Saturday, 29 August 2015

Project Considerations

Well this is my second post in this series.
In this post I'm going to be looking at the considerations that I need to review in order to take the next steps. Due to my vulnerability of getting distracted, I’m going to take a project style approach to keep things concise and on track as this seems to keep me on track in work.

Goals and Objectives:-
The fist consideration I need to look at is my goals and objectives of the project. This may seem like a very formal way of going about things, but it makes me consider if it is worth doing something or not. For a bit of time now, I can potentially save myself a lot of time and money later. The things I'm going to consider are: -

  • What do I want to achieve?
  • Why do I want to achieve it? - e.g. what am I going to get out of it at the end, what will I use it for?
  • What approach suited to get the best return on investment (RoI) of time and money vs the goals and objectives? - do I buy a kit and assemble or do I scratch build or is it even worth spending the time and money on the project at all. Is there a better way of doing it without the outlay in cost or time

So what do I want to achieve?
Well bluntly put, I want to build a 3d Printer that can output visually good quality prints, and with good dimension tolerance, within reason. Be able to print in a variety of materials, with the ability to upgrade to printing 2 or more at a time and allow multi colour/material prints.

Why do I want to achieve this?
I want to be able to rapid prototype components for various projects that are not easily obtainable due to cost, do not exist and would need to be fabricated in some way or to be able to replace a part for convenience (e.g. a replacement knob for a switch etc). I also want to develop my understanding and skill level in electronics and mechanical fabrication. The knowledge gained would then be applied to other projects in the future.

What is the best approach?
There are 3 main approaches I can take both with their pros and cons: -

1) Kit Build
A kit build involves looking for a suitable kit that meets the printing requirements above, ordering it and assembling it.

Pros
The good thing about kits is that you know what you are getting. You've seen the pictures online, the parts come in nice boxes ready to assemble. You get instructions on how to put it together and there should be no major surprises. Think of it like buying some furniture from IKEA that you have to assemble yourself. You also have the support of the supplier, if there is a problem with assembly or a part is defective the supplier will be on hand to take care of it.

Cons
Choice is limited to the available kits. You only learn how to plug and screw the unit together according to a set of instructions, skills which most of us have, hence why IKEA use this method, as it's easy to follow, and a know result can be achieved with little effort on the users part..

2) Scratch Build
A scratch build involves searching for different styles of printer, sourcing all the parts ensuring they are compatible, cutting enclosures from plans, soldering electronics together, assembling the components into a finished printer, programming the controller board, configuring and calibrating (more than the kit would need) and at the end hopefully it all works.

Pros
Choice! You are limited to you imagination and skills. You're in control. You're the boss. If you want the printer to look and behave a certain way, you got it. There is a lot to do, a lot to put together a lot to measure and cut....... accurately. In short, the potential for learning is huge as this project will bridge many topics. From fabrication to electronics to programming. A lot will be learned using this method.

Cons
Choice! You're in control. You're the boss. In short, the buck stops with you. If a part in not compatible, you have to fix it. If you don't know how to cut materials or program a computer, you have to learn it or find someone who can. You are your own support team, At the end of the project you may have spent £500 and still not have a working printer, well that's down to you, and you have to fix it or give up!

3) Outsource
The last option I will consider here is to outsource. This involves locating a group or business that is willing to take on a single or small batch job. Often if this is a business, it will be a high quality printer giving excellent results, far higher than can be achieved at home.

Pros
With this method, there is no outlay in cost or time for the construction of the printer. Print quality is likely* to be higher than can be achieved on a home built printer. A variety of material may be available that cannot be printed at home including metal. The end user only has to concern themselves with sourcing/making a 3d model and saving it in a format that the group or business can output
* Some groups may use home built 3d printers meaning that they would equal the quality on a home built system using the same technique.

Cons
With this method, you cannot print when you like. You will be limited to the regular office hours. Although print quality will be higher, the material cost will also be higher as exotic materials are often used especially if the printer uses powders or metals. Additional design constraints are needed for larger 3d models to reduce the cost of the output. This is particularly important if the printer users powder, as discrete holes will need to be placed in the model to get excess material out making it hollow and less costly on material as most businesses charge by the material used, even if it's trapped inside.

For me the choice is evaluated against the goals and objectives. I wanted to learn as well as have a working printer, so it has to be the scratch build. I also want the convince of being able to print whenever I choose. I may consider outsourcing if the prints have been proven and I can get a stronger, lighter and more reliable part if it is cost effective to do so. I'll need to lookout for the cons of the project as best I can, managing the risk as I go. I'm sure something will creep out of the woodwork that I didn't foresee. Providing I make informed choices, hopefully I can minimise any problems along the way. But hay, you don't learn to make an omelette without breaking some eggs right?

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