|Re: Halfnut and Fullnut cases interchange|
Message #7 Posted by Vieira, Luiz C. (Brazil) on 22 June 2003, 2:55 p.m.,
in response to message #6 by Jon
the fact is that I cut only the necessary out of the original rivets. I do not remove the "mushroom" completely, I cut around them. Then I use existing plastic slices (or styrene) and melt some of them back (not all) to settle the keyboard. What I use to melt the plastic is something that works for me: a 220Vac soldering iron (35 to 40 watts) connected to a 110Vac outlet. It heats the plastic enough so it melts but it's not hot enough to burn the plastic. You can also use a rectifying diode (my first experiences) in series with the soldering iron so it will take only half of the AC wave, and in this case you'll have about the same effect as connecting it to 110Vac. I gave up the diode because in one time its terminals touched each other and I did not see it, so one small plastic burnt out and I inadvertently smell the fumes. Believe me, not a good experience.
After this partial settling, I use a silicon-based glue in the remaining rivets. What makes me sad is that this technique gives good results, but is not 100% perfect. I'm sad to say that in at least two cases I did not get the best results. I reassembled some keyboards in Pioneers, Voyagers, Woodstocks, HP41 and two HP48. Spices have an extra advantage: no melted rivets at all. I also don't know what is the HP49 made of...
The HP41 is a particular case. I have a fullnut HP41C that has no refurbished rivets, the keyboard is solely maintained by the four case screws. I thought about the HP41 and it's a particular case: the keyboard is completely "pressed" by both cases. The two big screws (close to the LCD) lock the keyboard in place because of the BATT/IO assembly, and the two small screws must press the mainboard to the keyboard. The four screws lock both half cases together and the result is that the keyboard remains steady even if all rivets are loose.
I'd like to know what others are doing.
Luiz C. Vieira - Brazil
Edited: 22 June 2003, 4:58 p.m.