Best Way To Handle A Voyager Wobble?

[Jase]

My question stems from the recent purchase of a 12C that is chronicled in this thread HP-12C+ (2022 version)
(I do not want to hijack the intent of that thread, so I'm creating anew.)

My new 12C has a wobble. The high point axis is NE diagonal to SW, and the wobble axis is NW diagonal to SE.

If I place three printer papers at either NW or SE corner, then all is firm again. (And I'm assuming I could place 1.5 printer papers at both NW and SE corner, and likewise be good.)

It could be that the rubber feet are the issue, or perhaps a slight twist in the frame - or perhaps a little of both.

What is the best way to handle this?
My thought is to simply lower the NE & SW high points by taking a very fine sandpaper to those rubber feet.

Anyone have a better idea?
I'd rather NOT "fix" the issue by putting clear tape and "building up" the low points. Too much of a hack for my taste.
But other than that, I'm open to ideas and would love to hear how others may have addressed wobbles in the past.

Thanks,
Jase.

[AnnoyedOne]

(11-11-2024 03:14 PM)Jase Wrote:  (I do not want to hijack the intent of that thread, so I'm creating anew.)

It already has been IMHO but thanks. It became a 12C+ to 15CE/16C conversion thread.

(11-11-2024 03:14 PM)Jase Wrote:  It could be that the rubber feet are the issue...

I just checked mine, on multiple surfaces, and no "wobble". I suspect slight size variations in the feet. Replace them all? I think there are kits on eBay.

A1

PS: A "bent" plastic housing is possible but unlikely IMO. Take small slices off the rubber feet with a scalpel?

[Allen]

I really like the leather cases for the Voyager series, and I will take my 1XC calculator out and put the case underneath it while using it. A sock or cheaper case would serve the same purpose?

[Johnh]

As a test to find out if its the case or the feet that are uneven

On a level surface, sit it on four equal stacks of coins, bearing just next to the feet so the feet are raised off the table. Does that wobble? if so it's the case.

[John Garza (3665)]

Only tangentially related...

My favorite rubber feet are on the Woodstocks.
They are self-levelling. Simply pull them out a bit, then lay the calc on the work surface and push down.
No wobble.

-J

[Steve Simpkin]

Regarding this subject. The hardware and software design of the HP-48SX can be found in the June 1991 issue of Hewlett packard Journal magazine. It is a great read for an example of the extreme design effort that HP put into their products at the time.

From page 31:
"Completing the HP-48SX package are four molded feet, which are sculptured to conform to the bottom case radius. The feet are press fit into the bottom case while it is still warm at the molding machine. A small bump on each foot provides compliance so that the HP-48SX will resist rocking even if the surface is slightly uneven."

Here is a link to a PDF of that edition.
http://hparchive.com/Journals/HPJ-1991-06.pdf

[lvt]

My 12CP has the same problem, the plastic frame is slightly twisted.

You can replace one of the rubber pads with a thicker one. I bought a couple of rubber pads with different thickness from eBay, adding 0.5mm to the "highest point" will fix the issue.

[Jase]

Thanks to all for the replies and advice.

Yes, it's the frame that is ever so slightly out of alignment, causing wobble.

I'll tackle it this week.

Jase.

[Allen]

If you placed your 12c momentarily on the surface of a neutron star it would no longer wobble and would come back to you with some very interesting properties.

Unfortunately it might also be smaller than a hydrogen 1-s electron orbit, and the nice tactile keys would no longer work.