Machining a TI-89 Out of Aluminum

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Machining a TI-89 Out of Aluminum

Posted by timothy on Saturday August 28, 2010 @08:13AM from the fully-weaponized dept.

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 by FuckingNickName · 2010-08-28 08:14 · Score: 4, Informative

1. Serious engineers use HP calculators;
2. Cushioned innards no?
1. Re:ok but by Idarubicin · 2010-08-28 08:20 · Score: 3, Insightful
  
  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.)
  
  --
  ~Idarubicin
2. Re:ok but by DarkKnightRadick · 2010-08-28 08:23 · Score: 1
  
  Definitely something to consider.
  
  --
  "There is a way that seems right to a man, but its end is the way of death." Proverbs 16:25 (NKJV)
3. Re:ok but by ildon · 2010-08-28 08:25 · Score: 1
  
  This was my very first thought when reading the summary, too.
4. Re:ok but by Desert+Raven · 2010-08-28 08:29 · Score: 2, Interesting
  
  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.
5. Re:ok but by Devout_IPUite · 2010-08-28 08:37 · Score: 2, Funny
  
  3. Stop dropping your calculator? I have never damaged a calculator by dropping it.
6. Re:ok but by Jeremy+Erwin · 2010-08-28 08:44 · Score: 4, Insightful
  
  Well, he is an engineering student. He'll learn a valuable lesson that he can apply throughout his career.
7. Re:ok but by roman_mir · 2010-08-28 08:59 · Score: 1
  
  You are simply AMAZING!
  How DO you do it?
  
  --
  You can't handle the truth.
8. Re:ok but by Anonymous Coward · 2010-08-28 09:24 · Score: 5, Informative
  
  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.
9. Re:ok but by Chris+Burke · 2010-08-28 09:53 · Score: 1
  
  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.
  
  --
  
  The enemies of Democracy are
10. Re:ok but by Anonymous Coward · 2010-08-28 10:07 · Score: 1, Insightful
  
  ...Serious engineers ...Cushioned innards...
  Yeah, most serious engineers I know have have fairly cushioned innards.
11. Re:ok but by Chris+Burke · 2010-08-28 10:16 · Score: 3, Interesting
  
  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.
  
  --
  
  The enemies of Democracy are
12. Re:ok but by Anonymous Coward · 2010-08-28 10:48 · Score: 0
  
  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.
13. Re:ok but by Anonymous Coward · 2010-08-28 10:52 · Score: 0
  
  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.
14. Re:ok but by Anonymous Coward · 2010-08-28 11:16 · Score: 0
  
  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?)
15. Re:ok but by ukemike · 2010-08-28 13:45 · Score: 1
  
  1. Serious engineers use HP calculators;
  Unfortunately HP no longer makes serious calculators. sigh.
  
  --
  -- QED
16. Re:ok but by AmberBlackCat · 2010-08-28 13:54 · Score: 1
  
  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.
17. Re:ok but by MichaelSmith · 2010-08-28 13:57 · Score: 1
  
  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...
  
  --
  http://michaelsmith.id.au
18. Re:ok but by Devout_IPUite · 2010-08-28 14:50 · Score: 1
  
  Breath through my nose mostly.
19. Re:ok but by DarkKnightRadick · 2010-08-28 15:16 · Score: 1
  
  True, true.
  
  --
  "There is a way that seems right to a man, but its end is the way of death." Proverbs 16:25 (NKJV)
20. Re:ok but by ross.w · 2010-08-28 16:27 · Score: 2, Funny
  
  Didn't you mean
  1. Engineers HP Calculators use serious?
  
  --
  If my call is important, why am I talking to a recording?
21. Re:ok but by Anonymous Coward · 2010-08-28 19:11 · Score: 0
  
  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.
22. Re:ok but by mlts · 2010-08-28 19:31 · Score: 1
  
  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.
23. Re:ok but by mlts · 2010-08-28 19:37 · Score: 1
  
  The problem is that there are zero consequences in skimping on components and lots of rewards. The bean counter can demand manufacturing uses caps with bad electrolytic compounds that burst in 6-12 months and render the product useless. If the failure happen when the device is out of warranty, it just means more sales next FY.
  There is nothing to counter-balance this, because people will just continue buying stuff even when it has a self destruct mechanism.
24. Re:ok but by FuckingNickName · 2010-08-28 20:45 · Score: 1
  
  Do the HP calculators use special HP math to perform the calculations?
  Well, yes, obviously each calculator uses its own algorithms. What an odd question. Some of the firmware source has even been released, if you look hard enough (e.g.).
  
