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Machining a TI-89 Out of Aluminum

timothy posted more than 4 years ago | from the fully-weaponized dept.

Hardware Hacking 148

TangoMargarine writes "Sometimes, expensive calculators hit the floor. It's happened to almost anyone with a graphing calculator from TI or HP. Sadly, they don't always bounce. After this happened to [Howard C.], an Industrial Engineering student from U. of Iowa, he decided to spend $50 on milling his own replacement case out of aluminum rather than trashing the device over a broken battery compartment."

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ok but (4, Informative)

FuckingNickName (1362625) | more than 4 years ago | (#33405030)

1. Serious engineers use HP calculators;

2. Cushioned innards no?

Re:ok but (-1, Troll)

Anonymous Coward | more than 4 years ago | (#33405054)

It's good but it won't get them off their goatse [goatse.fr] .

Re:ok but (3, Insightful)

Idarubicin (579475) | more than 4 years ago | (#33405060)

2. Cushioned innards no?

I was just thinking the same thing. If you drop the plastic case, it deforms slightly on impact (or fails, as it did in this case), protecting the circuit boards and display from at least some of the shock.

The next time our engineer drops his calculator, the milled aluminum case will remain pretty and pristine, just as planned -- but without proper cushioning, the plastic circuit board screwed to it will fracture. (If the innards are free to move a bit, I also wonder if the buttons are all going to get sheared off when they bump up against the aluminum frame.)

Re:ok but (1)

DarkKnightRadick (268025) | more than 4 years ago | (#33405082)

Definitely something to consider.

Re:ok but (4, Insightful)

Jeremy Erwin (2054) | more than 4 years ago | (#33405202)

Well, he is an engineering student. He'll learn a valuable lesson that he can apply throughout his career.

Re:ok but (1)

DarkKnightRadick (268025) | more than 4 years ago | (#33406922)

True, true.

Re:ok but (1)

ildon (413912) | more than 4 years ago | (#33405100)

This was my very first thought when reading the summary, too.

Re:ok but (5, Informative)

Anonymous Coward | more than 4 years ago | (#33405348)

I know this guy personally. The durability thing was mostly just the spin HackADay put on it. As I recall, he milled this thing out mostly because it was a good way to get more experience milling complex items out of aluminum. And because the final product is seriously cool.

Re:ok but (3, Interesting)

Chris Burke (6130) | more than 4 years ago | (#33405634)

Yeah, and according to the comments he left, since he really needed a calculator he ended up buying a new one before finishing this project, so the aluminum TI-89 sits at home instead of traveling with him. So the lack of shock resistance in the new case is probably not a big issue anyway.

Re:ok but (0)

Anonymous Coward | more than 4 years ago | (#33405848)

If the innards are free to move a bit, I also wonder if the buttons are all going to get sheared off when they bump up against the aluminum frame.

They stopped using micro-switches a long time ago. Today they use a rubber membrane with conductive, springy pads directly on top of the PCB. No soldering needed. The rubber buttons on cheaper calculators is actually this membrane. If you open a calculator that has plastic buttons you'll see that the buttons are just bits of plastic that rides on top of the membrane.

So the buttons will actually work as a cushion against the printed circuit board.

Micro-switches can stand more wear and tear and are preferred when you have a nonflat surface , like a mouse.

Re:ok but (1)

MichaelSmith (789609) | more than 4 years ago | (#33406646)

I heard this in the 1970s about a guy who had a timber seat on his hang glider. He crashed the glider and broke the seat. Rather than replace it he reinforced the seat with a strip of steel so it wouldn't break in future hard landings...

Why not... (1)

RingDev (879105) | more than 4 years ago | (#33405114)

just use 5 cents worth of epoxy to put the broken piece back in place?

