This is no more a DIY EV than Lego Mindstorms is autonomous robotics. It's a one size fits all kit and the fit at 15 miles and 21 mph is pretty lousy. It might be a fun toy if priced at under $500, but where's the educational value? I'd guess it uses rudimentary components (simple DC motor, rheostat, lead-acid batteries). You could get the same education building an electric RC car, plane, or boat.
Surging can be handled, but even a high output (180 amp or greater) engine alternator won't be able to deal with the load. That's why auto manufacturers are looking at moving to 24 or 28 volt systems in the near future. I won't get into the inverter issue but I'll make a suggestion on the 12 volt supply side for your toys.
1. Power your kit from a small bank of sealed automotive batteries (gel or AGM) which can be mounted in any orientation and safer than traditional wet batteries. If you plan on pulling power from them for extended periods without recharging (eg gaming all night) consider deep cycle batteries. Build secure mounts for them in the back of your van so they don't move around and have some protection in case of an accident..
2. Charge these batteries with a high output alternator driven from the driveshaft (do a web search on "driveshaft driven alternator"). This will only charge your batteries while the van is moving, but I do assume you're planning on driving it some of the time.
3. If you don't know how to hook up the batteries in parallel, or attach them to the alternator, or how to correctly size, crimp, and route the wiring find someone who does and do it right. Screwing up here could make things a little more intense than you'd like.
Doing it this way has a number of advantages. The two big ones are:
1. The system is completely isolated from vehicle electrics so, for example, completely draining the rear batteries won't keep you from starting the van.
2. Having the batteries and alternator both at the rear of the van makes the wiring easier.
This seems to me to be rather shortsighted and doesn't really address the question. One of the problems we see in STEM (science, technology, engineering, math) fields is that women who would be good at them tend to eschew them for the obvious nerd reasons. I have a strategy that I use with my students that has had some success. It's certainly not my idea but I have seen it work. What you should help her do is discover uses for STEM that appeal to what research has shown women want in careers - the ability to make a difference at a personal or social level. Sure, teacher qualifies, but so does electrical engineer working on alternative energy technology for developing or areas, or civil engineer working on new construction techniques for building with local materials, or biochemist working on physiological or pharmacological problems in health and disease. You don't have to design chips, or bridges, or bio weapons. And there are probably hundreds, if not thousands, of other career paths like these that she could imagine herself if you support and encourage her. Will it make her time in an undergrad or graduate program any easier? Nope. Still the "boy" culture, still plenty of hard work to do, still many times she'll want to chuck it all. But if she can keep her goal(s) in mind and remember that school is just a short time in the overall scope of her future she can do it. I have examples in my own life of whom I'm very proud so I know it can work.
As a former mechanical designer and mobile robotocist, I've bought components from Berg (http://www.wmberg.com/) for nearly two decades. A little pricey, but reliable and robust. I'd highly recommend looking at their stuff.
Having taught both freshman composition and upper and lower division computer science courses let me offer a suggestion. Have your students spend some time reading and analyzing both good and bad writing of the type you want them to write. Incorporating the good and eschwing the bad when they write will go a long way towards improving their work. And don't ignore poor grammar; you might not have time in class to work on it, but the students should be able to write grammatically correct prose, properly spelled, and using the right words. Bring in hiring directors or managers from local tech businesses if you can and have them relate stories about the importance they place on communication in the workplace and why the writing in cover letters and resumes contributes heavily to moving an application to the next level or relegating it to the trash. Every engineer should be able to convey her thoughts simply and clearly with the written word.
Stallman was the recipient of a McArthur award (sometimes called a genius grant). If you're frugal (which he most certainly is) you can live a long time on half a million dollars and its interest.
Uh, you might want to check out the Polaroid SX-70 work he did. Not only color but instant. And yes, I believe that he would have found digital an exciting medium.
The VersaLaser is manufactured by Univeral Laser Systems in Scottsdale, AZ (http://www.ulsinc.com/) and comes in several versions. The VL-200 has a 25 watt laser and a 12" x 16" working area. The VL-300 can be had in 30, 40, or 50 watt versions with a 12" x 24" working area.
