Fabrication

[Anupam Goli]

We've all heard the arguments of in-house fabrication vs outside fabrication, and we know the answer depends on what your goal in FRC is and what your team wants to do. However, there is a point where things are taken too far.
FRC provides an engineering experience in designing and assembling a robot. However, the emphasis here is design. My team has become a team of fabricators. Our team does not do design, we design around the parts we fabricate. We avoid outside fabrication because fabrication is "the fun of robotics" I'm not arguing that fabricating parts is fun, but if you solely want to fabricate and not design, that is not engineering.

Has this problem occurred to anyone else, and has it gone to the other extreme?

[MichaelBick]

This year, we did very little in house fabrication. Everything had to be designed, before it was sent off to the machine shop. While I do not like having so little fabrication done by students, I feel we made up with it by have a 20 times better CAD and design process this year. Though I do not like the process we took this year, it was necessary in the advancement of our team. We do not have enough space for any kind of large machines, namely mills and lathes. This year, because we did so well in LA, we hope to get more space and funding for next year, and do more in house work than we have ever done before, while still having a complete design process.

[wilsonmw04]

This is a topic that comes up every season, if not 5-10 times a season. The answer to this question is simple: There is not a right answer to the question. Every team must answer the question based on their goals and the resources they have access to.

The real problem come when teams decide their answer is the right one and those who do not do it their way is wrong.

[RayTurner1126]

our team designs the bot, and we also mostly do in-house fabrication with VERY few parts being sent out to be made. we do run into a few challenges with this, as we tend to finish very, very close to ship date every year because we spend too much time designing before we actually get to building. we have debated sending more parts out for fabrication, but I feel it's part of being a part of FIRST to learn how to machine the parts we design too, and everyone can learn the maximum amount that way. However, that's my take on it, and the standpoint of most on our team.

[MichaelBick]

The Cheesy Poofs are able to do a lot of in house work. Part of it is a fast design process, and basically starting to machine on the first day of build. They can do this, because they know what type of drive train they are going with, and no the process of what they will have to machine. By adapting the same drivetrain to each game, they can already start to machine on day 1. By standardizing in this way, you can start machining much earlier, and have more time for practice and programming.

[jspatz1]

As we all strive to create new engineers, it is important that we try to expose them to both the design and fabrication aspect of creating these machines. Every engineer must design within the limits of the fabrication resources that they will have, and the best way to understand those limits is to experience the fabrication process for yourself. An engineer must design the nitty-gritty details of what is possible and economical to make, which is hard to do if you have never seen or done it for yourself. I find that my (limited) knowledge of fabrication options effects nearly every detail of every design decision that I make. Most designs that I consider to be "bad" or not workable are such because they are unnecessarily difficult or impossible to make.

When I was a brand new graduate engineer in my first job in industry, my company put us through a months-long apprentice program in the machine shop/toolroom where we worked along side toolmakers and learned basic machining and shop techniques. They knew we couldn't possibly send valid design work to the shop if we did not understand the details of what it took to make the stuff we designed. I realized then that it was something that was missing from my college curriculum. One of the biggest frustrations for those that have to work with new engineers is the new engineer's lack of understanding of what can and can't be made, or made economically. It is something that simply takes years of experience to develop.

Most FIRST mentors have the experience of having bright, enthusiastic students come to us very excited about their design idea, only to find out from us that it cannot be made. Learning to adjust your design hopes to the reality of what can be fabricated is one of the most difficult and important skills an engineer can learn. There is no better way to begin learning that lesson than to experience making parts for yourself.

Whatever your team's fabrication resources are, your students will need to learn to design within those resources. If your team is lucky enough to have fabrication sponsors that can do higher-level fab work for your team, take students on a field trip to the sponsor so they can see the work being done. Even if they cannot do the work themselves, seeing what it takes to create the parts they dream up will give them valuable insight.

Naivete about what can and can't be made is one of the most common obstacles for a new engineer. We are giving our FIRST students an enormous head start in understanding that lesson. It is one of the many things that will set them apart from their peers.

[Anupam Goli]

I understand that knowing and experiencing the fabrication process is important, and I would not be complaining about in house fabrication if it weren't for the attitude that building a robot is not about design, but fabrication. I don't know if I made it clear in the first post, but what is happening is that our team is not designing by engineering drawing or CAD. What we do is say what drivebase and type of manipulator we want and we come up with the dimensions while we are fabricating. As a result, the entire frame has parts mis-measured, inaccurate, and the robot does not work because things weren't pre designed, they were designed while being placed on the robot. As a senior on the team, I want to see my team go through the design process and design something before starting any fabrication.

