DIY Case for NP-25

[Sanjeev Visvanatha]

The NP-25 V3 is a little gem. Thank you Chris Chung for making it happen.

I know the intent of the NP-25 was to be worn on a lanyard, perhaps as a conference goodie. I wanted a neat package to go with it. Here it is:










Materials List:

1. Business Card Clear PVC Box 12 Mil (2 1/4" x 3 11/16" x 5/8" ). These hold 10 business cards, or one NP-25.

2. Packing Foam Sheet (approx 6mm thick). I did not purchase it for this purpose, it was lying around in my trinket drawer. You will need something to make up the thickness in the case so the calculator does not move.

Procedure:

1. The NP-25 has raised LED and switches. The top side of the business card box requires rectangular cutouts so these can poke out. This allows the keys to be directly behind the top surface of the case.

2. The back side of the calculator is uneven in height. I placed a piece of the foam above and below the coin cell, and then another longer piece the full length of the case. The piece of packing foam under the display has a cutout in it to accommodate the chips mounted on the back,

Next Steps:

I would like to put a keyboard overlay on the case, with a key's primary and shifted function(s) presented as on the real hardware.

Since the NP-25 is a 3-in-1 calculator, my plan is to use a transparent pocket on the front to hold an overlay. This overlay would be of the calculator you want to use. A second transparent pocket on the backside would house the remaining 2 overlays, with a NP-25 quick reference card visible on the back.

I found transparent business card pouches at the Dollar Store for this purpose. They are adhesive, so they would be placed on the front and back sides of the case.

My shortcoming is that I do not trust my handywork in creating a nice overlay. If there are any interested parties, please make yourselves known.

Finally, I have more of the plastic cases, if anyone is interested in trying this. There was a minimum order of 10, so I have some more. You would have to supply your own foam and cutting expertise. I also have the transparent pockets I plan to use to hold the overlays.