Newbie with a chuck query

The other option is buy a set of soft jaws you can machine and reserve this chuck for special duties.

Until you get things sorted out, if you find that the work run out is too bad to tolerate, you could chuck a bit of material, and bore it to the size of the material that you really want to machine. Mark the bush where it by a chuck jaw, (we usually use No.1 ) Remove the bush, put a cut in it (Don't remove the jaw mark!). Replace in the chuck in the original position,and use as a split collet to hold the work.

Howard

Just saw this quick and nasty way to grind chuck jaws on Youtube. . It works but I would not stand in line with the spacers and would run the chuck a bit slower.

**LINK**

One thing that could help with the spacer method would be to magnetise the spacers, yes it will soon end up all furry. Maybe double sided adhesive tape might do it, just to help setting up.

Ian S C

One of the best reasons for owning inexpensive Chinese kit is all these difficult decisions go away! When inexpensive chucks are damaged, just replace them.

A Bernerd chuck in good condition is well worth buying new jaws for. But fitting expensive new jaws to a clapped out Bernerd would be a horrible waste of money. Before spending any cash on it, I'd make sure the body and scroll are OK.

Should the Bernerd be scrap, it's not difficult to get a cheaper replacement to fit a Myford. A cheap chuck might not be as repeatable, but it will do the job.

Dave

As predicted, I spent £100 on a new 3 jaw from RDG. Does the job for me very well, and in the interim I have become reasonably proficient at dialling in work in the 4 jaw chuck, so my times not been wasted!

Many thanks to everyone for the advice and encouragement.

It,s difficult to understand how someone could "misplace" or "lose" a 3 jaw chuck. I don't think even I could manage that,and I can and do lose many things.

I bought a chuck at one of Chester,s Open Day,s some years ago, which turned out to have mismatched jaws.

Brought it back next time I was over, they were un able to find the missing jaw but gave me a set of jaws to machine myself. I think they called them soft jaws ?. As I recall, there were two sets of jaws with the chuck, but only one set was faulty. In point of fact a new chuck is not all that dear and will last you a long long time. I think I would use that one as a paper wt, Dont waste your time with it. I hope the previos owner took more care of the lathe than of the chucks ect.

As an aside; I bought my 6" vise about 1975 and paid £12 for it. The jaws are now showing their age [have done some heavy work in that time ] so I decided to think about buying new jaws for it. Having seen the price,I am now having second thoughts !

A new set of jaws can be mine for only £68 !+ p p !

Needless to say ,I am in no great rush to buy.

Any ideas anyone ?

As an extravagance, I bought a secondhand mini lathe.

In the process of making a Centre Height Gauge for it I checked the run out of the 3 jaw chuck. It was quite small, of the order of 0.005" (0.017 mm )

Imagine my surprise when I found that one of the jaws carried a different serial number from the other two!

Since i am the second owner of the lathe, I do not believe that the seller would have changed the jaws, so conclude that the machine left the factory like that!

Clamp a piece of Silver Steel in the chuck, and check the run out. If it small, like mine, I would not worry.

If it is excessive, then my suggestion would be to make up a ring and then grind the jaws.

If grinding in this way is impossible, a rough and ready way would be to clamp all three jaws in such a way that outer faces are all against a good flat surface, and then to grind the highest jaw down to match the others, CAREFULLY. This assumes that the OD of the jaws are all the same!

Might be worth checking to see if the outer sides of the jaws align exactly, when checkingb the run out of the Silver Steel.

Are there any outside Jaws with the chuck?  If so, have they all the same serial numbers?

Howard

Edited By Howard Lewis on 07/10/2019 19:15:15

I would carefully measure the jaws and make a drawing including the teeth pitch, and keep checking the ads on ebay, sets do come up from time to time. Rotagrip sell soft jaws for your chuck, which could give it a new lease of life for special jobs, where perfect running is important.