-Rick

Re:Why not... (1)

bsDaemon (87307) | more than 4 years ago | (#33405136)

If he were to glue the battery cover on, how's he going to change the batteries? I used to break the snaps off the battery covers all the time... started just using electrical tape. Fixed a TI-85, TI-86 and 3 TI-83s that way. I've had my TI-89 since 2000 or 2001 (got it some time in 11th grade, forget which half), but so far have avoided breaking anything on it. I might replace it with an HP50G soon just on general principles though.

Re:Why not... (1)

Splab (574204) | more than 4 years ago | (#33405164)

Was thinking, what's wrong with plain old gaffa?

Re:Why not... (2, Informative)

mysidia (191772) | more than 4 years ago | (#33405212)

There's an easier [ebay.com] more elegant way than machining a new case to fix a battery cover, that's for sure.

Re:Why not... (1)

guyminuslife (1349809) | more than 4 years ago | (#33405474)

Yeah, but you have to wait for bids to close, shipping, etc. I have an even simpler solution [wiringproducts.com] that I've used successfully for many household devices. Granted, the TI calculator presents some interesting challenges for engineering this solution, but I think a smart engineering student should be able to figure it out.

Re:Why not... (5, Funny)

Bing Tsher E (943915) | more than 4 years ago | (#33405244)

If he were to glue the battery cover on, how's he going to change the batteries?

He can throw on a black turtleneck, cop an attitude, and pretend it's an iPod.

Extra bonus points for throwing it away and buying a new one when the batteries wear out.

Re:Why not... (1)

TangoMargarine (1617195) | more than 4 years ago | (#33407066)

It wasn't breaking the battery cover that was the problem. One of the metal battery spring things (you can tell I'm not an EE...) that make the electrical connection broke off.

Re:Why not... (1)

evilviper (135110) | more than 4 years ago | (#33406056)

just use 5 cents worth of epoxy to put the broken piece back in place?

That was my thought exactly... BUT THEN I RTFA, took a look at the first picture of the old busted plastic case, and understood. Good thing, too. I'd hate to have posted a "why didn't he just..." comment on /. that makes me look like an idiot. Close call there...

Re:ok but (2, Interesting)

Desert Raven (52125) | more than 4 years ago | (#33405124)

Agreed, I went through a couple of TI calcs before buying an HP. I've never had an HP break. That's not to say I haven't dropped them. My poor HP 11C is now over 25 years old, and has been dropped too many times to count. It's still my favorite calculator. My 48G has likewise seen some rough handling, it is also still running fine.

TIs are decent from a functionality point of view, but they are unable to take any kind of rough handling.

My wife used TIs in college, and went through a couple of them as well.

Re:ok but (1)

Chris Burke (6130) | more than 4 years ago | (#33405492)

That's odd. When I was in school, TI calculators were preferred precisely for being designed to withstand drops from table height. Since the school was loaning them to students who didn't have one, this was a real concern. They were dropped onto the hard floor all the time, but breakage was really rare (and usually came from something like dropping them down a flight of stairs). I owned one for years that had been dropped I don't know how many times without a problem. Then it got swiped. Oh well it was a crappy 81, and the school loaned me an 85. Yay?

There weren't many HPs around, so no real experience on their durability. But the TIs were fine.

Granted this was over a decade ago. Quality degradation is pretty common.

Re:ok but (0)

Anonymous Coward | more than 4 years ago | (#33406004)

Yeah, it looks like a newer TI model. The older ones I remember from back in high school (early 1990s) had square buttons, and they had a good reputation for being neigh-indestructible. I've dropped a backpack with heavy books with my TI-85 calc in the back pocket down a flight of stairs and it wasn't ever bothered. Not to mention other countless times of being dropped or banged around. (I could pull it out of a drawer, and given that the batteries are good, it still works perfectly fine to this very day.) Seems it could take anything and survive short of directly hitting it with a sledgehammer. I guess TI's build quality has significantly changed over the last two decades.

Likely it's another example of an industry wide problem. Bean-counters and management types introducing fail into the design, and it doesn't take much cheapness to poison an entire product and turn it into shit. (Like how many new electronics costing more than $100 are still manage to be crap right off the shelf because some asshole thought it's great to save $0.02 per electrolytic capacitor. If the margin is that tight, how are the companies even staying in business?)

