- Mar 2, 2012
- Geilenkirchen, Germany
I very rarely find any even used and if you do, they are ridiculously expensive. Is anybody making these today?
I can't speak to whether anyone is making them today. I'd presume that it's such a tiny market no manufacturer wants to chase it for the specialized tooling required to supply them. Then also, it may be that with such a short sine, it's difficult to provide the accuracy that a user might want.
As a comparison, I frequently have to set a compound to 8 degrees to machine ER collet cavities. I use a sine bar to set up and hope to get a deviation of a tenth or less in about 2-1/2' of travel. If it were as much as three tenths, that would mean six tenths on the diameter, which doesn't sound very good. Sure, the collet itself is shorter than that, but even a little inaccuracy is discernible with a careful feel at either the inner or outer end or with marking compound. If I had to duplicate an existing taper from only a taper micrometer measurement, I'd have a considerable anxiety about accuracy and would be prepared to tweak the setting if necessary and if possible.
Given all that, if I were a manufacturer I'd either just give up or charge enough to make it worth the trouble for producing onesies or twosies..
It is easy to criticize taper mics, but I know of nothing better, do you?
I guess like other situations, if it's the only tool that will work, then you've got to have it.
You haven't said anything about the application so I can't comment on anything better. I use a 5" B&S sine bar and it's a lot cheaper. I can picture situations where a sine table would work better. And other cases where it would be a compound sine table I want. Or there might be instances where a CMM or optical comparator would work as well or better. Tell me why those won't work.
Make a cast of the end of the shaft, section it and use traditional methods to determine the taper. As you have said, setting up a machine to produce that taper will require tweaking.
Those of you criticizing the accuracy of taper mics have never used one. No, it isn't as accurate as a vee block on a sine plate, but they will me to quickly measure the part on the lathe or grinder and take a good piece to inspection for verification.
The repeatability is extremely good. You put the fixed end on the taper, and adjust the mic so the moveable end swings past the taper centerline. You can feel the drag, and a few tenths makes a significant difference in feel.
I'd think if somebody wanted to manufacture them, a deal could be made with somebody making digital micrometers so the thing could read out directly in angle, decimal degrees, DMS or radians to keep the physicists happy. I doubt there's enough demand to justify it, but you never know.
These are stupidly cheap for what they are and could probably measure tapers pretty well- eoocvt 0-320deg Universal Stainless Steel Vernier Bevel Protractor,Angle Finder for Woodworking, Carpenter, Construction, DIY Precision Angle Measuring Finder Ruler Tool - - Amazon.com
Anyone got pics...sounds interesting but I can't picture them.
Look at this seller in Canada.
Taper Micrometer Corporation Custanite External Tapermike Micrometer 4D-606 | eBay