Chuck running out

[Tanglefoot20]

Hello all...
I have just bought myself a 3xact chuck for my old Sealey SM42....wondering if anybody has ever had problems with the spindle of this machine...The morse taper seems to run true but when anything is screwed onto the nose there seems to be a runout on said item.
There isn’t much play in the bearings and runout seems to be rotational rather than on the face...
Wondering if anyone has any ideas ....remedies....aside from buying a new lathe that is.

Steve

 

[Lonsdale73]

Not much help I'm afraid but on reading the headline my mind raced back to my childhood and a Chewits advert with some woman screeching "Come back, Chuck, come back!"

 

[Dalboy]

Make sure that the threads in the chuck and on the lathe are both free of any swarf and that the register is also clean as any dirt swarf on this can throw out the chuck by just enough to notice.
Get in the habit of removing anything from the lathe and cleaning everyday it only takes seconds this ensures they are always clean as well as makes removal of attachments that much easier.

 

[Dominik Pierog]

You need dial indicator to check spindle run-out.

 

[Tanglefoot20]

Make sure that the threads in the chuck and on the lathe are both free of any swarf and that the register is also clean as any dirt swarf on this can throw out the chuck by just enough to notice.
Get in the habit of removing anything from the lathe and cleaning everyday it only takes seconds this ensures they are always clean as well as makes removal of attachments that much easier.

Thanks for the reply...I tried today to check spindle runout....the morse taper runs within 0.001”...but the spindle register is up to 0.008” out. Taking into account the thread limits I used some prefer tape and made a more tighter fit...no difference. I thnk it’s my bad luck the spindle thread is just badly produced...but 0.006” isn’t the end of the world......is it?

Steve

 

[Tanglefoot20]

Not much help I'm afraid but on reading the headline my mind raced back to my childhood and a Chewits advert with some woman screeching "Come back, Chuck, come back!"

Hi there...thanks for the reply...as you say...no help but boy did that make me chuckle....whoops ... chuck all...seriously I found it very amusing...cheers

Steve

 

[Lonsdale73]

By the power of the internet, I bring you Chuck running out

 

[Duncan A]

Is the chuck sitting on the register? It is the register that aligns it, not the thread, and if the spindle thread is too deep for the chuck, it will not come up to the register.
Duncan

 

[Tanglefoot20]

Thanks Duncan, I had a look at that today. Checked face of register and it was true....however I did notice the chuck insert is not sitting back on the face...the bore is near enough same size and the spindle register runs out....thread variation causes chuck to skew. I made up a washer to sit over the spindle and against face.the chuck jaws ran within..0.003”....with a prefix wrapping the chuck still ran out 0.006”.could be it’s too accurate for the old lathe...

 

[Duncan A]

I wouldn't worry about a few thou. In my experience most woodworking chucks (and lathes) are not very accurate when compared to engineering chucks but wood is a pretty unstable material so not a big problem usually.

Hope it's OK now

Duncan

 

[Tanglefoot20]

Thanks Duncan...I think I may try making a washer up with a register running true....but as you say a bit of runout is not the end of the world..as long as I have something to grip and turn safely.....result!
I’ve not done too bad Upto now.....hehe

 

[MusicMan]

As Duncan says, the threads are not required to be accurate (though they sometimes are). Try cleaning out the threads more - maybe get a chaser - so that the chuck screws up to the register (and is also a close fit on the shaft).

Having said that, it is only a three-jaw chuck which one does not rely on for accurate centring. You shouldn't use this for wood though, other than very light skimming work. Since wood compresses easily, a catch on a tool can quite easily dislodge work from a three jaw chuck and direct it rapidly at your face.