I'm a REAL machinist now :-)

[Buckshot]

http://www.fototime.com/12375D46A9E5AEF/standard.jpg

I feel so accomplished :-) My lovely daughter volunteered me to check out a co-workers old Remington M12 (I think) pump 22RF rifle. How do ya say no to your one and only? Externally the rifle shows it's age. It's not abused but wasn't the best kept up either. The bore is trashed. What I thought was leading was active rust. Big clumps of it. Bummer. Had a split in the wrist from the rear of the action back maybe 3". Got that taken care of.

Now the fun part. It was missing one of the 2 pump handle screws. I didn't know it then, but I know now that James Wisener sells these for I think $2 each. Oh well. Why do I feel so accomplished? As close as I could tell checking the less then wonderfull threads on the one remaining screw, is that they're 42 TPI. My QC box on the lathe skips that one.

I finally got to swap out some gears :-) HA! So by putting a 37 tooth on the stud with a 48 tooth on the QC box, left lever at 'C' and the right lever under what is labeled '56', I get 42 TPI (snapping fingers). This was a first for me.

Plus, doing these weensy threads I had to use a magnifying glass when I ran the carriage back to the beginning to find the start point. When closing the half nuts you could only crank in maybe 1 or 2 thou at a time. What tedium! Naturally the threads are done last so all the other fiddly stuff could go down the tubes if those are messed up.

Anyway, I got it made. It screwed in smoothly and snugged up fine. Too bad about the barrel though, as it looks like it'd be a fun rifle to shoot.

..................Buckshot

[Bret4207]

Have him send it off to Redman for a liner. IME 22's often shoot better with lined barrels than in original. No idea why.

[2400]

Congrats on the nice work Buckshot. I'm with Brett, go with the liner.

[danski26]

Do you have Roy Dunlaps book "Gunsmithing"? He describes a "last resort" cleaning method involving an 1-8 solution of water to sulphuric acid. Dunlap says "The rust removing solition eats all impurities, leaving pure iron or steel".

I have never tried it myself. Just trying to help........

PS

Very nice lathe work!!!!!

[JSnover]

As close as I could tell checking the less then wonderfull threads on the one remaining screw, is that they're 42 TPI. My QC box on the lathe skips that one.

I finally got to swap out some gears :-) HA! So by putting a 37 tooth on the stud with a 48 tooth on the QC box, left lever at 'C' and the right lever under what is labeled '56', I get 42 TPI (snapping fingers). This was a first for me.
..................Buckshot

Nice work! I usually don't have the right gears but my machine has a pretty good feed selection. I turned half a dozen "odd" threads last year by converting TPI to inches per revolution. Probably an old trick but the last real machinist in my shop retired a while ago.

[JIMinPHX]

If you use a 127 to 120 tooth adapter gear, you can cut metric threads on an imperial gearbox too. It turns a 16tpi into a M1.5, etc. I’ve also had to do some gear swapping to get down to a 50tpi for grip screws on a 1911 that had extra fat custom stocks. For some reason, most boxes don't seem to have a 50 on them. These days I’ve taken to using timing belts & their associated shivs in place of change gears. They are much quieter & give me very good accuracy. The lash adjustments are easier to keep correct too.

[JIMinPHX]

Single point thread cutting is one of the things that separates the men from the boys in turning work. If you can generate a good thread form & hold a P.D. then you’re good.

[John Taylor]

That size screw is not to hard, try turning a #1X72. Even using the magnifying lens it was tough. Redman liners are OK for an inexpensive repair but my choice would be a hammer forged liner from TJ'S.

[Morgan Astorbilt]

Buckshot, Don't mind John, I think he's only pulling your chain. A 1x72 is a job for a jeweler's lathe, or a screw machine. I've been doing this for over fifty years, and never chased a thread nearly that small. Nice job on that screw!:drinks:
Morgan

[miestro_jerry]

Buckshot,

Great turning. I own a machine shop and people have a trouble doing single point threading the first time.

Great Job,

Jerry

[JIMinPHX]

Hey Buckshot,
did anybody ever tell you about the 29-1/2 degree in-feed trick for single pointing? It's not needed on fine threads like that, but when you move up into bigger stuff, it can be handy.

