Taking Chinese 3 Jaw Metal Lathe chuck apart for cleaning

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Jim Dobson
Posts: 15
Joined: Fri Sep 06, 2013 6:05 pm

Taking Chinese 3 Jaw Metal Lathe chuck apart for cleaning

Post by Jim Dobson » Wed May 29, 2019 12:32 am

Taking the Chinese 3 Jaw Metal Lathe chuck apart for cleaning. Really happy I did this. The chuck hadn't been as smooth as it had been and there was a lot of crap inside it. Back to its usual smoothness and a pleasure to use again. Never done it before and it proved fairly easy. If yours isn't smooth, don't hesitate to take it apart and clean it.

[youtube]https://youtu.be/WK2veaUNyQ0[/youtube]
Cheers Jim
My Youtube Channel -
Blue Heeler's Model & Toy Steam Engine Room

Jim Dobson
Posts: 15
Joined: Fri Sep 06, 2013 6:05 pm

Re: Taking Chinese 3 Jaw Metal Lathe chuck apart for cleaning

Post by Jim Dobson » Wed May 29, 2019 12:32 am

Cheers Jim
My Youtube Channel -
Blue Heeler's Model & Toy Steam Engine Room

RSG
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Re: Taking Chinese 3 Jaw Metal Lathe chuck apart for cleaning

Post by RSG » Wed May 29, 2019 7:48 am

Nice Jim!
Vision is not seeing things as they are, but as they will be.

Jim Dobson
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Joined: Fri Sep 06, 2013 6:05 pm

Re: Taking Chinese 3 Jaw Metal Lathe chuck apart for cleaning

Post by Jim Dobson » Wed May 29, 2019 8:02 am

Thanks RSG.
Cheers Jim
My Youtube Channel -
Blue Heeler's Model & Toy Steam Engine Room

pete
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Re: Taking Chinese 3 Jaw Metal Lathe chuck apart for cleaning

Post by pete » Wed May 29, 2019 4:41 pm

As you've found Jim most lathe chucks are pretty simple. Any binding while opening or closing is a sure sign they need a cleaning. I've got a mix of 3 & 4 jaw European and far east chucks. I can't say about the Chinese one's, but the instructions for my Emco's were quite specific about making sure the scroll pinions go back in the same location each time you clean the chuck. The reason was that the master zero marked pinion was what was used to finish grind the jaws for the best concentricity. Tbh it's never seemed to make 100% logical sense, but I'm not about to second guess the chuck manufacturer. If they consider it important enough to mention then there must be some good reason behind it. A few weeks ago I watched a Haas video about properly cleaning and re-lubing a cnc power chuck and they made a point of mentioning the internal parts will have slightly different wear patterns and also wear into there location so should be placed back in that same location each time the chucks cleaned. Out of habit with my Emco's I just do the same with the Chinese chucks as well. And while those Emco's have never needed any deburring, spending an hr or so with some fine needle files and stones and deburring every surface on the Chinese chucks including the scroll & pinion teeth, scroll, the jaws and there teeth and slots etc make them much much smoother to operate and pull apart for cleaning. I've also found that polishing both the pinion slots and pinion retaining pins helps to smooth the operation out a bit more. All that gets done for you with the more costly chucks. But at the price of the off shore one's there's no money left for them to do so.

It's a standard chuck maintenance item, but for some reason not well known by the average person with a home shop that pulling chucks apart for a detailed cleaning once in awhile isn't optional. So maybe your video will help. Through drilling and boring parts obviously creates the most problems. When I remember I'll usually close the chuck jaws to just about where they grip the part and then stuff a rag or paper towel inside the chucks recess and just below where the parts rear face will be. It delays the inevitable chuck cleaning by quite a bit. Bison and maybe some others sell a "special" chuck grease. I've tried a few different automotive type greases and way oil and think a light film of the way oil works better since the grease tends to retain the chips in semi fixed locations while the oil seems to allow the chips to slide out of the way a bit better. I do know using any type of grease for lubrication seems require far more frequent chuck cleaning. I suspect but don't know for sure that the chuck grease might be a better idea if you were using flood coolant. The one issue with the oil is you'll get a slight spray of it coming out the first few times you spin the chuck up to high rpms.

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BadDog
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Re: Taking Chinese 3 Jaw Metal Lathe chuck apart for cleaning

Post by BadDog » Wed May 29, 2019 5:50 pm

Yeah, the worst is boring cast iron or cast steel where the back of the bore drops right in on the scroll. What a mess... I've tried pugging, but that usually just causes pile-up and recut problems for me.
Russ
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jcfx
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Location: NY

Re: Taking Chinese 3 Jaw Metal Lathe chuck apart for cleaning

Post by jcfx » Wed May 29, 2019 6:08 pm

pete wrote:
Wed May 29, 2019 4:41 pm
... but the instructions for my Emco's were quite specific about making sure the scroll pinions go back in the same location each time you clean the chuck. The reason was that the master zero marked pinion was what was used to finish grind the jaws for the best concentricity. Tbh it's never seemed to make 100% logical sense, but I'm not about to second guess the chuck manufacturer. If they consider it important enough to mention then there must be some good reason behind it. .....
I have often wondered what that zero mark is on my Emco chucks, interesting bit of info.

Jim Dobson
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Joined: Fri Sep 06, 2013 6:05 pm

Re: Taking Chinese 3 Jaw Metal Lathe chuck apart for cleaning

Post by Jim Dobson » Wed May 29, 2019 7:20 pm

Appreciate the replies one and all, I did whip it back off today and lightly grease inside.
Cheers Jim
My Youtube Channel -
Blue Heeler's Model & Toy Steam Engine Room

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