Live centres

[SignalFailure]

I have a live centre* that came with my mini-lathe 'bundle' but have never had occasion to use it, in fact I didn't really know what it was for! Googling tells me that it is commonly used in CNC and allows higher speeds and greater clamping pressure with no lubrication.

Does it have any use or advantage over a dead centre in day-to-day turning operations or any other application?

TIA

Paul

*Read 'center' if you are longitudinally challenged

 

[kustomkb]

A live centre will not overheat or marr the job as a dead centre might. Always use one when your job protrudes more than 3 times diameter. longer work will deflect away from the cutter resulting in a taper with a greater chance of chatter. For very thin work I have made a live chuck for the tailstock to pull the work taught rather than push which has worked very well too.

 

[Lew Hartswick]

For very thin work I have made a live chuck for the tailstock to pull the work taught rather than push which has worked very well too.

How do you keep it from pulling out of the taper in the tail stock? sounds like it would be very nioce
for slender rod work BUT????
...lew...

 

[Tin Falcon]

I use my live centers almost exclusively. I was taught to use a dead center for knurling . Dead centers are best limited to low rpm high load jobs.
Tin

 

[rake60]

I've never used the dead center at home.

In the soft metals such as brass a dead center will quickly wear
wear on the center drilled 60 degree.

Come to think of it, I've never used a dead center at work either.

I have played with the Extream Pressure Grease that is to be used on them.
Smear a little of that under the pull rail of a coworkers tool box and it's GAME ON!
Permatex Prussian Blue does create a more lasting game, but that's
just being mean! I've NEVER done that!

Rick

 

[BobWarfield]

Just for completeness of the thread, live centers sometimes have a reputation for being less accurate than dead centers. Not sure how true that is anymore, especially if you get a good quality live center. Skodas are good quality and cheap. Seems like I saw them on sale at Enco recently. I have a Royal I bought used off ebay that is extremely accurate.

Cheers,

BW

 

[kustomkb]

How do you keep it from pulling out of the taper in the tail stock? sounds like it would be very nioce
for slender rod work BUT?

with a clean undamaged taper and a good smack, it stays in there pretty good. Just a little pressure and lock the tailstock and you are in business. I just moved and dont have my shop or computer up and running, I'll post a picture when I do.

-Kevin

 

[Circlip]

Why risk burning the tip of a dead centre (center) if you have a live one Paul ?? Last time I used a dead centre (center) was as a "Wiggler" to centralise a bore centrepop, Regards Ian.

 

[alan2525]

I'd steer clear of the cheap Chinese or Indian live centres...those are the ones that sound like a pepper mill when you turn them by hand...

 

[Julian]

Hi All,
I only use live centres. First time i used the dead centre supplied with the lathe it burnt and damaged the work. Not used one since. Not found any problems with accuracy. They are either chinese or indian but no noise atall.



Julian.

 

[BobWarfield]

One other thought. My Royal is a pleasure, as I mention, but the tip of it is not small relative to small model engine parts. Here it is while I was trying to use it to make some connecting rods a little over 1" long:

Take a look at that tool and imagine starting a pass on the right (my lathe only feeds towards the spindle). I'm kinda stuck there between the live center and the collet. I've got the tool jacked way out and angled, but I still can't access the whole length of the workpiece.

I wound up not using the live center. No harm done, but I did have to be extra careful and take lighter cuts and I did screw up a couple parts while I was working out what I could do.

Along comes my latest Enco catalog with something they're calling a Royal "CNC" Live Center on sale:

Note the little extended tip. That little goodie would've given me the extra clearance to make this job work. The CNC model is also spring loaded to automatically maintain proper pressure, and TIR is half a tenth.

I love my existing Royal live center is also a Royal, so I'm tempted to at least consider one. Still not very cheap even on sale: regular price is $215 and the sale price is $172. Not sure if its worth that much to me, but I do keep thinking about little bitty parts!

I looked for one like this from Skoda or Bison, but theirs are just the same as my original Royal.

Cheers,

BW

 

[mklotz]

Bob,

You might want to consider getting a live center set with interchangeable points. Prepare yourself for all those weird jobs that are sure to arise.

Here's the one I have.

http://www.use-enco.com/CGI/INSRIT?PMAKA=251-3020&PMPXNO=2984208&PARTPG=INLMK3

No, it's not a Royal but it has the tiny tips to solve your problem as well as female centers and a pipe center. All the tips are taper mounted so a clever guy could even make up specialty tips for that *really* weird job.