The 3-jaw chucks never run exactly true which is why most machinists use a 4-jaw. The three jaw is OK for those quick and dirty jobs tho. Brand new very high quality 3-jaw chucks will repeat fairly well tho and are used on a lot of NC equipment for production work. I spent two years in a big tool and die shop on large engine lathes, and moonlighted in another one.

 

Torque is right, but a three jaw chuck works just fine for most things. Once the workpiece is cut it runs true. You may get some runout if you take it out of the chuck and put it back in again. All depends on the job, which to use.

 

That is why most machines will run a 4-jaw. A 3-jaw works for some things but a 4-jaw works on everything except hex stock. It is a pain to change chucks. Once you learn how to run with a 4-Jaw you never look back.

 

Well, I guess I better learn how to run a 4-jaw, huh? heh-heh.

I really want the 3-jaw on to start with, just because I don't have to deal with centering objects I intend to turn down for experimental reasons as I become familiar with the machine and it's operation. I have a pile of 1/2" steel dowel scraps that I wanted to play with threading, putting on a smooth finish, and so on.

The saddle is loose. I can't budge it by hand, but if I put a cutting tool in it and put it against the material I'm cutting, I can get it to wobble or tilt. Maybe I'm applying too much pressure with the tool?

 

Go to the library and check out some books on lathes. In the meantime get a machinist to come check out your toy and show you a few things.

 

Got the 3-jaw installed

http://frederic.midimonkey.com/yard-lathe-3jaw.html

 

Good for you, but learn to use the 4-jaw when you can. Set up on the 4-jaw is easy and quick once you learn how. Since the 3-Jaw is essentially new it should run fairly accurately tho.

I start taps in my drill press also but I just use my hand to twist the drill chuck. My main home drill press does have a very low speed setting but it does not reverse so I don't use the motor to power tap. I have used other drill presses and mills to do that tho. Maybe I will replace the motor sometime with one that will reverse. The one that is on the press can not be reversed with the wires available.

I have another press that does reverse but it is a very light duty model somewhat similar to but much lighter duty than:
http://www.atm-workshop.com/radial-drill.html
The head would have to be indicated in and it does not have nice slow speeds. I do use it for drilling out broken bolts etc with left handed drill bits since it is much better than hand drilling.

 

A friend of mine explained in extreme detail how to use the 4-jaw correctly, and the problem (for me) was I was trying to do it by feel, by eye, and with a tape measure. So once I acquire a dial indicator of some sort, I'll be able to use the 4-jaw as the dial indicator will help me center the material in the jaws. I tried nudging the jaws to find center but clearly that's not the way to do it as an inexperienced amatuer .

I turned the drill press by hand because the bench drill press doesn't turn slower than 600 RPM, which is way to fast for a 1/2" tap into a thick lathe chuck. The last thing I wanted to do was break the tap in the chuck. I could have used my floor standing, variable speed delta as that goes down to 150 RPM, but I have it set up and jigged for a project and I didn't want to mess with any of that stuff until I finish making that project.

MSC carries a $75 tapping stand which I've been meaning to purchase, which comes with two collets for larger and smaller taps.

A radial drill is a nice thing to have... it's another thing that was on my list for a long time, then I got the floor standing X-drive Delta and used the funds for that. I was looking at a Grizzly also, and if I recall correctly it's reversable?

While looking around the garage floor for steel pins I made before I got the lathe, I found three rotary optical encoders. I see a DRO in my future.

I also discovered something neat about the lathe... there's a lever that engages the lead screw so that the saddle moves side to side for threading. I moved a lever next to it that's been "stuck" and if the lead screw is engaged in the gearbox, it moves the saddle across the width of the bed instead, also in either direction. Made turning the brake rotor I was experimenting with that much easier (Hey, I'm desperate for material to play with!). The rotor is now nice and smooth, even though it's never going to see time on a car since it's been cut twice before I started playing with it. Was just experimenting with settings, levers, tooling, and so on.

Next I have to learn how to sharpen the carbide blocks. I unfortunately overheated a few of them and dulled them. I've been using the triangular carbide tips in a different cutter holder which is adjustable, thus really useful. My cousin's coming this weekend and going to help me out a bit... he spent 5 years running a lathe for a small shop until he got his accounting degree. Maybe I'll have enough time to weld together the coolant tank so I don't burn anymore cutters or cover myself and my garage with chips. Cutting the backplate flung chips everywhere!

I *really* like this machine a lot. I thought the saddle was loose and warn out, but there are six allen bolts that adjust these "feet" for lack of a better term that makes things tighter, so the saddle doesn't wobble anymore.

Thanks for your help and comments Torque... I'm really enjoying this machine... at this point I could turn things just for the fun of it

 

An indicator is required for 4-Jaw use. Also use it to check your 3-Jaw for accuracy. The "feet" are called gibbs. Your cousin should be a big help. A lathe is an incredibly versatile tool. For carbide you need the proper grinding stone. Usually green in color and uses powdered diamonds. There may be other materials but that is all I have ever used. Set up a small dedicated grinder and keep it covered with a big sign "For Carbide Only" on it. I try to use insert tooling only, I have had my fill of grinding cutters. Getting the feeds and speeds set right as well as tool geometry will help control chips and avoid dulling cutters. Coolant is not required for most operations and if you use it only occasionally it is a pain. DON'T SPIT IN THE COOLANT!!!! Cutting oil helps when threading.

Another tip you will not see often is to set the compound at 29° when threading so the chip load is only on one side of the cutter. This helps avoid breakage and erosion at the tip. Also remember that threads have a flat in the root and grind your threading cutter appropriately.

Get yourself a book on lathe operation.

Tooling for a lathe is often more expensive than the lathe itself.