Lantern Chuck

[neilg4dbn]

I needed to modify a lot of 5mm to 8mm stainless bolts, cutting them to specific lengths with a domed and polished end. I was inspired by the lantern chuck posted a few years ago by Shelly142 which included a hex socket to hold driver bits to hold screws and bolts firmly against rotation. I dug out some bar ends form my metal store and made myself a lantern chuck, using a black-finished hex driver socket with a magnet and clamp ring. Rather than pressing it in as Shelly142 did, I milled a groove in the side of the hex holder and locked it against rotation using a dog-point setscrew. To give me a bit of flexibility, I used a setscrew in a threaded bore behind the holder, and machined another setscrew with a cylindrical point to fit inside the socket of the first one to lock it in place without it turning.
I posted the video on YT a couple of weeks ago, but the audio mix was terrible so the link below is to the new, updated version with much less machining noise.
Huge thanks to Shelly142 for the inspiration.
Neil

[courierdog]

Beautiful Job!
Love the Chips
My only wince is the use of Carbide and the increased speed required.
Just a difference of operation.

[DIYer]

Thanks neilg4dbn! We've added your Lantern Chuck to our Workholding category,
as well as to your builder page: neilg4dbn's Homemade Tools. Your receipt:

Lantern Chuck by neilg4dbn

tags: chuck

[neilg4dbn]

I didn't have any inserts with a decent nose radius, so I had to be a bit delicate with DOC, but that 304 is horrible stuff. I can break a decent chip from it with a coated neutral insert with a good chip-breaker if I really push the feed rate, but with the 0.2mm radius polished inserts for aluminium used on stainless, it's hard to get the balance right without burning up the insert. I went to the box of 0.8mm radius inserts and it was empty. I'd actually written BUY MORE in BIG letters with a Sharpie, but then kinda didn't actually remember to add them to the last order. My hopelessness in the face of organisational matters gets worse all the time. I'm turning some leaded mild steel at the moment and getting a lovely finish at a serious DOC and excellent blue/bronze Cs and 6s, almost like it's 4140. The 0.8 high-rake positives for aluminium do seem to give a really good finish on stainless, but I'm probably wasting money compared with using the right inserts. I don't do much stainless though, so a full box would be overkill and the price each is silly. I should have dug out one of my HSS tools that are ground for finish cuts on stainless, but I didn't. I would have to hone it and find a toolholder and... well it was just a case of using what was in front of me. Must make some more toolholders.