Building A Reprap, pt. 2 (Motors)

Part one of this series is here.

You know what a motor is. But you may now know what a stepper motor is. A stepper motor is a motor where an exact, precise, jolt of electricity will rotate the shaft one complete revolution. This is very useful for when you need to move something in a measured manner, like say, a printer. The Reprap will use several of these.

The NEMA 14 stepper motor

In order to send those precise jolts of electricity, you have your computer (in this case an Arduino Mega) send a signal to a stepper motor driver. A stepper motor driver is yet another tiny circuit board covered in handy bits of electronics. (My astonishingly small familiarity with these technologies allows me to use these complex technical terms.)

I will be using Pololu A4983 stepper motor drivers.

Now that you  have background, here's what I worked on Saturday:

1. Converted the loose wire ends on the motors to convenient plugs (x4 motors).
2. Soldered the driver boards together (x4 drivers).
3. Programmed the Arduino Mega to talk to the Reprap software.

Before Pictures:

Pre-solder driver

During Pictures:

Lots of little bits to connect.

The USB cable is connected to a netbook which is programing this Arduino.

After Pictures:

Wires now a plug.

Driver, post solder. I'll try to get a better picture of this later.

Building A Reprap, pt 1: What Is A Reprap?

I have begun to build a Reprap, along with several other people from the San Diego Hackerspace (Don't look at me like that, go educate yourself on the real meaning of hacker.), and I plan to blog the process. But first, what is a Reprap?

A Reprap is an open source, 3D fabrication machine. If you are familiar with the Schlockverse, think of it as a primitive fabber. If you know about Star Trek, think of is as very (!) primitive replicator.

If you somehow are not familiar with ether of those references, I will describe a Reprap for you. In essence, a Reprap is a personal, printer sized machine capable of "printing" plastic objects.

They can make everything from the practical to the complicated to the whimsical. (Images from Thingiverse.com)

Practical

Complicated

Whimsical

There are many commercial 3D printers on the market, but the "cheap" ones tend to run in the $25,000 range. A Reprap on the other hand should cost me under $500. While it's true that the  print quality is not as fine as a commercial machine would produce, a Reprap is a clear winner in the affordability department.

Truth

Truth without love is like a naked singularity. Alone, if you get too close, it will tear you to shreds, leaving essentially nothing. 


With love, truth is (again like a singularity) an incredible, almost unending source of power.

Tree Hugging Dribble

I had to calculate my carbon foot print for a health (!) class and come up with five ways to reduce it. I had so much fun, I decided to do a few extra. I post my list, as I turned it in, here:

I have a carbon footprint of about 7.4 tons a year, about 1/3 the national average, and I've never even given it a thought. Most of the reason for this low number is due to the fact that I lead a (relatively) simple life due to religious convictions and common sense, along with a a good dose of frugality. These are some of the potential changes I've come up with:

1. Move to a smaller house (The 392 square foot place I'm in now is just so big. I would, but you can't build a legal house with a smaller footprint.)
2. Use zero cooling instead of a swamp cooler (which uses 1/2 the electricity of an air conditioner)
3. Take more online classes to reduce driving (I would but I always take the online option if it's available, so this one's an you, [name of school].)
4. I could drive a Tata Nano (I would, but the state of California won't let me, or anyone else, because they think the Nano is too dangerous for it's occupants - and they have decided not to lat me make my own choice in the matter of my personal safety, thinking they can live my life for me better than I can.)
5. I could jump off a cliff before I get married and have children ["Basically, too many people are the problem" -- One of the instructors, today, Aug. 2010] (But that's obviously poor idea: I don't get to decide when I die, that's God's job.)
6. I could disconnect my tankless water heater, and just use cold water.
7. I could throw away my bread machines and make my bread purely by hand, and cook it in an "eco-oven."
8. I could also buy 100 lb. sacks of flour, instead of 50 lb. sacks to reduce packaging.

Schoolwork # 2

Because of the inability of my computer to run Second Life, I have decided to expolor a different online world, with a lower equipment threshold. After a few quick searched on Google, I found a site (mudconnect.com) that rates MUDs. I located a MUD that both looked interesting  had a high rating, Cities of M'Dhoria, and went to it's website.
I found that although I could just use telnet to play that there would be a richer experience (colored ASCII, etc.) if I downloaded a MUD client. I located and downloaded MUSHClient.

It only took me a few minutes to install, set up and connect to CoM once MUSHCLient was on my computer. After that I ran through the tutorial and then headed out.

Even though the game is very complicated, there were a whole stream of people literally waiting in line to help me get on my feet. These were not players, but rather helpers who worked on shifts to help new comers such as myself. Second Life could take a lesson from this.

If you don't know what a MUD looks like, here is a short time period's worth of play:

• [Exits: (west) up]
•      A large sign is posted here.
• A little, smelly goblin named Klog is standing here with a sneer.
• 
  
• Ext: wU | HP: 29/29 | Mana: 116/116 | Status: T  
• kill klog
• You lunge forward and bite Klog with a snarling chomp.
• Your bite <<< ravages >>> Klog!
• Klog is stunned but will probably recover.
• Your pierce massacres Klog!
• Klog is stunned but will probably recover.
• 
  
• Ext: wU | HP: 29/29 | Mana: 116/116 | Status: T  
• murder klog
• You show no mercy to Klog.
• Klog splatters blood on your armor.
• You get a green key from the lifeless corpse of Klog.
• 
  
• Ext: wU | HP: 29/29 | Mana: 116/116 | Status: T  
• unlock west
• *Click*
• You unlock the door to the west.
• 
  
• Ext: wU | HP: 29/29 | Mana: 116/116 | Status: T  
• open w
• You open the door to the west.

