This is a tool gloat and midi chuck question.  I recently won a bid at a local online auction and got these tools for $66.40 for all of it.

Nova 48111 Midi Chuck with Tommy bars

One inch wood threading kit

Long Ranger III remote switch

It is all in great shape and works as advertised.  My question is the midi chuck.  It has a very limited range of opening compared to the One Way chucks I have which use a key instead of the Tommy bars.  I took it apart and know what I am looking at and it is fine. Does anyone have one that can confirm this.  If I hold one bar still the other bar turns only one revolution.

 

 

 

 

Edited September 21, 20169 yr by HandyDan

I think that's the same as mine. Mine goes a little over 1 1/2 turns from open to closed- when off the lathe. I found my delta iron bed lathe's head stock threads are a little long. If I thread the chuck completely onto the spindle, the the end of the spindle hits the underside of the movable jaws. The remedy was to get a thick, 1" hole washer to install over the spindle before mounting the chuck.

Dan, the Nova chucks are designed so the jaws don't extend past the chuck body, or only just. They call this a safety feature for a couple reasons. First, it eliminates that interrupted edge spinning around and secondly, it makes it impossible to open the jaws so far they might let go. I believe one of the slides has a stop pin that can be pulled to bypass this feature. If I can find it, there is an Ernie Conover  video where he discusses this.

Edited to add

Didn't find the video but this page discusses  the feature.

Nova chucks

 

Steve

Edited September 21, 20169 yr by Steve Krumanaker
New information

Thanks Lew and Steve.  From what I saw when I had it apart it was designed this way.  Just wanted to be sure.  The last thread boss on the jaws are made thicker than the others and the edge of the body screw hits and stops.  It is a nice idea that the jaws don't come past the body but does create a problem for a few items one may turn.  It is not a problem for me as I have other chucks.

Thanks again