Re:ok but (1)

AmberBlackCat (829689) | more than 4 years ago | (#33406622)

I agree. My TI-89 Titanium's lithium battery cover broke. Not only have I not dropped this calculator but I haven't ever replaced the lithium battery. The lithium battery cover apparently serves no purpose so I could just take it out and use only the main battery cover. I think they just put it in there so it could break.

Re:ok but (1)

mlts (1038732) | more than 4 years ago | (#33407532)

The problem is that TIs are "good enough" (IMHO, of course), and have always been at best par for the course. The HP calculators are made to a much higher standard, and even though they are more expensive, for someone who relies on a calculator often it is worth it.

One example is the engineering of the venerable HP-48SX. The memory card didn't just use a card edge connector, it had a well made shutter to protect the contacts when removed from the device. One doesn't see this type of engineering much anymore as the Chinese companies most product makers OEM/ODM to just care enough to do the absolute bare minimum of materials and workmanship so as not to get sued.

Re:ok but (2, Funny)

Devout_IPUite (1284636) | more than 4 years ago | (#33405172)

3. Stop dropping your calculator? I have never damaged a calculator by dropping it.

Re:ok but (1)

roman_mir (125474) | more than 4 years ago | (#33405252)

You are simply AMAZING!

How DO you do it?

Re:ok but (1)

Devout_IPUite (1284636) | more than 4 years ago | (#33406828)

Breath through my nose mostly.

Re:ok but (1, Insightful)

Anonymous Coward | more than 4 years ago | (#33405570)

...Serious engineers ...Cushioned innards...

Yeah, most serious engineers I know have have fairly cushioned innards.

Re:ok but (0)

Anonymous Coward | more than 4 years ago | (#33405822)

1. Serious engineers use HP calculators;

Why is that? Do the HP calculators use special HP math to perform the calculations? Do they use special HP math to present the results? Or do you base your remark on brand loyalty and ignorance?

/TI user, serious engineer, also uses a TI-89

// never dropped it, though.

Re:ok but (1)

ukemike (956477) | more than 4 years ago | (#33406578)

1. Serious engineers use HP calculators;

Unfortunately HP no longer makes serious calculators. sigh.

Re:ok but (0)

Anonymous Coward | more than 4 years ago | (#33407480)

Carly ended the real HP calculators, but they're on the way back now that she's gone. It's still a bit sad, but there's a chance they will recover.

Anecdote (4, Informative)

rdnetto (955205) | more than 4 years ago | (#33407104)

TIs are the standard amongst students where I live, I always thought that serious engineers use *computers* with MATLAB, Maple, etc.

Actually, this reminds me of a story I heard about a classmate a few years ago. He actually dropped his TI-89 (same one as shown here [wordpress.com] ) out of a 2 story high window. The case was cracked but apart from that the calculator worked fine.

Personally, I think that model is the best one so far. It had full programming capabilities paired with tech. The new NSpires have a higher res screen, but they're not as easy to use because the interface is much more advanced and relies on a cursor. Additionally, programs are limited to BASIC, unlike the 89s which supported programs written in assembly (and TI even provided an IDE to write them in, IIRC).

Re:ok but (2, Funny)

ross.w (87751) | more than 4 years ago | (#33407138)

Didn't you mean

1. Engineers HP Calculators use serious?

Terminator (3, Funny)

Xugumad (39311) | more than 4 years ago | (#33405036)

Anyone else disappointed this wasn't an obscure Terminator model?

Re:Terminator (1)

Beelzebud (1361137) | more than 4 years ago | (#33405046)

I misread it and thought I'd see a TI99/4A in a sleek aluminum case. :D

Re:Terminator (3, Funny)

PotatoFiend (1330299) | more than 4 years ago | (#33405246)

Uh, like the original [oldcomputers.net] ? :D

Re:Terminator (1)

dgatwood (11270) | more than 4 years ago | (#33405802)

Well, the original was half aluminum, anyway.... They were also pretty easy to take apart, if memory serves. Good times. Good times.

