I just finished working on my final Engineering Week video at Bucknell. Just like last year, each major must create a video that embodies engineering in their specific discipline. The video is the highest rated event, culminating a week of intense competitions between engineering majors. All the points prior to the video are tallied and announced at the Engineering Dinner; a fancy dinner with all the engineers, faculty, and some alumni. Then, at the dinner the videos are screened and winner announced.

This year, our major’s video remade and tailored classic TV Show themes songs to Electrical Engineering. The songs included: Happy Days, The Brady Bunch, Gilligan’s Island, Cheers, and Knight Rider. There was a lot of creative talent involved, as reflected in the film’s quality. As a result, the Electrical Engineers not only won 1st place for the video, but also brought home the golden hammer by winning 1st place in the whole competition. Most of the entries from this year are available here. Below is the Electrical Engineers’ submission for Engineering Week 2008.

Making Bode a miniature omelet proved to be too much fun. Ever since then he’s had a few very merry “un-birthday” breakfasts composed of miniature versions of whatever we eat on Sunday mornings, usually pancakes.

I’m posting the proof to follow-up on Brett’s request. You can’t really tell, but it’s a banana pancake with peanut butter chips, and it’s still warm! Is he spoiled? Maybe.

 

This article is a follow-up to my previous article to detail how I created my stop-motion film “Passing By.”

1. Choosing Your Subject

   This part is fairly subjective. For stop-motion films, just about any subject can be entertaining in stop-motion, but in limited quantities. Harping on the same location or subject for a long period of time will bore the viewer. I consider the jerkiness of stop-motion is best suited for fast paced themes. For instance, in “Passing By,” rather than dwell on the train for an extended period of time, I have it interspersed throughout the film. You’ll be able to get a better feel for this when you get to the editing stage.

2. Taking the Photo

   Your camera should be set to continuous (burst fire) mode, which depending on your camera and storage card speed, can offer 1.5 to 5 frames per second. Make sure you set your camera to manual exposure at a consistent exposure level. Nothing is more distracting than having the exposure change from one frame to next, a couple times a second. This may also entail avoiding natural light if you’re shooting multiple scenes indoors, as the change in daylight will seem amplified.

   If you wish to make your film in widescreen and your camera does not support it, don’t worry, the photo can always be cropped later—simply keep this in mind when you take the photo. I set the camera’s resolution to maximum possible, so if I wanted to do some cropping, the final image could still reach my target resolution of 1920 x 1080.

3. Editing the Photos

   This is the most crucial step to making your stop-motion look professional. Every single frame in “Passing By” was heavily edited before importing into the NLE. While this may seem like a daunting task, batch processing in Adobe Photoshop Lightroom makes it a breeze. Since each scene has approximately the same levels and lighting, each scene could be batch processed as a whole. I applied the desired settings to one photo from a scene, and then copied the settings to the rest of the photos in the scene. The process was repeated for each scene in the film. Below is a demonstration on how I batch processed the photos from the NYC scene.
   
   
   Lightroom Batch Processing Demonstration (Click for High-Resolution Video)

4. Importing into a Non-Linear Editor (NLE)

   This step is really going to depend on what NLE you use; I used Sony Vegas Pro 8. Before I even had a song picked out, I imported all the photos into Vegas. Then I pre-rendered all the footage (at very high video quality) with no audio, and then re-imported it back into Vegas. I did this simply because my computer played a rendered video better than thousands of pictures in the timeline. From this continuous video file, I created a bunch of sub-clips for each scene. Subdividing each scene into its own clip allowed me to put the scenes in any order and trim them as needed.

5. Editing

   This step is also fairly subjective. If you plan to use music, you should choose your song prior to editing. Choosing your song beforehand will allow you to edit based on natural divisions in the song (i.e. to the song’s beat). In “Passing By,” the first scene establishes a particularly length coordinated with the song. If you tap your foot, it’s about eight beats. Each subsequent scene is the same or a multiple of the first clip’s length, for example, the first train scene is sixteen beats. This allows you to maintain a desired consistency in throughout the film. Experimentation is key, try different songs, different orders, etc. until you get a feel for the direction you want.

