On Sunday 17 February 2019 02:28:07 Roland Jollivet wrote: > If this is for a touch probe or something of the sort, you only need > contact when the RPM < 500? > Getting <500 out of this vfd presents a couple problems, 1st being the resolution of its pot, its horrible and linear. I don't know the ohmage of the pot, but if its around 10k, I may have some 10 turn highly precise pots. But mounted where this one is might project out into thespace the vfd occupies.
2. asking a 3 phase motor to turn that slow, will, if the vfd is tuned to get and decent low speed torque, it will also burn up the motor by running it at only 5 hz or so. Tuneing a vfd to the task at hand needs a degree from Hogwarts as this vfd maker is Chinese, and speaks no Engrish. > So, have a setup that if RPM is higher than 500, then a little > solenoid that tensions the braid (not spring, as you say) is released > so there is no tension on it. > You want a copper braid around the spindle.. I've not progressed to the point where I can extract the rpms from it, yet. If I can the lcnc can handle the solenoid. But I've other stuff on my plate as I bring this new machine to a usable state. Doing that would be cake frosting. First you need a cake etc. I've gien some thought to sensing the wrench flats with a pair of ATS-667's and cobbling it a tach display from that. But that sort of stuff is months down the log yet. Thanks for the input Roland. 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-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
