We probably have all tried these things on rusted materials. The rusted surface will always limit what you can accomplish, especially if you are changing the chuck grip between operations .... the rusted surface varies at different positions so each time you re-grip on the rust the rod locations/angles are different. I have worked on rods where the rust is not nearly as uniform as yours appears to be. Some Hints.
1) Before making adjustments to the lathe make sure the material you are using grips correctly in the chuck etc. This cannot be possible if the surface is rough, rusted (or the rod it bent). If you adjust the lathe using bad materials, cuts, or with poor instruments it is likely that the lathe will be aligned even worse that before.
2) Carriage locks are required for accurate cuts. Depending upon tool position, the cutting can either pull or push the tool point causing variations in the surface..... Especially, when hitting rusty spots it will vary. (even when the cutting point is on the center line) Hence, use carriage locks and make a rough pass cut to remove all rust before trying to make a good cut. With out the locks you can commonly see or even feel the cross cut position moving as you are surfacing.
As a first pass to try to make the work piece a bit better (round and straight) I would chuck it up with a sufficient amount extending out to removed rust so that you can re-grip it in the chuck on the fresh surface .... this is so that it can be center drilled while the clean surface is chucked without hitting the rusty surface with the chuck. Even this will not necessarily be perfect as the first surfacing may have created an oval cross-section (due to the rust grip). Now center drill. Extend the rod, and using the tail stock center to define the work surface position, clear some more rust off..... And resurface the clean surface at the tail stock. (If the stock is too short or is very thick-stiff, the tail stock point will not define the work surface position.) This later step should make most of an oval into a circle/round rod at this end(only). Now reverse the rod and grip the cleaned/fresh surface near the center drilled end (make sure the chuck grip is cleaned of debris or rust materials). Since the full length of the rod is now extended out you can try to make a surface cut down the length you plan to work with ..... or of the whole rod without using the tail stock to center things. This should get you a work piece which is mostly round and with limited taper... if your lathe head stock/chuck is aligned to the lathe bed. At least now you have a better "starting" material.
Oh, yes, since you have a good level in hand, check out the lathe bed before you even begin. While it would be nice and would make life easier, it does not have to be level end to end, but must not be twisted. If it is twisted you should fix the leveling feed to remove the twist before anything else. If it is not level end to end then the head stock may not be parallel with the bed, especially if there are separate leveling feet for the head stock and the bed. Non-parallel head stock/chuck grip or a twisted bed can result in a tapper cut.
One last thing. I cannot tell the radius of your cutter point, but if the cutting tool point is too sharp and you come at it straight on you will be cutting threads rather than getting a smooth surface.
Having fun!
1) Before making adjustments to the lathe make sure the material you are using grips correctly in the chuck etc. This cannot be possible if the surface is rough, rusted (or the rod it bent). If you adjust the lathe using bad materials, cuts, or with poor instruments it is likely that the lathe will be aligned even worse that before.
2) Carriage locks are required for accurate cuts. Depending upon tool position, the cutting can either pull or push the tool point causing variations in the surface..... Especially, when hitting rusty spots it will vary. (even when the cutting point is on the center line) Hence, use carriage locks and make a rough pass cut to remove all rust before trying to make a good cut. With out the locks you can commonly see or even feel the cross cut position moving as you are surfacing.
As a first pass to try to make the work piece a bit better (round and straight) I would chuck it up with a sufficient amount extending out to removed rust so that you can re-grip it in the chuck on the fresh surface .... this is so that it can be center drilled while the clean surface is chucked without hitting the rusty surface with the chuck. Even this will not necessarily be perfect as the first surfacing may have created an oval cross-section (due to the rust grip). Now center drill. Extend the rod, and using the tail stock center to define the work surface position, clear some more rust off..... And resurface the clean surface at the tail stock. (If the stock is too short or is very thick-stiff, the tail stock point will not define the work surface position.) This later step should make most of an oval into a circle/round rod at this end(only). Now reverse the rod and grip the cleaned/fresh surface near the center drilled end (make sure the chuck grip is cleaned of debris or rust materials). Since the full length of the rod is now extended out you can try to make a surface cut down the length you plan to work with ..... or of the whole rod without using the tail stock to center things. This should get you a work piece which is mostly round and with limited taper... if your lathe head stock/chuck is aligned to the lathe bed. At least now you have a better "starting" material.
Oh, yes, since you have a good level in hand, check out the lathe bed before you even begin. While it would be nice and would make life easier, it does not have to be level end to end, but must not be twisted. If it is twisted you should fix the leveling feed to remove the twist before anything else. If it is not level end to end then the head stock may not be parallel with the bed, especially if there are separate leveling feet for the head stock and the bed. Non-parallel head stock/chuck grip or a twisted bed can result in a tapper cut.
One last thing. I cannot tell the radius of your cutter point, but if the cutting tool point is too sharp and you come at it straight on you will be cutting threads rather than getting a smooth surface.
Having fun!