  Or do you base your remark on brand loyalty and ignorance?
  I base my remark on having fairly quickly sold a TI-89 once I started to enjoy the speed and flexibility of RPN and the tremendous amount of configurability of an HP calculator vs TI. HP totally lost the plot in hardware build quality with the HP 49G and gradually got back to nearly-OK with the 50G, but I hung on because the firmware is so good.
  Also cool is the ability to program right down to Saturn / ARM assembler with the semi-official blessing of the vendor rather than the vendor trying to sue you.
25. Re:ok but by NormalVisual · 2010-08-29 01:44 · Score: 1
  
  Today they use a rubber membrane with conductive, springy pads directly on top of the PCB.
  
  This is true for some of them - others simply have a set of closely spaced intertwined traces on the PCB where the button is located, and the rubber button that the user touches is backed with a small carbon puck that shorts the traces together, with no intervening membrane between the button and the PCB.
  
  --
  Please stand clear of the doors, por favor mantenganse alejado de las puertas
26. Re:ok but by Anonymous Coward · 2010-08-29 01:49 · Score: 0
  
  Anyway, he's an engineering student. He has no business actually making things.
27. Re:ok but by YoungHack · 2010-08-29 03:01 · Score: 1
  
  HP calcs are my favorite as well. But I will say that the 28S was not a durable calculator. I think I've broken at least 3. But I loved that calculator model. If they would have just done something to improve the battery door, they could still be selling them.
28. Re:ok but by BrokenHalo · 2010-08-29 04:22 · Score: 1
  
  I have a TI-89 and used to have an HP48G+ (which despite its many advantages proved to be just too prone to failure), and have found that both tend to be dropped much more often when they are not being used. So a decent padded case like that shown here makes a hell of a difference. I have used (and abused) a case like this for 8 years, and my calculator is still working fine.
29. Re:ok but by BrokenHalo · 2010-08-29 04:28 · Score: 1
  
  And, to be fair, the buttons on my TI-89 were a bit overly snugly fitted, so they used to be a bit rough on the keystroke until I attacked the housing with a jeweller's file. The TI-89 just does not have anywhere near as good a keypad as the HP48* series.
30. Re:ok but by BrokenHalo · 2010-08-29 04:45 · Score: 1
  
  The HP calculators are made to a much higher standard...
  
  Although I loved the clicky keys on my HP48G+, (not to mention that lovely fat "Enter" button just where the index finger falls) and am quite happy with RPN, the quality was skin deep. The machine went into spasms of denial if anyone looked at it sideways, and such antics cost me grades in examinations in my undergrad university course.
  
  I treated the disease by selling off the HP and buying a TI-89. The build quality of the latter is vastly inferior, but the device is much faster and more functional, and reliability is rock-solid. Oh, and the myth about RPN requiring less keystrokes is pretty much just that: a myth (though I freely admit RPN is a great way of processing calculations "on the fly").
31. Re:ok but by pipingguy · 2010-08-29 06:51 · Score: 1
  
  I agree completely. The 28s had a terrible battery door (now looking sadly at my dead 28s).
32. Re:ok but by pipingguy · 2010-08-29 07:02 · Score: 1
  
  Funny, that is.
33. Re:ok but by ailnlv · 2010-08-29 07:33 · Score: 1
  
  serious engineers use matlab
34. Re:ok but by rwa2 · 2010-08-30 04:34 · Score: 1
  
  Awesome case mod, in that case.
  I hate to admit that I was that lazy, but when it happened to me, I ended up just memorizing the key locations and operating it without the case entirely :P
35. Re:ok but by Anonymous Coward · 2010-08-30 05:52 · Score: 0
  
  How DO you do it?
  He doesn't, that's the point!
36. Re:ok but by Anonymous Coward · 2010-08-30 06:46 · Score: 0
  
  Serious engineers use something like matlab, python, or whatever. Calculators are a thing of the past - obligatory xkcd:
  http://xkcd.com/768/
37. Re:ok but by Anonymous Coward · 2010-08-30 07:23 · Score: 0
  
  I got my HP49G+ about four or five years ago. After about a year, the 0 key and ANS key wore out (somewhat) such that the buttons rattle around in the case. Those two keys don't rebound very well when pressed, and often register two presses even when lightly touched.
  I blame it on my carelessness, just carrying it around in my backpack with the textbooks. It came with a soft, padded (leather? vinyl?) case that protected it from slashing and piercing damage, but I think my books crushed the springs, or something, on those two keys at the bottom of the keypad.
38. Re:ok but by Chris+Tucker · 2010-08-30 09:32 · Score: 1
  
  HP Forever! Not just a slogan, a reality.
  My HP-45 calculator is still going strong!
  http://img.skitch.com/20100830-3s3d9tu936f4wim7neihyej3f.jpg
  It's faster to use the real calculator that it is to call up a calculator app on the Mac.
  
