Gents,
My round slide rule is developing a sticky center wheel. I can still move it but afraid my thumbs will rub off the lettering over time. It's this model:
Obviously the old "rub with a bar of soap" trick like on the linear ones doesn't work here. I also haven't tried any semi-destructive methods to pull it off. Any safe tricks to unstick it?
I usually use the linear one but on the road this slide rule is nice because it fits into the shirt pocket.
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
Take it apart and carefully clean/de-grease. Then apply talc to the slides. Beware, it may be too late if it warped :-( ...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
I can't tell from the photos. Does this have a single center wheel or does the disc with the C scale ride on top of the one with the D scale (the T scale wheel on the other side would be a separate smaller disc).
If the single center wheel rides inside the outer wheel, can you tell how the two are kept flat w.r.t. each other? If this was a straight slide rule, it would be a tongue and groove, but I don't see how one could assemble (let alone take apart) such a circular device.
Looking at the trig side, I see what appears to be the end of what could be a screw in the hub. There's a possibility that one could grab each hub and unscrew them, allowing you to remove the cursor. In fact, each side of the cursor is attached to its hub and by unscrewing the spacer at the end, the center axle may be loose enough to unscrew by manipulating the cusrsors (gently). But from there, it depends on how the center and outer wheels are configured.
-- Paul Hovnanian mailto:Paul@Hovnanian.com ------------------------------------------------------------------ I have a very firm grasp on reality. I can reach out and strangle it any time!
If your slide rule has plastic-on-plastic ot plastic-on-metal, talcum powder should work. Disassemble to the point where the center can be cleaned with water/detergent solution, then dry completely and lube with dry talcum powder.
-- David dgminala at mediacombb dot net
Don't try this until your only alternative is to throw it out.
I have a 'Dead Reckoning Computer', a pilot's circular slide rule with a rectangular plastic panel that slides back and forth through the center. The slide had become so warped that its previous owner broke it in half trying to pull it through the body*.
I extracted both pieces and expoxied them back together. Then, I placed the slide between a couple of hand towels and applied a warm iron to soften the plastic. one it softened (I gradually increased the iron's heat), I placed it between two heavy books (thanks Winfield for the AofE) until it cooled and remained flat.
*I hope this didn't happen to the pilot during flight. There were some notes mentioning "Howland Island" that came with it, so I hope they made it OK.-- Paul Hovnanian mailto:Paul@Hovnanian.com ------------------------------------------------------------------ Dedicated to the unrestricted propagation of worthless information across the Internet.
Thanks, I didn't know you could just peel out the center wheel. Well, it's buckled upwards in the very center and there are serious wear marks underneath on the outer radius :-(
Cleaned it real good, gave it a dose of talc but no dice. It does turn ok with wet fingers but I guess spitting into one's hands wouldn't be looked upon favorably in engineering.
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
Done, but as Jim hinted, if it's buckled it's too late. And mine is :-(
So, scrape marks in the aluminum and the plastic wheel. Maybe if I could find really thin Teflon I can get some more life out of it. They don't make'em no more.
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
The center wheel is like an inlay but after Jim's hint I was able to gently pry it out. However, the thing looks a bit damaged inside, circular grinding marks, maybe from too much use or because the center has bulged up from the summer heat out here. Possibly the HP11C will outlive it.
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
Maybe not the SIC but... Concise still does
Cheers
To keep the writing from coming off, cover it with a thin layer of fingernail polish (carefully), like cloisonne.
Make sure it *is* talcum, many "baby powders" and others are actually corn starch these days.
The second-hand market?
If it really is that old (1962), I would stop using it and archive it. Put it on ebay and I will buy it as I collect them and have several (not round).
But yeah, that looks cool.
Jeez, the parting line for it is glaring, and he said "the center disc". The other side gives an illusion of another disc break because the ticks are not lined up between those two scales. Duh.Why would they be? Wouldn't need another scale if they were the same. Heheh.
I am reasonably sure that the 'button caps' are machine threaded hubs.
If you can gently wash it with mild soap and water, then dry it, that should do the job. But if that is not sufficient, one can add a drop or two of Labelle plastic compatible gear oil (used by model railroaders and other modelers). 40 years ago i got a 14.9ml bottle of it and a only half way thru it.
Goo off or lemon oil.
I've used a thin silicon oil for this - and a slide rule I had many years ago (Blundell-Harling ?) appeared to have been treated with this by the manufacturer. Just the slightest smear, of course.
If there's enough room in the sandwich to put a piece of teflon tape in there, the tape at Ebay item 190368526398 might do. It's 0.0045" thick, and has adhesive on one side. I have a couple pieces of it in a box somewhere, but after my recent move, I haven't a clue which box it might be in. Cheap enough, though.
Cheers!!!
-- David dgminala at mediacombb dot net
Is it a plastic disk? SOMEWHERE is my archives I have such circular one, but the disk is aluminum. ...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
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