Painted or Moulded Keys.



#3

I would like to know how can I see the difference between painted and plastic moulded keys.


#4

You'll see it when you have a machine with molded keys and a machine with painted keys side by side. Take for example the 32SII, which was made in various fashions. The molded key legends are *always* sharp edged and clear, with a high contrast to the surrounding dark plastic. The keys of the machines with legends painted on have a different surface structure (matte), the painted legends are not as bright and sharp as the molded ones, and the font is different, worse, and smaller in some places . At least on the 32SII, the paint on the keys is simply trash.
In about two weeks, when I get my new camera, I can provide photos which clearly show the difference!


My new 48G+ has painted keys, of course, because it's new,
and they don't make molded keys any more.
The contrast of the printing is high, but the finish of the letters is CHEAP! The writing on the SIN key isn't even horizontal:-/
From this I can only say 'hp' doesn't have product quality control. Nevertheless my 48G+ is much better than every 49G:-)


However, you still owe me an answer to your last question.

Raymond

#5

If you can locate some "reference" units -- Spice or earlier, or an early Voyager or Pioneer are (generally) examples with double-shot molded keys, and a later 32SII or most anything since as an example with painted keys, then looking at them side by side will help you appreciate the differences.

A careful look at most earlier examples with double-shot keys will reveal a very slight gap or fissure between the contrasting colors -- presumably the legends were injected after the keys themselves had hardened, and along some edges, the plastics don't meet exactly flush.

Later, as in middle-era Pioneers and HP-48's, it appears to me that H-P went to "grinding" down the keytops after moulding to remove the upper, flawed layer and reveal deeper slice of the keytops where the plastics were more uniformly filled in. The upper surfaces of these keys tend to have a dull, "sandpapered" look, that constrasts with their shinier sides. The top surfaces sport fine horizontal etching or grooving, suggestive (again) of sandpapering or grinding.

Either way, the double-shot legends tend to be larger, more fully formed, and offer indelible contrasting color that is unmatched by painted-on symbols. Again, a side-by-side comparison will reveal noticeable differences. (The differences to be noted between early and late examples of the HP-32SII are so striking that they'll bring a tear to the eye . . . )

The painted (or silk-screened?) legends on SHARP calculators, and lately the TI's and HP's 49G+ (among, I'm sure, many others) exhibit noticeably raised lettering when viewed at an angle in the glare of a bright point-source light. (Somebody help me with the technical jargon here . . . ) These clearly have a thick ink or paint laid on top of hard, plastic or metal keys. IMHO, SHARP has always done a good job of this, and the new HP-49G+ keytops are very crisply printed and offer great contrast, though some alignment problems have been noted in the printing on early examples of that model.

Some early models' painted keys have the paint laid into moulded-in depressions for the legends. These display obvously exaggerated relief, and tend to collect grime that softens the legends' contrast.

I don't think rubber keys work in any way, and their painted-on symbols tend to wear off the soonest. Of course, in general, any loss of the keytop legend indicates a painted key.

I think an article with close-ups would be a worthy contribution to The Museum -- I'll see if I can get 'round to it.


#6

I pulled out my 11C to look at its beauty in this regard - it is easy to see that the main legend on each key is molded.

However, these keys also have secondary legends (the blue "LOG" function on the lower slope of the 10^x key, for instance) that appear to be painted on. Is this correct? Double molding (at an angle!) would be a considerable manufacturing challenge, I suspect.

In fact assembling the keyboard for almost any calculator must be tricky. Does anybody know: are the plastic keytops made separately, and then added to the keyboard? This must be the case for molded keys - somehow, some machine must keep track of and place thousands of tiny little keys, in 40 or so different legends. How about painted keys: are they all placed on the circuit board and then painted (silk-screened?), or painted first?


#7

I suspect that the secondary functions on the key "fronts" are all painted on. (Someone will correct me if it's not so.)

Up through the HP-28C/S I believe the keys of all models were installed as individual, hinged units. (I'm neither acquainted with Voyager internals, nor with the earliest models.) By the time of the Pioneers and Charlemagnes, the keys were molded as part of the calculator front case, with flexing attachment/hinges.

Double-shot keys on the Pioneers then required separate molds for each model. Painting the keytops simplifies setup and saves money, by allowing a single mold, with the model differentiation determined later.

#8

"How about painted keys: are they all placed on the circuit board and then painted (silk-screened?), or painted first?"

[VPN]: Painted last.

#9

Then I have 1 HP48GX with serial ID00303828.
What do you think?
Thanks

#10

Then I have 1 HP48GX with serial ID00303828.
What do you think?
Thanks.
Sorry, is there a relation with the difference of the keyboard and the difference of newer 48 with black LCD?


#11

No, there's no direct relation (ok, there is, but that's another thing;-) . For the other thread: You asked, many answered, and I had expected to read some answer from you. Maybe I just overlooked it in these long threads.

However, you're the proud owner of one of the best calculators ever made, regardless if the display is b/w or blue/green.

Raymond


#12

Yes i Know, I think that i will buy one more.
Sorry Raymond, my opinion is that there is a relation,with the different keyboards and LCDs.
Those with blue and green lcd seem to be more smooth, the others seem less, I have a 32sii (brown) and it has very good keyboard, I think that better than the 48GX, and the 17Bii has not good Keyboard.
Thanks


Possibly Related Threads...
Thread Author Replies Views Last Post
  Voyager Painted Keys- a 16C with triple personality Allen 1 253 03-20-2008, 04:59 AM
Last Post: Frank Boehm (Germany)
  HP 19BII Versions... Beige Keys and Black Keys? Eric 0 174 03-17-2006, 04:43 PM
Last Post: Eric
  Voyagers with painted keys megarat 8 516 05-27-2005, 08:45 AM
Last Post: Stephan
  hp 12c's painted keys GS Leong 6 428 02-10-2005, 08:17 PM
Last Post: Randy
  painted keys voyager Tom 7 474 12-17-2003, 07:28 PM
Last Post: John
  11C non-painted logo Quemazon 3 305 09-08-2003, 07:08 AM
Last Post: Randy Sloyer
  Painted HP logos ? Jose Goncalves 1 220 05-10-2003, 12:01 AM
Last Post: Vieira, Luiz C. (Brazil)
  HP-12C with painted over keys. Mike Sebastian 0 167 07-15-1999, 07:12 PM
Last Post: Mike Sebastian

Forum Jump: