Re: Getting my SB 9C working

john kling

Was the simple use of headstockĀ  iron by South Bend on there entry level lathes such as the workshop lathes simply a cost cutting measure. This approach has been used Goodelll
Pratt and otherĀ  low cost manufactures but not all (such as Atlas).

On Friday, December 18, 2020, 3:17:00 PM EST, eddie.draper@... via <eddie.draper@...> wrote:

A number of points have been made in various posts on this topic, and I will now chuck in my five pennorth.

1. Anyone acquiring a lathe with a plain bearing headstock, particularly one that depends upon wick (felt) feeds, is strongly recommended to strip out the applicable bearings, muck out the oil containers and renew, or if only lightly soiled, clean, the wicks, felts, whatever BEFORE applying power for the first time, regardless of whether it is seized or not. If it is seized, I would regard it as absolutely mandatory, as there's no knowing what you might find that could cause immediate further damage. It might be "only" varnish, which is bad enough in itself, or it might be much worse. This also allows an opportunity for bearing inspection.

2. Applying a torque to a threaded fastener is only an approximate way of achieving bolt tension and stretch. The results are heavily dependant upon thread and under head friction, which can vary quite considerably. If you have an assembly that you want to put back together exactly as it came apart, forget about torque, and mark the rotational positions of each fastener in relation to fixed surfaces, ensure that each goes back in the same hole (and with the same nut & bolt pair where applicable) and retighten to the same position. You will have the same stretch as before, regardless of torque. You might want to record the torques as you tighten, but I suspect you will be amazed by the wide disparity.

3. Once you have cleaned all out, provided operating wicks / felts, and reassembled everything, set the endfloat, then perform a shaft lift and lateral displacement test. If you got there in time, they won't need adjusting. If they do need adjustment, follow the instructions.

MX & HNY to all,


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