[grumpy one]

Nice work as usual Buckshot, my best jobs don't come anywhere near meeting your everyday standards.

Gear swapping is often a frustrating business. I found out the hard way that my German lathe (which has an inch leadscrew, as used to be fairly usual) turns out not to have any provision for cutting 13 threads per inch, which is inconvenient since that is required for half inch UNC. Unfortunately 1/2" UNC is a fairly common drawbolt thread for ISO 30 series milling machine toolholders, which is the kind I use. I therefore convinced myself I needed a high tensile drawbolt with only the end turned down to thread size. (I already had a rack full of drawbolts with various other threads, of course.)

To cut a 13 TPI thread I needed a 55 tooth gear, and didn't have one (because around here at least, nearly everyone uses Whitworth rather than UNC, and for half inch that is 12 TPI - the only common Whitworth thread that isn't the same pitch as the same size UNC thread). So, in my usual "How hard can it be?" way I decided I could achieve "almost" the right thread pitch by making a double-compound gear train (six gears, two idler pivots) instead of the single-compound (four gears, one idler pivot) the lathe came with. All I needed was an extra idler gear pivot. Having done all that I made the draw bar, but ended up finding that "almost" the right pitch didn't really cut it, at least by my standards. I could have fixed it by running a die over it of course, but if I'd had the right die I wouldn't have been thread-cutting to begin with. I bought a metre of high tensile half inch UNC threaded rod, and have been happy with it ever since.

And the moral of the story is, if you want to cut American threads, use a lathe designed for the purpose.

[Buckshot]

Hey Buckshot,
did anybody ever tell you about the 29-1/2 degree in-feed trick for single pointing? It's not needed on fine threads like that, but when you move up into bigger stuff, it can be handy.

............Oh this wasn't my first threading job, just the tiniest and the first time I had to swap a gear out :-). BTW, my compound stays cinched down at 29-1/2*.

Since a lot of threading is done on stuff with a shoulder, I cut from the backside with the spindle reversed, and the compound can remain set as it is.

http://www.fototime.com/BA6361C20C96D6A/standard.jpg

That's a little 4" chuck on a 5C back. I like using collets as much as possible but sometimes ya just gotta have a 3 or 4 jaw chuck and even a little 4 incher can do a lot. Since they're on 5C backs I don't have to tear down the closer setup as much.

http://www.fototime.com/5D8266D7DD3697C/standard.jpg

And here is just some straight turning, but that compound is at 29 ena half!

...............Buckshot

[JIMinPHX]

BTW, my compound stays cinched down at 29-1/2*.



Just checking... I figured that there was a pretty good chance you were in on the finer points of chip loading only one side of the tool, but I just wanted to be sure. The only silly question is the one that you don't ask.

I usually keep my compound pointing parallel to the spindle axis. That way I can work off the dial to generate shoulder depths. I only use the 29-1/2 trick when I’m cutting threads that are wider than 16tpi or when I’m in tough material. What you can get away with all depends on how beefy your machine & your tooling are. I used to have a big greasy old Hendy with about a 9” diameter taper bearing in the spindle & ways that were about 14” apart. That thing could cut a 1-1/4” 8tpi in leadloy with a straight infeed. It was a brutal machine for heavy work. It was not so good for small diameter work. The spindle didn’t like high RPMs.



That's a little 4" chuck on a 5C back. I like using collets as much as possible but sometimes ya just gotta have a 3 or 4 jaw chuck and even a little 4 incher can do a lot.

...............Buckshot

I used to use a rig like that on a Hardinge that I ran about 15 years ago. It's sweet to be able to just dump a chuck in quick like that & still get good concentricity. I also agree that collets are the nicer way to work, when that option is viable. A good grip & no marred finishes…both beautiful things.

It looks like you have a pretty official rig there. I like it.

[JIMinPHX]

Since a lot of threading is done on stuff with a shoulder, I cut from the backside with the spindle reversed, and the compound can remain set as it is.
Buckshot
When I'm cutting right hand threads, I always try to cut from the back side. it's a good way to prevent spindle crashes.

