Myford chucks

[Mark Millward 1Participant @markmillward1]

How far should chucks go onto the spindle thread of an ML7 ? Put another way, how many turns is a minimum ? None of mine go fully on and all seems very clean.

Mark Millward

[Mark Millward 1Participant @markmillward1]

[Clive HartlandParticipant @clivehartland94829]

Mark, they should go right up to the face of the mandrel.

If they do not then re-clean the male and female threads and try again.

If you still have trouble then using a cotton wool bud apply a smear of blue on the male thread and plain part and see where it is catching.

I have noticed on my 3 jaw chuck some slight scrape marks inside the plain part of the chuck body as if someone has relieved the plain part!

I dont use any lubricant on my chuck threads at all. The only part I clean and lube is the scroll and jaw teeth. For this I use a stiff graphite grease.

Under no circumstance try and force the chuck onto the mandrel, it should go very easy if clean.

 

Clive

[Tony Pratt 1Participant @tonypratt1]

The chuck should screw on until the chuck register face meets the spindle register face, the threads shouldn’t bind at all.

Tony

[Chris TriceParticipant @christrice43267]

Are the chuck bodies threaded or are they fitted to a backplate? If a chuck backplate has been machined too thin, the spindle nose can protrude through it and contact the rear face of the chuck body stopping it screwing fully home.

[David Clark 13Participant @davidclark13]

Hi Mark

Take the chuck of the backplate.

Does the backplate go right up to the shoulder?

It should do.

regards David

[Mark Millward 1Participant @markmillward1]

Thanks for your replies. I have spent ages cleaning the threads and things are getting easier. I believe a bit of aluminium swarf got in the thread and caused the binding. I should like to run a tap and die over the threads but they seem a bit expensive so will persevere with the wire brush and magnifying glass. Thanks again.

Mark

[KWILParticipant @kwil]

Mark,

 

You can make a thread cleaner for the backplate from a piece of piano wire, a long half loop with the ends turned outwards, with enough spring to push into the bottom of the threads, but not that much that it scratches the metal. I am not as keen as Clive on no lubricant, a trace of sewing machine oil should suffice. I have the taps but I do not suppose you are anywhere near.

[Chris BParticipant @chrisb73862]

I used a 4″ nail bent into an L shape, the point gets into the root of the thread and will displace any swarf when you run it round the thread.

[The Merry MillerParticipant @themerrymiller]

 

I use a small wooden backed brass wire brush that effectively screws itself into the thread and out the other side.

 

 

[Author]

Posts