6. Rendering

   I rendered the project at 1920 x 1080 progressive at 15 Mbit/s using the H.264 codec, as it’s pretty much the standard for HD video. I rendered the audio using PCM uncompressed, as I was had a FLAC source.

Click here for the results. Hope this is a good starting point for many of you. Reply with your results or some comments/questions.

This morning Grant was cleaning out some green peppers. He found a surprise: a fully-formed, miniature green pepper growing inside of one of them!

So we took pictures.

The tiny pepper was cute, and I regretted having to cut it open. However we felt compelled, in the name of scientific discovery, to check if there was yet another green pepper growing inside. There was no nested pepper, but it did have seeds that were about the size of grains of salt!

Today our dog Bode, the mascot of PitelSpot,  celebrated his 10th birthday. That makes him 70 in dog years, therefore he is now officially retired, and about old enough to be my grandfather.  To celebrate the occasion I decided to make him a nice breakfast of a few of his favorite ”people foods.” I must admit that making a tiny cheese omelet was fun. The pop can is for scale. Naturally the whole process was documented.

He was also given two of his other favorites: orange slices and cooked green peas. I cut everything into tiny pieces since he practically inhales anything that is not dog food. Of course he is not normally allowed to eat from the table–this is a special occasion. And although I know he has no problem with getting on the kitchen table when we are not home, he actually hesitated to eat his small feast with us around.

Here you can see him eyeing the omelet. Once he built up the courage to start eating, the omelet was gone so fast that I did not have the opportunity to photograph him enjoying it. After the omelet was done he moved on to the peas, and a number of them “escaped” while he was eating.

Finally he finished with the oranges, and after the plate was spotless, he cleaned off his place mat.

 

The best part was that when he was done, he actually wiped his paw on the napkin!

Battery Selection

Battery life is often measured by cycle life, the number of full charge/discharge cycles before the battery reaches 80% of its original capacity. Keeping the discharge current relative to the battery’s amp×hour capacity low and the discharge shallow improves battery longevity. Typical 12 V sealed lead acid (SLA) cells, like the ones found a Go-Ped, can be cycled 300 times. Here are a couple of tips about buying replacement batteries. Manufactures that do not advertise cycle life are probably not worth buying from, as they may use lower quality materials. Also, be wary of vendors that claim their cheaper batteries are “replacements for” and “perform similar to,” yet have no datasheets to back up these claims. As it turns out, Best Batteries (B&B) provides lots of data about their batteries, and come stock with Go-Ped Scooters. The ESR 750 contains B&B HR-9 batteries intended for high-discharge rates. The replacement battery should have the same width and length but a taller height and also be designed for high-discharge rates and high cycle life. Below is a summary for three different batteries meeting this size and discharge rate profile. All the data was taken from datasheets on the B&B website. I decided to get the EVP12-12 which I purchased locally from Brandt Services Inc. in St. Louis, Missouri, which had excellent customer service, reasonable prices, and dirt cheap shipping. The discharge rate was calculated from the Go-Ped’s specified distance, max speed, and from the stock battery’s discharge characteristics.

Scooter Cavity Extension

The Go-Ped scooter base needs modification if it is going to accommodate the larger batteries.  Much inspiration came from user Goped19 on GopedNation and battery discussions on V is for Voltage Forums.  The height was increased by stacking additional wood boards that mimicked the original base. I purchased one 24×24×0.75 inch thick piece of plyboard and drew two outlines using the original base as a template. Drill a large hole into each board and the cut the outline with a jigsaw, as shown Fig. 1.

Fig. 1 Cutting the outline

The boards were stacked, carefully aligned, then locked into position with aluminum tension wire. The board’s height makes straight drilling difficult. Use a drill press to make mounting holes. When the holes are done, the boards can be clamped together with a screw, nut, and washer. This is handy for keeping boards together when sanding the edges with a belt sander a wood file, as shown in Fig. 2.