...Not that something like that would ever happen to me of course ;-)

[Buckshot]

...........Jim, well it isn't a "Big ole greasy Hendy", nor Monarch, Leblond, or American Pacemaker :-) just a lowly 11x36 Logan/Powermatic. Nice thing about it was it was made in 1981, and my buddy I got it from bought it from the original purchaser. They had used it as a chucker with a dual toolpost cross slide and a bed mounted turret (which I have both of). So there was almost no sliding of a carriage going on.

In fact when my friend picked it up they had to find all the stuff for it, as the tailstock, QC box and leadescrew had been removed and stuck up in he rafters (he said).

It IS a nice lathe, and I was lucky to get it. Has a hardened bed, L00 spindle with a 1-3/8" hole, infinitly variable speed underdrive (45 -2000 rpm's) with a 2 hp Leeson 3~ motor. My friend had a 50's vintage 11" Logan all setup and he didn't want to mess around swapping lathes, so he sold me this one for $1500. It came with the 5C collet closer, 8" travel bed mounted turret, dual toolpost cross slide and some turret tooling, steady, a 6 jaw Buck Adust-Tru, a 2 jaw Buck Adjust -Tru, a 3 jaw Rohm, 2 brand new face plates, a "T" slotted face plate, and a dog drive plate.

ENCO just started carrying Buck chucks and I showed him that without the back plates, a 6 Jaw Buck adustable chuck is like $1300 :-) He said, "Well I guess you got a free lathe with the chuck then." I've added 3 and 4 jaw Bison chuck's to the stable, and ER30 & 40 collets. The Rohm is a 10" and I can barely pick it up, so I've never used it.

................Buckshot

[Catshooter]

Man, Buchshot, I'd say you were lucky to get it! I'd love to fall into the same! Good going.


Cat

[JIMinPHX]

American Pacemaker

Wow, there's one I've never heard of before.

A Logan is a good machine. My brother had one. He did well with it.

You did real well on that deal in terms of price, especially with all that tooling. Rohm chucks are real good to work with, but they don't command the kind of money that a Buck or Cushman does. You still did super well on that deal.

I was unaware that Logan used an L-nose spindle. I've only seen them on Clausings. Most everything else these days that isn't a screw on seems to be leaning towards a D mount of some sort.

Bison chucks are a bit of a gamble. Some are better than others The concentricity on most of them is pretty good & the top jaw slots are usually (but not always) pretty well ground. They frequently tend to be prone to detail problems like poor quality threads in the base jaws, poorly finished scroll gears & pinions that are out of true. Not all of them have these problems, but it seems fairly common. That said, they are still probably the best value on the market. They are relatively inexpensive & with a little TLC they can usually be made into something that you can work with & not feel the need to cry about it. Anybody that owns a lathe should be able to whip up some custom top jaw screws, etc. to accommodate their idiosyncrasies.

You seem to be a little bit bigger fan of ENCO than I am. I haven't used them for anything in the last 10 or 15 years, so maybe they have gotten better. In the past, they were OK for buying name brand stuff, like a Jacobs chuck, from. But anything from them that was off brand back then was complete garbage & ended up in the appropriate receptacle. Conversely, I've always had good luck with MSC. They have some of the lower priced off-brand stuff too, but they have a full selection of mid & top quality stuff as well. They tell you honestly what the quality of each item is & their prices are fair. Occasionally I'll also go to somebody like Rutland. They're generally not too bad. If I knew of a good local shop, I'd buy stuff there, but the guys around here don't seem to have what I need.

You say that you have a vari-drive on that logan...Is that the belt with the variable shivs or the electronic type that changes the speed of the motor itself?

[lathesmith]

I have a Bison 5-inch 3-jaw here, and I consider it an outstanding chuck value. I ordered it from Enco, so guess what I have to say about them? They have always shipped promptly and seem to have most of their listed catalogue items in stock. Unfortunately, I cannot say the same about the local Grizzly here; I like their stuff and they are nice folks, but they don't seem to stock much of what is listed in their catalogue, at least machine stuff. They may be experiencing growing pains though, and hopefully this will improve with time. I hope so!
lathesmith

[JSnover]

I know a sizeable group of machinists using Grizzly and Enco lathes and they're all pretty happy with them. You don't have to look too closely at the Chinese imports to see that they're coming out of the same factory. You do have to spend a bit more for the higher-end models if you want a tight machine that doesn't need a lot of work to get up to your standards.

