Jzoe Blog

April 26, 2007

DIY hand-crank flashlight news

Filed under: Design, Electronics — jzoe @ 11:09 pm

I thought that a flashlight would be a cool project to use to help learn Pro/E, but it seems like there are a million good flashlights already out there. I said, why not one-up it a bit and make it a hand-powered flashlight? There aren’t that many out there that really produce a lot of light.

A little googling turned up this site, where somebody has used a cordless drill as a hand-crank dynamo. This person claims to get a maximum of 5 watts out of a cordless drill by turning the motor with a hand crank. I happened to have two cordless drills, so I ran a quick test to see what’s up. This is what that looked like:

As it turns out, it took a lot of cranking speed to get any kind of voltage- about four times faster than the linked article reported. An extra gear stage could help, but I doubt that I could make it as efficient and robust as a commercially manufactured gearmotor that’s already closer to my needs. If I get some free time soon, I’ll figure out what makes a motor attractive for this kind of project. Of course, I have two or three job interviews scheduled for next week- so this sort of project could get seriously sidetracked shortly.

On a final note- you can bet I’ll come up with something more ergonomic than a hand crank- probably a pull cord in the middle of the handle. In ideal conditions you can only get about 50 watts from your arms. If you use a bicycle or a rowing motion to involve more and larger muscles, it’s possible for fit people to produce somewhere around 200 watts.

April 24, 2007

Because I love all of you…

Filed under: goings-on — jzoe @ 8:43 pm

… And I said I’d be posting some more photos since I got a new camera- here’s what I made for dinner:

I made these calzones:

With spinach and cheese inside:

Since I started using a rolling pin, and started kneading the dough a lot more, it’s a lot easier to get good thin dough that doesn’t fall apart. Also I add gluten to the dough, but I’m not sure what that does for me.

April 23, 2007

LED flashlights, laptop fires

Filed under: Design, Electronics — jzoe @ 8:55 am

As folks may know from reading my blog, I’m trying to pick up Pro Engineer Wildfire to improve my marketability in the job hunt. I made it through the tutorials, and “know” how to do most of what I’d need to do, but I wouldn’t really tell anyone I know the software yet. I feel the need to actually do something with it, and push it a little bit, before I’m comfortable telling a potential employer that Pro/E is one of my skills.

I decided that a flashlight would be a great little design project to learn all the features of the software. I could do drawings (and maybe some thermal analysis) for a machined aluminum flashlight body, some injection molding for a charger cradle, and even a sheet metal clip to hold the flashlight on your belt.

I wouldn’t really be satisfied with cloning a maglight- that’s boring! Lithium Ion batteries are a million times cooler than alkaline batteries, and LEDs are advancing all the time. They already rival light output for conventional flashlight bulbs of similar electrical power, and they’re much more durable. An example of this advancement is the Pelican 7060 flashlight. It was recently adopted by the LA police department in place of the long favored D-cell mag light. It uses an LED produced by Cree, with an output of 130 lumens. This Cree LED is extraordinarily popular for high-end flashlights, as you can see in this flashlight forum.

Since everybody has designed a flashlight with this Cree LED, I wouldn’t be satisfied with it. Instead, I found a new company that just put an LED on the market in April. The LEDEngin LEDs look, on paper, to be moderately superior to the Cree LEDs. They look slightly brighter, with higher power versions available, and they claim to maintain their brightness closer to “brand new” for a longer portion of their life. I guess I just want to show off that I’m savvy, and I want to get a prototype of this thing built before the market is flooded with LEDEngin lights- assuming of course that Cree didn’t quietly come up with something better. They could do that, and just let their customers know rather than making a bunch of press releases. Anyway, that’s what I want to do.

So, since you read this far, I should reward you with some food for thought on laptop fires. When I was doing my research on cutting edge flashlights, I came across this YouTube video of a Laptop Fire.

So, we’re allowed to have laptops on airplanes, but no hand lotion or tweezers?!? Come on, look what laptops can do without even adding anything to their nastiness!

Also, the way machining costs work, the cost of making the first part made is about equal to making another five or ten. After that, the cost doesn’t go down so much- but it really helps cost per part if you make them in batches. If you’re interested in buying one of my prototype flashlights, Email me and let me know what’s on your mind. I’d also be interested in hearing from anyone with input on what they’d like to see in such a design.

So far I plan on about $12 for the LED, $18 for the battery and protection circuit, $20 for the charger, and $40 for all other parts. Other than the warranty and (maybe) aesthetics, it ought to compare very favorably with most $100+ flashlights out there. It’ll probably be at least as bright as the police flashlight I linked to, and will have about 2 hours of battery life. Any feature suggestions are welcome.