Fig. 2 Cleaning up the woodwork

Finally, I connected batteries as outlined in a previous post and screwed down the board with 3.5 in. long, 0.25 in. dia., 20 count thread screw. The first trip to work was 3.8 miles with a 170 lb payload in econo-mode. I arrived with 60% remaining capacity according to the state-of-charge versus terminal voltage chart found in technical manual on the B&B’s website.

If you are reading this post, you probably are experiencing decreased range and speed on your Go-Ped electric scooter. I too have experienced these problems, but I am going to share some solutions I came up with. I purchased a Go-Ped ESR-750 scooter this summer for transportation in Mountain View, CA for a summer internship. I rode that scooter every day to work on turbo-mode, which was about two miles. At the end of internship, I could not even get to work on econo-mode, and when I returned home I junked the batteries to lighten the shipping cost.

After only two months into the internship I could not get to work any more. I opened the scoot scooter top to find 4 sealed-lead-acid (SLA) batteries with a pack configuration shown in Fig. 1.

Fig. 1. Go-ped battery pack configuration.

From previous work I did with laptop batteries, I learned that manufacturers typically tie together parallel cells such that they form a pack similar to the one shown in Fig. 2, which has two advantages. First, it halves the number of sensors that measure voltage. Measuring two voltages, one across B_1A and another across B_2A is essential for determining when to end charge and discharge, major factors that affect battery life. Unfortunately, the scooter model only measured the stack voltage, the total voltage across B_1A and B_2A. The second advantage is that it provides a balancing effect. If a cell becomes weaker, the adjacent cell gives it charge. Having cells reach end-of-charge and discharge in unison is the most beneficial situation. After two months my batteries were significantly damaged. I parallel tied my batteries, which allowed them to die more gracefully and it also gave me about 20% more range, both which helped me get to work and back until the end of the summer.

Fig. 2. Modified Go-Ped pack configuration

IMPORTANT: Do not reconfigure the battery pack if you do not know what you are doing, and expect to void your warranty too. However if you want to take preventive measures follow these steps.

STEPS TO MODDING GO-PED BATTERY PACK

1. Find a well ventilated area to work in.
2. Disconnect the scooter from the charger and open the board with a torx screw driver.
3. Remove the four quick-connects at the top and bottom of the batteries.
4. Remove the two metal tabs that connect B_1A to B_2A and the one that connect B_1B to B_2B.
5. Create a wire harness that replaces the function of the metal tabs and will tie together the cells.
   1. You will need two short pieces of stranded 12 AWG wire and four yellow T2 female quick connect terminals and one long 18 or 22 AWG.
   2. Strip the wires and crimp both an the 18 AWG and the 22 AWG terminal into the same terminal.
   3. Crimp the other terminals so that the harness forms an H shape.
6. IMPORTANT: you must balance parallel batteries before you connect them together. Otherwise you will cause a spark and damage your batteries.
   1. Connect small resistors, about 100 Ω, between parallel batteries, and let them balance for a few hours.
7. Once balanced you can proceed to reconnect your pack.

The final connected harness should look something like the one in Fig. 3.

Fig. 3. Completed wire harness

Once you have made these modifications to you scooter there are some other life extension options to consider. Re-configuring the pack was a simple form of cell balancing, where charge moves between adjacent cells. There are commercial active cell-balancing products such as BattEQ and Power Cheq that moves charge from different levels of a stack. Check your scooter dimensions for free space. Another option is higher quality, larger capacity batteries. Ultimately I choose the last option, which I will discuss in another article and describe other scooter modifications.

A few years ago my wife Sheryl and I were very involved with freshwater fish.  In our 120 gallon show tank we had what are refered to as the “King of the Freshwater Fish,” the Discus.  A couple of our discus are shown on the left.  One of the greatest pains in maintaining a Discus tank is their finicky appetites.  Every week we found ourselves going to Sailfin pet store to pickup bloodworms (misqutoe larvea) just to get them to eat.  This was not only inconvenient and expensive, but somewhat gross. 

