10 Oct
2008
10 Oct
'08
12:58 p.m.
I had it all apart (it is difficult to take this thing
apart !)
There was a small 'sliver' of plastic cracked away at the front in front
of the keyboard... I glued that. The larger crack in the back doesn't
want to close well (even with a clamp), so I doubt superglue would
work very well... so since it is not very apparant, I'll probably fill the
I haev never had much success with isocyano acryllic hydro copolymerising
adhesives...
If you can find a solvent for the plastic (and for quite a few
thermoplastics dichloromethane (methylene choride) -- sold by good model
shops unde the name 'Plastic Weld' -- works well), you can weld the
plastic by pushing the edges together and then running a brush dipped in
the solvent along the cracks. To make the joint even stronger, cut a
piece of cotton fabric to fit over the back of the damaged area, put it
in place, and 'paint' it with the solvent. Then push the fibres into the
softenend plastic.
If I have a plastic that I can't weld like this, or that needs to be as
stong as possible, I cut a piece of metal or fibreglass (PCB material
with the copper etched or sanded off) to fint over the breaks and then
fix it in plasce with small nuts and bolts. It may not look neat, but
it'll keep the case together.
crack with epoxy to strengthen it and that should do.
The metal
that was bent was straightened... but a metal tab where the back
metal screws onto the side metal was a casualty... it broke off while
trying to straighten it.... but not a big deal, as it is held on by 3
Can you make an angle pracket to replace the damaged part here?
other screws.... assembled you'd never even
know.
I must say this thing is really difficult to take apart and put
together.... it has pretty good build quality though. The toughest
part is that the rear case binds on the floppy drive power
connector.... if I had followed the 3B1 FAQ recommended
disassembly procedure I probably would have broken the floppy
drive PCB. I took the monitor off the top, that allowed me to
see what I was doing... there was just enough room to use long
needle nose pliers to disconnect the floppy drive power connector.
reassembly will be fun....
On at least one amchine I've worked on, one of the drives has the power
connector desoldered from the PCB and replaced by a cable-mounted
connector (think of the male end of a PC drive power extension lead) with
wires soldered to the original holes in the PCB. This meant the power
connector didn't get in the way of another bit of the machine. If you try
to make this modification, make sure, and check again, that you've not
swapped the +5V and +12V wires round!
-tony