Hi, this might be really obvious to some, but im still pretty new to this and don't have anyone to show me the ropes, so take it easy lol. Stumbled across an issue i haven't run into yet, I have piece of 7075 that is 8"2"x1", and i need to cut the height down about .200". i have a 5" 4 jaw chuck (i also have a 6" and 8" 3 jaw, but i figured the 4 jaw would be better?). Is this a NO-NO, or am I over thinking it. My gut feeling is NO, as it could slip out since there isn't a jaw on each edge, or get knocked out of the chuck due to the height of the stock vs the amount of jaw contacting it... I have done interrupted cuts on smaller stock with no issues, but nothing bigger than the chuck and always had a jaw on an all 4 edges. I tried searching for an answer, but don't think I'm using the right terminology, a picture says a thousand words, so see pic below. any suggestions on how to do this would be appreciated, my other thought was chucking up a tool and mounting the stock to the cross slide, but i would only be able to cut half or less, the move it, re-square it up, ect. I only need to make 2 of them. Thanks in advance,
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Facing stock lengthwise that is bigger than the chuck
- Thread starter ganzey
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First, thanks for the photo!
What you are trying isn’t out of the realm of possibility, but you should be able to grasp the stock with all four jaws; the stock doesn’t need to be centered as long as you can reach the full length. Although you have an extreme example, this is how many hobbyists faced rectangular stock before hobby mills were common. Take it sliw, with light cuts and HSS tool bits.
Oh, and be very, very careful to stay clear of the rotating stock!!!
What you are trying isn’t out of the realm of possibility, but you should be able to grasp the stock with all four jaws; the stock doesn’t need to be centered as long as you can reach the full length. Although you have an extreme example, this is how many hobbyists faced rectangular stock before hobby mills were common. Take it sliw, with light cuts and HSS tool bits.
Oh, and be very, very careful to stay clear of the rotating stock!!!
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Turn the jaws on your 4 jaw inward and see if you Get a better grip. The current pic is an accident waiting to happen.
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I was originally thinking the same thing, but it looked like he wouldn’t be able to grip with the jaws flipped. However, he may be able to flip one pair of opposing jaws (at 9 o’clock & 3 o’clock in his photo?) and improve the grip?
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I think he will get the jaws in the same position as they currently are grabbing, but he will have the tall part gripping.
While it's better, it's still sub optimal considering how long the piece is, but if super light cuts are taken 5-10 thou at a time he might avoid the chatter.
edit: btw, you may need paper or sandpaper between your jaws and the piece to avoid slipping. even though it's not steel, it is still slippery enough, and paper or sandpaper will provide some preventive. I prefer a fine sandpaper of about 220. but that's just my opinion.
see what others think about the whole thing.
While it's better, it's still sub optimal considering how long the piece is, but if super light cuts are taken 5-10 thou at a time he might avoid the chatter.
edit: btw, you may need paper or sandpaper between your jaws and the piece to avoid slipping. even though it's not steel, it is still slippery enough, and paper or sandpaper will provide some preventive. I prefer a fine sandpaper of about 220. but that's just my opinion.
see what others think about the whole thing.
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^^^ What woodchucker said !!! ^^^
Please turn all the jaws around.
If not, I predict a learning experience that you will never forget.
Use a sharp cutting tool and take light depth of cut (DOC). Maybe .005" at first, if it's not too scary, you can slowly increase the DOC.
Stay out of the line of fire.
Please turn all the jaws around.
If not, I predict a learning experience that you will never forget.
Use a sharp cutting tool and take light depth of cut (DOC). Maybe .005" at first, if it's not too scary, you can slowly increase the DOC.
Stay out of the line of fire.
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I just looked at it again and I have an idea for you to consider. Drill and tap a 3/8-16 (or larger) hole about 1" deep into the center of the opposite face. Bottom a piece of all-thread in the tapped hole and run the all-thread through your spindle. Put a substantial washer and a Nylock nut on back end. Now you have a substantial "drawbar" that will keep the workpiece in the chuck jaws. Don't leave more than a few inches of all-thread protruding from the back of the spindle or you might have a different problem.
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I just thought of something else.
I have a piece of aluminum that has a center hole in it. It's flat on the other side about 2" round.
I would make a thing like that if you don't have one, and while you are cutting the outside, I would have the tailstock and that holding the piece in. Maybe leave the center until the end and then do a finish cut on the whole thing once it's removed. This will prevent the piece from launching out, as you will have a tailstock pressing on it. I actually have 3, just found the 2" after taking a pic of the larger ones.
I have a piece of aluminum that has a center hole in it. It's flat on the other side about 2" round.
I would make a thing like that if you don't have one, and while you are cutting the outside, I would have the tailstock and that holding the piece in. Maybe leave the center until the end and then do a finish cut on the whole thing once it's removed. This will prevent the piece from launching out, as you will have a tailstock pressing on it. I actually have 3, just found the 2" after taking a pic of the larger ones.
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I know you're a newbie and I don't mean to be cruel or even unfriendly, but . . .
IMO, you should print that picture, put it a nice sheet protector (a frame might be too much) and hang it behind your lathe. It will always remind you of "Safety First" and to keep asking questions. Leave the picture up at least until viewing it sends a chill down your spine.
IMO, you should print that picture, put it a nice sheet protector (a frame might be too much) and hang it behind your lathe. It will always remind you of "Safety First" and to keep asking questions. Leave the picture up at least until viewing it sends a chill down your spine.