Great video! I was having a lot of trouble trying to line them up! I ended up marking the the starting point with a red marker…and it worked! Thanks again!
Same here! Got tired of trying to figure it out and thought I'd check out UA-cam University for help. Runout is my issue and that's all I needed, was to know in simple terms how to fix them because mine doesn't have numbers anywhere. Thank you!
You can also take the three jaws in order but start from another point in the chuck... test the run out and than do the same thing in the next position. Likely one position will have less run out. If you have a D type chuck attachment (the type with three pins that rotate to hold the chuck in place) it is important to clean all the mating surfaces and as you start tightening the three lock bolts, don't do one at a time and tight. Instead run them up finger tight and than put a dial indicator on a test round you have chucked up. Gradually tighten the bolts starting with the high side to pull it in to place first. Finish in this manner. On my Smithy Granite 6" chuck I can get it to around .0002 concentrix which is amazing. I do have a 4 jaw chuck but rarely need it.
2 місяці тому
That's very cool. I've found out that I can get away with using the tailstop center to lock the work BEFORE I clamp down the piece and that they usually end up being pretty well centered.
What i found useful was finding the high spot and tighten with a specific chuck eye to reduce the run out and if it still has runout i would shim a piece of paper ,alu foil ,etc And of course to tap the end of the part to run true to the lathe bearing to finish it off.
This is great (if works!) Today i disassembled the chuck and change jaws its positions several time and got 0,04mm against the 0,12 at begining...i'll prey and ask God for you if this tapping works tomorrow.Thanks!
yes 100% I normally keep a set that have been bored all the way through for bar work like this. I would imagine lots of beginners don't have soft jaws so this method keeps them concentric for now!
Well, this beats drilling 4 holes, tapping them around the perimeter, then taking 10 off the mount lip. Then loosening the hold screws, adjusting the 4 tapped, and tightening the base.
I've always known to insert the jaws in order, but the video close up of the ladder on the jaws and the starting spline inside the chuck makes everything clear on how it works. When flipping your jaws to accommodate larger sizes, do you insert 3 first and then 2, then 1?
in the case of a 3 jaw self centering you can't just flip the jaws. This is because the teeth on the jaws are radiused to suit the scroll. instead you have to buy a set of external jaws, these are still installed in the order 1,2,3 :)
After hours of messing around, trying everything i can including milling the jaws to perfection (which didnt help), i found that: A) Spindle has 0 ranout B) chuck has .002 ranout C) cannot get 0 ranout on the inserted stock because chuck is not true. So the order to true the stock is to start with spindle, chuck and then jaws.
More often than not If you have run out... Your jaws are worn in their tracks... You must then grind the jaws on a surface grinder and remove a few thou on the inner rear edge washing out at the tips.....say 3 thou... If you don't....when parting off the job will move and shatter your parting off blade....
Even easier way: Jaw 1 , hold at bottom Place Jaw 2/3 on top REVERSE lathe chuck key until you feel jaw 1 drop/push in. FWD Chuck Key and watch 2 and 3 fall nicely “Home” .
“Got lucky”. You sure did. Honestly anyone working close on a machine lathe would not use a three jaw for close work or repeating set ups. Three jaws just don’t repeat. Even the high dollar Pratt and Bernerd will run out .001-.002 from one part to the next. 4 jaw for close stuff.. 3 jaw for the quick stuff. Good video.
I had a rockwell with a 6 jaw universal that was pretty good. Not good enough though... my dad said back in the day you'd use a toolpost grinder to tru them!
Question, you said to start with #1 but you put it in #3 slot, so your doesn't make a difference as to what slot you start with on your chuck or any chuck. I always keep my numbers in the marked slot on the chuck, Nice video, always very helpful.
As long as you put the jaws in order it doesn't matter what slot they go into. sometimes you might get better or worse runout depending on where you put jaws so it's worth playing about :)
I most certainly don't want to do this all the time, especially if I have several or more components to do. I would rather first check the alignment of the main spindle(head stock) and the bed to see if they are running parallel. Then regrind the jaws which would be a more permanent solution. But, if regrinding is going to help on your chuck, I don't know brother. With the amount of run-out on your dial indicator and the fact that you can just tap the jaws to get rid of it is seriously a worry to me. There must be a lot of wear on the inside of your chuck and obviously the jaws as well.
it's not excessive wear but being a 1985 machine there's certainly some. like you say a more permanent solution would be reground/new jaws. headstock alignment won't have any influence on runout. thanks for watching :)
with hydraulic power chucks you can sometimes improve results but not with the same success seen on scroll chucks. a CNC machine with a scroll chuck will be be no different to a manual machine hope this helps :)
Does this work if after one end of a piece is machined and then flipped end for end? This is where I tend to run into concentricity issues. I know, I need to invest in a 4 jaw chuck.