I started researching culturing my own Discus food.  Some people culture bloodworms by taking a filled baby pool and sprinkling some grass clippings.  That idea was immediatly shut down by the boss (A.K.A Sheryl) and I was back to the drawing board.  Later I read online that some people feed their Discus earthworms or earthworm flakes, which are high in fat and protein content, to help Discus grow.  An indoor compost pile provides a steady source of worms and also serves as a repository for kitchen waste.  I will discuss how we made an indoor compost pile by recollecting the steps we went through.

Step 1 - The Container
Any plastic container will do, it all depends on how many worms you intend to keep.  Some compost retailers sell containers specific to composting with multiple trays.  I built my own by stacking multiple containers, however I have only used one so far.   I recomend purchasing a plastic tub along with another tray that the tub can fit into.  Drill small drainage holes into the bottom of the plastic tub, and the tray will catch the drain fluid.   

Step 2 - The Worms
For the worms we choose red worms (species Eisenia fetida).  They can consume their own weight in food every day, reproduce quickly, and are readily available on Ebay.  The worms tolerate between 40-90 degrees F, consider this and your climate when ordering.

Step 3 - Worm Care
 The worms need biodegradable bedding that distributes moisture and eventually becomes worm food.  The most cost effective option is paper from the office shredder.  Remember to explain your noble intentions to the secretary, they might get suspicious.   Keep your worm box in a dark, warm place. We keep ours in a closet near our water heater.  Finally, you will need to feed your worms.   We give ours spoiled vegtables and fruit. For aromic reasons, avoid anything with lots of protein (meat, eggs, and fish) .

Since the beginning of Summer into early Fall, I’ve been compiling photos shot continuously during travel on numerous modes of transportation. All the photos were batch processed in Adobe Lightroom before being imported into NLE software. All the photos were taken on a high resolution digital camera versus my standard DV cam, allowing me to create the film in 1080p (my first HD project). The above video is HD conversion to Flash hosted by Vimeo at 720p. Since with stop motion there is significant change from one frame to another, much of the quality is lost in the compression to Flash. Unfortunately, embeddeding in HD is not available from Vimeo, but the film is available for download prior to compression via this link at the bottom right of the page. You can also view it in compressed HD on the same page (for best results, watch in full screen with scaling turned off).

Locations include the following (in no particular order):

• New York City (near Columbia University dorms)
• World Trade Center site via Path train
• Flemington, NJ
• NJ Transit between Bridgewater, NJ and NY Penn Station
• Newark Airport
• Chicago O’Hare International Airport
• Chesapeake Bay Bridge

Stay tuned for an article explaining how the images were processed and compiled.

Today Grant and I attended the Vermillion County Civil War Days, a Civil War reenactment held at Kennekuk County Park in Danville, Illinois. The two-day event recreates the Battle of Shiloh.  Near the battlefield, there was a large encampment of canvas tents. Some were only for sleeping, and others were blacksmiths and sutlers (traveling stores). Men, women, and children were dressed in period clothing. Abraham Lincoln and the first lady were both there, as well as Generals Sherman, Grant, Lee, and Custer.

Today, Saturday, was the first day of the battle, which in reality occurred on April 6, 1862 and continued until a Union victory the next day. At one end of the battlefied were the Union cannons, at the center a small Union camp, and hidden in the woods, the Confederates were waiting. Confederate forces led by General Johnson surprised and overran the Union encampment. As the Union soldiers fell back, a young girl in the crowd yelled “Scaredy-cats!” After trashing the camp, the Confederate assault continued. Both sides exchanged cannon fire, gunfire, and calvary fought with swords and guns. Eventually the Confederates pushed the Union men back to their artillery and forced them to surrender, after which the Union prisoners were taken and paraded past the grandstands in a final walk of shame. Of course, history tells us that Federal reinforcements will arrive, and the Union does win-but that’s not until tomorrow.

The cannons were most impressive, shaking the ground, filling the air with smoke, the largest weighing about 3,000 pounds. They created these amazing smoke rings, one traveled almost a quarter mile and grew to a diameter of about twenty feet before hitting the ground and disintigrating.  The booming cannons, gunfire, and galloping horses really do transport you back to the 1860s, and it was a memorable event.  And I look forward to finding a Revolutionary War reenactment next!