Interesting. My Taiwanese D1-5 Lathe didn't come with numbered nose cams.
No loss. I'd lose count if I tried to remember a number sequence anyway.
D1-5 Backplate
- Thread starter thestelster
- Start date
Interesting. My Taiwanese D1-5 Lathe didn't come with numbered nose cams.
No loss. I'd lose count if I tried to remember a number sequence anyway.
I machined the backplate to about 1.180" and left the flange longer and thicker than what is spec'd in the Atlas chuck dimensions, so that I can do the final fit while everything has cooled down.
I used a negative roughing insert taking 0.100" depth of cuts, and feed at 0.010" per rev, and 250rpm. I started with a feed of 0.005" but it was coming off in ribbons, so I increased the feed to 0.010" and all was good.
The tip of the insert broke after several passes during the interrupted cuts where the cam stud, and chuck holes where. Flipped to a new edge on the insert and reduced the feed to 0.005" and worked well, and no ribbons because of the interrupted cuts. Once past that, I increased the feed again.
I used a negative roughing insert taking 0.100" depth of cuts, and feed at 0.010" per rev, and 250rpm. I started with a feed of 0.005" but it was coming off in ribbons, so I increased the feed to 0.010" and all was good.
The tip of the insert broke after several passes during the interrupted cuts where the cam stud, and chuck holes where. Flipped to a new edge on the insert and reduced the feed to 0.005" and worked well, and no ribbons because of the interrupted cuts. Once past that, I increased the feed again.
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Well, I'm an idiot. After I reduced the thichkness of the backing plate down about 1.130", I realized that the threaded holes that the chuck will bolt onto by, had been almost completely disappeared. Well, after measuring, and determining I couldn't drill new holes in a different spot, I just deepened the existing threaded holes. The problem was that 2 of those holes also lined up with the screws that positions the cam lock studs, from the other side. Well, I just shortened those two screws.
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Ya, I should have warned you about that. It's not like I didn't know. I've been bitten by that too. It's a constant problem with 4 screw attachments on a 6 stud plate. Sometimes I put in 3 or 6 screws to deal with it. Unfortunately, 3 doesn't usually feel like enough and 6 seems like too many. I usually do 6. I hate tapping.....
Sorry about that Stell. My bad.
No problem. It worked out perfectly fine, just a whole bunch of extra work.
@thestelster - I've also sometimes overlapped threads on opposing screws to deal with this. It's not elegant or probably Kosher, but it works.
@thestelster - come to think of it, I believe I read someplace that this overlapping screw hole business is one of the reasons for thick back plates....... 
So now to mount the Atlas 6" 4-jaw independent chuck. But first, disassemble. This chuck is made in China.
There were no number markings to match up the jaw with it's slot, so I just used a Sharpie and marked the chuck, and as I disassembled, I put the parts in numbered stainless bowls, and into the Varsol wash tank. Cleaned out all the grit and some bits, and examined the parts.
It looked like the guy making these parts finished making one and pitched it 20 feet into a bin. Quite a few dings which I had to clean up using files, scrapers, and stones.
Of course the little red Atlas logo came out from the varsol.
The chuck key has this black oxide finish that was coming off on my hands, so wire wheeled it smooth.
The thrust bearing, that's what Bison calls it, the part that holds the operating screw in place, seemed like they were press fit in position. So I had to pound them out with a brass rod.
All the parts were hardened, but not glass hard. A file would just cut, so probably Rc40-45.
Deburred every thing, honed out the thrust bearing holes to a tight slip fit. I think the guy installing them at the factory just smashed them in with a hammer and peened the edges.
Stoned the back face of the chuck because of burs.
The jaws in their slots were tight, no perceived movement.
Installed the chuck to the backplate to a tight fit.
Bolted it together and checked TIR. Zeroed next to the jaws, and 0.0025" TIR at about 3.75" out.
Not so bad. Maybe one of these days I'll regrind the jaw faces.
