Comments on RepRap: Blog: Bug fixing

Lithium ion batteries are kinda tricky; polymer el...

2008-05-11T07:54:00.000+01:00

Lithium ion batteries are kinda tricky; polymer electrolytes, doubly so.

I built them for a couple years, as an undegrad, though to be honest I have much more experience with the liquid electrolyte. They're very sensitive to air, so you'd need to have your reprap in a dry box or similar, and there are lots of other nontrivial issues.

Sealed lead-acid may be a better first step. If you must make lithium ion, the cost of materials won't be as large a proportion, and you're presumably doing this for the sake of performance, so I'd recommend lithium cobalt oxide as your cathode material.

It seems worth note that a stepper motor and a gen...

2008-05-09T03:30:00.000+01:00

It seems worth note that a stepper motor and a generator like that are on a qualitative level the same device. It's just a matter of what the specific numbers are optimized for. In this case, you might want a microstepping controller, but apart from that.. could almost certainly even make one of those nifty little linear actuators. Now if I only had time to get myself a reprap and do the work... (maybe next school year.)

Now, what I think would be impressive is managing to lay down alternating layers of conductive material, bound graphite bits/something else that'll absorb ions, nonconductive polymer that will let ions move through it, and lithium iron phosphate or somesuch... print a battery, shaped to fit into whatever space is available.

I just posted the STL files for my 3 phase ac gene...

2008-05-09T00:01:00.000+01:00

I just posted the STL files for my 3 phase ac generator in the forums.
http://forums.reprap.org/read.php?1,11789

It's about the size of a CD, just a few cm thicker...

2008-05-08T04:05:00.000+01:00

It's about the size of a CD, just a few cm thicker though.

Gene Hacker,For the generator, if you designed a s...

2008-05-08T02:14:00.000+01:00

Gene Hacker,

For the generator, if you designed a spool holder and an upside horn or something else that smoothly lets wire out for the Darwin head, you could wind simple coils using Darwin.

What we actually need is a printable stepper motor...

2008-05-08T01:02:00.000+01:00

What we actually need is a printable stepper motor. :-)

Go with the generator. Look forward to seeing it....

2008-05-07T22:45:00.000+01:00

Go with the generator. Look forward to seeing it. Can I ask the rough overall size?

You sure seem to be having a lot of fun! :-D

2008-05-07T22:30:00.000+01:00

You sure seem to be having a lot of fun! :-D

So, do you want to print out a generator next? I'v...

2008-05-07T21:02:00.000+01:00

So, do you want to print out a generator next? I've made a couple of stl files for one that I'll post in the library whenever I get a chance.

It requires some unreprapable parts though, like a skate bearing, threaded rod, copper wire, 19 mm diameter toroid magnets, nuts and bolts.