Re:Terminator (1)

Beelzebud (1361137) | more than 4 years ago | (#33405938)

I can remember buying magazines for that computer, that had pages of games in BASIC code, so you could just copy the code and save the game to your tape drive. Good times, indeed!

Re:Terminator (1)

Chris Burke (6130) | more than 4 years ago | (#33405942)

I loved the TI-99 (probably only because I couldn't get a C64), but "sleek" isn't one of the adjectives I'd use to describe it. :)

Re:Terminator (1)

illumnatLA (820383) | more than 4 years ago | (#33405292)

You know... I read it the same way heh.

Bad title... (0, Troll)

damn_registrars (1103043) | more than 4 years ago | (#33405112)

The person did not machine the calculator out of aluminum, only the body for it.

Re:Bad title... (1)

Mike Buddha (10734) | more than 4 years ago | (#33405396)

Splitting hairs much?

Re:Bad title... (1)

Chris Burke (6130) | more than 4 years ago | (#33405532)

I don't think it's bad because there exists an interpretation that was wrong. If it was misleading, then sure, but were you seriously misled into thinking they'd discovered how to machine complicated electronics and a display directly out of aluminum? I think the misleading part there would be making it sound like a fun hobbyist project rather than a revolution in physics and technology!

Or were you just hoping for aluminum buttons?

Re:Bad title... (1)

TangoMargarine (1617195) | more than 4 years ago | (#33407092)

To be fair, my originally suggested title was "Machining a TI-89 Aluminum" or some such thing. As in, "TI-89 Aluminum edition." The mod probably interpreted it as poor grammar. Oh well.

Re:Bad title... (1)

rubycodez (864176) | more than 4 years ago | (#33407178)

right, for the display you'd have to use transparent aluminum, and for insulators aluminum oxide, and for semiconductors the aluminum oxide MOS-FET, but nowadays that has fallen out of favor for polysilicon

ok, I'm just BSing....

Aluminum (1)

thePjunisher (858667) | more than 4 years ago | (#33405160)

Lookin' at the pictures.

This guy is an industrial engineering student?

If I was his professor, I'd give him a D.

Re:Aluminum (1)

DigiShaman (671371) | more than 4 years ago | (#33405174)

Why?

Re:Aluminum (0, Redundant)

matthiasvegh (1800634) | more than 4 years ago | (#33405278)

because theres nothing to break the shock of the fall if he uses aluminium. he either has to cushion the innards, or figure something else out..

Re:Aluminum (1)

Bruiser80 (1179083) | more than 4 years ago | (#33405328)

The new frame is larger than the old one - maybe he designed some cushion into it?

Industrial Engineers Mechanical Engineers

Depending on his discipline, the prof would give him a A for unique design, ergonomics, or mass-producability (prototype was 3D lathed, but design could be cast?). Drop test durability would fall under a mechanical engineer, imo.

Re:Aluminum (0)

Anonymous Coward | more than 4 years ago | (#33405184)

He managed to make a TI graphing calculator bulkier? How is this an achievement?

Re:Aluminum (2, Insightful)

Chris Burke (6130) | more than 4 years ago | (#33405604)

Since this project would have been for a machining class, not a case design class, I'd think a higher grade than that would be appropriate.

More important: motherboard fittings, construction (4, Informative)

blind biker (1066130) | more than 4 years ago | (#33405178)

I've seen the drop-test instrumentation used for reliability testing in one of our uni's labs. They sell services to companies such as Nokia, to test the reliability of their gadgets. Anyhow, to make an almost indestructible case is not difficult, but what increases reliability and survivability of electronic equipment is correct fitting and damping of the motherboard to the case (you don't want it to feel the same deceleration as the case hitting the floor) and the components soldered on the motherboard must not break the electric contacts. This latter is very, very challenging, and hundreds if not thousands of engineers and scientists work around the world on improving the reliability of electronic IC packaging and solder.