Make no bones, this is not a Bison, which I have in 3-jaw. Is it better than an Accusize or Vevor? I don't know, I don't have one to compare.
I'll provide a follow-up in a couple months.
There were no number markings to match up the jaw with it's slot, so I just used a Sharpie and marked the chuck, and as I disassembled, I put the parts in numbered stainless bowls, and into the Varsol wash tank. Cleaned out all the grit and some bits, and examined the parts.
It looked like the guy making these parts finished making one and pitched it 20 feet into a bin. Quite a few dings which I had to clean up using files, scrapers, and stones.
Of course the little red Atlas logo came out from the varsol.
The chuck key has this black oxide finish that was coming off on my hands, so wire wheeled it smooth.
The thrust bearing, that's what Bison calls it, the part that holds the operating screw in place, seemed like they were press fit in position. So I had to pound them out with a brass rod.
All the parts were hardened, but not glass hard. A file would just cut, so probably Rc40-45.
Deburred every thing, honed out the thrust bearing holes to a tight slip fit. I think the guy installing them at the factory just smashed them in with a hammer and peened the edges.
Stoned the back face of the chuck because of burs.
The jaws in their slots were tight, no perceived movement.
Installed the chuck to the backplate to a tight fit.
Bolted it together and checked TIR. Zeroed next to the jaws, and 0.0025" TIR at about 3.75" out.
Not so bad. Maybe one of these days I'll regrind the jaw faces.
Make no bones, this is not a Bison, which I have in 3-jaw. Is it better than an Accusize or Vevor? I don't know, I don't have one to compare.
I'll provide a follow-up in a couple months.
Attachments
The only other thing I would check is radial balance (presuming you are using this more for accurate dial of cylindrical parts vs. holding non-symmetrical parts which will be unbalanced anyways).
I have read about some wobblers that adversely affected finish & accuracy. Sometimes you visually see casting thickness/geometry variations.
Coincidentally today on the HM forum, a guy used my links posted a few years ago to check prices of 6" 6-jaw Set-Tru type chucks, Gator vs Bison. Unless there is a typo on the Gator (which says it includes the ST backplate in price) Bison has become very expensive. And the USA prices are better than CDN distributers. I have Gator 5" 2-part style chucks, might be 8 years old now? They are IMO, 90% of a Bison & most of that is cosmetic. Scroll isn't quite as smooth, some grind quality finish, but jaw seat fit & TIR is comparable. Gator specifically has had some up & down QC over time so I don't know how they are lately & they are not as predominant among dealers. I think Asian chuck makers are up-ing their game though. Some chucks sizes are closer in price than others, so maybe that's a factor & Bison parts are abundant so that might be a factor.
I have read about some wobblers that adversely affected finish & accuracy. Sometimes you visually see casting thickness/geometry variations.
Coincidentally today on the HM forum, a guy used my links posted a few years ago to check prices of 6" 6-jaw Set-Tru type chucks, Gator vs Bison. Unless there is a typo on the Gator (which says it includes the ST backplate in price) Bison has become very expensive. And the USA prices are better than CDN distributers. I have Gator 5" 2-part style chucks, might be 8 years old now? They are IMO, 90% of a Bison & most of that is cosmetic. Scroll isn't quite as smooth, some grind quality finish, but jaw seat fit & TIR is comparable. Gator specifically has had some up & down QC over time so I don't know how they are lately & they are not as predominant among dealers. I think Asian chuck makers are up-ing their game though. Some chucks sizes are closer in price than others, so maybe that's a factor & Bison parts are abundant so that might be a factor.
6" GATOR Lathe Chuck 6 Jaw TRU ADJUSTABLE + ADAPTER FORGED
www.ajaxtoolsupply.com
6" BISON 6 Jaw SET-TRU Chuck Forged Steel 7-868-0600
www.ajaxtoolsupply.com
I'll be using this new 4-jaw for dialing in bores that are not concentric with their OD. Usually only off by a couple thou'.