# Drill chuck on 3/4-16 spindle?



## Raymond (Jan 15, 2009)

I'm looking for a way to mount a 3/8-24 threaded drill chuck on a lathe with a 3/4-16 threaded spindle.  Does anyone know where I might find an adapter that will let me do this?

Another option is to mount the chuck on a morse taper on the lathe.  Arizona Silhouette sells such an item but I don't need the chuck, just an MT1 taper with a 3/8-24 thread on the other end.  Any ideas where I can find that?

So you know what I'm doing, I need to turn a small (1/4" diameter) short (1-1/2" long) piece of acrylic.  I can turn it down between two centers then I want to mount the acrylic in the chuck so I can round over and polish the free end.


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## jskeen (Jan 15, 2009)

I've never seen an adapter to allow a jacobs chuck to thread onto a spindle (don't mean it don't exist however)  Most jacobs chucks use a specific taper, called a jacobs taper(who'da thunk it) that press fits on, sometimes with an arbor press.  They can still be disassembled with a little work.  

You can get a jacobs chuck with a MT1 taper installed on feebay most anytime.  I got mine for $5 + shipping, and it's a real jacobs brand jacobs chuck.   If you plan to use a jacobs chuck in the headstock end of your lathe with the tailstock end unsupported by a live center (like to polish a dome) you really want to get one where the inside end of the mt1 taper is threaded to accept a drawbar of some type, to keep that fairly heavy chunk of metal from bouncing around your shop should it decide to come loose at speed however.  

I googled for mt1 3/8 24 and found one listed at JT machine in england.  It's 17 pounds sterling + international shipping.  Much more than you can get a whole new MT1 chuck for.  

A dedicated MT1 jacobs chuck is a very handy thing to have around.  Once you buy a scroll chuck to fit on the spindle of your lathe, you can use the two to drill blanks, usually more accurately than most vise and drill press combination's manage.


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## Raymond (Jan 15, 2009)

Thanks.  I noticed that for some reason most (but not all) of the Google hits for these items are for UK or Australian sites.

I have a few chucks here and want to use something lightweight if I go the MT route rather than threading the chuck onto the spindle.  I'm thinking lower mass will reduce the risk of the chuck coming loose.  One is a small Jacobs 1A 1/4" chuck with a JT1 taper in the chuck itself.  If I can find an MT1 to JT1 adapter, that will work.  I'm not real excited about relying on TWO tapers to hold together, though.

I'm surprised no one has an adapter that will thread into a chuck and onto a spindle.  I guess there's little demand for that.

The best solution seems to be a scroll chuck but I'm trying to minimize my cost to make a few prototype parts until I know if they'll work.


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## Randy_ (Jan 15, 2009)

Try www.littlemachineshop.com .  They have lots of little goodies and maybe something that you could adapt to your particular situation.
 
I'm guessing you have a chuck off a cordless drill that died that you want to use.  It is nice to recycle things when possible; but I suspect this is a case where it will be more expensive to get an adapter than to just buy a new chuck on a #1 MT.

Is this a one time job or something you plan to repeat many times?  If this is something you plan to do for many repetitions, you might want to think about a collet chuck or a scroll chuck rather than a Jacobs chuck.  If this is a one time affair, there are probably some ways to cobble up something.

If you have a drill press, you might do the polishing on the drill press??


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## Randy_ (Jan 15, 2009)

You have some odd-ball stuff there.
 
I took a quick peek at the Little Machine Shop out of curiosity.  They have a #1 MT arbor to JT2; but not to JT1.  I also found an arbor with a 3/8x24 thread; but only on #2 and #3 MT, none on a #1 MT.
 
You might want to give them a call and see if they have stuff that is not on their web site.......you might just luck out.???
 
Seeing what LMS has, I'm thinking that some more Internet searching might turn up what you need; but this would seem to be low demand stuff so it might be hard to find!!


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## jlg2x (Jan 15, 2009)

Try Victor Machinery Exchange. www.victornet.com They have them for only $5.90. But they say that they are currently out of stock. That is the 1MT 3/8-24 arbor.


