After buying my lathe last summer (2000 13x40 Acra-Turn) I got it leveled with a lot of help from a member here. Anyway I'm waiting for a few things to come in the mail before I start my next project so decided to pull out my two collar test bar. It was out quite a bit .023". It's cold here now so I'm sure that has a lot to do with it. I monkeyed around with it for a while and decided to start from the beginning. Got the level out and started levelling. Took a while but I have levelling casters that really make it a breeze. First got the headstock leveled then move to tailstock. Took several times back and forth, as soon as I'd level the TS the HS would go out. Always kitty-cornering the same two casters.
On a side note. I put my level on the cross slide only moving the carriage up and down the bed. Once I got it leveled I used 123 blocks and put them on the flat ways out of curiosity. I had to put .011" of shims to get it level. Not sure why that is other then they are simply not level with each other. Did the same with the V ways and not even close to level.
Moving on. Chucked up my two collar test bar 2.65" Ø aluminum about 6" between collars I think it is using the 4JC. HS end is larger so I start lowering, or raising the TS, back caster. So here is one of my questions. I have to move the caster a lot to get any change in cuts. I'm not sure exactly how much I raised, or lowered that back caster but it was many turns. To me it seems like there is another issue here. The first pic is the lathe level according the bubble. The next is where I'm at now cutting very little taper.
One thing I need to mention. When I chucked up my test bar and trued it up with zero run-out on the outside collar I had four thou run-out on the inside collar. I thought that was very odd. My next test was a skim cut on a 6" 1.5"Ø aluminum bar. At this time I don't own a 1"-2" mic so used a indicator and ran the length. The next pic is my setup. And the next I my starting point and then chuck end. Now look what happened when I rotated the chuck 90°. Four Thou? I then ran the lathe touched the stock and sure enough nice and smooth on the outbound side and about 2/3 in starts to jump around.
Can anyone explain this? Thanks for responding.
Duane
On a side note. I put my level on the cross slide only moving the carriage up and down the bed. Once I got it leveled I used 123 blocks and put them on the flat ways out of curiosity. I had to put .011" of shims to get it level. Not sure why that is other then they are simply not level with each other. Did the same with the V ways and not even close to level.
Moving on. Chucked up my two collar test bar 2.65" Ø aluminum about 6" between collars I think it is using the 4JC. HS end is larger so I start lowering, or raising the TS, back caster. So here is one of my questions. I have to move the caster a lot to get any change in cuts. I'm not sure exactly how much I raised, or lowered that back caster but it was many turns. To me it seems like there is another issue here. The first pic is the lathe level according the bubble. The next is where I'm at now cutting very little taper.
One thing I need to mention. When I chucked up my test bar and trued it up with zero run-out on the outside collar I had four thou run-out on the inside collar. I thought that was very odd. My next test was a skim cut on a 6" 1.5"Ø aluminum bar. At this time I don't own a 1"-2" mic so used a indicator and ran the length. The next pic is my setup. And the next I my starting point and then chuck end. Now look what happened when I rotated the chuck 90°. Four Thou? I then ran the lathe touched the stock and sure enough nice and smooth on the outbound side and about 2/3 in starts to jump around.
Can anyone explain this? Thanks for responding.
Duane
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