[Buckshot]

Wow, there's one I've never heard of before.

A Logan is a good machine. My brother had one. He did well with it.
You say that you have a vari-drive on that logan...Is that the belt with the variable shivs or the electronic type that changes the speed of the motor itself?

..........It's the variable width pully system. The motor runs full speed all the time. I think the 9" and 10" Logans only came with threaded spindles. The 11" was either threaded or the L00. The 12" & 14" machines were threaded, 'L' series (L0 I think on the 14"), or 'D' camlock. As Logan was bought by Powermatic in 1971, I don't know if those spindle nose options were solely Powermatic's doing or not.

http://www.fototime.com/0CF5A5E9AD5C3C1/standard.jpg

This is the only photo I currently have of 'most' of the whole lathe :-). I had the carriage off trying to stop an oil leak. It has a wet apron and the oil would slowly ooze out through the seam. Turns out there is no gasket and they depend on a close machined fit. I cleaned it up and used some form a gasket and put it back together.

Still leaks but now I only have to add a little oil maybe once a month instead of adding a little every time I went to use it.

Speaking of that, that's how some people ruin machines. Either ignorance or just plain laziness. When I was looking at my lathe to buy it I noticed the square head of a drain plug under the apron and asked Glen if there was supposed to be oil in it. He said "Yeah but it leaks out so don't bother". [smilie=b:

It was a few months after I got the lathe when I had the carriage off, I had to do some turning so he offered the use of his lathe. Now I'm an oiler. If I had a crane and big enough tank I'd probably dunk the whole thing in it. Anyway I asked for his oil can. There is an oil hole in the handle of the leadescrew reverse lever, that carries oil to the stud gear sleeve.

So when I swung the guard out of the way to get to it he asked what I was doing. He didn't even know it was there, or what it was for. The next thing was to oil the backgear shaft that's under the spindle. His older Logan has the motor on the back and drives via a leather belt. When you lift the cover, it slacks the belt. He thought I was wanting to change the speed, but I explained I was going to oil the backgear shaft and he didn't know about that oiler either.

God only knows how many years he's run the machine never oiling either place. The other spots he knew about. I suppose that's a testament to oilless bronze bushes?

................Buckshot

[John Taylor]

Buckshot, Don't mind John, I think he's only pulling your chain. A 1x72 is a job for a jeweler's lathe, or a screw machine. I've been doing this for over fifty years, and never chased a thread nearly that small. Nice job on that screw!:drinks:
Morgan

Morgan, I wasn't trying to put Buckshot down. There are a lot of "machinist " out there that can't do single point threads. The 1X72 screw is used in some of the model 42 Winchesters. My customer would like me to make a bunch more and after having a conversation about the project he sent a tap and die for that size. The first one was made on an old Select 12X37 lathe. I did mess up a few before I got one to work. No patience on my part to wait for the die. Very hard to keep from loosing one of these small screws, if it drops you might as well make another one because it can't be found in the chip pan. It is much easier to turn threads on a barrel than do some of the small screws.
You did good Buckshot.

[Morgan Astorbilt]

John, I'm sure you weren't. I know only too well about trying to find small parts in the chip pan. Below is a photo of a tailstock 1-1/2" die holder I made, using a #3 MT center of unknown origin.
I've long planned to make one for 13/16" dies, with a 1/8" shank, and use it with my spring loaded Albrecht micro chuck, mounted in the regular tailstock chuck, and let the threads advance the die against soft pressure of the return spring. This should make threading even 0-80 screws possible. Just one of those jobs I've never gotten around to.
Morgan

http://i201.photobucket.com/albums/aa159/pgfaini/100_1820.jpg

[JIMinPHX]

It's the variable width pully system.