  --
  Guaranteed! This comment 100% Anthrax free!
39. Re:ok but by toddestan · 2010-08-30 14:26 · Score: 1
  
  I've found that the screens on the HP-48 series calculators are kind of fragile. It's due to the LCD being snug against the front of the case and unprotected. If the calculator is dropped, the case can flex, and if the screen doesn't have room to move then it will break. The old TI's like the 81 and 85 have the screen inside the calculator, which is protected by a clear plastic lens. This makes it harder to see the LCD, but the screen kind of sits loose inside, it's nearly immune to breaking when the calculator is dropped (my TI-85 has withstood an amazing amount of abuse and still works flawlessly). Note that the newer TI's (83+, 89) have the screen mounted like the HP's and thus seem more prone to breaking in the same manner.
40. Re:ok but by Chris+Burke · 2010-08-30 16:12 · Score: 1
  
  The old TI's like the 81 and 85 have the screen inside the calculator, which is protected by a clear plastic lens. This makes it harder to see the LCD, but the screen kind of sits loose inside, it's nearly immune to breaking when the calculator is dropped (my TI-85 has withstood an amazing amount of abuse and still works flawlessly). Note that the newer TI's (83+, 89) have the screen mounted like the HP's and thus seem more prone to breaking in the same manner.
  That makes a lot of sense. Like I said I don't have much experience with the HPs, but I do remember thinking the screen was exposed. If the later TIs are similar, that plus a healthy dose of penny-pinching would explain the claims of fragility.
  
  --
  
  The enemies of Democracy are
41. Re:ok but by Anonymous Coward · 2010-08-31 03:02 · Score: 0
  
  Your mom has cushioned innards... mmmm yummy.
Terminator by Xugumad · 2010-08-28 08:16 · Score: 3, Funny

Anyone else disappointed this wasn't an obscure Terminator model?
1. Re:Terminator by Beelzebud · 2010-08-28 08:19 · Score: 1
  
  I misread it and thought I'd see a TI99/4A in a sleek aluminum case. :D
2. Re:Terminator by PotatoFiend · 2010-08-28 08:55 · Score: 3, Funny
  
  Uh, like the original? :D
  
  --
  "Liberty may be endangered by the abuses of liberty as well as the abuses of power." -- James Madison
3. Re:Terminator by illumnatLA · 2010-08-28 09:07 · Score: 1
  
  You know... I read it the same way heh.
  
  --
  Web hosting that doesn't suck!Dreamhost
4. Re:Terminator by dgatwood · 2010-08-28 10:44 · Score: 1
  
  Well, the original was half aluminum, anyway.... They were also pretty easy to take apart, if memory serves. Good times. Good times.
  
  --
  Check out my sci-fi/humor trilogy at PatriotsBooks.
5. Re:Terminator by Beelzebud · 2010-08-28 11:05 · Score: 1
  
  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!
6. Re:Terminator by Chris+Burke · 2010-08-28 11:05 · Score: 1
  
  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. :)
  
  --
  
  The enemies of Democracy are
7. Re:Terminator by DickMoohan · 2010-08-28 20:16 · Score: 1
  
  Had the exact same thought.... this is going to be awesome ;)
Bad title... by damn_registrars · 2010-08-28 08:27 · Score: 0, Troll

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

--
Damn_registrars has no butt-hole. Damn_registrars has no use for a butt-hole.
1. Re:Bad title... by Mike+Buddha · 2010-08-28 09:32 · Score: 1
  
  Splitting hairs much?
  
  --
  by Mike Buddha -- Someday the mountain might get him, but the law never will.
2. Re:Bad title... by Chris+Burke · 2010-08-28 09:59 · Score: 1
  
  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?
  
