On Wednesday 27 February 2019 22:54:05 Jon Elson wrote: > On 02/27/2019 08:57 PM, Stuart Stevenson wrote: > > Every Renishaw probe I have used has had to have the spindle > > oriented when probing. Otherwise I could not trust the results. Try > > the probe. It will measure much better than .005. > > Yes, the docs from Blum for their probe have a comparison > between their scheme and the 3-ball Renishaw-style probe. > Their design supposedly has about 5 um variation anywhere > around the circle, they show a 3-lobed pattern for the > others, with about 20 um variation depending where the touch > comes from. > For me, 20 microns isn't much. But on testing this with finger pressure on the probe, I was amazed to see it was a single contact design, breaking contact quite gradually. I had no trouble with my shaky hands, holding just enough pressure to maintain an ohm-meter reading between 200 ohms, and 3000 ohms. I suspect the contact, the end of a brass screw, is contaminated, fingerprint oils or whatever. Certainly not very impressive considering I had pushed its probe around 20 thou sideways.
> You can see the picture in this link: > > https://www.blum-novotest.com/en/products/measuring-components/workpie >ce-probes/tc50-tc60.html Konqueror wouldn't connect, but firefox did, Impressively made but I expect the pricing is well plus of a renishaw. The one I bought was $68. And its possible it way well work inself into a solid switch, but I've no clue if 12 volts from the 7i76 is enough to clean it. But since I don't know what lag in sserial would be, I'll probably put it on an input of the other BoB as that will register at servo-thread time. And a contact opening isn't going to work as well as a closure. With a closure such as I have used, a capacitor can be discharged quite rapidly, by a contact in the spinning spindle, guaranteeing a circular sensitivity pattern and will hold that voltage low plenty long enough to register with LCNC. I used that spindle running technique on the HF, and I still use it on the g0704. Repeatability is typically .0002". Time and use will tell I suppose. However a lack of locking on this spindle, combined with its T.I.R., 3 or so thou there, doesn't impress me. > I have no way to measure how good MY probe is. I am in that same boat, Jon, which is why I am pretty much sold on the running spindle version used to find the center of an arbitrary sized hole. The real question is, is it good enough for everyday use. I suspect, once the T.I.R. is known and can be taken back out, that the answer even for this POS is yes. But where is the T.I.R? In that ER11, only the spindle can be a known, the nut and collet assemble randomly. And in fact could be a huge source of the heating I encountered by letting the tool wobble so that the cutting edge is not the first contact point. Loosening the tool and rotating it s few degrees in the collet could make a huge diff in how it cuts, and heats. Its worth investigating with my .0001" dial. > Jon > > > _______________________________________________ > Emc-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-developers Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
