I recently bought a 4900 lathe. Built in 1969, it has lived its whole life as a hobby machine. It is in great overall shape as far as I can see. I got it home and roughly leveled the bed within .002 over 12". I played around a little bit making a 8" cut and measuring taper. Less than .001. However the finish left something to be desired. I played some more. tried different tools, speeds/feeds, oil/no oil, different materials. The finish is consistently poor. It looks like a light wavy chatter, like nothing I have ever seen. Not typical chatter from incorrect feeds/speeds/geometry. So if decide I'll thread a part and see how that goes. Terrible. I can watch the tool deflect leaving torn threads and a horrible finish.
I have checked the usual. Gibs are adjusted, saddle is secure on the ways, spindle bearings are tight, tool on center etc.
The tool post is a piston style BXA sized Chinese knock off. Could this be the culprit? I took it off, inspected it, and cleaned the top of the compound and base of the post to make sure there was no debris for the post to rock on. We use wedge style posts at work,I am not against piston type. But I have to question this piece of Chinese crap. It just feels inferior compared to the Dorian and Aloris posts at work.
Any other ideas????? I really need to get this lathe to cut.....
I have checked the usual. Gibs are adjusted, saddle is secure on the ways, spindle bearings are tight, tool on center etc.
The tool post is a piston style BXA sized Chinese knock off. Could this be the culprit? I took it off, inspected it, and cleaned the top of the compound and base of the post to make sure there was no debris for the post to rock on. We use wedge style posts at work,I am not against piston type. But I have to question this piece of Chinese crap. It just feels inferior compared to the Dorian and Aloris posts at work.
Any other ideas????? I really need to get this lathe to cut.....