Others, you will find, accomplish do not have the imagination or vision that you just do. Help them out.
With a good prototype or model, your audience will not need to have an imagination. It can make new service "real" on their behalf, adding tremendously for your credibility. Having a good prototype may help sell the merchandise even if it's not even in production yet.
DON'T postpone prototype building until after you file your patent application. You'll likely discover flaws or additional features, or discover possible manufacturing problems. With rare exception prototyping is quite worthwhile. There are more often than not unexpected discoveries from construction of InventHelp invention prototype.
Tests are extremely important. A prototype allows you to actually try out your invention in a meaningful way. You can look at it with people other than yourself if appropriate, and you should discover that others could have constructive criticisms and suggestions that could be very valuable.
By doing a search online you can find model and prototype building companies who are able to construct it for you personally unless you hold the skills yourself.
Sure there are times when a prototype isn't practical, when it is too expensive for instance, however, if it is possible, I suggest an invention prototype or model be produced.