On 07/14/2015 04:02 AM, Gene Heskett wrote: ... snip
> Interesting Kirk. Does that roller actually roll? On the good units the roller rolls well. The pins and the center section are round and smooth. The bad roller has gone from round to a gear thoothed shape all the way around. The "tooth" pitch mismatch causes a double detent which allows the MPG wheel to stop in an unstable, signal wise, position between marks so can be a bit annoying. When adjusted, the good units seek and center the marks well. All the MPGs had a generous application of a messy black grease. I'm guessing it's some type of molybdenum grease. > If all that wear is on just the side we can see, it apparently wasn't > rolling. Critical lubricant needed on the axle pins? I don't see > any plain evidence of wear either on the pins or the socket where it > lives. IMO there should be at least a polished mark/area on the axle > & holder. > > OTOH, if its worn like a 3 or 4 tooth gear, I'd wonder if the > passing teeth on the detent disk were a perfect mathematical fit, > meaning 1 full turn of the roller, for either 3 or 4 teeth passing on > the detent wheel. When making a new roller, I'd try to have its > diameter 3.5 linear teeth or 4.5, so the wear would be more evenly > distributed in the future. Having an even fit, it would not take a > lot of wear to assure it remained sync locked. > > In any event, thats a huge amount of wear. Not a normal looking wear > pattern at all. Two MPGs are dated 1982 and the bad one 1985 so I suppose they have a right to be worn. The plan is to use some drill rod to reproduce some new pins and leave them unhardened. That way the cheap part, the roller, will wear out, and not the detent disk or roller carrier. The center section is 3mm dia. and the pins 1.8mm. If it doesn't work out, I know a guy that can make more ( :) ). -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/ ------------------------------------------------------------------------------ Don't Limit Your Business. Reach for the Cloud. GigeNET's Cloud Solutions provide you with the tools and support that you need to offload your IT needs and focus on growing your business. Configured For All Businesses. Start Your Cloud Today. https://www.gigenetcloud.com/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
