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Which chuck? Opinions requested
- Thread starter Razzle
- Start date
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- Jan 31, 2016
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- 13,385
Shoot , can't help you with the back plates but I have a few chucks up here not being used . They're going to make their way down to the swap meet in July .
- Joined
- Jul 22, 2013
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- 135
So my current 4 jaw is a Watson 6". it takes a 9/32" or 7mm chuck key. It has this funky back plate that sticks it out about 2" from the spindle and is only about 1/4" thick at the back of the chuck. Too thin to reface and fit to the lathe. I thought about getting a new backplate for it. But I don't know if it is worth spending money on it.
My 3 jaw is probably as old as the lathe and definately needs jaw grinding to just square up the jaws.
Both are functional but have given me trouble on projects.
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My 3 jaw is probably as old as the lathe and definately needs jaw grinding to just square up the jaws.
Both are functional but have given me trouble on projects.
Sent from my Pixel 4a using Tapatalk
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- Dec 20, 2012
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- 9,408
My vote goes to a good 3 jaw chuck, just a plain scroll chuck without the set-tru feature. This will work on all nominal stock and will be dead on accurate for first operations work if the jaws are in decent shape. For a hobby guy, this is the cheapest way to go and will handle 90+% of the jobs you'll do on the lathe. They also tend to be the cheapest chuck configuration.
4 jaw independent chucks are the most potentially accurate chucks and are also useful for turning off-axis features on a part but they are slower to use. For first op work, this would not be my choice. However, you should have one for second op work when accuracy counts.
Set-tru scroll chucks are nice to have IF you are doing multiples in a production run and want the speed of a 3 jaw or scroll chuck. You can dial them in for a specific diameter and they will minimize run out for that specific diameter. However, if you chuck up something that is not of the same diameter then run out can increase significantly, even in the same production run. Not all nominal stock is the same size, trust me. The common argument you will see is that "I dialed in my set-tru 3 jaw for minimal run out and it is the most accurate chuck I have". True, too. However, the reality is that if the application is first op work on nominal stock then a plain old 3 jaw will be just as accurate. Where a set-tru 3 jaw has an advantage is if you use it for second op work or you're turning accurately ground stock; then it is clearly a better option if speed is important. Otherwise, a 4 jaw is probably as good an option, if not better.
So, I would suggest a 3 jaw from a good maker - Pratt Burnered International from England, Rohm from Germany, Yuasa from Japan, Samchully from Korea are all top shelf and there are others. Soul from Japan and Bison are also good. The best chucks are forged steel, have published minimal run out numbers and the most accurate pinion will be marked.
Last edited:
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- Jan 1, 2018
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- 1,358
It seems like lapping the jaws because they are too tight is better than the jaws arriving too loose.I am well pleased with the 6" Sanou I got for my SB Heavy 10. I did have to lap the jaws to make them slide more freely.
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I had never heard of a Set-Tru chuck before. Is the whole chuck dialed in with relation to the backing plate? Just curious how they work?
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- Jul 29, 2014
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I had only a 4 jaw on my 10” Logan, and I got spoiled by always having approximately zero runout. You can get pretty fast at dialing a part in, work on it, then flip it around and work some more with no significant error.
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- Jan 20, 2018
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Yes, exactly. The entire scroll/jaw assembly can be adjusted to run true by the means of socket screws around the periphery of the chuck after the part has been clamped. Think of a 3-jaw held in a 4-jaw.
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- Dec 20, 2012
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To clarify a little bit, a set-tru chuck is simply a scroll chuck that can be moved around on the back plate by screws on the periphery of the back plate. You loosen the screws that hold the chuck to the back plate and indicate on the work piece being held in the chuck while adjusting the screws on the back plate. This allows you to dial in the work piece to zero or close to it. Then you lock the screws that hold the chuck to the back plate and ideally nothing moves. At that point the chuck is able to hold any work piece of the specific diameter that was used to dial the chuck in very accurately. The catch is that if the work piece diameter changes then your alignment changes and you have to do it all over again.
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- Feb 13, 2017
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Early on, when I first made the transition from Pop's electic drill chucked up in a vise to a "real" lathe, I learned on a 4 jaw chuck. It was a bear to learn, but i got pretty good at it eventually. A three jaw scroll chuck makes most work a lot faster, but the bottom line is that it is nowhere near as accurate as a 4 jaw. Even a worn out 4 jaw chuck can do accurate work.
With that in mind, I would say to purchase a middlin' good three jaw for use where speed is more important than absolute accuracy. You already have a 4 jaw. Use it where accuracy is more important than speed. There's an entry above where a fellow comments his 4 jaw rattles as it runs. The key is that it is accurate.
I have a couple of 3 jaw chucks. But then I got a couple of lathes with the same nose spindle thread. One is old, likely from the '50s, the other is relatively new from Taiwan. Neither is particularly accurate, but both have livable runout. On the rare occasion that I am looking for zero runout, there is a 4 jaw independent. It was bought used, and well worn whan I acquired it. But it still runs true.
I also have a 4 jaw scroll chuck, but it's not really necessary. I bought it when I was doing work on square stock. Setup was faster than dialing in the independent. A "classic" machine deserves a fancy chuck, yes. But the average work doesn't call for it. You have a good enough 4 jaw for accuracy, all you need is a 3 jaw for speed. If you're working on the cheap like I am, that's the bottom line.
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With that in mind, I would say to purchase a middlin' good three jaw for use where speed is more important than absolute accuracy. You already have a 4 jaw. Use it where accuracy is more important than speed. There's an entry above where a fellow comments his 4 jaw rattles as it runs. The key is that it is accurate.
I have a couple of 3 jaw chucks. But then I got a couple of lathes with the same nose spindle thread. One is old, likely from the '50s, the other is relatively new from Taiwan. Neither is particularly accurate, but both have livable runout. On the rare occasion that I am looking for zero runout, there is a 4 jaw independent. It was bought used, and well worn whan I acquired it. But it still runs true.
I also have a 4 jaw scroll chuck, but it's not really necessary. I bought it when I was doing work on square stock. Setup was faster than dialing in the independent. A "classic" machine deserves a fancy chuck, yes. But the average work doesn't call for it. You have a good enough 4 jaw for accuracy, all you need is a 3 jaw for speed. If you're working on the cheap like I am, that's the bottom line.
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