How do you Use this Chuck?

[oskar]

A few months ago I bought the chuck shown in the attached picture thinking it’s nice to have a small chuck but I can’t figure out how to use it on my Taig lathe although the decryption of the item says it can be used for both turning and drilling applications.

The 2 shafts shown in the picture are marked JT0-3/8 and one end is tapered and fits on the back of the chuck. To attach it to the Lathes chuck it says to first turn a spigot on the piece and attaches the spigot on the chuck. What is this spigot?

The last paragraph on the picture I don’t know what it means

Thanks
Nicolas

 

[francist]

Hi Nicolas. Hmmm, Lee Valley is usually better than that at descriptions. However....

Starting last question first, I believe they are saying that the two taper adapters have one end threaded 1/4" - 20 so that you can use a length of 1/4" threaded rod as a drawbar to hold the morse taper into the headstock spindle. Without a drawbar, morse tapers can come loose if they are subjected to side loads. Not usually a problem with drilling, but if used for turning as they suggest, I think you would want to have a drawbar in place so that the taper can't wiggle loose and come out of the spindle.

As for the spigot, again I think they are referring to a reduced section you would have to turn on your material so that you could grip it in this chuck. The chuck has a maximum capacity of 1/2", so if you wanted to turn a piece of 3/4" bar, say, and use this chuck to hold the one end for turning you would first need to turn an end down to 1/2" or less (forming a short "spigot") so that it would fit into the chuck.

Does any of that make sense?

-frank

 

[Hawkeye]

The fun part of what Frank says is that the example 3/4" piece wouldn't fit in the chuck to turn the 1/2" spigot. You would have to mount the piece between centres to turn the spigot, then mount it in the chuck.

 

[oskar]

Well the two adapters do not have one end threaded 1/4-20. One of them has both ends covered with a plastic cover (fit on the inside) and the other adapter has both ends open, no threads.

My initial thought with these adapters was that one end holds the chuck and the other end I can put it into the Lathes chuck but since now you are saying that the taper can wiggle loose, that’s not a good idea.

Thank you both but still have no idea how to use this chuck

 

[mikey]

The adapters have either a MT 1 or 2 to fit whatever your spindle or tailstock taper is. The other end on each adapter is the same and presumably fits the taper in the chuck. As Frank said, if you use it in your headstock spindle you need to use a drawbar to hold the MT in place. If the adapter is not drilled and tapped for that drawbar (as is stated in their ad) then you either cannot use a drawbar or you have to drill and tap it yourself. Holding a tapered work piece that may or may not be hardened might be troublesome.

Assuming you found a way to mount it in your spindle, your work piece size would be limited to the capacity of the chuck or you would have to turn the end of the work down to fit into the chuck.

Just so you know, a drill chuck is probably the least accurate and secure way to hold work and I don't think any of us would recommend it. This product might be okay for use in your tailstock but for the cost, don't expect much in terms of quality.

 

[GL]

Another way I could interpret the statement (except for the tapping for a drawbar part) would be that they are suggesting you turn the taper off of the arbor so you have a straight shank (the spigot) to put in the headstock chuck to make the drill chuck into some sort of mini 3 jaw as a creative solution to a specific problem. This would have limited application and, as others have said, creates other issues

The other piece of this is that, while not impossible, once you mount the chuck on an arbor you don't swap them around to other arbors. It's kind of a one and done thing. The traditional setup would be to mount the chuck in the tail stock, use it to hold a drill bit to drill a hole in something spinning in the headstock held by the chuck that is already there. The irony of having to turn down a shaft, between centers or in a normal chuck, to reinsert into this chuck as a work holder is a possible indication that whomever wrote the description has minimal idea what a lathe does and a flair for creative marketing.

I think I would mount the chuck on the arbor for your tail stock, use it like you think it works, and write off the rest to bad information.

 

[oskar]

Searching Lee Valley’s site I found this page which gives more info and pictures of this little chuck.

http://www.leevalley.com/en/wood/Page.aspx?p=75987&cat=1,180,42334

I gather it’s up to me now to find a suitable way to hold this chuck if I want to use it and as GL mentioned above “…..use it like you think it works, and write off the rest to bad information.”

Thanks to all
Nicolas

 

[KMoffett]

Wow, I can't imagine the person that thought it is a great idea to put the (2) flutes of a drill bit deep into a 3-jaw chuck.

Ken

 

[BaronJ]

Hi Guys,

What was it PT Barnum said !