- Joined
- Nov 28, 2021
- Messages
- 70
Looks like a good machine. There are days when I wish my 1440 was a 1425.
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New (to me) Grizzly DF-1224G or G1003 lathe (aka Busybee/ Dai Fong DF-1224G)
- Thread starter lSherlockl
- Start date
- Joined
- Mar 12, 2021
- Messages
- 63
That was my goal or intent so then its safe to assume or adjust anything else based on bed or twist or the stand if I need too
and to verify or dial in the headstock i need to prove or ellimate twist from the bed/ways was my understanding
I also was partially wondering if I should be using HSS cutters for such test cuts as they require less tool pressure less likely to flex the material when cutting.
I also just got a larger micrometer which would allow me to dot he same test on larger diameter stock which could help rule out the flex of a .9" diameter bar, but i think my biggest variable at the moment is stability of the stand (and the fact that even if i left it on the casters I am not in a measurable range with the level to validate no twist in the bed.
- Joined
- Mar 12, 2021
- Messages
- 63
correct I don't have a great way to measure the exact difference but from a comparative standpoint its the same height from the flat to the prismatic. indicator less than .0005 of variance along the length of either of the ways. Indicating say the back flat to the top of the back prismatic then to the front prismatic distinctly the front prismatic is taller by more than the measurement of my dial indicator. The carriage rides on the front prismatic and rear flat way, and the tailstock on the front flat and rear prismatic way. So i ended up doing my comparisons using 123 blocks as the two flat ways were on the same plane but threw me for a loop for awhile trying to do anything with a level off of the prismatic ways.
ha ha, you are no doubt right some of it is I have absolutely no clue of what is normal aside of trying to match what the test accuracy is in the original test certification sheet from the factory from 1883NASA just called and said your parts are within tolerance so nothing to worry about
John
Clearly I am feeling a case of far too much research reading and overthinking, which in the lack of experience I prefer to revert to doing, rather than screw up my "fancy" new or rather in this case old toys
- Joined
- Dec 3, 2017
- Messages
- 1,909
Seems like you're trying to work ahead. Just take one problem and address it. Set the lathe up where and how you want it. I doubt you need to fortify the stand. But after that's done, worry about fixing bed twist. After that's done, worry about headstock alignment. Take smaller bites. Yeah?
- Joined
- Mar 10, 2015
- Messages
- 248
Have you considered putting the level on top of the cross slide and moving the carriage from one to the other to measure? The measurement you are interested in includes the relationship between the carriage and the bed.
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Very nice write up, thanks for sharing. I understand the desire to make it as accurate as possible as a goal in itself. From a practical standpoint, if I have a taper of a mil or 2, I hit it with a file. By the way there are special long angle files made specifically for lathes that work better. Also turning between centers or with a steady rest.
If you did need to stiffen the cast iron legs you could bolt diagonal braces on, the bolt holes are typically made a little oversized, torqueing down the nuts clamps the two parts together. Not really sure that is desirable or necessary as even a very rigid cast iron tool will bend and twist a little over time. Also it messes with under lathe storage.
Flex of your test bar (or chuck jaws) under cutting loads can easily cause a tapered shaft, 1" dia by 5" or 6" long. I think very sharp HSS is a good idea, make sure GIBs are adjusted, well oiled, make sure compound rest and cross slide screws were last turned inward. If cutting forces are part of the confusion I think you will typically have a larger diameter further from the chuck. Aluminum will have lower cutting forces than steel.
Consider getting a test bar that fits in the headstock taper. Or use the dumbell you have made and use a test indicator on it as the saddle is moved back and forth to more quickly see the effects of changing leveling up and down with no cutting force. Having leveling feet that can be adjusted will be way easier than shims, I suspect these could be at the floor, adjacent to the rollers or between the lathe and table. I think being able to adjust the headstock relative to the bed could be a huge advantage, on my lathe it is machined to fit so not easy to change if its out.
For leveling the lathe there are different ways to attack it. 1) Adjust it so it cuts strait who cares how level. 2)Adjust it level to the original machined lathe datums, need to find surfaces on your lathe that are not worn. Or as navy chief suggested use the top of the saddle which adjusts it level based on the existing possibly worn V way surfaces. If I were adjusting to cut strait, I think I would record how far out of level it is so I could adjust it back if the lathe is moved.
If you did need to stiffen the cast iron legs you could bolt diagonal braces on, the bolt holes are typically made a little oversized, torqueing down the nuts clamps the two parts together. Not really sure that is desirable or necessary as even a very rigid cast iron tool will bend and twist a little over time. Also it messes with under lathe storage.
Flex of your test bar (or chuck jaws) under cutting loads can easily cause a tapered shaft, 1" dia by 5" or 6" long. I think very sharp HSS is a good idea, make sure GIBs are adjusted, well oiled, make sure compound rest and cross slide screws were last turned inward. If cutting forces are part of the confusion I think you will typically have a larger diameter further from the chuck. Aluminum will have lower cutting forces than steel.
Consider getting a test bar that fits in the headstock taper. Or use the dumbell you have made and use a test indicator on it as the saddle is moved back and forth to more quickly see the effects of changing leveling up and down with no cutting force. Having leveling feet that can be adjusted will be way easier than shims, I suspect these could be at the floor, adjacent to the rollers or between the lathe and table. I think being able to adjust the headstock relative to the bed could be a huge advantage, on my lathe it is machined to fit so not easy to change if its out.
For leveling the lathe there are different ways to attack it. 1) Adjust it so it cuts strait who cares how level. 2)Adjust it level to the original machined lathe datums, need to find surfaces on your lathe that are not worn. Or as navy chief suggested use the top of the saddle which adjusts it level based on the existing possibly worn V way surfaces. If I were adjusting to cut strait, I think I would record how far out of level it is so I could adjust it back if the lathe is moved.