8mm live centre

[LainchyParticipant @lainchy]

I have a Chester DB7 lathe, with adjustable tailstock, and I also have a tapered conrod to machine.

I decided that I didn't really want to move the tailstock from alignment, and the next best thing was to fit my boring head, and offset that, BUT… that only has 8mm tooling.

OK, so I got on eBay, and bought what was descibed as an 8mm live centre Result. That came, and it's only the centre, from a live centre… with an 8mm spindle. So… I'm decided to try and construct a live centre from it as best as.

I have some bearings now… sealed ball bearing, and some thrust bearings. I need to turn a holder for that, with an 8mm spindle to go into the boring head. I'm used to R/C heli blade grips and the bearings within, so…. why not?

Has anyone done this, or something like it?

Pictures below of what I got through the post, and the bearings I'm going to fit.

Cheers

Ian

[LainchyParticipant @lainchy]

[EmgeeParticipant @emgee]

I think you would be better off with a length of 8mm diam silver steel, long enough to allow 2 bearing support with a spacer between the 2 bearings to provide better support, allow enough material at the front for your centre to be machined on the lathe.
Harden and temper before assembling and fitting into the adaptor to fit in your boring head tool socket.

Emgee

[Bob StevensonParticipant @bobstevenson13909]

[Paul KempParticipant @paulkemp46892]

I feel very old now! When I did my apprenticeship live centres were about as common as rocking horse droppings! We had dead centres and a tin of tallow. I think I would stick that point in my boring head, spot of grease and off we go, if it's only one rod. If it's a run of them, ok it might be worth the effort.

Paul.

[JasonBModerator @jasonb]

It is a live ctr if you hold it in the chuck, you should have bought a revolving ctr. You could just use it as a dead ctr in your boring head with a bit of grease

[Michael GilliganParticipant @michaelgilligan61133]

Posted by JasonB on 14/11/2019 07:07:33:

It is a live ctr if you hold it in the chuck […]

.

… and next to useless there, unless the chuck holds it concentric

MichaelG.

[LainchyParticipant @lainchy]

Thanks guys. I have two of these centres, so I think I'll have a go anyway, as it'll be good practice machining for me, and if it's no good, which looking at the above, it may not be, I'll use the other one with some grease It is only a small centre after all I guess.

Interesting video link though Bob, I'm sub'd to that chap already and enjoy his content, although I've not seen that one.

[JasonBModerator @jasonb]

Posted by Michael Gilligan on 14/11/2019 08:58:44:

Posted by JasonB on 14/11/2019 07:07:33:

It is a live ctr if you hold it in the chuck […]

.

… and next to useless there, unless the chuck holds it concentric

MichaelG.

Really, I do it all the time, just skim the taper each time and don't remove from the chuck until the job is done, quite common practice. Though not much point is spending out on one when any bar end will do.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by JasonB on 14/11/2019 09:19:57:

[…]

just skim the taper each time and don't remove from the chuck until the job is done, quite common practice. Though not much point is spending out on one when any bar end will do.

.

Exactly, Jason … it’s next to useless when any bar end will do.

[BazyleParticipant @bazyle]

There is also the point that a 'live centre' should be soft material so it can be skimmed and the 'dead centre' hard so it doesn't get deformed by the job rotating on it. Until you let it overheat when it gets relegated to the other end.

[LainchyParticipant @lainchy]

Well, that's tonight's little job complete. I'll have a go at the S50 conrod next with this to offset. Quite pleased with that.

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