@@ChrisMaj Tightening all three jaws clamps them all to the spiral with the same force, meaning more accurate and predictable centring. AFAIR, I'm not a machinist.
Wow!!! Never heard of this solution!!! BRILLIANT!!!
Great video! I was having a lot of trouble trying to line them up! I ended up marking the the starting point with a red marker…and it worked! Thanks again!
I machined the backplate drilled 3 holes with bolts to create an adjustable 3 jaw chuck with no runout
Damn we struggled for over an hour your video saved us another hour . Thanks. Man. You earned a sub
Same here! Got tired of trying to figure it out and thought I'd check out UA-cam University for help. Runout is my issue and that's all I needed, was to know in simple terms how to fix them because mine doesn't have numbers anywhere. Thank you!
Top tips - thanks! 👍👍
Never thought about sitting the jaws in a row for identification as the numbers wear off. Excellent video.
Succinct and definitely to the point. Thank you for these tips. Just what I needed.
that tap on the jaw trick......brilliant. thanks mate!
You can also take the three jaws in order but start from another point in the chuck... test the run out and than do the same thing in the next position. Likely one position will have less run out. If you have a D type chuck attachment (the type with three pins that rotate to hold the chuck in place) it is important to clean all the mating surfaces and as you start tightening the three lock bolts, don't do one at a time and tight. Instead run them up finger tight and than put a dial indicator on a test round you have chucked up. Gradually tighten the bolts starting with the high side to pull it in to place first. Finish in this manner. On my Smithy Granite 6" chuck I can get it to around .0002 concentrix which is amazing. I do have a 4 jaw chuck but rarely need it.
That's very cool. I've found out that I can get away with using the tailstop center to lock the work BEFORE I clamp down the piece and that they usually end up being pretty well centered.
Only real helpful tip all week. Thanks for sharing.
What a good tip! Didn't know it but used it on test piece and spot on. We never stop learning do we?
What i found useful was finding the high spot and tighten with a specific chuck eye to reduce the run out and if it still has runout i would shim a piece of paper ,alu foil ,etc
And of course to tap the end of the part to run true to the lathe bearing to finish it off.
Dude iv been fighting with my chuck for ever. tried grinding it true and still all over the shop. never thought to give it a good tap. works a treat !
Thanks a lot ❤❤❤❤
Thank you very much for this, very helpful.
Excellent info!!
Great video
This is great (if works!) Today i disassembled the chuck and change jaws its positions several time and got 0,04mm against the 0,12 at begining...i'll prey and ask God for you if this tapping works tomorrow.Thanks!
the video has helped me a alot after I removed the teeth I didn't know how to put them back.🎉
If you buy a better chuck its more precise to begin with?
this is a good quality chuck but it is now worn. but yes, a new and good quality chuck will be MUCH better!
awesome vid thank you
Outstanding.
Simply brilliant!
You could always use soft jaws!
yes 100% I normally keep a set that have been bored all the way through for bar work like this.
I would imagine lots of beginners don't have soft jaws so this method keeps them concentric for now!
thank you for the video!! my came with no numbers, got my lathe at a garage sale with frankenstein parts
Well, this beats drilling 4 holes, tapping them around the perimeter, then taking 10 off the mount lip. Then loosening the hold screws, adjusting the 4 tapped, and tightening the base.
Good tips.. thanks
Now what I'd like to know is "Why Didn't I Think of THAT?" THank You! JD
I am guessing its the threads on the jaw and the chuck have too much play or not cut consistently, causing this issue to exist ?
yes its normally caused by a worn chuck, the slots in the body alway wear over time too
I've always known to insert the jaws in order, but the video close up of the ladder on the jaws and the starting spline inside the chuck makes everything clear on how it works. When flipping your jaws to accommodate larger sizes, do you insert 3 first and then 2, then 1?
in the case of a 3 jaw self centering you can't just flip the jaws. This is because the teeth on the jaws are radiused to suit the scroll. instead you have to buy a set of external jaws, these are still installed in the order 1,2,3 :)
@@mcgrorymachined7596 Thank you, I DID see that, but for some reason my brain didn't register the radius on the jaws.
