How to unstick center disk of round slide rule?
in [Design]
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From: Joerg on 21 Feb 2010 16:48 Phil Hobbs wrote: > On 2/19/2010 9:31 PM, Joerg wrote: >> Jim Thompson wrote: >>> On Fri, 19 Feb 2010 17:46:11 -0800, Joerg <invalid(a)invalid.invalid> >>> wrote: >>> >>>> 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: >>>> >>>> http://sliderulemuseum.com/SIC/C35_SIC_SINCO_250_1962.jpg >>>> >>>> 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. >>> >>> Take it apart and carefully clean/de-grease. Then apply talc to the >>> slides. Beware, it may be too late if it warped :-( >>> >> >> 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. >> > > Chalk dust tightens it--use graphite. > My wife would read me the riot act if I came back from a biz trip and there's faint black stains on all the shirts :-) -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Joerg on 21 Feb 2010 16:48 Tauno Voipio wrote: > Joerg wrote: >> Dave M wrote: >>> Joerg wrote: >>>> 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: >>>> >>>> http://sliderulemuseum.com/SIC/C35_SIC_SINCO_250_1962.jpg >>>> >>>> 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. >>> >>> >>> 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. >>> >> >> 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. >> > > The old Nestler advice was silicone oil, but for slide rules > on plastic base (not wooden). > Well, mine's plastic sliding on aluminum. Maybe I give that a try, talc definitely did not do the trick :-( -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Tim Williams on 21 Feb 2010 17:10 "Phil Hobbs" <pcdhSpamMeSenseless(a)electrooptical.net> wrote in message news:4B818809.9000504(a)electrooptical.net... > Chalk dust tightens it--use graphite. Err... hexagonal boron nitride? Tim -- Deep Friar: a very philosophical monk. Website: http://webpages.charter.net/dawill/tmoranwms
From: life imitates life on 21 Feb 2010 17:17 On Sun, 21 Feb 2010 16:10:33 -0600, "Tim Williams" <tmoranwms(a)charter.net> wrote: >"Phil Hobbs" <pcdhSpamMeSenseless(a)electrooptical.net> wrote in message >news:4B818809.9000504(a)electrooptical.net... >> Chalk dust tightens it--use graphite. > >Err... hexagonal boron nitride? > >Tim Moon dust.
From: Paul Hovnanian P.E. on 21 Feb 2010 19:31
Joerg wrote: > > Paul Hovnanian P.E. wrote: > > Joerg wrote: > >> Dave M wrote: > >>> Joerg wrote: > >>>> 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: > >>>> > >>>> http://sliderulemuseum.com/SIC/C35_SIC_SINCO_250_1962.jpg > >>>> > >>>> 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. > >>> > >>> 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. > >>> > >> Done, but as Jim hinted, if it's buckled it's too late. And mine is :-( > > > > 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. > > Thanks for the hint. I'll try, but first I'll ask a guy who seems to be > a slide rule enthusiast: > > http://public.beuth-hochschule.de/~hamann/ Let me know what you find out. I've used this technique (successfully) on exactly one slide rule. So I don't know what the pro restorers would have to say based on broader experience. -- Paul Hovnanian mailto:Paul(a)Hovnanian.com ------------------------------------------------------------------ There's plenty of room for all God's creatures. Right next to the mashed potatoes. |