My MS was in igneous petrology with the intent of going into mining, but when I graduated in 1982 all the mines in North America were closed other than coal and I *think* Sudbury. So I went into reflection seismology and had a lot of fun. I'd love to be able to work, but at present prices no one is looking oil in deepwater, so as with many friends, employment is not an option.
I sent an email to Harnoy asking for any suggestions he might have of a comprehensive analysis of conical bearings, but have not heard anything back yet. He's retired, so I may not get a response from his faculty address.
To get journal access I have to go to Little Rock to the UALR library. I've made 2-3 trips collecting IEEE papers. I don't yet know if they have ASME papers or not, but will find out soon enough.
You would not believe the abuse I got from the denizens of the 7x12minilathe list on groups.io. After a good bit of time with "Metal Cutting Principles" by Milton C. Shaw to obtain an estimate the maximum spindle forces possible from the OEM motor I calculated that the L10 life was 100,000 hours for a quality ABEC 1 deep groove Conrad bearing taking a maximal cut. So I wrote it up, scanned the appropriate sections from Shaw and the Torrington Service Catalog and posted it. It's become painfully clear why discussion of hobby lathes are prohibited on the PracticalMachinist forum. The result was a long series of personal attacks. No one ever addressed the issues I'd raised. The central complaint is I write about things, but don't post pictures of what I've done. Never mind that my lathe was damaged in shipping and I am still waiting to get the 6" and 12" cast iron straight edges I ordered from Martin Modles in early May which I shall have to mill and scrape before proceeding. And my MT 2, 3 & 4 test bars took over a month to arrive from India.
Of course, the idea that some stranger can demand I do what they want me to do is more than a little over the top.
There's a YouTube video by some Aussie who is "reconditioning" a mini-lathe. With the bed in an unknown state of stress, he puts the carriage on with the rear gib tight and notes that it binds at the headstock end, i.e. there is wind in the bed.
So he "fixes" it by gluing 100 grit silicon carbide paper to the vee, puts several layers of cardboard and masking tape on the flat section of the bed and proceeds to sand the carriage vee!
There was great enthusiasm for the video. So when I pointed out that the problems with what he had done they unloaded on me.
Not having trained as a mechanical engineer, the virtues of the mini-lathe were not immediately obvious. But the more I learn, the more impressed I am with the design. It's built to a very low price point, so the manufacturing QC is dubious, but so far my measurements indicate that it's actually decently made so long as you accept that you're going to need to scrape it if you want an accurate machine. And it is so much more solid than the 6" Atlas and Dunlap lathes sold by Sears or the Sherline, Taig and Unimat 3 there is no comparison.
My first post to the list outlined my intent to rescrape it to a tenth. That elicited a string of comments about how lousy they were and "He's a noob. Wait until he learns about backlash." I didn't bother to explain I knew a great many ways to make a nut with a backlash adjustment. I merely noted I'd owned a 10x20 Clausing 4902 lathe and 8x26 Clausing 8520 mill for 20 years. So now the complaint is that I post stuff based on literature research. So I am looking for another venue to document the process.
I sometimes spend a lot of time on the EEVblog forum which I have found very impressive. There are some *very* sharp people there. Quite a few of the higher skill people in electronics also have impressive metalworking shops and scientific skills.
I'd very much appreciate any suggestions you have with regard to the mini-lathe rebuild. I just received four 4"/2 mm level vials from AliExpress and have ordered swivel feet and 4 mm carbide balls. I've still got to suffer through ordering the rest of the parts, but am building a 3 point mount for holding the lathe for scraping and a version of a King Way. I have Connelly and did learn algebra, geometry and trig in high school, so I'm not going to copy King's design exactly. But at $12 a 4"/2 mm vial will give me a very sensitive measurement for almost nothing. There is more to the plan, but I'll send that as a PM.
Have Fun!
Reg
