Four into three may be the ticket

[malmac]

I have a small job to do for a friend. I need to cut some 6mm threads into some square section brass. I wanted to do it in the lathe but just did not want to go to the effort of lugging the 4 jaw chuck up onto the lathe.

So I bought a small 4 jaw chuck (100mm) and made a mounting plate for it that slots into my 3 jaw chuck. So for a small quick and dirty job - here is my solution.

The mounting plate is made from an upcycled hub from a small chinese built camper trailer I used to tow behind our motor bike.

I am sure there are other options but I think this will be a useful bit of kit to have on the shelf for small jobs requiring a 4 jaw chuck.


Cheers Mal

 

[T Bredehoft]

Bravo. I think I'd been tempted to chuck the four jaw in the three jaw and go with it.

 

[FLguy]

Me too.

 

[macardoso]

Chucked straight on my mini 4 jaw. Definitely left bite marks. Cheap Chinese cast iron. But its great. I have a 4 jaw scroll chuck for just this purpose.

 

[malmac]

Chucked straight on my mini 4 jaw. Definitely left bite marks. Cheap Chinese cast iron. But its great. I have a 4 jaw scroll chuck for just this purpose.

I would have done that too, but my 3 jaw just did not play - I could not easily adjust the jaws on the four jaw once I had it securely locked into the 3 jaw. That problem, for me is now solved. Lucky for you that you did not have to go to the same amount of trouble I went to.

 

[Mark Needham]

Just on 53 seconds. 1 minute. to change the chucks. Not sure what the problem is. I spend, ( read waste) more time on the crapper. lol

 

[malmac]

My four jaw chuck weighs in at around 45kgs - I can't even lift it without the small crane device I have built to lift off the three jaw and replace it with the four jaw. The downside of having a medium sized lathe. But if I could do it in 53 or even 153 seconds I would not have gone this way.

 

[Tozguy]

Mel, great job, having the trailer wheel hub on hand sounds like a stroke of luck.
Did you size the 4 jaw to fit the hub or did you want a particular size of chuck from the start?
What size 4 jaw is it?
Although I change out my 8'' 4 jaw without hesitation, I can see how handy it would be at times to have a quicker option.

 

[malmac]

Mel, great job, having the trailer wheel hub on hand sounds like a stroke of luck.
Did you size the 4 jaw to fit the hub or did you want a particular size of chuck from the start?
What size 4 jaw is it?
Although I change out my 8'' 4 jaw without hesitation, I can see how handy it would be at times to have a quicker option.

I just wanted really the smallest 4 jaw which is a four inch job. I thought I would be able to just throw it in the three jaw which is about 10 inches across - but did not work well because I could not easily adjust the 4 jaws. I could have made a long reach tool to do the job, but opted for a backing plate.
I just found the old hub on my shelf and thought, aaah this might work.

Have a great day.


Mal

 

[Janderso]

Very nice work!