Getting the workpiece straight in the chuck.

[kd4gij]

A few years ago I saw franks tool on his web site. So I found a good use for those useless single wheel knurling tools that come in tool sets. Replaced the knurl with a bearing.

 

[DAT510]

What part of the work piece are you trying to machine? If it's the end, then as others have suggested a steadyrest would be a way to go, since it sounds like piece is too big to fit through the bore. If it's the "side" of the work piece, what about mounting it between centers and using a dog drive?

 

[Tailormade]

If you have a steady rest set it up for anything long .
I don't know what size lathe you have but it is most
Likely a small lathe like my 10" swing Clausing 4900

It's a 12X36, but its headstock has a pretty narrow openning, so I assume I'll be getting to know that steady rest pretty well.

Don't run any work in a steady rest very fast no faster than your back gear will run .

I'm pretty sure the prior owner didn't listen to that advice, the arms on the steady ready rest are.. a bit rough at the ends. I don't see any indexing on the arms, can I just dress up the ends of the arms or must they be replaced? On that same topic, are those steady rest arms with bearings on the ends worth having?

Here's a method I adopted from my master machinist friend, who learned this from from old time master machinists 35 yrs ago when he was starting out in the trade.

Loosely Chuck up your part in the three jaw, and turn on your machine at slow speed (50-100 rpm or thereabouts).

Lightly tap the high part with a light hammer 2 or 3 times as it spins around.

After you get the hang of it, this will true up the part 9 times out of 10. If not, loosen and repeat.

Tighten up the chuck enuf to hold the work.

I hardly ever use a dial indicator with my three jaw now, after I learned how to do this.

Glenn

I'm going to give that a try with a wooden mallet tonight, thanks.

A few years ago I saw franks tool on his web site. So I found a good use for those useless single wheel knurling tools that come in tool sets. Replaced the knurl with a bearing.
View attachment 232689

I haven't seen a tool set with a single knurl, what makes them useless? Of course with the existence of google and ebay now I've seen many of them. Still not sure why useless.

What part of the work piece are you trying to machine? If it's the end, then as others have suggested a steadyrest would be a way to go, since it sounds like piece is too big to fit through the bore. If it's the "side" of the work piece, what about mounting it between centers and using a dog drive?

Thanks for mentioning the lathe dog. I'd heard the term turning between centers but not understood how it would be done.

 

[Frank Ford]

I haven't seen a tool set with a single knurl, what makes them useless? Of course with the existence of google and ebay now I've seen many of them. Still not sure why useless.

NOT useless, but quite useful! Great for straight knurls on the lathe to avoid double-tracking, among other regular uses.

Here's an irregular use, renewing the knurling on a bar clamp:

 

[dontrinko]

I use the tail stock to put a little pressure on the work as I tighten it. This helps but I still end up trying several times until I get it close.
If you are not using the part that is in the chuck you can turn the extended part and it will end up round even if you do not have it perfect in the chuck. I have done this on long pieces: turn one end then turn it around and turn the other. This helps if the work is not perfectly round to start with. Don

 

[jlsmithseven]

Sorry for asking, but what exactly does this little wheel do that touches the piece. Is it meant for tool height or runout of the piece? I am just a little confused on how this little tool works, but it looks like a good tool to have?

 

[428Bird]

I use a centering roller mounted in my tool post:

Here's the full deal: http://www.frets.com/HomeShopTech/Tooling/CenteringRoller/centeringroller.html

Just bookmarked your page. Awesome stuff!

Britt

Sent from my SM-G935V using Tapatalk

 

[mikey]

Sorry for asking, but what exactly does this little wheel do that touches the piece. Is it meant for tool height or runout of the piece? I am just a little confused on how this little tool works, but it looks like a good tool to have?

It's just a bearing mounted on a piece of square stock. In use, the work piece is mounted in the 3JC and lightly snugged. Then the lathe is run at low speed and the bearing is gently brought into contact with the work. Initially, only the high spot contacts but as you slowly feed the tool in, the work is brought into relative concentricity with the spindle and you will see the work start to run true(r). At that point, you stop the lathe and tighten the chuck firmly and you're set.

This works for shorter pieces or even thinner work like a washer that you're trying to get to run true in a 3JC (you bring the tool into the face of the washer). It is not a precise method but it is better than nothing. Its actually a good tool; I've had one for years but I cannot recall who came up with the idea to use a bearing. An old machinist friend of mine used a piece of maple with a rounded end that worked just as well.

In the case of the OP, this tool would not be useful due to the length of his work piece. A steady rest and a dial indicator would allow him to center drill for live center support but that has been discussed already.

 

[jlsmithseven]

Oh so you're saying loosen the chuck jaw a little bit, run it at like 35 rpm or something and it will true it up and then just tighten the screws. Sounds simple and awesome, not sure if I will be able to do that though.

 

[benmychree]

Not always necessary to turn a blank piece to line up the steady rest; I just get it close, then put a center drill against the shaft end lightly and see what trace it leaves on the shaft end if not on center, then adjust the SR jaws until the center drill hits the shaft dead center and drill the center hole, With a bit of practice it is easy and quite accurate. There is nothing wrong with running things fast speed in the steady rest as long as the jaws are not overly tightened and a lubricant is used; way oil, center lubricant, white lead or whatever is at hand. If the jaws are roughed up, they can be re machined. I have thought of using a hand reamer in the spindle and carefully adjusting the jaws, one at a time against the rotating reamer, but have never tried it; same could be done using an end mill, the more flutes the better.