The $10K (US) price tag is for the VL-200 without any of the extras you'll need to make it work (exhaust ventilation, colinear air/NO2) and only in the engraving version. The honeycomb table for cutting table will set you back $240. And the VL-300 and accessories are even more expensive. Figure $15-$20K to make it really useable, and >$25K if you want in at 50 watts.
We've been using a 30W VL-300 for a couple of months now in our research lab. We were told to expect 6-8 weeks to get the machine, but in fact it took over twice that. The machine is nicely designed, but in places the fit and finish are pretty bad (at least on the early one we got). The current driver won't work on anything older than Win2K (we bought a cheap XP box for it since we're a Mac only group) and comes preconfigured with a set of materials and thicknesses (for cutting} which can't be changed. When I first tried to cut 1/4" basswood (a material I'd previously cut with a 10 Watt CO2 laser) I was told that a 30W VersaLaser couldn't do that job. No workaround since you don't have access to power levels or cutting speeds.
Also, Epilog Lasers in Golden, CO makes a similar machine, the Legend 24TT.
Is it a cool toy? You bet. But be aware that Universal has a fixed notion of the niche for these things and they're pretty reluctant to modify that notion. So if you've got the next, great market for their product don't be surprised if they're not interested.
AppleCare is a must have. While I'd never buy it for a desktop machine (and never have) laptops take a tremendous amount of abuse and no matter how careful you are and how good the hardware is things will break. I've seen screens, optical and hard drives, motherboard connectors, keyboards, and batteries replaced without a hitch under AppleCare.
While the price of AppleCare for PowerBooks is the highest Apple charges (that might be indicative of the percentage of claims that relate to PowerBooks), it's less than the cost of a replacement motherboard or screen.
After ditching AD&D 20 years ago and working through a dozen homebrew variants we hit upon GURPS. It let us get to the role playing without having to be lawyer/accountants. And it translated well to any genre we wanted...
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This is no more a DIY EV than Lego Mindstorms is autonomous robotics. It's a one size fits all kit and the fit at 15 miles and 21 mph is pretty lousy. It might be a fun toy if priced at under $500, but where's the educational value? I'd guess it uses rudimentary components (simple DC motor, rheostat, lead-acid batteries). You could get the same education building an electric RC car, plane, or boat.
The same way 3 wheeled cars in the UK (like the Morgan) were classified as motorcycles - for tax purposes.
1. Power your kit from a small bank of sealed automotive batteries (gel or AGM) which can be mounted in any orientation and safer than traditional wet batteries. If you plan on pulling power from them for extended periods without recharging (eg gaming all night) consider deep cycle batteries. Build secure mounts for them in the back of your van so they don't move around and have some protection in case of an accident..
2. Charge these batteries with a high output alternator driven from the driveshaft (do a web search on "driveshaft driven alternator"). This will only charge your batteries while the van is moving, but I do assume you're planning on driving it some of the time.
3. If you don't know how to hook up the batteries in parallel, or attach them to the alternator, or how to correctly size, crimp, and route the wiring find someone who does and do it right. Screwing up here could make things a little more intense than you'd like.
Doing it this way has a number of advantages. The two big ones are:
1. The system is completely isolated from vehicle electrics so, for example, completely draining the rear batteries won't keep you from starting the van.
2. Having the batteries and alternator both at the rear of the van makes the wiring easier.
This seems to me to be rather shortsighted and doesn't really address the question. One of the problems we see in STEM (science, technology, engineering, math) fields is that women who would be good at them tend to eschew them for the obvious nerd reasons. I have a strategy that I use with my students that has had some success. It's certainly not my idea but I have seen it work. What you should help her do is discover uses for STEM that appeal to what research has shown women want in careers - the ability to make a difference at a personal or social level. Sure, teacher qualifies, but so does electrical engineer working on alternative energy technology for developing or areas, or civil engineer working on new construction techniques for building with local materials, or biochemist working on physiological or pharmacological problems in health and disease. You don't have to design chips, or bridges, or bio weapons. And there are probably hundreds, if not thousands, of other career paths like these that she could imagine herself if you support and encourage her. Will it make her time in an undergrad or graduate program any easier? Nope. Still the "boy" culture, still plenty of hard work to do, still many times she'll want to chuck it all. But if she can keep her goal(s) in mind and remember that school is just a short time in the overall scope of her future she can do it. I have examples in my own life of whom I'm very proud so I know it can work.