[EricH]

Failing to plan is planning to fail.

In industry, building without a drawing is extremely rare. And engineers who do their own building are almost as rare. This is because close to 95% of engineers would simply turn the part they need over to manufacturing. (The other 5% are likely classed as engineering technicians.)

So the normal process is to design, then build and refine the design.

We just had this discussion in one of my senior-level college classes today actually. Apparently, back in the 80s, at least one company designed by fabrication--they focused entirely on ease of manufacture. This cost them a lot of business because once built, the product could not be serviced easily. Fabrication drove their design process, and this damaged the company. They have since refocused to designing with all the other factors (and believe me, there are a LOT of other factors!) in mind, and are producing better products.

If I were your team, I would go to a local but large engineering/manufacturing company, and have them spend a day there shadowing the engineers and possibly the fabricators and talking to them. I think it would be an eye-opening experience for the team leadership. Sometimes, it's not all about the fun.

[sanddrag]

In before thread close...

[tsaksa]

Originally Posted by EricH

Failing to plan is planning to fail.

Agreed. After re-reading the original post I now see that I did not fully understand the question.

There are things to learn from both design and fabrication, and if a team chooses to emphasize one more than another that is hardly wrong. But completely avoiding the design phase is never a good idea unless you are referring to a completely trivial problem. And the more experienced I become, the more I believe that there are no completely trivial problems.

[Brandon_L]

How is fabricating not a part of engineering?

How do you think they did it in the days before CAD? They built it and tried it out. Theres nothing wrong with it. At all. Don't force a method on your team that they don't want to use. If they have fun doing it, their being inspired. This is exactly how our team works. You build something, try it out, and use your engineering skills to improve it or redesign it if it didn't work out right. I personally don't see how people can get students into engineering by having 2 students cad it while everyone else waits around for parts.

[BigJ]

Originally Posted by Brandon_L

How is fabricating not a part of engineering?

How do you think they did it in the days before CAD? They built it and tried it out. Theres nothing wrong with it. At all. Don't force a method on your team that they don't want to use. If they have fun doing it, their being inspired. This is exactly how our team works. You build something, try it out, and use your engineering skills to improve it or redesign it if it didn't work out right. I personally don't see how people can get students into engineering by having 2 students cad it while everyone else waits around for parts.

While I don't necessarily have a problem with your answer, before CAD there was Plain Old Drafting.

[Racer26]

Originally Posted by Brandon_L

How is fabricating not a part of engineering?

..

This is exactly how our team works. You build something, try it out, and use your engineering skills to improve it or redesign it if it didn't work out right. I personally don't see how people can get students into engineering by having 2 students cad it while everyone else waits around for parts.

Because that's not what happens.

There's a LOT of misconceptions about how the pretty powerhouse robots are created.

The students involved in CAD are typically CADing the drivetrain, while the other students work on designing, manufacturing prototypes, and testing an end effector, which then gets CADed, and all of the parts get manufactured in a professional shop, and then assembled by the students.

They're involved at every step except for manufacturing of the final product. The difference between them and a majority of teams is that a majority of teams are basically fielding their prototype, rather than a finished product.

[Mr. Van]

Originally Posted by Brandon_L

I personally don't see how people can get students into engineering by having 2 students cad it while everyone else waits around for parts.

In their first year, I'd suggest that they don' t try to completely CAD out the robot before any tools touch material. It will most likely take too long. As the initial model is being developed, students can be fabricating and testing prototypes, or building components that they know they will be using. As components are finalized, they can begin fabrication - even without a complete CAD model. If nothing else, CAD in parallel with the fabrication.

Make the transition with as little disruption to the way the team works as possible. Most likely, everyone will see the advantages to introducing a bit of design before fabrication begins.

Perhaps watching the Grant Imahara "FIRST Design" video might help.
http://www.youtube.com/watch?v=YNweJ7QbF7Y

- Mr. Van
Coach, Robodox

[jspatz1]

Originally Posted by Brandon_L

How do you think they did it in the days before CAD? They built it and tried it out....

Not true. We drew it. The process was no different, only the tools and medium were different. There was such a thing as design before CAD. Cars, bridges, airplanes, and televisions were not cobbled together by trial and error.