Seems to me a resolver would be the best choice for position on start up. Velocity could be derived also. A resolver on the cam and crank could tell you the next piston to reach tdc. On Nov 23, 2012 8:30 AM, "Gene Heskett" <[email protected]> wrote:
> On Friday 23 November 2012 09:14:56 andy pugh did opine: > > > On 23 November 2012 04:04, Gene Heskett <[email protected]> wrote: > > >> To buy the crank code-wheel new is not that cheap ($100) but there > > >> ought to be many in the junkyards now. The correct pickups are less > > >> likely to exist, but those are $17. > > > > > > Since the requirement is that its ferrous, I seen no reason that can't > > > be a milling machine project. > > > > The target wheels we have on our engines are _not_ ferrous. They are a > > magnetic track and the crank sensor has no internal magnet. > > (I can't find that actual sensor on the Allegro site). > > For a hall sensor to work, there must be a magnetic field for it to sense. > Generally that requires a ferrous material. It can be magnetized, or a bias > magnet in the sensor can make a soft iron toothed wheel work. > > Not all steels are magnetic though, as you can check by trying to pick up > with a magnet, an exhaust valve from one of the engines Ford has been > making since 1955. :) Its 'austenitic'(sp). You would have to warm that > valve back up to near melting, and let it cool slowly in order for it to > regain its magnetic properties as it cools below its 'curie' point > temperature. > > > Having said that, ebay has many "trigger wheel"s at quite low prices > > which could work, though most seem to be quite low-resolution. > > http://www.ebay.com/itm/261124381577 > > > > You can see the one I have in my drawer at the bottom of this picture > > here: > > http://images.sklepy24.pl/87078282/3668/large/kolo-pasowe-walu-korboweg > > o-1-8-tdci-dayco.jpg You can just about make out the magnetic track. > > (There are two parts there, 6B319A and 6B319B) > > > 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! > No foreign coins. > > > ------------------------------------------------------------------------------ > Monitor your physical, virtual and cloud infrastructure from a single > web console. Get in-depth insight into apps, servers, databases, vmware, > SAP, cloud infrastructure, etc. Download 30-day Free Trial. > Pricing starts from $795 for 25 servers or applications! > http://p.sf.net/sfu/zoho_dev2dev_nov > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