  --
  
  The enemies of Democracy are
3. Re:Bad title... by TangoMargarine · 2010-08-28 16:08 · Score: 1
  
  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.
  
  --
  Unity? Screw that: XFCE. Slashdot Beta? Screw that: SoylentNews. Australis? Screw that: Pale Moon. UX developers DIAF
4. Re:Bad title... by rubycodez · 2010-08-28 16:40 · Score: 1
  
  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....
Why not... by RingDev · 2010-08-28 08:27 · Score: 1

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

--
"Most people in the U.S. wouldn't know they live in a tyrannical state if it walked up and grabbed their junk." - MyFirs
1. Re:Why not... by bsDaemon · 2010-08-28 08:30 · Score: 1
  
  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.
2. Re:Why not... by Splab · 2010-08-28 08:35 · Score: 1
  
  Was thinking, what's wrong with plain old gaffa?
3. Re:Why not... by mysidia · 2010-08-28 08:46 · Score: 2, Informative
  
  There's an easier more elegant way than machining a new case to fix a battery cover, that's for sure.
4. Re:Why not... by Bing+Tsher+E · 2010-08-28 08:55 · Score: 5, Funny
  
  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.
5. Re:Why not... by guyminuslife · 2010-08-28 09:50 · Score: 1
  
  Yeah, but you have to wait for bids to close, shipping, etc. I have an even simpler solution 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.
  
  --
  I don't believe in time. It's a grand conspiracy designed to sell watches.
6. Re:Why not... by evilviper · 2010-08-28 11:32 · Score: 1
  
  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...
  
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  Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
7. Re:Why not... by TangoMargarine · 2010-08-28 16:02 · Score: 1
  
  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.
  
  --
  Unity? Screw that: XFCE. Slashdot Beta? Screw that: SoylentNews. Australis? Screw that: Pale Moon. UX developers DIAF
8. Re:Why not... by Mirey · 2010-08-28 19:45 · Score: 1
  
  He could've just used duct tape and be the envy of his class mates! Besides, it'll give him the same grey finish that he wants..
9. Re:Why not... by RingDev · 2010-08-29 01:37 · Score: 1
  
  Did I miss something in the picture? It looked like the only broken part was the corner of the battery case. epoxy the broken piece back in, glue the spring back in place, and run a small lead from it back to the power line.
  Or does this guy have access to a 5 axis milling machine, but not a soldering iron?
  -Rick
  
  --
  "Most people in the U.S. wouldn't know they live in a tyrannical state if it walked up and grabbed their junk." - MyFirs
10. Re:Why not... by Anonymous Coward · 2010-08-29 05:59 · Score: 0
  
  Epoxy works for a lot of repairs, but not small things like the small tabs on battery compartment covers. That's what duct tape and metal repair tape are for.
  Actually you should use gaffer's tape. It's the real thing. Cheap duct tape is crap. Gaffer's tape, along with metal repair tape (also called 1000 mi/per/hr tape or aircraft skin tape) as well as epoxy should be in every true nerd's desk/work bench.
11. Re:Why not... by krapski · 2010-08-29 08:24 · Score: 0, Offtopic
  
  geeky fucking signatures like that do not make you look cool
12. Re:Why not... by exomondo · 2010-08-29 19:22 · Score: 1
  
  Extra bonus points for throwing it away and buying a new one when the batteries wear out.
  He doesn't have to go that far, he could just do what the Cupertino folks do to solve a major design flaw...whack a rubber band around it.
13. Re:Why not... by morphotomy · 2010-08-30 03:50 · Score: 1
  
  yes they do
14. Re:Why not... by krapski · 2010-09-02 10:04 · Score: 0
  
  fucking geek
Aluminum by thePjunisher · 2010-08-28 08:34 · Score: 1

Lookin' at the pictures.
This guy is an industrial engineering student?
If I was his professor, I'd give him a D.
1. Re:Aluminum by DigiShaman · 2010-08-28 08:37 · Score: 1
  
  Why?
  
  --
  Life is not for the lazy.
2. Re:Aluminum by Anonymous Coward · 2010-08-28 08:39 · Score: 0
  
  He managed to make a TI graphing calculator bulkier? How is this an achievement?
3. Re:Aluminum by matthiasvegh · 2010-08-28 09:03 · Score: 0, Redundant
  
  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..
4. Re:Aluminum by Bruiser80 · 2010-08-28 09:13 · Score: 1
  
  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.
  