The mechanical vari-drives were used quite successfully by both Hardinge & Clausing too. They were also quite common on J-head Bridgeport mills. When they are kept in good condition, they work very well for many years. Basic maintenance usually consists of running them through their full range of speed semi-often plus a little cleaning & lubrication once in a while. If that little bit of attention is given to them, then the eventual belt change should be the only repair that is needed for a good many years. Unfortunately, many people ignore the simple instructions that are written right on the side of a J-head & even this minor care is not given to them.

The advantage of the mechanical vari-drives over the electronic ones is that they are always running constant horsepower. As you reduce speed, you get an increase in torque & visa versa. With the electronic ones, you have a constant horsepower region & a constant torque region in the speed range. When the motor is run at or above the nameplate RPM, you are running in constant horsepower & torque diminishes as speed increases. Below nameplate RPM, you are running constant torque & horsepower drops off as speed decreases. You don’t get the increase in torque as speed goes down like you do in the mechanical systems. With the electronic gizmos, you are better off gearing down & overspeeding the motor to get the spindle speed that you want. That way, you have full power available. The next best thing is to simply oversize the motor to give you some breathing room.

The advantages of the electronic vari-drives are three fold. First, they are quick & easy to retrofit to any standard three phase motor. Second, they can be easily controlled by a little speed dial that takes no effort to move & can be located anywhere or preset speed switches. Third, they can frequently be used to run a three phase motor off of a single phase primary. That is to say that most of them will take either single phase or three phase as primary power & still be able to give you a 3 phase output. In many cases, you can even use one of them to run a 220-volt motor off of a 440-volt or even 600-volt primary. There are some considerations regarding power derating when you single phase their primaries & there are some considerations about derating a standard motor when you run it off an electronic drive, but they are a real quick & handy way to get a lot of new functionality out of a basic machine. With minor controls finagling, they can even let you get constant surface speed on a facing cut or a taper cut in a lathe. They can be real handy little gizmos at times.

[JIMinPHX]

I have a Bison 5-inch 3-jaw here, and I consider it an outstanding chuck value. I ordered it from Enco, so guess what I have to say about them? They have always shipped promptly and seem to have most of their listed catalogue items in stock. Unfortunately, I cannot say the same about the local Grizzly here; I like their stuff and they are nice folks, but they don't seem to stock much of what is listed in their catalogue, at least machine stuff. They may be experiencing growing pains though, and hopefully this will improve with time. I hope so!
lathesmith

As I said, I haven’t ordered from Enco in a very long time, so maybe they have gotten better. MSC is also excellent about having stock & shipping promptly. They are on par with McMaster Carr that way.

Also, I didn’t mean to imply that Bison chucks always have problems. Many of them are good right out of the box. It’s just that their quality can’t be counted on to be 100% on each individual unit that you buy like it can with a cushman or something. Of course, for the price of the cushman, You could buy 5 Bison chucks, throw away the imperfect one(s) & still have a good spare or two left over after mounting up your pick of the litter. My brother seems to have better luck than I do getting stuff from them that is good right out of the box. I’m glad to hear that your luck seems more like his than mine. I had to do a little extra work to get what I wanted out of mine. It’s a good unit now though.

[Buckshot]

...................Both my Bison 3 jaw and 4 jaw are fine unit's and no complaints from me. I do recall there was a machine tool company that carried Bison products but they were actually warning people AWAY from Bison made collets. Don't recall if it was ALL bison made collets or just maybe 5C's, R8's or what. They were saying that Bison didn't have collet making figured out yet :-) This was maybe 3 years ago.

...............Buckshot

[JIMinPHX]

...They were saying that Bison didn't have collet making figured out yet :-) This was maybe 3 years ago.


My first Bison chuck was bought about 12 or 14 years ago. That may have something to do with it.

[Morgan Astorbilt]

Not to steal the thread, but I've got a 10" Polish 4-jaw, which I purchased from MSC about 15 yrs. ago. It has given me excellent service, and I was wondering if someone on the board might know the name of the manufacturer.
It's got a logo with the letters F R J inside of a hexagon,( A large "R" in the center, and a small "F' and "J" on each side) the model designation: 4354-10/LO (It's a 10" chuck with an L-O back). Thought I'd check here, before I contact MSC, and post on the Practical Machinist site.

Morgan