Adding pics of mine since I do not know where the originals are.
Clutch
The following is how I removed and modified the bubble strip from an Exactra 20 calculator.
First remove any batteries, and then locate and remove the 2 Phillips head screws on the lower back of the calculator.
Remove the circuit card.
The bubble strip is held in by tabs that were melted down to the display board.
Using a hobby knife, remove as much of the melted material as possible.
To avoid scratching the back of the lens, use a suitable piece of rigid plastic to carefully pry the bubble strip away from the board.
The rest of the calculator can be tossed. ItÂ’s not much good anymore
.
The back of the bubble strip has raised edges all the way around it.
ItÂ’s also longerÂ…
Â…and thicker than the folded area (flange) of the Graflex clamp.
I used a razor saw and hobby miter box to cut off the ends of the strip. For me, the cut was right on the inside edge of the raised area, but IÂ’d suggest that a careful comparison be made of strip to clamp before any cutting is done.
I then used various grades of very fine wet/dry sandpaper to refinish the cut ends. Be careful to keep the plastic square to the paper, or the corners will round off.
Now for the tricky part . Just the raised edges along the long sides of the bottom of the strip needs to be removed. I used a woodworking router set in a router table, a flat mortising bit, an ice cream stick and a lot of test scraps of wood. (Note: only use a router if you’re thoroughly familiar with its operation). Another possibility would be to use a Dremmel tool and grinding wheel. Definitely, cover the area behind the bubbles with heavy tape to prevent wayward grinding from ruining the transparency. Note that the edges will be under the “flange” of the clamp and won’t need to be perfectly clear.
I then smoothed the cut edges with 400 grit sandpaper after covering the area below the bubbles with tape. I kept sanding until the strip would fit into the clamp. I used a wide flat blade screwdriver to spread the clamp flange in some of the places where it was too snug.
After I was able to get the strip to fit properly, I centered it in the clamp flange and put a dab of hot melt glue in each of the 4 corners to keep it from moving or sliding out.
Keep in mind the ideas presented here are merely suggestions (how I did it). Each person should consider their skill set and available tools before tackling this project.
Thanks wackychimp for hosting.
ATL
Clutch
The following is how I removed and modified the bubble strip from an Exactra 20 calculator.
First remove any batteries, and then locate and remove the 2 Phillips head screws on the lower back of the calculator.
Remove the circuit card.
The bubble strip is held in by tabs that were melted down to the display board.
Using a hobby knife, remove as much of the melted material as possible.
To avoid scratching the back of the lens, use a suitable piece of rigid plastic to carefully pry the bubble strip away from the board.
The rest of the calculator can be tossed. ItÂ’s not much good anymore
.
The back of the bubble strip has raised edges all the way around it.
ItÂ’s also longerÂ…
Â…and thicker than the folded area (flange) of the Graflex clamp.
I used a razor saw and hobby miter box to cut off the ends of the strip. For me, the cut was right on the inside edge of the raised area, but IÂ’d suggest that a careful comparison be made of strip to clamp before any cutting is done.
I then used various grades of very fine wet/dry sandpaper to refinish the cut ends. Be careful to keep the plastic square to the paper, or the corners will round off.
Now for the tricky part
. Just the raised edges along the long sides of the bottom of the strip needs to be removed. I used a woodworking router set in a router table, a flat mortising bit, an ice cream stick and a lot of test scraps of wood. (Note: only use a router if you’re thoroughly familiar with its operation). Another possibility would be to use a Dremmel tool and grinding wheel. Definitely, cover the area behind the bubbles with heavy tape to prevent wayward grinding from ruining the transparency. Note that the edges will be under the “flange” of the clamp and won’t need to be perfectly clear.
I then smoothed the cut edges with 400 grit sandpaper after covering the area below the bubbles with tape. I kept sanding until the strip would fit into the clamp. I used a wide flat blade screwdriver to spread the clamp flange in some of the places where it was too snug.
After I was able to get the strip to fit properly, I centered it in the clamp flange and put a dab of hot melt glue in each of the 4 corners to keep it from moving or sliding out.
Keep in mind the ideas presented here are merely suggestions (how I did it). Each person should consider their skill set and available tools before tackling this project.
Thanks wackychimp for hosting.
ATL
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