Linards Ticmanis wrote:
Hi all! I wonder if anybody here could help me with a little mechanical
question: do you think the following bit of information describes the
Apple II+'s bottom plate fastening screws correctly and more or less
completely, so that it could be used to order some replacements (the six
on the real bottom, not the four below the front edge)?
***Major diameter 1/8", 26 threads per inch (TPI), thread length 1/4",
60 degrees angled flat countersunk head with cross slit, made of steel.***
They definitely seem to be in a non-metric size (even though this Apple
was assembled in Ireland), as they don't fit either M3 or M4 size nuts
but are in-between those. The dimensions given above are more or less
educated guesses that I made from simple metric measurements and the
assumption that their size in inches is a simple fractional value. 26
TPI was guessed from the fact that the thread-to-thread measurement is
pretty close to one millimeter, and from some quick googling it seems
that 26 is a fairly common TPI number in inch-sized threads. I don't
have any fitting nuts or other threaded things to really test the
measurement.
Since non-metric screws are pretty hard to find here in Continental
Europe and I doubt whether I can find any real store that will sell them
to me, I'd need to make sure I've got all the facts right before I order
something without having actually tested it before. So if you live in a
non-metric country and can actually check the dimensions I gave above,
I'd be very grateful.
(let's hope Apple didn't change them during production... my Apple, or
at least its case, has serial number A2S2-39763)
I don't have a ][+ with me at the moment, but I don't recall countersunk
screws. IIRC, the bottom plate is flat stamped metal, and the screws
go into metal inserts molded into the plastic case.
They are, IIRC, "English" screws size 6-32 (number 6 size, and
32 threads/inch), about 3/8" long and what we call "panhead" with
a philips ("+") head.