  --
  Arguing with an engineer is like wrestling a pig in the mud. After a while, you realize the engineer enjoys it.
5. Re:Aluminum by Chris+Burke · 2010-08-28 10:13 · Score: 2, Insightful
  
  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.
  
  --
  
  The enemies of Democracy are
More important: motherboard fittings, construction by blind+biker · 2010-08-28 08:38 · Score: 4, Informative

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.

--
"The agriculture ministry is not in charge of Gundam" - Japanese ministry official.
He is no Jedi by Tumbleweed · 2010-08-28 08:39 · Score: 3, Funny

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.
1. Re:He is no Jedi by snikulin · 2010-08-28 09:30 · Score: 1
  
  "Heavy is good, heavy is reliable. If it doesn't work you can always hit him with it." (C) Boris-the-blade
2. Re:He is no Jedi by zippthorne · 2010-08-28 15:50 · Score: 1
  
  Duck tape is cheating. You can "fix" anything with it, but.. not well. Sometimes not quickly.
  
  --
  Can you be Even More Awesome?!
Measuring by Animats · 2010-08-28 08:50 · Score: 1

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 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.
1. Re:Measuring by vlm · 2010-08-28 23:44 · Score: 1
  
  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.
  Not sure how you figure the machining is simple... Nothing funny at all about square cornered holes, or using extremely small endmills to simulate a square (radiused) courner. Yes I know the "+" sign is oval so no problemo, but look at the 2, 5, 8
  Also machining it thin enough to be usable/light will make clamping it to the table/fixture quite challenging. Make multiple positive and negative "molds" and machine small sections at a time to minimize bending? Its going to be a lot more complicated than "bolt the bar stock in with two step clamps"
  
  --
  "Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
Good Calculator by Murdoch5 · 2010-08-28 08:59 · Score: 1

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.
Uh... by Anonymous Coward · 2010-08-28 09:06 · Score: 2, Insightful

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.
Slashdot Delay by hydromike2 · 2010-08-28 09:10 · Score: 1

I really wish slashdot would actually find articles that I did not already read about on another site some days ago
1. Re:Slashdot Delay by Grishnakh · 2010-08-28 10:17 · Score: 2, Insightful
  
  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! by SuperTechnoNerd · 2010-08-28 09:16 · Score: 1

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 by donnyspi · 2010-08-28 09:16 · Score: 4, Interesting

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/
1. Re:cost by omglolbah · 2010-08-28 11:08 · Score: 1
  
  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 ;)
2. Re:cost by Anonymous Coward · 2010-08-28 11:12 · Score: 0
  
  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.
3. Re:cost by hedwards · 2010-08-28 11:16 · Score: 1
  
  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.
4. Re:cost by soupforare · 2010-08-28 11:24 · Score: 4, Interesting
  
  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.
  
  --
  --- Do you believe in the day?
5. Re:cost by blai · 2010-08-28 12:35 · Score: 1
  
  same features and functions
  
  cost the same
  
  --
  In soviet Russia, God creates you!
6. Re:cost by MightyYar · 2010-08-28 14:07 · Score: 2, Interesting
  
  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 :)
  
  --
  W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
7. Re:cost by BungaDunga · 2010-08-28 14:53 · Score: 1
  
  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!"
8. Re:cost by InfiniteWisdom · 2010-08-28 15:47 · Score: 1
  
  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.
9. Re:cost by Anonymous Coward · 2010-08-28 20:13 · Score: 0
  
  The screen resolution only went up because they couldn't source the old screens anymore! Similar situation for the USB— computers don't have serial ports anymore.
10. Re:cost by soupforare · 2010-08-29 04:31 · Score: 1
  
  Preaching to the choir. The drop in quality for the new HP calcs is disheartening though. I haven't played with 50 yet but the 49G/+es I've had were dogs. :(
  
  --
  --- Do you believe in the day?
11. Re:cost by AdamHaun · 2010-08-29 17:06 · Score: 1
  
  Do you want your calculator to have the battery life of a cell phone? Go ahead and put a fast CPU and a fancy backlit display on and see what happens.
  
  --
  Visit the
12. Re:cost by tangent · 2010-08-30 05:32 · Score: 1
  
  If the 35S I bought a few months ago is any indication, they're back on the right path. They're not the same as the 1990's and earlier generation HPs I have, but they suck a lot less.
  I hear the 50G is part of this return to high build quality standards, but I haven't tried one myself.
13. Re:cost by operagost · 2010-08-30 09:29 · Score: 1
  
  It would actually be impressive to have 1 GB of RAM in a desktop PC in 1995, but to have Windows 98 years before it was released...
  
