Currently, we’re working on a low-cost plotter to move a specimen slide around on the x-y plane while also having the z-axis to adjust the focus of the optical element. Whew, that’s a lot of moving things. This, of course, begs the question: what is the best way to move things? Currently, we have two options:

 

Ball Screw:

The ball screw would traverse the screw shaft.

From camaster.com “Ball screws are best known for being smooth and friction-free. Over a long axis however, a ball screw-driven system is susceptible to “screw whip”, which is vibration that worsens the faster a screw rotates. This is because of the critical speed of rotation needed over a long axis. To alleviate this, a ball screw driven system requires more gearing or larger motors to compensate for the weight and need to maintain the rapid positioning speeds. This makes the use of a ball screw on an axis over 4’ in length not ideal. That being said, for shorter lengths, this is rarely realized which makes the use of a ball screw a good choice for a short axis on the machine.”

Rack and Pinion:

For our purposes, it is likely the pinion would be fixed while the rack would move.

Rack-and-pinion drives are far better at handling long axis of motion. Indeed, because of its design, rack and pinion drives can be faster at traversing distances than the ball screw because they can utilize torque more effectively.

They do however have some downsides. From camaster.com,  “Rack-and-pinion’s shortcomings include higher friction and potential backlash if the pinion is not properly engaged.”

 

Sources:

http://www.cncrouterparts.com/which-is-better-a-screw-or-rack-and-pinion-drive-p-99.html

http://www.camaster.co/faq/whats-better-rack-and-pinion-or-ball-screw/

 

 

 

Different stepper motors are rated at different amounts of steps. For example, we are currently looking at two different stepper motors. One has 32 steps the other has 200 steps. Using the formula 360/(# of steps) we can calculate the step angle.

Step Angle of 32 Step Stepper Motor:  11.25 degrees

Step Angle of 200 Step Stepper Motor: 1.8 degrees

 

Given the size of the plotter that we are building it seems that buying the 2o step stepper motor is the better choice.

So I was able to acquire the new Lab computers without an issue (huge thanks to Jeff–the wonderful sysadmin–for helping me!). I slapped a 1TB SSD in both of them and it was off to the races…almost. Unfortunately,  the very expensive software that we need to use requires Windows. The Lab machines were running Ubuntu, so I contacted ITS to see if they could install Windows on the new Lab machines. After much back and forth, the ultimate answer was yes! Now, with the new Lab machines equipped with Windows, we are finally ready to put them to work.

E-waste is a real issue. A report from the United Nations’ International Telecommunication Union states that 45 million tons of e-waste was generated in 2016.

Like any good Swattie, I am concerned about our environment and want to do what I can to help reduce, reuse, and recycle. However, the fact remains that the Lab needs new computers.

My solution to this predicament is pretty simple. Any institution maintains a set of public use computers. These computers are replaced on a predefined upgrade/replacement cycle which lasts about 3-5 years. If your institution is smart about it,  different sets of computers will be at different stages in this cycle. Meaning, it’s a good bet that your institution is about to throw out some computers.

You should ask for one of those computers.

 

Here is what I did:

I knew that our CS dept just recently upgraded one of their CS labs. With this knowledge in mind, I went to the sysadmin and asked him if I could have two of the computers he was planning on recycling to use in the Lab I am working in. He said yes. And, just like that, I was able to acquire two new(ish) computers for my Lab.

Now, these computers are on the older side so I have provided some suggestions to speed up and extend the life of your newly acquired computer.

 

Tips To Extend The Life Of An Older Computer

• Add more RAM. Older computers usually come with 4 GB of RAM as that was what was deemed a normal amount in the early 2010s. 8 GB should be your minimum.
• Replace the hard drive with an SSD. This, by far, is the single best thing you can do to speed up an old computer. Even if you don’t want to shell out the money for a large SSD (at the time of writing they are $0.10/GB), replacing the hard drive is a good idea anyway since you don’t know how much use the preexisting hard drive has.
• If feasible, put on a lightweight operating system like lubuntu. 

 

Earlier this week I learned the baffling fact that academics have to pay to get their work published. I decided to do a little digging and this is what I found:

• There is a huge concentration of power: In 2013, a mere five academic publishers (Reed, Elsevier, Wiley-Blackwell, Springer, and Taylor & Francis) published over half of all scholarly papers!
• Customers have to pay to read papers, but the authors also pay to submit their papers. Moreover, the research submitted isn’t paid for by the publisher either!
• This means that the publishers make an absurd amount of money. The Guardian reported that in 2010 “Elsevier [had] total global revenues of more than £19bn” (24,510,000,000 USD)!

How did all of this come about?

Well, in the 1950s there was no good way to disseminate scientific findings so the British government tried to improve this by incentivizing book publishers to publish scientific articles.  These publications turned into journals. At first, publication in these journals did not have a huge bearing on one’s academic career. However, over time, some journals were known for publishing a higher frequency of novel and influential papers. These journals gained prestige. As a result, it was desirable to publish in them. Suddenly, one’s worth as an academic depended on their publications. This resulted in the now familiar mantra of “publish or perish.” Even though publishing was an essential part of academia, some publishers were struggling financially. The larger publishers took this opportunity to acquire smaller publishers — thereby consolidating their power and creating today’s publishing landscape.

 

What happens next?

Unfortunately, its really hard to get a large enough portion of academia to forgo publishing in prestigious journals because their livelihood is on the line. Thus, the move from these closed off publishers to open access publishing has been a slow process. Moreover, many publishers have co-opted the open access movement to squeeze even more money out of academics. Now, many publishers have the option for academics to publish their work open access, but to do so is considerably more expensive than publishing not open access.  Given these factors, it is unclear what will happen next.

Sources:

The Oligopoly of Academic Publishers in the Digital Era

Is the staggeringly profitable business of scientific publishing bad for science?