April 12, 2007

More interviews

Filed under: Design, goings-on — jzoe @ 12:19 pm

I had an interview with someone yesterday, but it turned out that he didn’t have any jobs that match my skills right now. He said that maybe by the end of the summer he would need someone like me, but until then he gave me another lead to follow.

Today I had a brief phone interview with someone else who does not presently have a job for me, but this person said that in 6-9 months his San Francisco office would be ready to hire someone just like me- except only if they’re good with Pro/Engineer.

It’s official- I completely missed the wave when everyone decided Pro/E is where it’s at. I’m going to get serious about Pro/E now, and after I finish the tutorials I may enroll in a class. I’d prefer to just find a job using Solidworks, but if Pro/E is so amazing, I guess I’d better get on the bandwagon. Actually, this is a bit of a rant- the people using Pro/E are mostly designing plastic injection molded parts. If I go someplace that doesn’t do that, then it’s less critical.

April 10, 2007

Fun with zoom

Filed under: goings-on — jzoe @ 9:24 pm

I took my camera out on BART today, and I had a little fun with the zoom. Here’s what you can see from the El Cerrito Plaza platform, looking toward the San Francisco skyline:

On a clear day it’s nicer, and you get a better angle of it from our stop. The red oval is circling the oakland Bay Bridge Golden Gate Bridge, approximately 6 miles away. With the zoom, I was able to get this shot:

Pretty neat, eh? You can clearly see the cables on the bridge, as well as the low arched section to the left where the bridge anchors.

Finally, if I blow it up to show you the actual pixels that came out of the camera, it looks like this:

You can see that the bridge deck is in two layers, and you can just barely make out the truss work between the two decks.

I think that my next camera will probably be about the size of a deck of cards, just for snapshots of friends. This one is going to let me do a lot of cool things (just wait till I get to a power soccer game!), but it’s not always convenient.

Edit- boy do I feel dumb! Although the bay bridge is visible from up north, that’s a photo of the Golden Gate!

New camera, cat storage

Filed under: Electronics, goings-on — jzoe @ 11:59 am

My new camera showed up yesterday, and I’m fairly happy with it. Onyx is probably enjoying the box it came in a little bit more-

She’s been spending a lot of time in that box, especially since I moved it into the sun.

Since I don’t want this blog to turn into one of those absurdly lame ones where people just post photos of their cats and make “funny” comments about them, I’d better give you all a good rant about DHL. Those jerks were suppose to come on Friday, and they never did. They said that they attempted delivery, and because I was away for 20 minutes I believed them. I was home on Monday, and was periodically checking the tracking number to see if DHL was lazy and just gave the package to the leasing office. At 3:00 the website said that they had attempted delivery again and didn’t leave the package! I called their number and got put on hold for 10 minutes while the woman helping me figured out what was wrong. She sent a text message to the driver and had him come back from wherever he went, so that he could attempt to give me my package. If I hadn’t called them to let them know I was home, they probably would have just given it back to Dell and said “Sorry, this guy didn’t want it.”

Actually, I’m no longer just posting images of cats- now I’m complaining about DHL. That’s seriously lame- I had hoped that this blog would never have to go there. Anyway, here’s a blow-up of what that camera can do:

That’s taken from the above image of Onyx in the box. This camera is taking MUCH better photos than my last one. I hope to start posting far more interesting shots in the near future.

April 8, 2007

That was an unhappy cat

Filed under: goings-on — jzoe @ 11:16 pm

This past summer Kendra and I had the displeasure of cat-sitting a grumpy old cat from France. He was a long haired gray cat the size of a medium dog. When I carried him in a cat carrier through the BART station, someone seriously asked me if he was a bobcat. He had some kind of freaky cancer and had lumps all over his back and sides. His hair was long, and every single day he would get a hairball and throw up.

What I didn’t know until he’d stayed with us for a long time was that whenever he was feeling especially upset, and was about to really heave up something nasty, he would make a sound like this:

Geppetto.mp3 (100kb)

The first time I came home and heard the cat making this sound, I just looked at it with my eyes wide and asked him, “Are you serious??” It turns out that, yes, he was serious. I have never used a carpet shampooer so much in my life. These days I’m actually considering putting that on my resume.

This is what he looked like:

April 7, 2007

Crappy

Filed under: Computers, Random thoughts. — jzoe @ 12:36 pm

Disclaimer: This is another rant about stupid people on the internet.