  --
  
  Gamingmuseum.com: Give your 3D accelerator a rest.
What a waste by twoears · 2010-08-28 09:26 · Score: 1

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? by Anonymous Coward · 2010-08-28 09:32 · Score: 0

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.
1. Re:Usefulness of High-End Graphing Calculators? by Anonymous Coward · 2010-08-28 13:17 · Score: 0
  
  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.
2. Re:Usefulness of High-End Graphing Calculators? by walshy007 · 2010-08-29 13:47 · Score: 1
  
  what is the point in ponying up money for one of these
  Battery life, form factor and button placement.
  That being said I do haul around a netbook with octave on it anyway, but sometimes it's easier to just pull out the calc.
Awesome. How do I do that? by vadim_t · 2010-08-28 09:36 · Score: 4, Interesting

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.
1. Re:Awesome. How do I do that? by aluser · 2010-08-28 10:12 · Score: 4, Informative
  
  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/ . 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.
2. Re:Awesome. How do I do that? by Grishnakh · 2010-08-28 10:20 · Score: 1
  
  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).
3. Re:Awesome. How do I do that? by DaveGod · 2010-08-28 10:21 · Score: 1
  
  Look up CNC. 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.)
4. Re:Awesome. How do I do that? by the_macman · 2010-08-28 15:15 · Score: 1
  
  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 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.
5. Re:Awesome. How do I do that? by SheeEttin · 2010-08-28 17:29 · Score: 1
  
  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.)
  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. ;)
6. Re:Awesome. How do I do that? by icebrain · 2010-08-30 01:30 · Score: 1
  
  You can buy a small benchtop CNC mill for well under $10k. If you don't mind Chinese-made Harbor Freight and similar products (which are actually pretty decent machines for cheap Chinese-made tools, though they take a bit of work), you can get a conversion kit and have a 3-axis CNC mill for about $3k. Of course, then you'll need tooling, cutters, and software, but that's not all that expensive either.
  These machines are really only useful for hobby work or little projects. You won't find major manufacturers using them.
  
  --
  The meek may inherit the earth, but the strong shall take the stars.
Now he's in trouble by Len · 2010-08-28 09:41 · Score: 2, Funny

TI's lawyers will be after him for DMCA violation because he's bypassed their physical copyright protection mechanism.
1. Re:Now he's in trouble by rdnetto · 2010-08-28 16:06 · Score: 1
  
  You jest, but he probably won't be able to use it for exams anymore, since it's clearly been modified.
  
  --
  Most human behaviour can be explained in terms of identity.
Fake by Main+Gauche · 2010-08-28 09:54 · Score: 1

He'd have gotten away with it if he didn't post the picture
.
It doesn't make sense to replace titanium with aluminum. Busted, mofo.
1. Re:Fake by MightyYar · 2010-08-28 14:09 · Score: 1
  
  He says that the Titanium model is the replacement that he bought while he was fabricating the aluminum case for the broken unit.
  
  --
  W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
I'm working on an aluminum HP 11 by NixieBunny · 2010-08-28 09:58 · Score: 3, Interesting

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.

--
The determined Real Programmer can write Fortran programs in any language.
Re:More important: motherboard fittings, construct by Grishnakh · 2010-08-28 10:13 · Score: 0, Troll

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).
No Jedi, he is by CortoMaltese · 2010-08-28 10:20 · Score: 1

Fixed the subject for you.
repair rather than replace :D by ksandom · 2010-08-28 10:33 · Score: 2

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

--
Funnyhacks - Wierd, unusual, and fun hacks
Wait this guy broke a TI 89 -Titanium-... by SlashDread · 2010-08-28 11:34 · Score: 3, Funny

and replaced it with Aluminium? Isnt that a step back? Whats next? Casted iron?
1. Re:Wait this guy broke a TI 89 -Titanium-... by Tablizer · 2010-08-28 17:55 · Score: 1
  
  Aluminium? Isnt that a step back? Whats next? Casted iron?
  http://paradoxoff.com/files/2007/08/antique-calculator-andy-aaron-1.jpg
  
  --
  Table-ized A.I.
2. Re:Wait this guy broke a TI 89 -Titanium-... by mjwalshe · 2010-08-29 03:10 · Score: 1
  
  no wrought Iron would be better as cast iron is brittle :-)
Re:More important: motherboard fittings, construct by Anonymous Coward · 2010-08-28 12:56 · Score: 0

Yeah, the morons that care about lead poising and such! Retards!
Re:More important: motherboard fittings, construct by Grishnakh · 2010-08-28 13:15 · Score: 1

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.
And after the next drop by Attila+the+Bun · 2010-08-28 14:02 · Score: 1

Coming soon: how to mill new floorboards out of titanium, after the old floor was shattered by a falling calculator.
Carbon Fiber by theJML · 2010-08-28 14:08 · Score: 1

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.

