CNC vs. standard point live center

I've got a manual lathe I've been looking to get another live center for. I have a junky one I use for basic stock removal and reserve the Royal I bougt new for more high accuracy work. My beater center was never that great thus I'm looking for a replacement. SI've been looking at "quality imports" like a Skoda. I keep seeing both "standard" pont and "CNC" point configurations. For a manual lathe I see the benefit of increased clearances to the part when turning to the end of the shaft. It looks like the longer more slender CNC nose would sacrafice stiffness, and thus repeatability when turning work with different depths of cut.

Don't exactly know what I'm giving up, if anything. Any insight into those that have used both. Tradeoffs or shortcomings... is there a new world I'm missing because I don't have one.

I like my CNC point center. You might also consider one of the interchangable point live centers, which adds some useful variations.

Larry

You might give these folks a call first if just the point in your center is bad. Their website advertises that most dead or live centers can be reground for $7.00. I don't have any first hand experience with them though, but I did speak with him on the phone the other day about a #4 1/2 to #3MT spindle adapter and he seemed like a pretty good guy. BTW he said that adapter would be about $75.00 in case someone reads this that needs one.

Miller Machine & Fabrication

Skoda makes a good revolving centre.What ever make you pick check what maximum rpm it`s good for.I don`t know where the cnc point description started from as we were using these extended point centres on manual machines long before cnc became common.The choice is yours but unless you are turning parts weighing tons I would go for the extended point version otherwise you are forever limited in the shape of the tools you can use close to the centre.
Mark.

oliverdude said:

You might give these folks a call first if just the point in your center is bad. Their website advertises that most dead or live centers can be reground for $7.00. I don't have any first hand experience with them though, but I did speak with him on the phone the other day about a #4 1/2 to #3MT spindle adapter and he seemed like a pretty good guy. BTW he said that adapter would be about $75.00 in case someone reads this that needs one.

Miller Machine & Fabrication

Click to expand...

I've had Miller Machine regrind a live center as well as do some other work for me. They do quality work and I highly recommend them.... Ask for Brian.

alg4884

Forgot to mention....

J&L has Skoda "CNC" live centers on sale until, I believe, the end of July. Saw them listed in one of their two latest special flyers on their website.

alg4884

I've been using the Enco "Made in USA" cnc-point center on my South Bend, with very happy results. For big cuts on the Pacemaker I stick to a regular center.
Mark

i Just bought the #4 extended live center (import)
It is in the 08 wholesale tool catalouge
i think it was ~35$ because of overstock
but the want over 100$ in enco

cody

i checked it with dial indicator and the runout was under .0005

Well last year someone here mentioned Nakane live centers(made in Japan) and I've been extremely pleased with the Mt2 size I bought. Runs super smooths, but doesn't have an extended nose or any such thing although some other models from Nakane might. Next time I order from MSC I'm getting a few more as spare, you know.. for the next 40 years or so.

I would have to add another vote for the CNC extended point centers. They really come in handy on small diameters. I do admit that on larger diameter work I switch to a conventional center. Skoda is good.

I wouldn't get too carried away stocking up on spare non-consumable tooling. The next thing you know you will be upgrading to a different lathe and then you will have a mound of N.O.S. stuff to put on ebay. Don't ask me how I know.

The center in question came with my 13" Colchester and doesn't provide consistent cuts.
If I set 0.050 as a DOC, it will taper at the tailstock end with say 0.038 of actual material removed. A lighter cut of say 0.010 DOC would provide less taper but still only remove 0.008 of stock. Center is basically deflecting away from tool due to cutting forces. Bigger cutting forces, more deflection. Makes it very challenging to get things to size. When I work with my Royal center which I got new, my lathe cuts straight and consistent without taper on long cuts. My guess this old live center will need bearings and a point regrind. Frankly it isn't worth the effort.

The CNC point appears to be a bit of a misnomer. Thanks for the feedback that they provide added value for a manual machine. I don't turn anything massive on my 13" machine so I'll definitely look into getting one. When using TPG inserts, I have on more than one occasion been a bit cramped at the tailstock end when turning at the very end of the shaft.

Enco has a Royal CNC point spring loaded center on sale for basically what their non-sale price is for a Skoda. I like the idea of the bearings being inside of the morse taper body keeping the exterior profile slim.

I'll check J&L as well.

Thanks again for sharing your experience with me.