How Much Runout is Too Much?

[Charlie Barnes]

Good Evening Everyone,

I posted this in the General Woodworking forum, but thought I'd try here too.

Long story short, I'm looking at an old Rockwell lathe, model 46-450. I went to see it tonight and it seems to be in good running order. It doesn't make any unusual noises and the variable speed works nice and smooth. I don't have any idea how old it is, but I'm guessing 40-50 years. I've been wanting to get into turning and want a good, solid, basic machine to learn on.

Here's the concern - I set up a dial indicator and I measured .004 runout on the head spindle (right term?) measured on the shaft right behind the drive spur/mounting plate. Of course the shaft I was measuring could have been out of round too, but it's the best place I could see to get a measurement.

Question: Is that too much runout? If it is, what is the "limit" for basic turnings (bowls, spindles, table legs, etc.)?

Thanks.

Charlie

255439

[Dennis Ford]

I don't know about any limit on run-out. I would expect that an old machine like that might have some dings in the shaft that would make measuring run-out next to impossible.

[Jerry Marcantel]

Charlie, indicate inside the Morse Taper. If that has the same runout, the spindle is probably bent.That .004" isn't much, but still not good.
I have one of those lathes. It's an excellent lathe, but I don't use it and will not part with it. It's my backup.. I think it's built in the early 70's. Go to Old woodworking machines and find Rockwell tools, find the search box and put in your serial number. You should find out what month and year it was made.... ........ Jerry (in Tucson)

[Sid Matheny]

.004" is no problem IMHO. Now if it was a metal lathe it might be but not a big problem.

Sid

[Jerry Marcantel]

I'm gonna give this another try. Charlie, I have that same lathe, and also have extra spindle on my desk as I reply to you. From what I can see, I don't see any place on the spindle where you could get an accurate reading, unless you indicated off the nut diameter. If that the case, the nut OD runout doesn't matter. It's the nut face that is critical..... Reindicate, both nut face and inside the MT, and I'll bet it's less than .001"..... How much is the current owner asking, if I'm not too presumptuous??? ......... Jerry (in Tucson)

[Charlie Barnes]

I'm gonna give this another try. Charlie, I have that same lathe, and also have extra spindle on my desk as I reply to you. From what I can see, I don't see any place on the spindle where you could get an accurate reading, unless you indicated off the nut diameter. If that the case, the nut OD runout doesn't matter. It's the nut face that is critical..... Reindicate, both nut face and inside the MT, and I'll bet it's less than .001"..... How much is the current owner asking, if I'm not too presumptuous??? ......... Jerry (in Tucson)

Jerry, I think I understand what you're saying. The lathe was set up with a drive spur coming out of the headstock (not as pictured). I indicated on that shaft between the headstock face and the drive spur (drive spur shaft). I did not indicate off of the face as you mention, but I can certainly now see how that is critical. I'll follow back up with the owner and see what I come up with. Thanks for the input.

I can get it for $500. What do you think assuming all checks out well?

Sid - Thanks for your input as well.

Charlie

[Jerry Marcantel]

I can get it for $500. What do you think assuming all checks out well?

Sid - Thanks for your input as well.

Charlie[/QUOTE]

Charlie, I paid 400 for the one I got. It looked as good as the one you pictured and works great. It aslo came with another headstock housing and spindle. I need bearings for that headstock, but 9 bucks each is good. I don't know what I'm going to do with an extra headstock for a lathe I'm not using. I'm a hoarder I guess.hehehe
Where is the panel for the motor housing?? ..... Jerry (in Tucson)

[Harry Robinette]

Charlie
check the center line, put drive and tail centers in and bring them together see how much the points are off if any. A 1/16 is good 1/8 is a problem but can be fixed over that you have a problem thats not good.