Turning between centers, the why.

Seems strange to make apprentice engineers take their fancy 3 jaw chucks off and use old style drive dog, the old methods are sometimes the best. Here is a quick demo showing how using centers and a drive dog can allow you to maintain concentricity in a part even if you have to take it out of the lathe.

[@garyreisdorf1363]

In addition, one end may be machined to spec the part turned end for end, using copper sheet to prevent lathe dog damage to the part, then machine the other end exactly concentric to the beginning work. This process works great in a cylinder grinder as well. Best regards I would encourage the making of additional videos.

[@h11cwg]

I had no idea what this technique was, but had been told I needed to use it for a particular job. Thanks to you I now know what it is, how to do it and why I should do it. Very concise and very helpful - Cheers!

[@bilbo_gamers6417]

i love the four jaw chuck because it allows me to do facing cuts and take stuff out and put it back in again perfectly concentric. i do punch and die grinding as a hobby and i have to machine the Ends of punches a lot

[@dermotkelly2971]

I think in the older days when guys just had center lathes only one guy did roughing out in a 3 jaw or 4 jaw and then it was past on to a guy on another lathe guy who finished between centers and that was how production was done years ago.

[@ypaulbrown]

I had never thought of the advantage of being able to remove part and then replace.... and have no runout.....thanks so much.....Paul in Florida, USA

[@macrokamusic5971]

Nice, I used to work with a metal lathe that got custom built into a wood lathe and used to do my bed legs like this. Now I'm a metal machinist and didn't even think of doing this with metal. Cheers, thanks for the video and reminding me of this technique

[@m.a.p.4hp737]

I bet this technique is older than your lathe. Great demonstration. Thank you.

[@samehdarawshi3537]

exactly the video i was looking for. much appreciated. became one of your sybscribers

[@danielmoore2555]

Always wanted to try it out never had the chance at work but there's been a few instances where it would have saved a heap of time. The face that you can take the part out and turn it around is a big plus. Especially on pins that are one dimension all the way along. Had to take thou off the whole length of some 3" pins. Fiddling with ally in the jaws of the 4 jaw and only being able to grab the big heavy pin in the tips of the jaw caused a lot of teeth gritting 😂

[@RustyInventions-wz6ir]

Just found your channel and subscribed. Very nice work.

[@MeetAnEcoregion]

Timeless. I suppose this isn't too different from how the first lathes functioned - just a belt spinning the work directly between two dead centers to guarantee concentricity - and from that, an entire host of machine tool parts and the birth of the industrial revolution.

[@cdrive5757]

Hence, this timeless quote: 'The Lathe is the only machine capable of reproducing itself". I don't know who that was but it's been kicking around machine shops my entire life and I'm 78. Wakodahatchee Chris

[@ikkiiiieee]

Can you remove the dog when you would put it on the mill for example and the put the dog back on it, put it back in the lathe and it would still be concentric?

[@mechanntraining4115]

Thats the advantage! the concentricity is provided by the centres at both ends, to dog just transmits the drive, so you can take it on and off as much as you need to.