--
-=JML=-
Necessary? by ponraul · 2010-08-28 14:21 · Score: 1

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.
1. Re:Necessary? by Glendale2x · 2010-08-28 14:57 · Score: 1
  
  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.
  
  --
  this is my sig
2. Re:Necessary? by Glendale2x · 2010-08-28 15:07 · Score: 1
  
  Er, make that 1997. I don't think the 86 existed yet in 1996.
  
  --
  this is my sig
Waist high drop by CmdrPorno · 2010-08-28 15:13 · Score: 1

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.

--
Sent from my iPhone
Don't make the calculator hard by billcopc · 2010-08-28 15:26 · Score: 1

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.

--
-Billco, Fnarg.com
1. Re:Don't make the calculator hard by IorDMUX · 2010-08-28 17:30 · Score: 1
  
  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?
  
  --
  >> Standing on head makes smile of frown, but rest of face also upside down.
2. Re:Don't make the calculator hard by u38cg · 2010-08-28 18:44 · Score: 1
  
  Where?
  
  --
  [FUCK BETA]
Anecdote by rdnetto · 2010-08-28 16:13 · Score: 4, Informative

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) 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).

--
Most human behaviour can be explained in terms of identity.
1. Re:Anecdote by walshy007 · 2010-08-29 13:24 · Score: 1
  
  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
  I have an n-spire, and find the interface rather nice. You don't use the cursor at all after a short while, while it's there it's not really meant to be used for fast operation. And while true that you only have basic unless you hack the calculator, for actual math uses you really don't need anything more. Considering the extensive api it supports.
  For games it's limiting, but if I want to play games I'll pull out my laptop or DS.
2. Re:Anecdote by afidel · 2010-08-30 06:59 · Score: 1
  
  The TI-89 is essentially embedded Maple.
  
  --
  There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
3. Re:Anecdote by rdnetto · 2010-08-30 17:26 · Score: 1
  
  But without the full size keyboard+screen and processing power of a desktop. Good for some applications (e.g. students, maybe if you need to do some math on the go), but for most a laptop/desktop with Maple would be a better solution.
  
  --
  Most human behaviour can be explained in terms of identity.
Text by jones_supa · 2010-08-28 20:19 · Score: 1

Those engraved labels look kind of fuzzy...
Titanium.... right... by Anonymous Coward · 2010-08-28 23:41 · Score: 0

... should be PI-84 Plastinium.
LEGO ! by daveime · 2010-08-29 00:23 · Score: 0, Troll

When I was six, I once built a car out of LEGO. Can I have a story on Slashdot too ?
Slow news day or what ?
Anonymous Coward by Anonymous Coward · 2010-08-29 02:05 · Score: 0

I bought a TI-83 plus graphics Calculator. It lasted only a year then the screen turned black. Don't buy any Graphics calculator. Use the computer.
Planned Obsolesce by Anonymous Coward · 2010-08-29 02:49 · Score: 0

I bought a TI-83 plus years ago and it lasted only a year. The screen turned black. Don't buy one. Use a computer.
A Jedi, he is not by skine · 2010-08-29 13:28 · Score: 1

Fixed the subject for you.
Re:More important: motherboard fittings, construct by walshy007 · 2010-08-29 13:40 · Score: 1

Why is the parent modded troll? there are valid reasons for wanting leaded solder.
Way too early on a monday morning. by vegiVamp · 2010-08-29 18:11 · Score: 1

Am I the only one who thought this guy was building a terminator ?

--
What a depressingly stupid machine.
it's called corner guard... by layer3switch · 2010-08-29 18:12 · Score: 1

$10 bucks at hardware store... aluminum, only protective as deodorant for your sweaty palm... not so much for graphing calculator with screwed down pcb.

--
"Don't let fools fool you. They are the clever ones."