On 11/25/2014 10:30 PM, Leonardo Marsaglia wrote: > 2014-11-25 18:19 GMT-03:00 Dave Cole <[email protected]>: > >> Since you have limited availability of local parts; you might want to >> consider using some automotive sensors such as the camshaft and >> crankshaft sensors used by most cars these days. >> >> I've replaced some on Fords over the years and they typically fit into a >> hole recess in the engine block and extend to sense a gear or segmented >> ring. Around here (Midwest USA) I have seen them as cheap as $15 or >> so. I believe the sensors I was checking/replacing were run off 5 volt >> power, so they should not be difficult to interface. Apparently the >> Ford sensors I was testing were hall effect sensors. >> >> More cam and crank sensor info that you probably need. >> >> http://www.aa1car.com/library/crank_sensors.htm >> >> http://easyautodiagnostics.com/misc-index/ckp-cmp-sensor-basics-1 >> >> If you stagger two hall effect sensors on a gear so they are out of >> phase by 90 degrees, you can create a full quadrature signal fairly easily. >> >> If you have a timing belt pulley, that may work as well. >> > Well for the Mazak I can still use the original encoder since I can scale > it, even if it's not that exact. But I'm giving it a try since it's already > there. > > I'm planning on using some sensor like the ones you mentioned for the heat > treating machine we're finishing to retrofitt because I have some of these > encoders without index pulse. The maing thing is I need to position the cam > to get a homogeneous heat around the profile. The idea of making the 360 > teeht gear is not out of the question either, but I think I'm going to use > the encoder and add the physical index with a hall sensor. > > Here's a link of the process with a round coil, the idea is to use coils > with the shape of the lobe. The problem of the non homogeneous occurs more > with high lift camshaft. > > http://youtu.be/RmW3_c0-4Oc.
I re-controlled a very similar induction heat treat machine for a local heat treating shop. They usually heat treat linkage pins for farm tractors on that machine (John Deere is one of their customers). It's very impressive how quickly they can bring a solid bar of steel to a cherry red color with that machine. I used Mach3 and a PLC to do the re-control ( a few years ago). Mach3 serves as the user interface and the PLC does all of the machine logic. I tore off the old vertical motion motor and installed a new AC servo drive. The first one, a Parker servo drive couldn't deal with the RF noise. So I tried a cheaper Automation Direct servo drive and it has been running everyday for years now. It took them only a short period of time to figure out how to write G code programs do different parts. Dave > > > > > > --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! Instantly Supercharge Your Business Reports and Dashboards with Interactivity, Sharing, Native Excel Exports, App Integration & more Get technology previously reserved for billion-dollar corporations, FREE http://pubads.g.doubleclick.net/gampad/clk?id=157005751&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
