best way to fix chuck?

[mick70Participant @mick70]

[mick70Participant @mick70]

i am getting a southbend 9" model c in 2 wks.

among the chucks i have been given for it is pratt bernard 4 jaw independant 6" chuck threaded for myfords.

not sure best way to fit it.

1 get blank pce of 6" rd steel and turn stub on it to match chuck so i basically have a reverse backing plate then bolt it to a southbend backing plate.

2 get pce of 3" 0r 4" rd drill and thread one side for southbend and turn top section to match chuck.

there are no holes in chuck for mounting a plate to and worried if i drill into it i might ruin it.

any ideas or suggestions welcomed.

[JasonBModerator @jasonb]

Just bear in mind the more backing plates and adaptors you start to add the further the chuck and therfore work will be from the headstock bearings and you will put more strain on them and get a less ridgid setup.

Option 3. sell it on and put the money towards one that will fit your lathe.

J

[Swarf, Mostly!Participant @swarfmostly]

Hi there, NaughtyBoy and Jason,

Have you actually set eyes on the 4-jaw chuck yet?

The Burnerd 4-jaw chuck with the Myford ML7 thread is fairly slim (I guess that's its raison d'etre) but because it's threaded to fit the mandrel nose directly it doesn't need or have a register in its rear face.

It might be argued that there is a register, i.e. the one to fit the Myford mandrel nose BUT that's probably smaller than the mandrel nose of the 9" SouthBend. So making the centre hole of a 9" SouthBend fitting back-plate will remove the material that would have made the male register for the chuck! (If that's confusing tell me and I'll try again .)

So I agree, it's option 3.

(But, if the particular chuck concerned does turn out to be the general purpose (i.e. not ML7 specific) version that does have a separable back-plate, then it'll have a register and we're back to option 1.)

Best regards,

Swarf, Mostly!

 

Edited By Swarf, Mostly! on 01/05/2015 15:35:20

[JasonBModerator @jasonb]

I thought option one was to machine a male threaded stub onto the bit of steel to screw the myford specific chuck to and then bolt that to a female threaded southbend backplate.

Option 2 is smallerf dia bit of bar with myford make thread on one end and southbend female on the other

 

J

Edited By JasonB on 01/05/2015 15:45:56

[Swarf, Mostly!Participant @swarfmostly]

Hi there, Jason,

Yes, sorry, a slight attack of brain-fade on my part there!

I should have written 'option 4, conventional back-plate'.

Best regards,

Swarf, Mostly!

[mick70Participant @mick70]

no register on back, and it is slimline version.

might have ask around see if anyone with myford is interested in swapping for another one i can bolt to backing plate.

if i do sell it what sort of price are they going for?

[mick70Participant @mick70]

you answered whilst typing jasonb but yes pics show what i was thinking.

just been and checked it as four big hollow sections in back so bolting through it is out.

[JasonBModerator @jasonb]

Well I paid about £100 for a similar second hand Bison slim/lightweight backplate mounting one, the myford ones go for a bit more from dealers depending on condition.

Edited By JasonB on 01/05/2015 16:09:22

[RobboParticipant @robbo]

If you are near to Preston, Lancs, I have a nice clean Pratt Burnerd 4-jaw for backplate fitting that could swap for yours.

Postage/carriage is expensive as they weigh about 6 kg.

[mick70Participant @mick70]

Robbo am near leeds but couple of guy's at work are from over your way , will speak to them next week when back on shift.

will get someone at club to double check this one out but wont be till after harrogate im afraid.

[RobboParticipant @robbo]

No rush, this one's been sitting round for months since I stripped and cleaned it – it was previously used on a woodworking lathe, so was dusty not rusty.

Send me a PM when you're ready.

[Boiler BriParticipant @boilerbri]

My Hermes £7.28 for 5-10kg. Pretty reasonable and reliable.

No connection.

Brian

[mick70Participant @mick70]

Posted by Boiler Bri on 03/05/2015 02:30:09:

My Hermes £7.28 for 5-10kg. Pretty reasonable and reliable.

No connection.

Brian

worth knowing

thanks

[RobboParticipant @robbo]

Please have a look at your messages, naughty.

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