6 Jaw vs 4 chuck any users

[shortgrass]

HUGE difference between gunsmithing and production work. I didn't say anything about "cheap" lathe chucks, I mention "middle of the road". And again,,, I know of NO ONE doing barrel work who is "hoggin' " off material at speeds & feeds you'll find in a prduction shop. If ya' are (on a manual lathe) you won't be around long. Nothing wrong with a Bison or Pratt Burnerd for gunsmithing work. I own both. Both will easily out last me (for gunsmithing). I can get repair parts for either, if need,, but I doubt they will be (needed). Disassemble, clean out the chips, rub a little grease on the moving parts, and they're ready to go again. The cheap Chineese chucks are just that, cheap and unreliable.

 

[SidecarFlip]

I just priced a new Buck 6" independent, flat back, 4 jaw,,,,,,,,,, $765.

Funny I never saw this thread before. I use this stuff everyday, I'm actually taking a break from the machines right now.

Contrary to some opinions expressed here, I don't consider Buck chucks to be the best and I have a couple. Couple Bisons and a couple Skoda's. some 3 jaw, some 4 jaw and a 6 jaw which is referred to as an 'Oilfield' chuck.

No matter what holding device you use, it will only be as good as the spindle runout and the mounting. design, like, D1 Camlock or threaded spindle nose (which are the 2 common).

By far the most accurate and repeatable means of fixturing any part, cases included will be a drawbar collet, if a lathe, they will be C3's unless it's an old machine and in that case they may be 3AT's or a number of other bastard designs. I tend to use ER (extend range collets). I do all thin wall with collets or I make specialty collets for odd sized work. Thay are referred to as 'emergency" collets, come in solid nose and can be bored to the desired dimension.

You can but the most expensive chuck and it will never be more accurate (radial and TIR) than the mounting plate to spindle runout, taking into account the actual TIR of the spindle itself.

...and yes, just like everything else, you get what you pay for, chucks included, but thats a very small part..... You guys think guns are expensive, my 6" x 6" Brown and Sharp magnetic sine plate (that I use on the surface grinder) cost almost $5000.00 and the Weber gage block set that I use to adjust the chuck (sine angle) cost $3500.00 for 126 blocks. My LSS height master that I use on the surface plate ($700.00) was over 1500 bucks.....

Guns are real cheap compared to measuring instruments, fixturing and tooling.

For mills, the accepted standard is R8's but I also use CAT 40 with through the spindle coolant.

Probably the most accurate chuck made as far as jaw to body accuracy is a 'Set-Tru'.

Got to back out and make parts, I have customers waiting........

 

[Trickymissfit]

Funny I never saw this thread before. I use this stuff everyday, I'm actually taking a break from the machines right now.

Contrary to some opinions expressed here, I don't consider Buck chucks to be the best and I have a couple. Couple Bisons and a couple Skoda's. some 3 jaw, some 4 jaw and a 6 jaw which is referred to as an 'Oilfield' chuck.

No matter what holding device you use, it will only be as good as the spindle runout and the mounting. design, like, D1 Camlock or threaded spindle nose (which are the 2 common).

By far the most accurate and repeatable means of fixturing any part, cases included will be a drawbar collet, if a lathe, they will be C3's unless it's an old machine and in that case they may be 3AT's or a number of other bastard designs. I tend to use ER (extend range collets). I do all thin wall with collets or I make specialty collets for odd sized work. Thay are referred to as 'emergency" collets, come in solid nose and can be bored to the desired dimension.

You can but the most expensive chuck and it will never be more accurate (radial and TIR) than the mounting plate to spindle runout, taking into account the actual TIR of the spindle itself.

...and yes, just like everything else, you get what you pay for, chucks included, but thats a very small part..... You guys think guns are expensive, my 6" x 6" Brown and Sharp magnetic sine plate (that I use on the surface grinder) cost almost $5000.00 and the Weber gage block set that I use to adjust the chuck (sine angle) cost $3500.00 for 126 blocks. My LSS height master that I use on the surface plate ($700.00) was over 1500 bucks.....

Guns are real cheap compared to measuring instruments, fixturing and tooling.

For mills, the accepted standard is R8's but I also use CAT 40 with through the spindle coolant.

