Need help machining chuck backplate

[Iain GordonParticipant @iaingordon81374]

My chinese 9×20 lathe came with a 4 jaw chuck that is worse than useless. so I need to get something decent to replace it. This means having to bore and thread a backplate casting 39 x 4mm. This is beyond my skill level.

Is there anyone in the Leeds / Bradford area willing to machine this for me?

Many thanks,

Iain

[Iain GordonParticipant @iaingordon81374]

[RICHARD GREEN 2Participant @richardgreen2]

Hello Iain,

Did you buy the lathe new ? if you did, I would send the 4 jaw chuck back and ask for a decent replacement.

Richard.

[Iain GordonParticipant @iaingordon81374]

Hi Richard,

I did buy it new, but that was about 13 years ago. I've struggled along with it but now I would prefer to get something decent. I believe that this particular style of chuck was originally meant for wood turning lathes.

Iain

Edited By Iain Gordon on 10/05/2016 10:45:58

[JohnFParticipant @johnf59703]

Ian look at your PM John

[JasonBModerator @jasonb]

Can you not take the backplate off the existing 4-jaw, give its a skim and cut a new register to suit the new chuck.

[Iain GordonParticipant @iaingordon81374]

second attempt at posting this.

Not possible Jason. The existing chuck is more like a faceplate with 4 jaws in the slots. It's a really crude piece of kit. I'll post some pictures later when I get the chance.

Regards,

Iain

[Iain GordonParticipant @iaingordon81374]

Photos of the 4 jaw chuck. As you can see it quite crude. There is so much backlash in the adjusting screws that it is a really tedious job centering work.

[frank brownParticipant @frankbrown22225]

If this "chuck" is a good fit on the spindle and the problem is the floppy jaws, then turn it into the "new" back plate. This way you can use the good spindle thread. Else your first job is to get accurate sizes of the thread and the register (+-.001" !!). The next job is to get your new chuck and measure its register, its a bit tricky as it will be a small .1" depression about 3/4/5" diameter (depending on the chuck size). This so the chuck body is located centrally before its bolted to the back plate. So the back plate needs a close fitting spigot to align in this depression.

Frank

[stan pearson 1Participant @stanpearson1]

Hi Iain

To be accurate back plates should always be finished on the lathe its going to be used on

Stan

[RobboParticipant @robbo]

If you haven't already done so you will find lots of info on 9 x 20 lathes on Steve Bedair's website **LINK**

[Iain GordonParticipant @iaingordon81374]

Posted by stan pearson 1 on 10/05/2016 22:18:08:

Hi Iain

To be accurate back plates should always be finished on the lathe its going to be used on

Stan, I intend to finish the machining on this lathe. I only need the bore threading and the spindle register machining by someone else.

Iain

[Iain GordonParticipant @iaingordon81374]

Posted by frank brown on 10/05/2016 17:02:03:

If this "chuck" is a good fit on the spindle and the problem is the floppy jaws, then turn it into the "new" back plate.

Frank, that's a good idea, I will give it some thought

Iain

[Iain GordonParticipant @iaingordon81374]

Robbo, I am aware of the late Steve Bedair's site. It is full of very usefull information.

Iain

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