Actual max distance between centers (including chuck and live center)

[Eben Fourie]

Hi

My understanding is that the distance between centers specification is usualy the maximum "theoretical" distance.

Once you add a chuck and live center, this distance is substantialy less.

I would like to get a lathe to primarily turn legs for tables etc.

On a lathe with 900mm center distance, how much would you typically loose by adding a chuck and center ?

+/- 100mm for the chuck and same for the live center ?

Am I correct in saying that the actual maximum center distance you could turn would then be around 700mm ?

Thanks in advance,
Eben

[Ed Morgano]

Eben,
If you're doing spindle work, the head stock usually has a #2 Morse Taper that you can put a spur center in. That will only take up about an inch (25 mm). The live center will probably take up about 2" on the tailstock end. On my chuck, I have an adaptor that extends out past the end of the chuck so the chuck and adaptor take up about 7" (177 mm). Hope this helps. I would also check with the manufacturer of a lathe that you're looking at buying and ask them the same question.

[Eben Fourie]

Thanks Ed, so just to confirm my reasoning:

If you have a 40 inch between centers lathe, and use the spur center and live center, would the actual distance normally be 40 - 1 - 2 = 37 inches ?

Understand your comment about specific manufacturer, just talking in in general.

Newby question: for turning table legs, what are the reasons for using a drive center rather than a chuck ? Purely to maximize the center distance, or is there something else ?

[Jon McElwain]

A chuck is generally used for a turning that will at some point be supported only at the headstock, without tailstock support. In the case of a table leg, these would typically be turned from start to finish between centers, so you would not need a chuck to hold the piece. Of course, a table leg could be held at the headstock end by a chuck. However, by using centers, you can finish the table leg all the way to each extremity of the leg without interference.

[Eben Fourie]

thanks John, that makes perfect sense