Getting the proper chuck size

[Creativechipper]

I am thinking of adding a 4 jaw chuck to my toolbox.

Looks like lots of size options, tapers, thread count, back plate, .etc, looks confusing to me.

I know my lathe has a spindle bore of 1.02" and a MT4 spindle taper.

What critical size, thread count info do I need to know before getting a new chuck?

Thanks

 

[ttabbal]

You need to know the chuck mounting information. It's specific to the lathe. The taper and bore don't help you. If you post your model number, I'm sure we can figure out what you need though. Another option would be to remove the chuck and take pictures and measurements of the mounting features.

 

[dlane]

Mounting info and lathe size ?

 

[BaronJ]

What size was your machine originally supplied with ? It should tell you in the handbook.

 

[RJSakowski]

If you still the Weiss, the manual states that you have a flange mounting with three studs and nuts. This is not a common mount and you may have to make a custom backing plate. DRO Pros carries the Weiss machines and should be able to sell a four jaw chuck for your lathe.

 

[projectnut]

Personally I would go with a chuck slightly smaller than the advertised "throw" of the machine. Rule of thumb says not to extend the jaws more than 3/4" beyond the body. If you have a machine with a 10" throw the maximum size chuck I would buy would be 8". With the jaws extended the 3/4" you would be swinging a 9 1/2" diameter piece.

The chuck and backplate are usually purchased separately. You can either buy a backplate with the proper mounting features for your lathe spindle and "finish" it to fit the chuck you buy, or buy a "blank" and make both the chuck and spindle mounting features. I have never been able purchase a backplate with the proper spindle features for any of my lathes. I just purchase blanks and make my own.

 

[Creativechipper]

It is a
Weiss WBL250F 10" x 30" Metal Lathe

I was looking at the specs for it off DRO's web page but did not see any other specifics than MT4 spindle taper and 1.02" spindle bore.

Just trying to learn how to tell and what info is important in relation to a new chuck.

Thanks!!

 

[mikey]

You need a 5-6" chuck. You can buy cheap Chinese chucks with the 3-bolt mount from LMS, Amazon or ebay or you can use a 3-bolt back plate and mount any plain back chuck to it. I don't know of any maker of high quality chucks that makes one that directly mounts to your spindle.

 

[Creativechipper]

Oh no, no good quality chucks..lol Thats ok I dont have the budget for a good one, I am sure its well over my budget.
But I do like quality tools and often buy used to get a better tool for my money.

Thanks , good info.

What is involved with finishing the mounting features of back plates and chucks?

 

[Bob Korves]

Oh no, no good quality chucks..lol Thats ok I dont have the budget for a good one, I am sure its well over my budget.

I think Mikey's post was not so much about the chuck quality you purchase as it was about the inability to be able to purchase a one piece chuck assembly, complete with backing plate, ready to purchase and immediately bolt it on and put it to work. There will be "some assembly required..."