On Friday 11 January 2013 15:38:36 Jon Elson did opine: Message additions Copyright Friday 11 January 2013 by Gene Heskett
> On 01/11/2013 11:58 AM, Gene Heskett wrote: > > Greetings; > > > > Actually, thinking of the springs out of old 1" wide 15+ foot tape > > measures. > > > > Has anyone done this, and taken a pix of how you anchored the ends of > > the spring so that there was enough pivot available so that it didn't > > force the spring out of shape with potential dirt leaks as it > > telescoped? It seems to me that solidly anchored ends would > > encourage its warping as it telescoped. I am inclined to machine a > > hub the right diameter for each end but doing a knob only the springs > > thickness high to fit a hole in the spring may be beyond my machining > > ability even with EDM. > > > > Thanks for any URL's I can plagiarize. > > > > Cheers, Gene > > The commercial ones seem to be tapered, ie. the strip is wider in the > middle, and > narrows at the ends. I'm not sure that is necessary. > > Jon > Was that perhaps a lopsided taper? eg the end edge trimmed so as to allow the taper to approach the anchoring end flange when collapsed? I just took a cheap but still good "Great Neck" 25 footer apart, and the springs normal position when the tape is fully retracted, is in a fairly tight coil against the inside of the spool, and drawn toward the center of the spool as the tape is pulled out. That would indicate that its relaxed shape is likely flat & about 26 feet long. The inner diameter of the containment pocket in the spool is of course determined by how much space the tape fills in a nominally 2.75" diameter spool, and looks to be about 1.75" with another 25 feet of tape on the spool. I think it could be made to work, with or without putting the spring thru forming rollers as long as it was suitably anchored on both ends. But it would have to have the ability to pivot on the anchor points by 20 degrees or so sideways in order not to cause it to buckle near the anchors when the length changes. Cheap tape measures with big enough springs can be had for a total spring cost of 15 to 20 USD. The hubs would be the shape controlling factor there. Which is why I'm looking for ideas. In fact, it might be best to make the larger diameter end that I'd put against the bearing bosses, not a hub, but a containment cup. Put the hubs against the nuts flanges. This screw I have on order is 675MM long so I can put the right end floating bearing about 2" to the right of the existing bearing, so I'd have room for the cup without losing any travel. Needs about 625mm according to my very rough measurements. About 6" of the left end of the screw is inside the electronics housing and not usable for carriage travel anyway. I knew there was a reason I bought the longer screw. :) The left end is not a problem unless I can find a collet setup for that small a spindle, which would gain me about 40mm of travel there. That would be nice, but probably made out of pure un-obtainium for the 7x12. In fact, I am not at all sure if the headstock even has a Morse taper capability on this toy. Ugly thought just now Jon. Do these nuts have a lube port I'd have to leave uncovered? There was some sort of a red plug, looked flush with the OD on the side of it in the poor res pix on fleabay. Thanks Jon. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! My views <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> Do you mean that you not only want a wrong answer, but a certain wrong answer? -- Tobaben I was taught to respect my elders, but its getting harder and harder to find any... ------------------------------------------------------------------------------ Master HTML5, CSS3, ASP.NET, MVC, AJAX, Knockout.js, Web API and much more. Get web development skills now with LearnDevNow - 350+ hours of step-by-step video tutorials by Microsoft MVPs and experts. SALE $99.99 this month only -- learn more at: http://p.sf.net/sfu/learnmore_122812 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
