New Guy with an Atlas 10200 metric lathe

[o0norton0o]

Hi all,
I bought this lathe this summer to do some turning down and threading for a project. It was aluminum material, so I got it done, but the quality could have been better. So after doing multiple turning and threading operations, I was finding the limitations of the machine and it's operator... as follows:

I thought the compound was pulsing ever so slightly, so I tightened the Gibs carefully. I made some more cuts and shortened up my tool as much as I could and it seemed better. A day or two later, my compound again seemed to be loose, which I had trouble understanding since the gib screws had not moved. I took it apart and found plastic gibs, and did some research on them. Honestly, I can't see how these could even be a choice for Gib material but there they are. I've purchased a pair of steel gibs made for this machine. I was wondering if there are any problems with using them and what kind of improvement in performance I could expect.

The other thing I don't like is that there is no reverse on the lathe and I see the benefit of threading away from the headstock with an upside down cutter, but I have 2 potential problems.
1) The motor is reversible, but the 4 pole windings have pairs of wires on 3 poles that have to be split and recombine with different wires on another pole. The Drum switch that I bought have some bonded contact options but there wasn't enough poles on the switch to handle the permutation of changes needed to be made because any two wires that shared a bonded pair of poles in the switch could not be on those same poles to reverse the spin, and if you just removed the bonding arms then they aren't connected for the forward spin. Is there such a thing as a reversible motor that has too many permutations to be used with a switch?? I see all kinds of motors which have much simpler wiring and can easily hook up to a 8 pole drum switch to be reversible, but my current motor while reversible, seems to require a switch with a much larger number of poles to achieve both configurations.... perhaps I'm not seeing the obvious, so I figured I'd ask if the motor winding configuration could be one that doesn't lend itself to a switched application yet still be a reversible motor.

2) I'm also thinking about making a drawbar with reverse threads and a face plate to sit at the bottom of the chuck to keep the screw-on chuck from unscrewing when turning in reverse. I've read both sides of the "unscrewing chuck in reverse" debate online. It doesn't seem like it would be too hard to make a draw bar style retainer for the chuck when turning in reverse. I realize that I would lose the hollow spindle capacity, and that threading operations are probably a pretty slow RPM process too so I might be a little paranoid about crashing into the headstock. I'm just wondering if the draw bar idea has a flaw that I don't yet see?

*I did turn the lathe backwards by hand to keep my cutter aligned with the threads and once I forgot that I disengaged the back gear to back up easier. Then, when I started the next pass, I just about freaked out when the cutter moved out at much higher speed and I just turned the machine off in time for the compound to coast to a stop with the cutter almost beyond the gutter which it had to stop inside of. That close call had me thinking about the video I saw about turning with upside down cutters, away from the headstock...

Thanks in advance for any opinions or suggestions.

 

[DavidR8]

2) I'm also thinking about making a drawbar with reverse threads and a face plate to sit at the bottom of the chuck to keep the screw-on chuck from unscrewing when turning in reverse. I've read both sides of the "unscrewing chuck in reverse" debate online. It doesn't seem like it would be too hard to make a draw bar style retainer for the chuck when turning in reverse. I realize that I would lose the hollow spindle capacity, and that threading operations are probably a pretty slow RPM process too so I might be a little paranoid about crashing into the headstock. I'm just wondering if the draw bar idea has a flaw that I don't yet see?

No need to make reverse threads. As long as the drawbar threads are a different pitch than the spindle nose which I assume is 8 tpi, then the pitch difference will prevent the chuck from unscrewing.

 

[markba633csi]

I think at some point the factory stopped treating the small lathes like a real tool and started regarding it more like a toy.
Hence the plastic gibs, and other cost-cutting measures
If you can post some pics of your motor and wiring I can give some help with the reversing hookup
When you have reverse you don't have to go in and out of backgear when threadcutting

 

[o0norton0o]

thanks, I've read that but wanted to ask it directly to see if I got a different answer based on my particular machine and some quality it possessed that made a draw bar style fixture impossible.

