Thread: 4 Jaw Chuck Question

I've recently been given an older little metal lathe, it came is a 100mm 3 jaw chuck.

I am looking to purchase a 4 jaw independant chuck for it. The backing plate on the lathe has 3 holes not the more common 4 hole layout.

I am struggling to find a 100mm 4 jaw with 3 mountng holes. Can anyone suggest an online supplier? or should I look at replacing the faceplate as well?



I've attached the only pic I have of the lathe at this stage.

IMG_7775.jpg

If the mounting plate that the 3 jaw chuck bolts too is able to be removed from the spindle you could either drill 4 new mounting holes to suit the 4 jaw or just make or get made an new backing plate to suit the chuck and spindle.
Not sure of your type of mounting but if you wanted to often change between the two it would be better to have the chucks mounted to their own backing plates.

the chuck backing plate is usually fitted to each chuck so you probably need another for the four jaw.

not familiar with these lathes but I assume the chuck/backing plate will unscrew.

That looks like the BV 20 Chinese lathe I started with a while ago.The chuck backing plate is a fixture to the spindle(don't bother asking how I found out!) I had to turn up an intermediate 4 holed plate to fit the 4 jaw .Three additional holes were then added to match the non detatchable backing plate.Never worked out why they made them like that.

Was on my way to post this in the Ebay / Gumtree thread but figured might put it here also since your looking for a 4 jaw and in Melb

https://www.gumtree.com.au/s-ad/chel...cks/1181539665

Might have something that could be of use ?

Originally Posted by MasterSpoon

Was on my way to post this in the Ebay / Gumtree thread but figured might put it here also since your looking for a 4 jaw and in Melb

https://www.gumtree.com.au/s-ad/chel...cks/1181539665

Might have something that could be of use ?

Thanks, ofcourse I purchased a chuck online 2 hours ago! Might still check them out, I can see a larger chuck coming in handy in the future.

Originally Posted by Garthrobinson

That looks like the BV 20 Chinese lathe I started with a while ago.The chuck backing plate is a fixture to the spindle(don't bother asking how I found out!) I had to turn up an intermediate 4 holed plate to fit the 4 jaw .Three additional holes were then added to match the non detatchable backing plate.Never worked out why they made them like that.

That sounds right, I think I have the same issue, what material did you use for the adapter?

I guess that is the reason I was struggling to unscrew it.

Originally Posted by Garthrobinson

That looks like the BV 20 Chinese lathe I started with a while ago.The chuck backing plate is a fixture to the spindle(don't bother asking how I found out!) I had to turn up an intermediate 4 holed plate to fit the 4 jaw .Three additional holes were then added to match the non detatchable backing plate.Never worked out why they made them like that.

A friend with a small engineering business turned it up on his lathe out of a piece of mild steel plate.We then fitted it to the BV20 spindle and faced it off.Finally drilled the holes to mount the 4 jaw chuck.