Post Reply 
Yes, calculators are made from plastic ^^
02-20-2014, 06:10 PM (This post was last modified: 02-20-2014 06:21 PM by jebem.)
Post: #16
RE: Yes, calculators are made from plastic ^^
(02-14-2014 12:37 PM)Stefan Wrote:  I think the HP-300s+ is *exactly* the same as the fx-991DE Plus, it has exactly the same features (minus the localization). Only the keypad is a bit different. (Does anybody have more information about that whether it is a contract work from Casio for HP?). It is cheaper (15€) than the Casio (21€), looks nicer and more sturdy in my opinion (But since I don't own the HP I can only judge this from the photos).

@Everybody who mentioned rubber keys: Right, I totally forgot those. compared to rubber keys, plastic is really a quality attribute ^^

I have one HP-300s+ in my collection.
- The case is made of resistant nice plastic Smile in nice piano black color except for the gray side ring, very compact and sturdy build;
- 4 x rubber feet, hiding the 4 case fixing screws;
- The keys are made in hard plastic, but there is no click when pressing them, we just feel the rubber membrane underneath being pressed.

After reading you post, i was curious to find some more information.
So I opened it (it was quite easy in fact) and I can confirm how good are the materials and build. No cracking plastics when separating the upper and lower sides.
So yes, there are good and bad plastics, and this one uses the good quality plastic.

There is no sign of CASIO signatures anywhere in the PCB.
I don't know if there are extra information on the other side of the PCB (besides the keyboard membrane and plastic keys) as the PCB is fixed to the upper case cover with plastic rivets and I didn't want to break them.

The CPU is covered with black resin (maybe plastic? Smile ).
The solar panel gave me a reading of 2.6 Volt under direct sunlight (with a professional digital multimeter).

The PCB itself is not very informative, but shows some prints:
Juniper EA-631
The attached picture show the details.

A few sites like "" reports that HP subcontract Kinpo Electronics since 2001 for their calculators:
Can someone comment on that?

Jose Mesquita member

Find all posts by this user
Quote this message in a reply
Post Reply 

Messages In This Thread
RE: Yes, calculators are made from plastic ^^ - jebem - 02-20-2014 06:10 PM

User(s) browsing this thread: 1 Guest(s)