Re:More important: motherboard fittings, construct (0, Troll)

Grishnakh (216268) | more than 4 years ago | (#33405618)

Yep, all those thousands of engineers need to waste lots of time re-inventing the wheel, because some government morons thought it'd be a good idea to ban leaded solder, which has superior properties not only for soldering, but also for durability (leaded solder is less brittle than lead-free solder).

Re:More important: motherboard fittings, construct (0)

Anonymous Coward | more than 4 years ago | (#33406414)

Yeah, the morons that care about lead poising and such! Retards!

Re:More important: motherboard fittings, construct (1)

Grishnakh (216268) | more than 4 years ago | (#33406464)

You don't think tin, copper, silver, bismuth, indium, zinc, and antimony are going to poison you? A couple of those are needed in trace amounts by humans (copper and zinc), but the rest sound poisonous to me, and all of them are poisonous in anything above a trace quantity.

If you don't want lead poisoning, then don't eat electronic components and circuit boards. I for one haven't had much trouble keeping those out of my diet.

He is no Jedi (3, Funny)

Tumbleweed (3706) | more than 4 years ago | (#33405182)

No duct tape fix, not an industrial engineering student worthy of respect. He could make a fine machinist, though. He should go with his true talent.

Re:He is no Jedi (1)

snikulin (889460) | more than 4 years ago | (#33405382)

"Heavy is good, heavy is reliable. If it doesn't work you can always hit him with it." (C) Boris-the-blade

No Jedi, he is (1)

CortoMaltese (828267) | more than 4 years ago | (#33405664)

Fixed the subject for you.

Re:He is no Jedi (1)

zippthorne (748122) | more than 4 years ago | (#33407038)

Duck tape is cheating. You can "fix" anything with it, but.. not well. Sometimes not quickly.

Measuring (1)

Animats (122034) | more than 4 years ago | (#33405228)

I wonder how he measured the holes for the keys. That's the tough part. Once you have a good model, it's a simple enough CNC machining job. Although the front panel is thicker than the original, and the keys don't project as much as they should.

It might work to simply put an undamaged calculator in a flatbed scanner, get a good image of the front, clean it up so it just has the hole outlines for the keys, vectorize, then clean up the vectorized form.

Front Panel Express [frontpanelexpress.com] specializes in making panels with holes and lettering. They could easily do that front panel, if you laid out the design and sent it in.

Uh... (2, Insightful)

Anonymous Coward | more than 4 years ago | (#33405286)

He DID have a template. He had to remove the innards from the stock body, leaving an easily scanned front case that will produce high contrast hole outlines.

As noted, the new casing is too thick for proper button operation. Also, the imprinted legends have poorer contrast than on the original body. Not a bad hack, but I'd prefer the original case. His reminds me of homebrew projects stuck in featureless Hammond boxes.

Good Calculator (1)

Murdoch5 (1563847) | more than 4 years ago | (#33405260)

I have a Ti-89 and I must say that it is a rocking device. It's so nice to have a CAS in hand, in the classroom. My last Ti Calculator, the Ti 83 Silver, dropped one day and it never recovered, the device never turned on. One day I threw it because I pissed off and then it worked for like 2 months before one day during a test the calculator called it quits lol.

Slashdot Delay (1)

hydromike2 (1457879) | more than 4 years ago | (#33405314)

I really wish slashdot would actually find articles that I did not already read about on another site some days ago

Re:Slashdot Delay (2, Insightful)

Grishnakh (216268) | more than 4 years ago | (#33405636)

Slashdot isn't a cutting-edge site for whatever particular niche you're interested in. It's a more general-interest site, with lots of different topics of interest (politics, free software, mathematics, games, etc.), so it's a little slower, but has a wider breadth.

