# Lathe Chuck Anti-spin Dog



## astroracer (Jun 11, 2015)

Quite often I have a need to drill  some larger diameter holes in pieces set up in the lathe chuck. I use a drill chuck on a taper in the tailstock. Over the years I have spun the chuck on the taper a few times when the drill catches in the work piece. Not a good thing but what is a guy to do?
 I had that problem tonight drilling out some 5/8" nuts with a .6195 dia. drill. All the chuck wanted to do was spin. Especially when a little bit of chatter freed it up. I needed to fix this so I could finish a job.
 I dug thru one of my scrap aluminum drawers and came up with this... A slip collar from a computer shaft.


It fit perfectly over the nose of my drill chuck.


 I thought oh man this is doable!
 I grabbed another piece of scrap aluminum. 3/16 thick, laid out a pattern off the top of my head and cut it out on the VBS. Smoothed it off with a flap disc and some ScotchBrite and here it is.


Drilled and tapped three holes in the collar and dog and bolted them together.



The dog worked like a charm, I got the nuts drilled out without a hitch (or a spinning chuck) and was pretty pleased with the work I did tonight.






These were the pieces I was drilling out. Made them a heavy slip fit over the bolt to use as axles for a wagon I am building




Mark


----------



## Nammar (Jun 12, 2015)

Dear Mark, You have the same China special mill / drill / lathe that I have. This was the first machine I bought, before buying proper machines. Unfortunately the standard of build is not up to any standard. The term "a rattling good fit" comes to mind when I think of this machine. The bed and cross slide ways are not parallel and just like your tailstock, the Morse taper is out. I've had more crashes with this machine than on any other machines I have worked on in my lifetime. No wonder that this lathe manufacturer went out of business in China. This lathe of mine just collects dust now an I'm intending to re-purpose it to a tool and cutter grinder sometime in the future.

On your work around to stop the Jacobs chuck from spinning, well done. Geoffrey.


----------



## darkzero (Jun 12, 2015)

Nice work on the stop but you shouldn't need it. I always seat my drill chuck in the tailstop using a mallet. I just use a rubber mallet but a copper or lead hammer would be better, that is if you care about not marring up the drill chuck when you strike.

I've never spun the taper in my tailstock, even with a 1" drill bit (largest I have & need currently). If you still have problems spinning the taper seating it with a mallet, you might want to check the taper & ream it if necessary.


----------



## GarageGuy (Jun 13, 2015)

I've had two lathes with damaged tapers in the tail stock.  It is very annoying.  I bought taper reamers to remove the internal burrs and galling, and true up the Morse taper.  In both cases it fixed the problem.  The reamers I bought were cheap Chinese imports found on eBay, but they did the job.  I understand about doing the best you can with what you have.  

GG


----------



## astroracer (Jun 14, 2015)

Thanks for the input guys. I have jumped thru all of the hoops you have mentioned. Lead hammer, cleaned up sockets and tapers, and right now, there is even a mix of 6.5 micron aluminum oxide mirror lapping compound and WD40 on the taper. The lapping compound works the best but it just couldn't handle the chatter from the bit and thread contact.
And, just to clarify, this is the taper in the back of the chuck, not the #2 spindle in the tailstock. I've never had an issue with that.
I am going to order a new chuck and taper. This one has just about seen it's last days. It came with the machine when I bought it in 1992. The chuck key is worn out and I think the taper has gotten to the point it can't grip the spindle any tighter.

And Geoffrey, sorry you had bad experiences with your machine. Like I mentioned above, I bought this one though Smithy in 1992 and, up to this point, have replaced nothing other then the belt and the on/off switch. It has been an incredible machine. I wish I knew exactly how many hours I have on it but I know it has to be well over 3,000. I think that is a lot for a hobby machine.
Mark


----------