Woah! That tapping tip was great, and very impressive that you got it right off 😂
Does it repeat when you unclamp and clap a different piece?
more or less. A few gentle tap normally get it running true :)
thanks for watching!
Probably not just keep u nice chunk of Brass or Copper to use to bump it NOT a Steel Hammer.......
After hours of messing around, trying everything i can including milling the jaws to perfection (which didnt help), i found that:
A) Spindle has 0 ranout B) chuck has .002 ranout C) cannot get 0 ranout on the inserted stock because chuck is not true.
So the order to true the stock is to start with spindle, chuck and then jaws.
That's incredible
OMG,never konw that!thank u~~
nice
More often than not
If you have run out...
Your jaws are worn in their tracks...
You must then grind the jaws on a surface grinder and remove a few thou on the inner rear edge washing out at the tips.....say 3 thou...
If you don't....when parting off the job will move and shatter your parting off blade....
Even easier way:
Jaw 1 , hold at bottom
Place Jaw 2/3 on top
REVERSE lathe chuck key until you feel jaw 1 drop/push in.
FWD Chuck Key and watch 2 and 3 fall nicely “Home” .
Is miter ka naam kya hai
Ya saved me pal. Thnx
good one thank you
“Got lucky”. You sure did. Honestly anyone working close on a machine lathe would not use a three jaw for close work or repeating set ups. Three jaws just don’t repeat. Even the high dollar Pratt and Bernerd will run out .001-.002 from one part to the next. 4 jaw for close stuff.. 3 jaw for the quick stuff. Good video.
Good enough for me!!!
I had a rockwell with a 6 jaw universal that was pretty good. Not good enough though... my dad said back in the day you'd use a toolpost grinder to tru them!
Question, you said to start with #1 but you put it in #3 slot, so your doesn't make a difference as to what slot you start with on your chuck or any chuck. I always keep my numbers in the marked slot on the chuck, Nice video, always very helpful.
As long as you put the jaws in order it doesn't matter what slot they go into.
sometimes you might get better or worse runout depending on where you put jaws so it's worth playing about :)
I most certainly don't want to do this all the time, especially if I have several or more components to do. I would rather first check the alignment of the main spindle(head stock) and the bed to see if they are running parallel. Then regrind the jaws which would be a more permanent solution. But, if regrinding is going to help on your chuck, I don't know brother. With the amount of run-out on your dial indicator and the fact that you can just tap the jaws to get rid of it is seriously a worry to me. There must be a lot of wear on the inside of your chuck and obviously the jaws as well.
it's not excessive wear but being a 1985 machine there's certainly some. like you say a more permanent solution would be reground/new jaws. headstock alignment won't have any influence on runout.
thanks for watching :)
Will this work for a cnc lathe?
with hydraulic power chucks you can sometimes improve results but not with the same success seen on scroll chucks.
a CNC machine with a scroll chuck will be be no different to a manual machine
hope this helps :)
Ive never seen that done before. Im guessing it settles the jaws.. Cheers
Thank you for these tips. Just what I looked for. Thanks again.
Bravo
wow. thanks
Greets from Ireland, let me tell you a story, of Johnny McGrory …
Does this work if after one end of a piece is machined and then flipped end for end? This is where I tend to run into concentricity issues. I know, I need to invest in a 4 jaw chuck.
Hi, yes it does. of course you must clock off a diameter machined in the first setup.
many thanks for watching
Abom 79 tightens each of the pinions in turn, amounts to the same thing I guess.
He has a 4-jaw independent chuck
@@ChrisMaj Tightening all three jaws clamps them all to the spiral with the same force, meaning more accurate and predictable centring. AFAIR, I'm not a machinist.
well I'll be hornswoggled, one learns, I have a 16-inch pratt, has 6 heavy screws to hold the back on, just loosen sc rews a bit, tap tap tap
I said screw it......012" runout. I got good with my 4 jaw😂
ohhhh
How about just get a chuck that's not worn out.
yes at great expense, this works well for now :)
Achieve no runout? But there is runout
Run out ok face out