Mark, I'll take a picture of the schematic on the motor and post it once I get past 3 posts..... and I'm allowed to post images

 

[o0norton0o]

I got my steel gibs saturday. I installed them in place of the plastic originals. The tooling seems much more rigid under load. I made some passes on a hunk of mild steel and the whole compound assembly felt rock solid. I used the power feed, so I had one hand adding lube and brushing chips, and the other hand resting on the compound, feeling for any pulsation. Rock solid. One issue resolved

I'm going to make the drawbar mechanism next to secure the chuck for work on reverse direction spin functions, before I work on the switch wiring to reverse the motor spin direction. The cheap drum switch I bought off amazon won't work for my motor's wiring. When I get to that stage of the work, I'll post the wiring diagram for the motor and the switch...

 

[o0norton0o]

I made 2 draw bars style mechanisms to secure the screw on chuck for reverse spin operations on my atlas 10200 in a few hours work using some threaded rod, a few Tee nuts, some aluminum tubing and a 4" plastic wheel as a handle to torque the draw bar. I have a part or two coming from Mcmaster on thursday to finish them up and I'll post a picture of them both once they are finished. To be continued,...

I'm currently pursuing the information to wire the drum switch I bought from amazon and posted on an ongoing thread about wiring this same switch.

 

[wa5cab]

I seem to have temporarily misplaced it and can't this afternoon quote the manufacturer's name but there was a West German company who made a 6-inch chuck that had 1-1/2"-8 threads that also was split between each jaw and had three bolts which tightened the female threads onto the male spindle threads. Obvious purpose was to allow turning towards the tailstock without worrying about unscrewing the chuck while turning. Outside of a few minutes spent confirming that it worked and that the chuck screwed freely off and on the spindle after tightening and loosening the radial bolts, I have never actually needed to use it. But if I ever need it I have it.

 

[o0norton0o]

That's a nice feature, Wa5. I've read many threads on the subject of "chucks loosening in reverse" and regardless of expertise the opinions are all over the place. Guys who have 50 years of experience working on metal lathes saying that they never had this happen to them, and just as many with the same experience saying that it never happened to them UNTIL it did. So,... I decided to do some homework and found this "draw bar" style mechanism to lock the chuck for reverse spin. It was so simple to make, and I inspected the hole down the center of my chuck and it has a convenient shoulder for a plate to rest on that has space above the draw bar plate so it doesn't interfere with the jaws of the chuck at all. The one thing you give up for reverse spin with this draw bar is the hollow spindle, but if your work piece can extend out from the headstock because it's length runs down your spindle, then you don't need to thread away from the head stock anyway. You can just move the work piece out and have more breathing room...

So here's the whole mess

The parts are:
a single 12" long 3/8" - 16 threaded rod
2 tee nuts 3/8 - 16 tpi
12" long 1/2" OD aluminum tube
6" long 5/8" OD aluminum tube
1- 4" plastic wheel

I threaded the "chuck side" tee nut onto the threaded rod and drilled a hole through them and put a roll pin so it can't unscrew at the chuck end. I slid the 1/2" OD tube over the threaded rod so it would help center the rod in the spindle. the 1/2" tube also sticks out about 1-3/4" past the spindle. The 5/8" OD tube sticks out 2", so the smaller tube lines up the bigger tube perfectly with the back of the spindle. I melted the rear Tee nut into place in the plastic wheel. When you assemble the plastic wheel on the threaded rod, it pulls on the tee nut inside the chuck and pushes the 5/8" tube against the back of the spindle. Simple and cheap...

I made the wheel stay back 2" from the back of the spindle so I could use the back gear pulley mechanism without disassembling the draw bar mechanism when it is being used. I also trimmed off the extra threaded rod after I took the picture you see here. I did leave enough space for a Nylock nut in the future just in case it has a tendency to unscrew.

 

[o0norton0o]

Here's a picture of the 10200 metric lathe. QCTP, reverse spin switch, metal gibs in place of plastic, draw bar style chuck locker. (not shown) motor guard with clear splash screen to keep chips and oil off the motor.

 

[wa5cab]

Who made it and/or sold it?