Look out! (1)

SuperTechnoNerd (964528) | more than 4 years ago | (#33405334)

Look out! HP and/or TI may send you a cease and desist letter for this unauthorized case mod. Your case will break when you install the next software update. When will you people learn that WE THE COMPANY still own everything you buy from us. THIS IS UNAUTHORIZED! PREPARE FOR LAW SUITS!

cost (4, Interesting)

donnyspi (701349) | more than 4 years ago | (#33405336)

I can't begin to understand why these calculators, which have been around for many years and still have the same features and functions, cost the same as they did when I was in school about 15 years ago. http://xkcd.com/768/ [xkcd.com]

Re:cost (1)

omglolbah (731566) | more than 4 years ago | (#33405950)

Because they are required by most schools.

The 'demand' is 'forced' so why should the price drop? The same group of people buy them every year regardless of the cost ;)

Re:cost (0)

Anonymous Coward | more than 4 years ago | (#33405972)

I can't begin to understand why these calculators, which have been around for many years and still have the same features and functions, cost the same as they did when I was in school about 15 years ago

I'm sure there's no good reason for this from a pure manufacturing standpoint. However, many (most?) schools in the U.S., both high school and college, require TI graphing calculators for their math courses. So TI has a pretty solid monopoly that they're exploiting. I doubt it will change any time soon because graphing calculators are just complicated enough that switching brands would be too much of a pain in the ass for teachers to be bothered with. Schools also have years worth of stockpiled TI calculators and accessories like projectors and serial cables that would have to be replaced if they changed models. Many math text books are also written to include problems that require TI calculators to solve per the provided instructions.

I can't say that I dislike TI calculators (they were the platform for my early programming escapades), but they really cost about 5 times as much as they should.

Re:cost (1)

hedwards (940851) | more than 4 years ago | (#33406000)

Technically speaking that's not quite true, the newer ones have a bit more processing power and memory and use a USB cable instead of the old serial one, and they include it in some models. Additionally the resolution is a bit higher than on the older ones. But it's not really enough of an improvement to justify the lack of price drops over the intervening years.

Re:cost (4, Interesting)

soupforare (542403) | more than 4 years ago | (#33406034)

They're test-legal and a de facto standard in schools. It's ridiculous but it's kept prices high as hell. The casio graphers are speedy, work well and are cheap. Unless you expect to be taking a placement test anytime soon, there's no reason to stick with TI.

Re:cost (2, Interesting)

MightyYar (622222) | more than 4 years ago | (#33406672)

The casio graphers are speedy, work well and are cheap.

I used Casios for years until I was converted into the RPN religion. Casio had a algebraic entry system that was ALMOST as fast and clear as RPN, and the calculators were much, much cheaper than the TI models.

Of course, now I've gone RPN and I'm spoiled - even have to seek out software RPN calculators for all my computers and devices :)

Re:cost (1)

blai (1380673) | more than 4 years ago | (#33406346)

same features and functions

cost the same

Re:cost (1)

BungaDunga (801391) | more than 4 years ago | (#33406838)

The point being, Moore's Law has had 15 years to work and if someone was selling you a PC from 15 years ago for the same price as it cost 15 years ago, you'd be a bit confused.

"It's 150 Mhz with a WHOLE GIGABYTE of RAM! $1300, with included copy of Windows 98!"

Re:cost (1)

InfiniteWisdom (530090) | more than 4 years ago | (#33407024)

Ugh, single click moderation with no way to correct (besides posting a comment and undoing *all* mods on this story). Didn't mean to mark that redundant.

What a waste (1)

twoears (1514043) | more than 4 years ago | (#33405360)

The case might be indestructable, but the crappy keys are still there. A V-8 moment: He could have had an HP, such as a 50g. I still like my one-of-a-kind HP-41CX, with a case injection molded in blue instead of the almost-black color, purchased from a former HP Corvallis employee. Talk about a geek magnet.

Usefulness of High-End Graphing Calculators? (0)

Anonymous Coward | more than 4 years ago | (#33405394)

Honestly, with a netbook and a copy of Octave, what is the point in ponying up money for one of these (besides the obvious "required for class" argument)? You get very little for the money you spend.