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## Raymond (Jan 15, 2009)

Randy_ said:


> You have some odd-ball stuff there.
> 
> I took a quick peek at the Little Machine Shop out of curiosity. They have a #1 MT arbor to JT2; but not to JT1. I also found an arbor with a 3/8x24 thread; but only on #2 and #3 MT, none on a #1 MT.
> 
> ...


 
Thanks, Randy.  Yeah, I called LMS this morning and they don't have anything to make the thread-to-thread connection.  I found the taper-to-taper adapter on a web site last night but it was pretty pricey.  Sears actually has an affordable ($25) setup with a 1/2" chuck on an MT1 taper but they sell it for use with the tailstock only.  Safety being an issue, I'm sure.

For now, I'm considering this a limited project.  I'm trying to turn custom bridge pins for a guitar out of exotic wood and/or acrylic.  If it works out and doesn't take an hour to get each pin right, I won't mind investing a little more $$$.  First, I want to see if it can be done and what they look like.


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## Robert Taylor (Jan 15, 2009)

here is the mt-1 to jt adapter(s)
http://cgi.ebay.com/MT1-JT1-MT1-JT2...14&_trkparms=72:1205|66:2|65:12|39:1|240:1318

here is a mt-1 chuck
http://cgi.ebay.com/3-PC-KEY-DRILL-...14&_trkparms=72:1205|66:2|65:12|39:1|240:1318

here is a mt-1 keyless chuck
http://cgi.ebay.com/3-8-KEYLESS-DRI...14&_trkparms=72:1205|66:2|65:12|39:1|240:1318


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## Robert Taylor (Jan 15, 2009)

and if you have a 3/4-16 tap i have a homemade adapter that was made for a shopsmith with a 5/8 bore and a short 3/8-24 thread to hold a drill chuck just like you are wanting to do. there would be plenty of material to tap it to 3/4-16.


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## jskeen (Jan 15, 2009)

I'd bet he'd be willing to list the MT1 to JT1 in a separate auction if you emailed the request, he's pretty flexible usually.


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## me2cyclops (Jan 15, 2009)

premade for taig lathes check cartertools.com
$11.10 Drill chuck arbor (3/8-24 thread), attaches Jacobs chucks to headstock spindle (headstock is 3/4-16)


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## Raymond (Jan 15, 2009)

me2cyclops said:


> premade for taig lathes check cartertools.com
> $11.10 Drill chuck arbor (3/8-24 thread), attaches Jacobs chucks to headstock spindle (headstock is 3/4-16)


 
Perfect!  I just sent Nicholas Carter an email for a quote.  I think that's exactly what I was looking for.  Good find!


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## me2cyclops (Jan 16, 2009)

I've been using a taig for several years and you can't go wrong with nicks service


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## jskeen (Jan 17, 2009)

SCORE!! There you go.  Don't let anybody (especially me) tell you that you can't find what you want if you look hard enough.  Now that get's me wondering just exactly how much less runout can you expect by threading onto the spindle vs using a MT fitting.  Inquiring minds want to know.


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## bitshird (Jan 18, 2009)

Taig mills and lathes have a 3/4 x16 tpi spindle and has an adapter for them that has a 3/8 24 tpi which is pretty much standard for most inexpensive drill chucks, Try  http://www.cartertools.com/catalog.html item #1140 and 1092


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## Raymond (Jan 20, 2009)

I've ordered the Taig 3/4-16 spindle adapter to let me thread a 3/8-24 chuck onto the headstock and avoid the Morse taper.  It's on its way thanks to Nick Carter.  



jlg2x said:


> Try Victor Machinery Exchange. www.victornet.com They have them for only $5.90. But they say that they are currently out of stock. That is the 1MT 3/8-24 arbor.


 
I tried to also buy a couple other arbors, including the out of stock 1MT 3/8-24 arbor from Victor Machinery Exchange for use in the tailstock.  (Will have them in stock next week, they say.)  I appreciate your pointing me in that direction, but it turns out they will not even consider an order for less than $25, online or on the phone.  Mine was about $11 total before shipping.  I ended up buying from Sherline.

Ray


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