tag:blogger.com,1999:blog-1592992209402300549.post9162303160091814250..comments2024-03-29T07:33:41.566-04:00Comments on The Silicon Graybeard: Threading Breakthrough - Almost Done SiGraybeardhttp://www.blogger.com/profile/00280583031339062059noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-1592992209402300549.post-90597487895881470392018-12-20T22:06:08.966-05:002018-12-20T22:06:08.966-05:00Exactly. Toward the left end of the 10-32 screw o...Exactly. Toward the left end of the 10-32 screw one thread almost looks cut in half vertically. <br /><br />It almost seems like perhaps the system is missing the sync pulse, or perhaps messing up its timing. <br /><br />I looked for problems in the pulse and don't see any errors more than a couple of percent. It doesn't seem like 4% timing error, say, could make that big a difference. <br /><br />That's the target of research now. <br />SiGraybeardhttps://www.blogger.com/profile/00280583031339062059noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-24728862872639643642018-12-20T21:55:34.150-05:002018-12-20T21:55:34.150-05:00A second look reveals that at least some of the th...A second look reveals that at least some of the threads have a strongly asymmetrical profile. Not sure how that might happen. Maybe the threads are getting pushed to one side? Ritchiehttps://www.blogger.com/profile/08075903551422300106noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-30533962248740701382018-12-20T08:12:45.719-05:002018-12-20T08:12:45.719-05:00I'm still in awe of CNC can do. Changing threa...I'm still in awe of CNC can do. Changing threads on my small Grizzly means going to the chart, swapping gears, and usually finishing with a die nut to get clean threads. John in Phillyhttps://www.blogger.com/profile/16196033252818387245noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-91439877245726600362018-12-20T08:09:29.360-05:002018-12-20T08:09:29.360-05:00Not really. I'm also not 100% sure it's g...Not really. I'm also not 100% sure it's gone. And I'm not 100% sure it wasn't that the chuck wasn't tightened enough. <br /><br />My first suspicion was jitter, because some is visible on the pulse. The length of the pulse varies while I watch on the scope. It's not what seems to be a lot, say about 8% total, but it doesn't make a lot of sense. <br /><br />I have the option of taking the motor and headstock off my other lathe and seeing if it changes. That's probably the next experiment. <br />SiGraybeardhttps://www.blogger.com/profile/00280583031339062059noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-36646835115205013092018-12-20T01:59:41.408-05:002018-12-20T01:59:41.408-05:00Any idea why the previous try's paths weren...Any idea why the previous try's paths weren't on top of each other, and why speeding it up kept it in sync better? My guesses: one flash per revolution isn't a lot of resolution, and maybe there's a PLL in the controller that works better when it runs faster. Maybe the slower spindle has more RPM jitter from loading, or worse motor performance.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-2255369186812131102018-12-19T23:07:04.070-05:002018-12-19T23:07:04.070-05:00Ahhhh....feels good, doesn't it?
Machining al...Ahhhh....feels good, doesn't it?<br /><br />Machining aluminum has a few tips, as I'm sure you know. As my Dad used to pound into me..."Speeds and Feeds"!drjimhttps://www.blogger.com/profile/05647484115197408897noreply@blogger.com