How to unstick center disk of round slide rule?
in [Design]
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From: Joerg on 20 Feb 2010 16:03 JeffM wrote: > Joerg wrote: >> They don't make'em no more. >> > The second-hand market? > http://google.com/froogle?scoring=p&q=intitle:circular-slide-rule But you easily end up with one that has the same issues. Those things don't seem to like California temperatures. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Joerg on 20 Feb 2010 16:04 Jim Thompson 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. > > Is it a plastic disk? SOMEWHERE is my archives I have such circular > one, but the disk is aluminum. > Yes, looked like hard plastic, maybe melamin-based. Riding on aluminim. Both scratched :-( Maybe I'll have to find some PTFE tape like Dave suggested. Can be thicker though because there's lots of clearance. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Joerg on 20 Feb 2010 16:05 Robert Baer 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 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. Ah, another trick. Thanks, didn't know about the oil. Washing did not work, didn't do a thing. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Joerg on 20 Feb 2010 16:07 life imitates life 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. > > > 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. Well, I'd really like to revive it :-) It still works but I don't want to keep forcing the center wheel since it'll probably rub off the lettering over time. Unless I always use 4.7uH, 47uH, 470uH, then I won't have to move it :-) -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Jim Thompson on 20 Feb 2010 17:29
On Sat, 20 Feb 2010 13:03:04 -0800, Joerg <invalid(a)invalid.invalid> wrote: >JeffM wrote: >> Joerg wrote: >>> They don't make'em no more. >>> >> The second-hand market? >> http://google.com/froogle?scoring=p&q=intitle:circular-slide-rule > > >But you easily end up with one that has the same issues. Those things >don't seem to like California temperatures. Here's my round one, found behind books on the shelf... http://analog-innovations.com/SED/RoundSlideRule.png But my K+E "Slip Stick", found similarly... http://analog-innovations.com/SED/K+E_Slipstick.png didn't fare so well. In it's standard green leather case, unopened for I'd guess at least 35 years,... the thin metal holding the graticules has literally turned to dust :-( ...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. |