Re:Usefulness of High-End Graphing Calculators? (0)

Anonymous Coward | more than 4 years ago | (#33406470)

Bought mine at Walmart for $80. While I agree with the previous posters that the prices on these TI calculators is artificially high, $80 doesn't exactly require much "ponying".

It was pretty weird that the TI-89 cost less than the TI-84s and TI-83s next to it on the rack. It does significantly more and it is rapidly replacing my 17-year-old TI-85.

Awesome. How do I do that? (4, Interesting)

vadim_t (324782) | more than 4 years ago | (#33405414)

I'd like to do the same thing. So I'm hoping somebody could give me a few hints on it.

First, how did he manage to come up with a design for the new case matching exactly all of the buttons? Do you just take some calipers and start measuring? The curved layout of the buttons, and the shape of the buttons themselves look tricky. Also I imagine that accurate positioning of screw holes is critical.

And second, how does one get such a thing manufactured? Are there places available to normal people that would take an order for a single piece or a small run, and what file format would they require? Or a place where I could get access to the hardware and operate it myself?

I would be really appreciate some pointers about how to get started.

Re:Awesome. How do I do that? (4, Informative)

aluser (771756) | more than 4 years ago | (#33405596)

I haven't used this place, but here's one place that will do small one-off machining jobs for you: http://www.emachineshop.com/ [emachineshop.com] . That's been sitting in my bookmarks for "future reference" for a while now :)

Looks like they want you to use their own cad software, which apparently can estimate the cost while you work on the design. I bet some googling can find other, similar, shops.

Re:Awesome. How do I do that? (1)

Grishnakh (216268) | more than 4 years ago | (#33405662)

I'll take a couple of guesses.

1) for the buttons, he used a scanner, and generated a pattern from the old case, and used that to generate a CAD file and then a G-code file for the milling machine.

2) he's an engineering student, he probably had access to a CNC machine at school. There's tons of cheap CNC machines out there these days (even under $1k).

Re:Awesome. How do I do that? (1)

DaveGod (703167) | more than 4 years ago | (#33405672)

Look up CNC [wikimedia.org] . Probably quite expensive unless you have one at work or know someone using one at college - they'll be quite expensive capital equipment so while the incremental cost to actually use it is probably quite small, anywhere doing it as a business is looking to recoup the cost of the machine.

(I'd be more helpful but I'd only be looking it up myself.)

Re:Awesome. How do I do that? (1)

the_macman (874383) | more than 4 years ago | (#33406916)

As an engineer you'll draw the model in CAD using software like Solidworks. Then you'll use other software tools that let you program code to tell a CNC machine HOW to make your model from a solid block of aluminum. Then you feed the code into a CNC machine and let it go to work on the block. If you did everything correctly you have a new calculator case if you botched it, you have to start over.

A local machine shop will be able to help you with this. CAD software is expensive but if you're interested in learning, Google Sketchup [google.com] is free and comes with TONS of online tutorials. It's the simplest of simplest of simple CAD programs but you can learn the basics using Sketchup.

Re:Awesome. How do I do that? (1)

SheeEttin (899897) | more than 4 years ago | (#33407298)

First, how did he manage to come up with a design for the new case matching exactly all of the buttons? Do you just take some calipers and start measuring?

Well, many of the buttons are in a regular pattern and of the same shape and size, just warped, so using calipers would be a little easier than you'd think at first. (Photo of original TI-89 Titanium and milled case here [wordpress.com] .)
After viewing all the pictures, though, it seems the holes are approximations of the buttons. Dunno how that'd affect debris entry.

Of course, one could always just take an original case, use a 3D scanner, and then tweak the 3D model. ;)

Now he's in trouble (2, Funny)

Len (89493) | more than 4 years ago | (#33405440)

TI's lawyers will be after him for DMCA violation because he's bypassed their physical copyright protection mechanism.

