Dave,
some things to consider on the SB13.
1. Big spindle bore or small? Mine is from 1940 and has the small bore spindle, 1" I.D.
2. Single tumbler or double? Mine has the single tumbler...
3. Flame hardended bed ways?
4. Is it under power and can be run for a period of time? If so run it and see how hot the bearing get...
5. Test the Longitudinal feed and cross feed...
6. Grab the lead screw and roll it upward, toward the top of the bed, (by hand while power disconected) look at the Quick Change gear box shaft... how much play is there in the bushings in the QC gear box shafts.
7. Look at the back of the compound, where the gib sticks out. How much gib is there sticking out? Same thing on Cross Slide...
8. Look in all the oil points to see if there is oil in them... especially the two for the spindle head and the two for the motor spindle.
These are all things I am doing to my lathe and finding some things are good... some not so good. I learn something new every day!
toolman_ar
In addition to that I would suggest:
9. Engage the half nuts with the lathe stopped and check how much wear there is in the half nuts by rocking the carriage handwheel back and forth. There should be very little.
10. Run the cross feed to the extremes of travel and note if it is tight at one end or the other and sloppy in the middle. Ideally, the slide should be snug with no binding at either extreme of travel.
11. Are there score marks on the ways? If so, best to pass it up.
12. are there any shims under the tailstock (between the tailstock and its base casting). This would show that the machine has had a lot of use, and probably a lot of wear in other areas.
13. If the spindle is pried upwards with a dial indicator on top, how much clearance is there? Should be very little, perhaps a thou. or two.
14. As suggested in (4), run it on the highest speed and observe bearing heat; if you can hold onto the bearing cap without discomfort, OK. This is also a good time to have the feed train connected and listen for excessive noise, which can be quite irritating. Also engage the back gear in the fastest belt speed and note excessive noise, good also to remove the back gear guards and check for broken or missing teeth.
15. Check for excessive wear in the cross feed nut; perhaps 1/8 turn is not so bad, but more is not at all good; this is not a fatal flaw, and can be replaced, but is indicative of excessive wear and tear on the rest of the machine.
16. Check to see if the tailstock quill is sloppy in its bore and if the taper has scores in it, just feel around inside the taper with your finger; if scored, you will never be able to remove and replace the center in the same place with resultant taper problems and possibly chatter.
So far as how much the gibs are sticking out, this is subjective, but if there is nothing left for adjustment, and the slides are still loose, this shows excessive wear, and even worse is to find shims under the gibs.