Ok, so I was learning a new CAD program today when I noticed that my present mouse is terrible. The problem is that the mouse wheel is also a button, like most mice, but the wheel is very hard to click and hold down. The new program I’m learning makes extensive use of this button, so it was a little frustrating trying to use it. Obviously it’s not the software’s program that my mouse sucks- it’s microsoft’s fault!

I was shopping for a mouse, reading reviews of what people thought of their mice, when I came across somebody who said that he loved how the mouse worked with his “lappy”. Yes, this reviewer called their laptop a lappy. It was funny when Strongbad had a computer named “Compy 386″, but it was not funny or part of a joke when this internet reviewer called his laptop a lappy.

Why does this irritate me? Why could something like this actually get under my skin on a quiet saturday afternoon? It’s because this is just another example of the degeneration of the internet. It’s not an accepted abbreviation, it’s just laziness and a casual attitude that doesn’t help anybody. I was looking for reviews of home theater receivers to see if my Panasonic was a good buy. Do you know how many people post long and interesting discussions of the pros and cons of this receiver without ever once typing “Panasonic”? They shorten it to “panny”!!!

I want to look for more information about transformers used in specific, non-textbook ways- and people are calling them “tranny”s! If I google for that, I might get some transformers- but I’m also going to get car people talking about transmissions, students talking about getting transfer credits, and engineers talking about transfer functions. Damn it people!!! We can’t use one cute little non-word to describe whatever it is that we’re talking about at the moment, assuming that everyone will just know what you mean! Google is watching, and it would be a far more useful tool for all of us if you’d just type properly!

Now I know that some of you will ask, “Joe, why do you care to find things that people typed if they aren’t even smart enough to type correctly?” and that’s a very valid question. Most of the time I don’t hold these people in high authority. All I’m usually looking for is somebody posting a link to a more authoritative source, or maybe if I’m researching a product then I’m just looking for a few independent people who aren’t marketing robots who can say, “Yes, I bought this product. It is legitimate and not a scam.”

Also, on a final note of what’s crappy- my new camera showed up on Friday, but it was during the 10 minutes when building management was showing an apartment and I was at the gym. Now I have to wait until monday before they redeliver.

April 4, 2007

Pro Engineer woes

Filed under: goings-on — jzoe @ 5:01 pm

I’ve been searching for a job for over a month now, and it seems that I’ve missed out on three really sweet design jobs because I don’t use Pro/E Wildfire. The first one told me that’s why they didn’t want me. The second one claimed in the interview that it wasn’t a big deal, but they haven’t hired me yet so I think that maybe it was an unnecessary strike against me. Today I had a third opportunity vanish because they weren’t willing to consider someone who wasn’t already an expert.

It’s no big deal, I’m fast at picking up software. I managed to find a way to get exposure to the software. Now I’m just going to have to redouble my efforts and learn this new tool. I’ve already started, and so far almost everything seems very familiar and similar to how Solidworks does things. CAD is a general skill that goes beyond just one program, and since I’m already a pro with most of what I need in Solidworks it shouldn’t hurt me too much to pick this up on my own.

There haven’t been as many posts on my blog since I got laid off as you would think. I’m keeping busy, but could find time to blog more if I wanted to. I partly avoid it because I don’t want to publicly dwell on unemployment, and it’s something I think about a lot lately.

That’s all the posting I’m doing for now, maybe until my new camera shows up. Tonight Kendra and I are going out (hopefully with friends) to see a movie, Zodiac. It’s based on real events, and one of the professors at Kendra’s school was even a suspect in the murders!

April 3, 2007

Polarity

Filed under: Electronics — jzoe @ 11:00 pm

This evening I built a 12 volt regulated power supply. The first time I plugged it in the regulator chip went *SNAP CRACKLE POP* and smoke came out. It turns out that I installed the supply voltage backwards. The reason I did that was because my cheap multimeter had its positive and negative leads poorly labeled and reversed.

After I replaced the regulator (good thing I bought a 6 pack), I wired a new one onto a board with a couple of capacitors to buffer the supply. After plugging this in, one of the capacitors blew up with an even louder pop, and a squirt of hot electrolytic fluid on my notebook. Surprisingly, this capacitor was backwards even though it was clearly labeled. This was a cheaper mistake than the first one- but all in all the broken parts added up to less than a dollar.

When I connect this to my servo controller, I won’t need batteries for it anymore. Now I just need to make sure that the controller will take an analog voltage as a control signal, and isn’t using the resistance of the potentiometers as part of a resonator. That was a pitfall I ran into when I was making the infrared theramin in 2003. I had assumed that by changing a resistor I was altering an input voltage, when really I was altering what a capacitor discharged through. That really limited how usable the device was, since it required you to really get your hand close to the device to make noise.

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