1. Where did I go?
1. I finished with the tutorial, I explored the Academy Square with it's temples, banks, gardens and more.
2. What did I do?
1. I explored, enraged in combat and commerce and had social interactions.
3. How did I design my avatar?
1. The avatar in CoM are of course simply text. You get to select your race, size, weight, and various colorings. I chose to be a Canidae, a canine like creature.
4. What challenges did I face?
1. The interface is complex as I mentioned before, but with the help also mentioned earlier, it was a simple matter to overcome these challenges.
5. How does CoM compare to other inversive experiences?
1. It was very different from other experiences. Even in other ASCII based games I have played, there have been visual maps that showed my exact location. In CoM, there is only verbal descriptions, so that took  a good deal of time to get used to.
6. From the textbook?
1. The anonymity granted by the virtual experience was similar to and in the case of chapter 35, identical to, what was described in the book. The real-time communications with others from around the world in a non-existent reality could be very absorbing.
7. Predictions of the future?
1. Within 20 years there will be full immersion, HD, 3D environments that can be experienced for free.

Schoolwork: Real people, Feel Free to Ignore

I went to start the "Blog Project" and found that it requires me to install and run Second Life. My computer is woefully inadequate to run this software. Additionally, my internet connection is far to slow to run it, even if my hardware could handle it.

The hardware requirements for Blackboard are listed in the class documents, but the requirements for Second Life were not, so I had no forewarning that I would need anything other than what I had. I don't know of any way that I can complete this assignment.

Me vs Best Buy. The Rematch

My camera had another issue. I sent this email to Best Buy.


To: S**** P*****
Geek Squad Public Defender
Executive Resolution Specialist
23 March 2010


A year ago, a camera that I had purchased from Best Buy had an issue and had to be sent in for repairs. That issue was eventually dealt with. A few weeks ago it again started showing symptoms, and then stopped functioning correctly. No problem. I shelled out a lot of money to get your super-duper best warranty, and I still have almost two years left on it.

I took it into the store and turned it over to the Geek Squad. A week later, I received a phone call telling me that although the camera could not be repaired, I could just come in and they would give me a brand new one off the shelf. Great! That's much better than the solution from last year which took several months to get resolved.

So I went in this morning to pick up my new camera. I should be in and out in ten minutes. Key word: should. Two hours and six employees later I finally left the store. I left the store Very Unhappy.

It turns out that Best Buy no longer carries my particular model of camera. No problem they said. We'll just get you one with equivalent features. I spent the next hour helping your salesman try to find something that would work. Every time I / we found a camera with the right features (optical viewfinder, optical zoom, small size and sufficient resolution) or even close to them, he'd spend five or more minutes to go through the process to get it ordered in, because it would invariably not be in stock at the location where I was. Each time he found that he "could not get that one." While it's true that there are not many cameras on the market today with all of my required features, there are still some.

Finally they gave up on finding a camera with the key features of the camera that I bought originally. They said that the equivalent camera today (without all of the required features.) costs $229.99. Therefore I could have that particular model, or $229.99 in store credit to replace my camera. After some deliberation I took the so called "equivalent" model.

I spent $500 on my original camera. That's enough to buy a brand new SLR today. That's not some low end piece-of-junk Kodak. That's nice, high quality equipment. I walked out the door today with a partially plastic product that is clearly inferior to the camera that I bought originally.

After I got it home, it became very clear within minutes that the camera I had been given was truly inferior. The next morning I called the store and finally found someone helpful. He apologized repeatedly for the poor treatment that I received and when told of my situation instantly concurred that the camera I had been given was inferior to the one I bought. He stated that the employees I'd dealt with clearly did not know about my original camera or they would never have tried to give me the low end camera they had. He told me to just come on back in and that they would give me what I should have been given as soon as I walked in the door.

I live an hour away from the Best Buy location where this all took place. I was told that I would have to return to the same branch in order to fix this. I was not going to be in the area for a week and a half, so I asked my father to stop by on his way to work and swap them out. When he went in this morning it took him over 40 minutes of arguing with the customer "service" employee to get the camera.

And then, to add insult to injury, I was told that because Best Buy was replacing my camera with a brand new one (instead of repairing the old one) that the warranty had "been fulfilled" and that therefore Best Buy would henceforth no longer be bound by the original warranty--even though I still have almost two years left on it. However, if I would care to spend more money, I could buy a new warranty!

A warranty is essentially a guaranty that the item bought will last for so long. If it stops working, you repair or replace it. You don't give excuses about how you can't repair it, and now it's worth less, so here, have a low end piece of junk. And by the way, would you like to buy a NEW warranty?

a1ca81090f

I spent a great deal of money on a four year warranty. I was told that because of the manner in which you chose to fulfill your end of the agreement, that you were going to arbitrarily void almost half of my warranty. I not only find this to be a despicable business practice, but also deceptive, if not downright fraudulent.

--
C.W.Holeman III
**Sig removed**