How to unstick center disk of round slide rule?
in [Design]
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From: Jim Thompson on 22 Feb 2010 13:56 On Mon, 22 Feb 2010 09:49:11 -0800, Joerg <invalid(a)invalid.invalid> wrote: >Jim Thompson wrote: >> On Mon, 22 Feb 2010 10:09:18 -0700, Jim Thompson >> <To-Email-Use-The-Envelope-Icon(a)My-Web-Site.com> wrote: >> >>> On Mon, 22 Feb 2010 09:00:50 -0800, Joerg <invalid(a)invalid.invalid> >>> wrote: >>> >>>> YD wrote: >>>>> Late at night, by candle light, Joerg <invalid(a)invalid.invalid> penned >>>>> this immortal opus: >>>>> >>>> Hey, the power outages were gone after the previous governor got kicked >>>> out :-) >>>> >>>> >>>>>> 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/ >>>>> Place it between two glass plates, as heavy as available on top. Leave >>>>> in the sun for a few hours, then take back in to cool off. Well, works >>>>> for warped LPs. >>>>> >>>> Got to wait for some global warming first because so far we haven't >>>> gotten our fair share in that department. Last night was another freeze >>>> night, ice in the stairs :-( >>>> >>>> Sun? Yeah, there must be some, somewhere behind the clouds. >>> The East is about to get slammed again. I just heard that I17 is >>> closed south of Flagstaff... impassable. >>> >>> ...Jim Thompson >> >> Between plates, then apply a hair drier? >> > >Or apply the wood stove. It's cranking full bore again, in California, >in February, one neighbor is almost out of firewood by now ... It's terrible here again! 56�F and rain squalls, and wind gusts sufficient to tear pieces from traffic light backing plates, even those with "wind slots". Going to be nasty when it gets to the East. ...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.
From: Joerg on 22 Feb 2010 16:21 JosephKK wrote: > On Fri, 19 Feb 2010 18:51:53 -0800, Joerg <invalid(a)invalid.invalid> wrote: > >> Paul Hovnanian P.E. 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 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. >>> >> 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. > > Photos, Photos, Photos. Oh and some dimensional measurements might be nice. http://www.analogconsultants.com/ng/images/sliderule1.JPG The center wheel that goes into the aluminum area is 2-3/8" in diameter, the whole thing is 3-1/4". -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Joerg on 22 Feb 2010 16:39 MK wrote: > "Joerg" <invalid(a)invalid.invalid> wrote in message > news:7u8t7eFgi2U1(a)mid.individual.net... >> 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. >> >> -- >> Regards, Joerg >> >> http://www.analogconsultants.com/ >> >> "gmail" domain blocked because of excessive spam. >> Use another domain or send PM. >> > > Buy a calculator - been around more than 30 years now - some of them pretty > good. > > Mine's an HP32S which works in RPN so has enough obscurity factor to put off > casual borrowers ! > Got that, a HP11C. However, when calculating part value ratios a slide rule is more practical because you typically only have 6 or 12 values per decade if you must use catalog inductors. Which I nearly always have to. Sometimes even down to 3-4 values because of notorious no-stock situations. So you de-focus your eyes a bit, squint, and then scoot the slide rule until a combination of values gets close enough. With a calculator you'd be typing on blisters pretty soon. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Dave Platt on 22 Feb 2010 17:21 In article <7ugaq1Fb9qU1(a)mid.individual.net>, Joerg <news(a)analogconsultants.com> wrote: >http://www.analogconsultants.com/ng/images/sliderule1.JPG > >The center wheel that goes into the aluminum area is 2-3/8" in diameter, >the whole thing is 3-1/4". I wonder whether you might be able to polish the worst of those abrasions out of the aluminum recess? Perhaps a piece of something like crocus cloth, wrapped around your fingertip, rubbed in a circular direction? -- Dave Platt <dplatt(a)radagast.org> AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads!
From: Joerg on 22 Feb 2010 19:35
Dave Platt wrote: > In article <7ugaq1Fb9qU1(a)mid.individual.net>, > Joerg <news(a)analogconsultants.com> wrote: > >> http://www.analogconsultants.com/ng/images/sliderule1.JPG >> >> The center wheel that goes into the aluminum area is 2-3/8" in diameter, >> the whole thing is 3-1/4". > > I wonder whether you might be able to polish the worst of those > abrasions out of the aluminum recess? Perhaps a piece of something > like crocus cloth, wrapped around your fingertip, rubbed in a circular > direction? > Possible but some are rather deep and the outer dial would inevitable suffer. Maybe I can get a thin layer of PTFE somewhere. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. |