Unimat SL-1000/DB-200 Tail-Stock Chuck?
Everyone as mentioned being a model builder and a maker of my own parts at times, I get to needing special tools, one being my Unimat, (WELL I've got 2 of them!) but anyway, they are limited, somewhat..... That said those that have them and those who know of them, they're limited in size of what can be machined in them.
That said, something I've ran into is bits........ specifically in the 1/4 inch chuck. I've found myself needing to either turn down a BUNCH of bit shafts, OR simply find a chuck, machine it to fit the Unimat that holds a much bigger capacity....
Now again, that said, my best choice was to take a larger Chuck I have, and make it fit the Unimat, OR turn down EVERY bit I have to fit the small chuck (which in some cases could cause severe vibration at higher RPMs).... And to that end, turn down EVERY bit I buy with a semi-standard shank, OR buy special bits with small shanks... SO I choose to go the more practical route!
Take a larger chuck, and chuck it in a Atlas 9 inch Lathe, in a 4 Jaw independent-jaw chuck, and turn out the collar to be able to cut threads in it for the Unimat.... which is metric 12X1.00 threads.....
I've got a friend with the Atlas 9 Inch lathe that allowed me to set-up and do the work needed to the chuck I had, which was a Jacobs 1/2 inch chuck. So to get all going on it, and did it in a couple hours (Set-Up to get it as true to center was challenging.) I got within .005" tolerances of spinning true round to center.. With the help of a dial indicator, as well as making sure the tool used (the lathe) was spinning true to start with.....
So as you guessed I got it all done, and heres how it all turned out in the end......
https://i.pinimg.com/originals/f5/b8...03e3f0bc50.jpg
You got the standard Unimat Lathe.. and seen here is the Factory Unimat Chuck......
https://i.pinimg.com/originals/a0/df...27e5559a6d.jpg
Close-Up of the Factory 1/4 inch chuck!
https://i.pinimg.com/originals/1b/a2...b1ea1b2b64.jpg
BOTH the Factory Unimat 1/4 inch Chuck, beside the NEW Jacobs 1/2 inch Chuck!!!!!
https://i.pinimg.com/originals/12/f2...1f14c92eb3.jpg
Up-Side-Down. Showing the way the chucks "thread" onto ANY place of the Unimats! This work will allow me to use this single 1/2 inch chuck, in the tail-stock, in the head-stock of the Lathe, OR used in the Unimat Milling Machine for a 1/2 inch Chuck, or as the Unimat is also able to be used as a Drill Press, as a Drill Press Chuck, (NOT to be used for any sort of Milling! Drilling ONLY!) I can also use this same chuck to use as a round stock holder in the Face-Plate, as well as the Drill Press Table, and even the Milling table, and to go further it will also mount to the Dividing Head with the same threading of the rest of the machine!!!!!!
https://i.pinimg.com/originals/ed/df...c7f21bb5a1.jpg
NOT fully "tightened" to the tail-Stock "stop".......
https://i.pinimg.com/originals/08/22...269010341b.jpg
Fully tightened to the "stop"..... AND I drilled the center out for the treading about .020" deeper then needed, to give it that "Back-Stop" built into the Unimats Tail-Stock, as well as everywhere else!!!! WITHOUT effecting the jaw closure of the chuck and opening, It will hold a 1/2 inch bit easily, and it even has a little bit "more" to hold slightly larger diameter then exactly 1/2 inch!
https://i.pinimg.com/originals/aa/be...2ff6737f1e.jpg
Unimat Lathe fully "Dressed" with a 1/2 inch tail-stock Chuck!
Sure BEATS what I would have had to do, to turn down all the bits with larger diameter shanks, and even the new ones I bought to fit the machine, and does the trick just as good as the original 1/4 inch chuck! AND that BIG 1/2 inch chuck does in fact CLEAR my Lathe Cross-Slide too! Again, just like the original does!
