Purpose:

Last week we spent some time considering the ATX power supply and how it can be modified ("hacked") to meet our needs and had some direct experience with a commercial 3D printer. This week I am asking you to consider some process aspects of the 3D printer build as an engineering management challenge. The motivation for this week's lab comes from my experiences not knowing what parts or materials you all need first to move forward on the build.

Procedure:  

When we approach a project of this magnitude it is natural for us to rely on past patterns of problem solving and that will certainly work for building 3D printers. For most of us this past pattern is to collect all the parts and materials together before we start to build. This is what many are realizing is one of the benefits of the kit builds. On the other hand this is not particularly typical of a modern engineering production environment. Because there is a potential "supply chain" challenge for many of the groups it seems like a perfect opportunity to explore some aspects of a modern "just in time" engineering operation.

1) The build manual lays out a sequence of actions that lead to a completed 3D printer. The first task I would like you to do is to lay out the sequence of materials that you need. This can be broken down in any way that makes sense to your group but look at it from the perspective of your supplier (me) and whether it tells me what I need to provide first, second, and third. Make a point to distinguish between raw material needs, printed parts, and electronics or tools.

2) While it may appear that any break in the chain of supply needs that you generated in part 1 will interrupt the build process that is probably not quite true. In many cases a missing part will hold you up on a particular task but other tasks can move forward. Take some time to identify tasks that can move in parallel or can proceed independently while you "wait" for a needed supply. Can you move foward with preparing the power supply if you are stalled on the frame? Can you work on the extruder and hot end separately from the frame? Are there some points that seem likely to cause a "work stoppage" if the parts are not available?

3) If you have never seen a Gantt chart you need to look at one on the interwebs. In many cases Gantt charts are inappropriately simplified to suggest a linear process where every step depends on the one before it and is absolutely critical to the one after it. This is rarely the case for all the tasks that need to be accomplished. Being clear about the relationship between various parts of the project and when they come together is really important. Create a Gantt chart (can be done in Excel relatively easily) that communicates your understanding of the serial and parallel aspects of this 3D printer build.

4) Another feature of any engineering build process is the need to be efficient with your use of materials. While it may appear that a kit is perfectly efficient (no extra or wasted materials) you are in fact paying for any manufacturing inefficiency in the cost of the kit. Given that the raw material for both the threaded rods and the smooth rod come in 1 m lengths determine the cutting schedule that will minimize your waste if you are only making one printer. Calculate the percent waste for both the threaded and smooth rod. Can you improve this efficiency if you are making more than one kit (sometimes this makes no difference)? How much can you improve your use of raw materials. Explore whether you could improve the efficiency by scaling all the lengths up or down by some factor less than 20%.

5) One of the things most of you will need to do is learn how to cut threaded rod to length without buggering up the ends. Regardless of whether you have a kit or are doing a scratch build search either the web or professionally skilled resources (better yet, both) and write down a clear process for cutting threaded rod and ending up with "good ends".

LAB Deliverables:

 

 

 

Answer all the prompts above in a LaTeX memo that is complete and documented so that someone else would have no need to worry about such concerns if they had access to the memo: