HP Voyager keyfeel

[joebob]

I have been looking at getting a HP-15C, since it seems to be a pretty classic model. I had a chance to play with someone's voyager style keyboard which had the "hp feel" except for the ENTER key which seemed harder to press, and without the same "keybreak" that all the other keys had.

I figure the ENTER key might get worn out faster, but this calculator was really mint looking and showed no signs of heavy use, so I just wanted to check whether that is normal for a voyager-style HP.

PS, Thanks to everyone. I have learned a lot from this board.

[Randy]

The Enter key on Voyagers actually has two metal discs underneath so they could use the same stamped keystrip throughout the keyboard. See Dave's internal photos of 15C for a visual on this http://www.hpmuseum.org/tech10.htm

The Enter key is hinged at the bottom and only presses on the top disc so when you press in the middle of the key, you're pressing in the middle of the lever, not on the end, thus the higher force required to actuate the key.

A very fine point, something we tend to forget and quickly get used to in day to day use.

Edited: 20 Oct 2004, 9:13 a.m. after one or more responses were posted

[joebob]

Thanks for the reply and the pointer to the packaging page.

When I was playing with the ENTER key, I noticed that it was easier to press at the top, which falls in line with your observations. That just leaves the keybreak issue. Should I figure that his calculator has a worn-out snap disk on the ENTER key, since the keybreak/snap was almost nonexistent?

I guess my next question is whether that is pretty common with the 10 series? If everyone's 20 year old voyager ENTER keys have lost their crispness, then its probably not worth worrying about when shopping.

[Randy]

Voyagers and 41's have VERY good keyboards. Wear and dirt are the two factors that you must be concerned with. If it's been pounded on for 20 years, it's tired and needs a rest. If you count on your calculator, avoid those no matter how much a bargain they may seem . There are lots of nice Voyagers out there, it's worth the extra money to get a low usage unit. Not necessarily mint, just low use. Keyboards tell the tale.

There are several things that I have seen that go wrong with Voyager and 41 keyboards (similar design) in the order of observation:

1) LOTS of dirt inside the calculator which works it way inside the workings of the key snap disc chamber. The keys don't click at all and have little physical travel. This can usually be cleaned. This is about the only easy fix, the others below require major surgery.

2) The rubber sheet between the snap discs and the keys gets holes worn through the rubber from the key pin that pushes on the snap disk. This results in keys that are lower than surrounding key. They otherwise work okay, they just don't have the correct or same physical travel as the others. This is most common on the right hand side of the keyboard, i.e. the heaviest use keys (0 and . seem to go first).

3) The keytop itself can break at the bottom hinge half of the key, this results in a loose, wobbling keytop which reminds me of a loose tooth in its socket. The key has its normal click but the keytop is lower than normal and is hard to press since the force is not directed due to the loss of the hinge point.

4) The snap disk fractures. Pretty rare actually, the key is flat and has no click, similar to #1. Sometimes you'll hear a weird cricket like click when pressed.

A good indication of heavy use is if the sides of the keys are worn with shiny and rounded edges. If the lower blue shift legend is missing or worn, it has seen a LOT of use as well.

[joebob]

*NullMessage*

[Karl Schneider]

Randy posted,

Quote:

---

The bottom line is the Enter key, when pressed in the middle of the key, requires a much higher force to regsister a keypress since you are pushing on two discs. Pressing towards the top of the key will result in a much lower force required to actuate the key since you are only pressing on one.

---

The user is pressing against two discs on any place on the button; it's easiest at the top (and toughest at the bottom) due to force-moment -- distance of the applied force from the axis of rotation at the bottom edge. Kinda like pressing against a door at the doorknob versus near the hinge.

With that bit of physics out of the way, on to something constructive. :^)

I have a 1983 15C, '85 16C, '86 11C, and '93 12C. The first three are US-made; the last one, Singapore. All are well-constructed. The 15C I bought new; the other three are very lightly-used models I bought in the last two years. All work perfectly and are in good-to-excellent cosmetic shape.

• The 15C's keys are a little stiffer with less travel than the other three.

• The keys at rest have some freeplay (rattle when shook) on the 15C and 12C, but not on the other two.

• Some printed legends (yellow and blue) are not quite centered on the 11C, 12C, and 16C.
  

-- KS

[Randy]

Karl, when I reread my quote with your commentary, I realized my original statement was incorrect. You are never pressing on two discs, the enter key actuation pin only presses on the top disc.

I edited my original post to read:

Quote:

---

The Enter key is hinged at the bottom and only presses on the top disc so when you press in the middle of the key, you're pressing in the middle of the lever, not on the end, thus the higher force required to actuate the key.

---

[m currie]

I have an 11C and a 10C, both clearly well-used, especially the latter, but in good working order. On both, the enter key has a slightly different feel from the others, without quite the same "over-center" pop.

By the way, I got the 10C at a yard sale a couple of weeks ago. The seller had used it in college. He was happy I knew what it was. The price: one dollar.