I'm borrowing a friend's 618 lathe in return for me getting it all cleaned up and working well.

So far so good, except that the headstock has a LOT of play in it. When I go to take cuts, the entire workpiece lifts probably 10 thou.

I assumed it was bad bearings, but when I did a search someone mentioned something about "tuning" the headstock to have less radial movement in it.

I found collars with set screws to tune axial movement, but nothing for radial movement.

Any thoughts?

Wow, I think I stumped GRM. Do I get a medal?

Try dropping a note to Motomoron. He was very helpful when I was looking for a South Bend lathe.

Might as well open 'er up and check out those bearings:

http://www.deansphotographica.com/machining/atlas/spindle/spindle.html

I don't have an Atlas - but my Grizzly has one sealed bearing and one raced bearing like a chevy wheel bearing. When I first got it it could only hold about 5 tho but when I repacked and snugged it up according to the directions... perfect. It holds to under 1 thou now.

Is it a removable chuck? Remove it, make sure everything is spotless and try again. Maybe something was holding it out, keeping it from properly locking.

Dan

Yes, removable chuck. I'll check that.

I was having a hard time opening up the chuck to clean it. The halves wouldn't separate. Any tips?

http://alloyavenue.com/vb/forum.php

Sign up - they have a machining section that has some seriously intelligent machinists - most of which have rehabbed a lathe or 6.

I'm here, I'm here.

That was my first machine tool, a wee Atlas 618. Know in advance that in less than 10 years you'll go from one you can carry yourself to several hundred square feet completely full of machines that weigh as much as cars.

The atlas 618 had a few configurations of spindle bearings over the decades of production. Mine had some not-particularly-high-grade Timken tapered roller bearings. There's a collar at the far end of the spindle tube that should thread on. Loosen set screws and tighten to preload the bearings.

Good Atlas info at: Atlas Craftsman Yahoo Group

Also: Home Shop Machinist

And: Chaski Home Machinist

Motomoron, my only tools right now are a 0.001" dial caliper, a 1" to 2" micrometer, and feeler gauges. What are my next essentials if I want to spend less than $100 on tools? Just to get started, of course.

I was thinking a dial indicator with a mag base and a machinist square.

Also, I only have a single carbide right hand turning tool. I think I should look for a boring bar and some HSS stock. What are your thoughts?

Go here and buy one of everything.

For cutting tools, learn how to cut your own and buy HSS blanks. I get a much better finish with HHS. Most carbide tipped tool also take more HP to run than a properly formed HHS tool. Not to mention the HHS blanks are dirt cheap and you can form them for any purpose. I've probably got 30 of them all cut a little different. You also need a cutoff tool.

Calipers, I keep a 6", 8" and a 12" digital handy and use them for everything. Micrometers, a full set is handy, but expensive and you can get by without them as long as you have calipers. I lucked up and got a 0-9" set for next to nothing. A set of ID gauges is nice to have.

1 thing I would look into is a quick change tool post if your machine doesn't already have one. The older lantern posts will drive you to drink.

Last and most important is metal stock. There is nothing worse than wanting to make a part and not having a piece of metal to make it out of. I keep an assortment of steel, aluminum and brass on hand. Check with the local scrap yards.

Head stock now has no play in it!

But, it does seem to be off axis compared to the bed. Autofeed cuts result in a 5 thou (radius) taper over 2 inches.

That may be caused by deflection of the part. It can be a particular problem on small diameter stock. The farther you get away from the chuck the more the part deflects. Cut a test piece between centers and check it again.

yeah but the taper is thinner away from the chuck, wouldn't deflection do the opposite?

what I did was chuck up some pipe, true it up using the cutting tool and a feeler gauge about 12" from the chuck.. then I checked it with a feeler gauge at the end, and against the chuck. more gap the closer i got to the chuck. I figured this would be a fairly accurate test to confirm my suspicions

Yeah, that's kind of bass ackwards. Check the ways with a good straight edge and make sure it isn't sway backed. Old lathes get a worn spot close to the chuck. If it's out .005 in 2 inches it would have to be noticeably worn.

Also look for an adjustment in the head stock. I'm not familiar with the Atlas lathes, but there should be a ton of information on Google.

Taiden wrote: Head stock now has no play in it!

What was the cure?

For the taper. find a nice smooth, shiney piece of round stock. Something like the rod out of shock, only bigger.

Chuck it up and put an indicator on the tool post. Without rotating the chuck, crank the carriage left and right, look for indicator movement.

Put your hands on the tool post and yank toward and away from you. This will tell you if the gives in the carriage are shot, they may just need adjusting. Easily could cut a .002 taper if loose.

Dan

There's a nut on the back of the spindle that you adjust to change bearing preload. I followed the directions to adjust it and now there is no deflection under cutting.