Another chuck question

[Guest]

I have a perform CCBL lathe with a clubman chuck. The problem is the thread on the chuck requires an adaptor which means the chuck is about 50 mm further out from the headstock. I feel this is adding to the vibration I get when turning. I have noted the thread on the Axminster super and wonder whether to plunge for this or get another backplate for the clubman.Any opinions would be appreciated.

 

[Happy amateur]

50mm seems a very big gap. Have you spoken to Axminster.
I had a similar problem with that chuck and a similar lathe, but the gap was about 5mm. The solution was to file a bit off the lathe spindle which allowed the chuck to register without any runout or vibration.

Hope this helps

Fred

 

[Anonymous]

Circa 50mm is standard for one of the thread adapters supplied by Axmin.

 

[Guest]

I suppose what I was really asking was is there much advantage in buying the SP chuck over the Clubman in terms of performance

 

[La Truciolara]

you should go for Oneway or Vicmarc chucks. That wouyld be the end of your problems :wink:

 

[SVB]

You have two issues here.

Firstly, make sure both the headstock register (the bit after the thread next to the headstock (sorry if that is teaching & eggs)) is 100% clean.

Secondly, using an adapter will lay you open to more vibration. The further you are from the supporting bearing, the higher the dynamic moment forces are (10x static loads often) and you will see a bigger effect.

So, what can be done. Simply putting a SP chuck on will not help unless you use it without the thread adapter but it is really a big, heavy chuck for the machine which (with all due respect to perform) will not have top of the line, grade A1 industrial bearing fitted in the headstock. Is the thread in your existing chuck changeable? If so, I would go that way.

Also, have another look at your set-up. It the lathe well held in place? You could either bolt the feet down (put a rubber cushion in-between the floor and the legs if bolting to concrete) or build a sand-box under the shelf in-between the legs to add extra, vibration absorbing, mass. (Really dry sand is the best for this and will be much more effective that wet sand).

If you are still stuck, as I said on the other thread, give either Colwyn or Jason at the APTC shop a bell and they will be able to sort you out I am sure.

BRgds
Simon

 

[Guest]

Thanks Simon, that is really the answer to my question. I did realise that the distance from the headstock would cause a problem and I can fit a new backplate but the tool devil was sitting on my shoulder urging me to buy a new chuck, but as you say the lathe is probably not of a good enough quality to carry the weight.