Re:Now he's in trouble (1)

rdnetto (955205) | more than 4 years ago | (#33407084)

You jest, but he probably won't be able to use it for exams anymore, since it's clearly been modified.

Fake (1)

Main Gauche (881147) | more than 4 years ago | (#33405500)

He'd have gotten away with it if he didn't post the picture [wordpress.com]
.
It doesn't make sense to replace titanium with aluminum. Busted, mofo.

Re:Fake (1)

MightyYar (622222) | more than 4 years ago | (#33406678)

He says that the Titanium model is the replacement that he bought while he was fabricating the aluminum case for the broken unit.

I'm working on an aluminum HP 11 (3, Interesting)

NixieBunny (859050) | more than 4 years ago | (#33405522)

but it will use Nixie tubes for the display, just to make it interesting. It's fun to do the CAD design. Someone else will have to help me with the software, as I'm more of a hardware guy.

repair rather than replace :D (2)

ksandom (718283) | more than 4 years ago | (#33405730)

I really like stories like this. Where ever feasible, I try to repair rather than replace.

Wait this guy broke a TI 89 -Titanium-... (3, Funny)

SlashDread (38969) | more than 4 years ago | (#33406074)

and replaced it with Aluminium? Isnt that a step back? Whats next? Casted iron?

And after the next drop (1)

Attila the Bun (952109) | more than 4 years ago | (#33406660)

Coming soon: how to mill new floorboards out of titanium, after the old floor was shattered by a falling calculator.

Carbon Fiber (1)

theJML (911853) | more than 4 years ago | (#33406674)

Carbon fiber would have been cooler, thinner (what's with that raised edge and the fact that the buttons don't protrude at all from the face, that'd drive me nuts!) and a lot lighter weight, not to mention being easier to construct.

Necessary? (1)

ponraul (1233704) | more than 4 years ago | (#33406720)

I've had the same Ti-86 since 11th grade---about a decade ago---and I must have dropped it a few thousand times over that period. While this is a neat engineering exercise, the original design is more than capable of surviving the day-to-day paces that a student will put it through.

Re:Necessary? (1)

Glendale2x (210533) | more than 4 years ago | (#33406846)

I've had the same Ti-86 since 11th grade---about a decade ago---and I must have dropped it a few thousand times over that period. While this is a neat engineering exercise, the original design is more than capable of surviving the day-to-day paces that a student will put it through.

My TI-86 is from 1996. Never broken, never erased/lost the memory. The case has plenty of scratches and the sliding cover isn't quite as snug as when it was new, but it works just as good. I still use it today.

Re:Necessary? (1)

Glendale2x (210533) | more than 4 years ago | (#33406882)

Er, make that 1997. I don't think the 86 existed yet in 1996.

Waist high drop (1)

CmdrPorno (115048) | more than 4 years ago | (#33406912)

We had a bunch of TI-82s in high school. Our Algebra teacher helpfully explained that they had been engineered to withstand a waist high drop. Whenever one would inevitably slide off someone's desk, we would exclaim, "waist high!"

I was the nerd who bought his own TI-83 and the Graph-Link cable to plug in to the COM port of his home computer.

Don't make the calculator hard (1)

billcopc (196330) | more than 4 years ago | (#33406960)

Why not make the ground soft ? :)

I mean, semi-seriously, all our shiny expensive toys are very fragile. If the greatest danger is having them hit the floor, then let's make the floor mushy and soft instead of these steel-and-concrete gear crushers.

I'm sure I'd have gone through a dozen smartphones this year, if my apartment weren't covered in nice fluffy carpet.

Re:Don't make the calculator hard (1)

IorDMUX (870522) | more than 4 years ago | (#33407308)

Why not make the ground soft ? :) I mean, semi-seriously, all our shiny expensive toys are very fragile. If the greatest danger is having them hit the floor, then let's make the floor mushy and soft instead of these steel-and-concrete gear crushers.

...

Because some of us go outside?

Re:Don't make the calculator hard (1)

u38cg (607297) | more than 4 years ago | (#33407430)

Where?
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