Probably the most accurate chuck made as far as jaw to body accuracy is a 'Set-Tru'.

Got to back out and make parts, I have customers waiting........

several good points.

* The tapered nose end that the LeBlonds used is very accurate if it dosn't have any hickeys on the male part. I kinda like the good old cam lock myself, but I did seome serious spindle checks on a few LeBlonds awhile back, and I'd almost swear the ground that nose in while it was in the spindle bearings. If the bearings are installed right, they're be very accurate. The spindle could be a little heavier in construction, but have yet to ever see one taxed beyound it's limits.

* when it comes to prehardened steels and your serious about the accuracey, you probably will use the collet system. There are chucks that make up for these issues, but are not as reliable. I've seen collet systems that ran .0005" all day long cutting some fairly nasty stuff (not the small Hardingh collets)

* I know what your talking about when it comes to buying gauge blocks! I bought the same set your talking about plus the samething in metric. Then turned right around and bought the set that has all the long blocks out to 12". Used them everyday, and actually wore some of the blocks out when I had them checked. I seemed to always have a bunch of gauge pins on order, and at onetime must have been buying twenty to thirty a month. I know where your comming from here!

* few years back I found a compound sine plate setting in the racks. Took it back to the shop and checked it out. Great shape electricly, and really just needed to be completely reground (not exactly fun). I worked off and on on the plate for a month grinding it one tenth at a time, and ended up with a nice plate. So about six months later I'm walking past that same rack and I see this crate with about a quarter inch of dust and crud all over it (everything over there was to be scrapped). I find a brand new Nikken rototary table (12") that was their super precision grade. (this is the one you use Jo blocks to set the angles). There was another crate right next to it that had a thirty year old shipping tag on it. It had six angle plates in it, and all were menonite and unground. (i'd hit the mutha load!!) I bring everything back and give away three of the angle plates. I scraped in the other three (takes three angle plates to do it right). I ended up with a matched set of three angle plates that had less than a half tenth of error in them. So even later I see a large crate full of mics and indicators with a cadillac gauge setting in the mess. Was all labled to scrap! I grab that cadillac gauge and find out that it was as new, and much better than the one I was using. The one thing that always elluded me was a good (and also large) horizontal centers to gauge spindles. I did find one once and it was gone before I got my hands on it.
gary

 

[ken snyder]

I'm pretty sure that the large volume rifle manufacturers use the latest and as fancy as can be bought equipment and certainly do not consider them a pinnacle of quality. There has to be hundreds of little guys down the street that are producing very good examples of quality on the old manual stuff and equipment that is no better than good.

Outside of high volume work there is no need of better than good Chucks or equipment. If a person does not know how to set up with anything more than decent equipment then he or she will learn how to if given the chance.

Lots of shops require a dozen different of everything and a zillion dollars worth of toys. It is Apples and Oranges and most of us do not require the ability to make fruit salads. we have the ability to make our main interests very nicely.

 

[Jinx-)]

Very interesting information, I might buy some of the expensive toys if I get some spare change... Now I got another question, but I might have to open new topic, its about an old ProtoTrak Plus, had anyone tried connecting to it using RS232 male outlet on the back to upload program, just entering program from the console is plain pain specially when it can't be saved...

 

[SidecarFlip]

Well... Everything CNC I have is conversational programming, a quantum leap in CNC control. No G codes and no knowledge needed except real time dimensions.

Anyone (even me) can program because the on machine hardware intreprets the dimensional attributes and converts to linear G codes, all within the console.

Much simpler, much easier and quicker.

By the way TM, my Servo Shift has a Camlock spindle nose, actually all my machines are Camlock with the exception of one.

My take on machine tools and precision instruments versus firearms is, I make money with the machines, a livelyhood. I spend money on firearms. When I spend money with no tangible return, I'm very cost attentive. Making money (to buy luxury toys like firearms) with machine tools, I have no qualms about spending what I need to, to insure the end product is the best I can make it.

 

[Jinx-)]

SidecarFlip, I'm not sure about quantum leap, but what I have was design when tape recorders were quantum leap, however they did make parallel port entrance, so there should be a way to get connection to and from dnc - pc using null modem cables which are crosswire version of parallel port printer cables.... As far as LeBlonds Regals that's basically what I have to deal plus combination of gauge blocks and dial indicators...