As a former mechanical designer and mobile robotocist, I've bought components from Berg (http://www.wmberg.com/) for nearly two decades. A little pricey, but reliable and robust. I'd highly recommend looking at their stuff.
Having taught both freshman composition and upper and lower division computer science courses let me offer a suggestion. Have your students spend some time reading and analyzing both good and bad writing of the type you want them to write. Incorporating the good and eschwing the bad when they write will go a long way towards improving their work. And don't ignore poor grammar; you might not have time in class to work on it, but the students should be able to write grammatically correct prose, properly spelled, and using the right words. Bring in hiring directors or managers from local tech businesses if you can and have them relate stories about the importance they place on communication in the workplace and why the writing in cover letters and resumes contributes heavily to moving an application to the next level or relegating it to the trash. Every engineer should be able to convey her thoughts simply and clearly with the written word.
Stallman was the recipient of a McArthur award (sometimes called a genius grant). If you're frugal (which he most certainly is) you can live a long time on half a million dollars and its interest.
Uh, you might want to check out the Polaroid SX-70 work he did. Not only color but instant. And yes, I believe that he would have found digital an exciting medium.
The VersaLaser is manufactured by Univeral Laser Systems in Scottsdale, AZ (http://www.ulsinc.com/) and comes in several versions. The VL-200 has a 25 watt laser and a 12" x 16" working area. The VL-300 can be had in 30, 40, or 50 watt versions with a 12" x 24" working area.
The $10K (US) price tag is for the VL-200 without any of the extras you'll need to make it work (exhaust ventilation, colinear air/NO2) and only in the engraving version. The honeycomb table for cutting table will set you back $240. And the VL-300 and accessories are even more expensive. Figure $15-$20K to make it really useable, and >$25K if you want in at 50 watts.
We've been using a 30W VL-300 for a couple of months now in our research lab. We were told to expect 6-8 weeks to get the machine, but in fact it took over twice that. The machine is nicely designed, but in places the fit and finish are pretty bad (at least on the early one we got). The current driver won't work on anything older than Win2K (we bought a cheap XP box for it since we're a Mac only group) and comes preconfigured with a set of materials and thicknesses (for cutting} which can't be changed. When I first tried to cut 1/4" basswood (a material I'd previously cut with a 10 Watt CO2 laser) I was told that a 30W VersaLaser couldn't do that job. No workaround since you don't have access to power levels or cutting speeds.
Also, Epilog Lasers in Golden, CO makes a similar machine, the Legend 24TT.
Is it a cool toy? You bet. But be aware that Universal has a fixed notion of the niche for these things and they're pretty reluctant to modify that notion. So if you've got the next, great market for their product don't be surprised if they're not interested.
AppleCare is a must have. While I'd never buy it for a desktop machine (and never have) laptops take a tremendous amount of abuse and no matter how careful you are and how good the hardware is things will break. I've seen screens, optical and hard drives, motherboard connectors, keyboards, and batteries replaced without a hitch under AppleCare.
While the price of AppleCare for PowerBooks is the highest Apple charges (that might be indicative of the percentage of claims that relate to PowerBooks), it's less than the cost of a replacement motherboard or screen.
90 volts, 20 Hz. I used to repair them when there was a Western Electric...
After ditching AD&D 20 years ago and working through a dozen homebrew variants we hit upon GURPS. It let us get to the role playing without having to be lawyer/accountants. And it translated well to any genre we wanted...