Nova G3 & 75mm Bowl Jaw Questions

[Jim Bennett]

I’ve got a Nova 16-24 lathe and a G3 chuck. The chuck came with a 50mm jaw. I’ve built up a laminated blank out of plywood that I want to turn into a decorative bowl. The blank is 11” diameter and 5-1/2” deep and is ready for it’s “turn” on the lathe. Got it mounted on a beefy 5” faceplate. After I true it up nice and round, I’ll work on the exterior shape and then turn a dovetail in the bottom for an expanding jaw attachment.

Not sure if the basic 50mm jaws are a good choice for a blank of this size. I was thinking about getting the Teknatool 75mm Bowl Jaws for the job.

Question one: any issue using the 75mm jaws with the G3?

Question two: would I be better off with the Supernova 2 chuck?

Question three: the Teknatool accessory jaw booklet recommends max speed of 1,000 rpm. Are they being over cautious?

Thanks, Jim

 

[R Henrickson]

I’ve got a Nova 16-24 lathe and a G3 chuck. The chuck came with a 50mm jaw. I’ve built up a laminated blank out of plywood that I want to turn into a decorative bowl. The blank is 11” diameter and 5-1/2” deep and is ready for it’s “turn” on the lathe. Got it mounted on a beefy 5” faceplate. After I true it up nice and round, I’ll work on the exterior shape and then turn a dovetail in the bottom for an expanding jaw attachment
Not sure if the basic 50mm jaws are a good choice for a blank of this size. I was thinking about getting the Teknatool 75mm Bowl Jaws for the job.
Question one: any issue using the 75mm jaws with the G3?
Question two: would I be better off with the Supernova 2 chuck?
Question three: the Teknatool accessory jaw booklet recommends max speed of 1,000 rpm. Are they being over cautious?
Thanks, Jim

[1] The Teknatool info I have notes that the 75 mm can be used on the G3 "with caution".
[2] So -- yes -- a Supernova would probably be better, certainly in the opinion of Teknatool. What you are intending to turn is NOT small. If I were using 75 mm jaws, I would mount them on a Supernova, especially for something that size.
[3] I don't know if Teknatool is being overcautious in specifying a max speed of 1000 rpm but for something the size you describe -- 11 x 5 1/2 -- 1000 rpm is too fast.

 

[Dennis J Gooding]

I’ve got a Nova 16-24 lathe and a G3 chuck. The chuck came with a 50mm jaw. I’ve built up a laminated blank out of plywood that I want to turn into a decorative bowl. The blank is 11” diameter and 5-1/2” deep and is ready for it’s “turn” on the lathe. Got it mounted on a beefy 5” faceplate. After I true it up nice and round, I’ll work on the exterior shape and then turn a dovetail in the bottom for an expanding jaw attachment.

Not sure if the basic 50mm jaws are a good choice for a blank of this size. I was thinking about getting the Teknatool 75mm Bowl Jaws for the job.

Question one: any issue using the 75mm jaws with the G3?

Question two: would I be better off with the Supernova 2 chuck?

Question three: the Teknatool accessory jaw booklet recommends max speed of 1,000 rpm. Are they being over cautious?

Thanks, Jim

Kind of curious; if you already have it on a faceplate, why do you want to remount in on a chuck?

 

[Jim Bennett]

Kind of curious; if you already have it on a faceplate, why do you want to remount in on a chuck?

The faceplate is mounted on what will become the inside of the bowl. After it is trued to round I can finish up the other end (the bottom) and make the dovetailed recess to mount the chuck. Then it gets turned around with the chuck mounted in the headstock, the faceplate comes off, and I hollow out the interior of the bowl where the faceplate had been.

 

[Mike Johnson]

After you true up the rounded blank and remount it on the bowl chuck you can always use the tail stock for additional support until you get most of it hollowed out and then remove the tail stock to finish turning the bottom the bowl, at this point most of the weight has been turned away and the chuck jaws have less weight to deal with. You always want to snug the jaws up after hollowing the inside of the bowl to make sure the jaws are firmly holding the piece when you have no support from the tail stock.

 

[hockenbery]

The faceplate is mounted on what will become the inside of the bowl. After it is trued to round I can finish up the other end (the bottom) and make the dovetailed recess to mount the chuck. Then it gets turned around with the chuck mounted in the headstock, the faceplate comes off, and I hollow out the interior of the bowl where the faceplate had been.

Big danger with plywood is delamination.
A recess can delaminate. The quality of the plywood and the width of the ring around the recess are variables that contribute to success or failure.
Don’t use a tenon with plywood it is more likely to delaminate than a recess.

A better option is to use a wood glue block on a faceplate or in a chuck with a tenon.

 

[Bill Blasic]

There is no reason why you cannot use the 75mm bowl jaws on the G3. The 75mm jaws are my go to bowl jaws on any of my chucks. Be very careful with plywood as noted above.