 

[Trickymissfit]

Very interesting information, I might buy some of the expensive toys if I get some spare change... Now I got another question, but I might have to open new topic, its about an old ProtoTrak Plus, had anyone tried connecting to it using RS232 male outlet on the back to upload program, just entering program from the console is plain pain specially when it can't be saved...

I've been around it in a Bridgeport and also a Southwest Trac. Seems to work well with a machine that's capable of running with it. You really want a machine with ball screws and a good spindle head (in otherwords not worn out). We rarely used the RS232 port, but it can be done easilly. Most of the time we simply programed the data into the machine. The RS232 port is better suited for use with a Grecko Box, or something similar. On full bore CNC stuff we often used a Grecko Box after doing the program on a regular PC. An even better solution is the Meridian software package or else switching over to CAD Key. The later works well with the ProtoTrac system while AutoCad is not as easy.

In a milling machine like a typical Bridgeport your not going to do anything too complicated anyway, and the real advantage is with bolt circles and single layer stuff. Don't expect it to run like a typical CNC machine center, because it simply can't. We did some fooling around with it in some lathes, and was less than impressed. I'd take an old GE Dynapath seven days a week over it. The real problem you'll encounter is not in the electronics, but with the axis drives. They sell ball screw packages for Bridgeports, and probably the best money can buy is the one from Lead Screw International. The others use soft roll thread screws, and they don't hold up well.
gary

 

[Phil3]

I am just an older guy starting machining with a 9" Southbend 9A and an old Rotex mill. The lathe came with worn out 3 jaws, but got a 6" 4 jaw. As a perfectionist, I like the fact I could get indicated runout to zero on the chuck. And I can do it reasonably quickly...most of the time. Slow is the only downside. I also like the fact it can hold irregular shaped materials. Who would ever think you can make a cube on a lathe? I have a Bison 3-jaw I am getting ready to mount, which will be fine for most things, but still have a soft spot for the 4-jaw.

Phil

 

[Trickymissfit]

I am just an older guy starting machining with a 9" Southbend 9A and an old Rotex mill. The lathe came with worn out 3 jaws, but got a 6" 4 jaw. As a perfectionist, I like the fact I could get indicated runout to zero on the chuck. And I can do it reasonably quickly...most of the time. Slow is the only downside. I also like the fact it can hold irregular shaped materials. Who would ever think you can make a cube on a lathe? I have a Bison 3-jaw I am getting ready to mount, which will be fine for most things, but still have a soft spot for the 4-jaw.

Phil

I used to work in a shop that got a new Southbend every third year! They then sold it to the first employee that came up with the cash. The one I learned on went for the huge sum of $235 fully tooled up and with the old style collet head and chucks. Great little lathes back then. That same shop had a DoAll surface grinder (small one) that the only thing they did with it was grind carbide. It was all hand feed and was in absolute mint condition. Nobody liked it because it didn't have a power table, so only one old guy ever ran it. He actually kept the frame waxed! The guy had a massive heart attack and died, and it just sat there. They sold it for less than $500 complete. Replaced it with a Brown & Sharpe gauge quality grinder, and it wasn't as good as the DoAll! The best two I ever did was a couple of Hurcos that they picked up from another plant. They had me scrape them and do a complete rebuild on the slides and head. The machines had about two and a half tenths compound error in them for 16" (the factory specs were one thousandth in twelve inches). I told them about half way thru the first machine that they'd better have somebody go thru the elctronics, and was assured they were just fine (I knew better). Got them done and had them moved and leveled. They electronics were shot, and they didn't make spare parts for them anymore! I said that we should simply buy a couple new Bridgeport spindle motors and the motorized axis stuff. They sold them as is for $250 a piece! I couldn't buy them because I was an employee, and some guy that had a cabnet shop bought them!! The other was with two Excello thread grinders that they had me rescrape. This is a rather involved job that has to be near perfect. The machines were the deluxe versions that had the motorized dressers. Got them done, and ran some parts accross them. The gauge folks said they were the best they'd ever checked anywhere. They sold them for scrap six months later, and a buddy of mine bought both for less than $1500. He said the dresser alone was worth over $5000 used and unrebuilt. He grinds ball screws with them, and once told me they were better than any new machine he owned.
gary