Gunsmithing Lathe

[Black Diamond 408]

I started out on a old South Bend Lathe, 3/4" hole in spindle so you know what thats like. I then bought a new lathe, Enco 13x36" with 1.375" spindle, so I was in heaven. I must of done hundreds of barrels and many other projects for local shops. It got tired and needed some re building. I saved up my $ and started to look for a larger lathe. I researched the Grizzley's, talked to people that own them and got good reports. I ended up with the larger of the two
gunsmith lathes, 5200 or somthing like that. It is amazing on how smooth it runs and so many gunsmith options built in, this lathe makes my old one seem like a meat grinder. I needed a lathe that i could work on 2" dia barrels and the Grizzley has the 2" bore through the headstock. Only draw back for me was the 3 phase power it required. Where I live there is none so I had to go the Converter route, just an added expense. My advice is spend the extra cash and get a good lathe, you will be happy in the long run. I now have two lathes and two mills in my shop. Newest addition is a Bridgeport Series 1 CNC mill with 4th Axis.

Dave

 

[goldnuggetprinting]

Hi there-

I saw your 2008 post regarding a gunsmith lathe. I have been looking at the Smithy. What did you end up settling on?

Please reply.

Michael

 

[Trickymissfit]

well to start with if your really shopping for a good quality lathe your gonna need 440 three phase electricity. The best current production small lathe on this planet is a Hardingh, and they don't come cheap. Probably the next would be a Colchester. The best lathe for accuracey, but still be had on the cheap is to look for a War Surplus Monarch EE. I've seen these often go for under $500 in great shape. Just be sure to buy the one with the solid state drive instead of tubes (you can still buy the tubes, but not the rest. For serious work the Monarch is the Cadillac. The Leblond tool room lathes are very good, but no where near as durable or the quality of the Monarch hand lathe. You also might want to make sure your lathe will turn metric as well and SAE threads, and check the quick change box to see what threads they will and will not do (this may surprise you).

Guys ask me all the time what lathe to put in their garage, and if they are just doing barrel work I tell them to either look around for the Monarch or a Southbend with flame hardened ways. If the lathe is used you might need to scrape the compound and cross slide back in (pretty much any lathe that's been used will develope wear here). Next thing to check out is the condition of the half nut and lead screws (especially the cross slide). The next thing to check out is the spindle group and clutches (it it has them). I do a two part check with a lathe, and get cussed a lot from sellers. The first check is with the chuck installed, and with a two inch diameter (or larger) ground pin about 8" long. Chuck about an inch and a half of the pin, and put a .0005" indicator (wand type) as close to the face of the chuck as you can get. Now do the same about six inches out. Mark the high spots and low spots (we're assuming the jaws are in good shape and the chuck is either indicated in or it's a standard three jaw chuck. If everything is within .001" your probably gonna be OK with the chuck (we're looking to see if the chuck face is bent or it has been in a major wreck). Now take a piece of aluminum, and chuck it up, and make a series of very fine cuts till it cleans up 100% (2" diameter is what I prefer). Polish this with some fine emery cloth, and then wipe it with a Scotchbrite pad at a low rpm. Reset the indicator close to the chuck again, and run the spindle as low an rpm as it will go. Now speed it up to about 150 rpm and compair the readings (they'll increase slightly). Now go upto about 300 rpm. If you see a drastic change in the readings you may have a problem. Do everything in the opposite direction of rotation. If they get worse you will need to look at the spindle bearings. Now without moving the indicator from the 12 oclock position take a 2x4 that's about 2 1/2 ft long and pryup on the bottom of the chuck (you will not need a lot of pressure [maybe 100 ponds of pressure]). If you see much more than .00075" you need to at least tighten the spindle bearings, but if it's a good tool room lathe you want nothing more than .0004". (a Monarch EE will max at about .00025"). Remember these errors will double when your actually cutting metal! Now remove the chuck, and place the indicator on the spindle nose, and check for runout. Should be less than with the chuck. Some spindles also have a shoulder machined on them that is square with the chucking face. Indicate that. Should be very close (less than .0005").

Lets look at the tail stock! It's probably in need of attention if it's a used lathe. The worst thing in the tail stock to go bad is the quill bore and the quill itself. Put an indicator on the quill at the 9 oclock position. Tighten the clamp that locks up the quill. Dose it move? (it will a very small amount). Now loosen it and see how much movement is in the bore at all four positions 90 degrees apart. You can live with it if it's under .003", but if you looking at .006 or more you can plan on addressing this issue in the future (will not drill or ream right). Lastly loosen the tail stock from the ways till it's just barely got tension on the clamp bolts. Try to shift it sideways. If you see much more than .0015" you may need to do some work there (tail stocks are a pain to get right). Now put a Jacobs chuck in the quill with as big a dowl pin that can be chucked in it (also a good time to check the bore in the quill taper for slop). Slide the tail stock up to the area you'd probably be working in, and clamp it down. Indicate the dowl pin in till it's inline with the spind bore at the chuck end. Write the readings down at four positions 90 degrees apart, starting at the 12 oclock position. These numbers are critical, so do it several times till it gets consistent. The difference between the 12 oclock and the 6 oclock position indicates wear in the base of the tail stock. If the lathe is in extremely good shape the tail stock should read about .0003" to .0006" high at the 12 oclock position. If it's low you got a problem (well maybe).

After you get the lathe home, set it on 3/8th's thick 1018 steel pads. If it's one of better quality it will also have holes for lag bolts to anchor it to the floor. I highly recommend using the lag bolts!! After you have it on the pads, you can level it. Now set the level on top the compound with modeling clay under it. True the level as close to the chuck as you can (I will remove the chuck to get even close to the headstock). Move the cross slide till it's over the next set of leveling screws. Adjust everything level. Goto the next set of leveling screws and do the same. After awhile you will find high points and low points in the machine frame. Pull down the high points with the lag bolts and jack up the low points with the leveling bolts. After awhile it will all be in the same plain. After that put the level up as it's no longer of any use to you (you only level machines to make the oil and coolant flow in the right directions).

If you have to scrape the cross slide and compound you looking at some serious cash. I get a minimum of $75 cash an hour (four hours minimum). To do a compound alone I get about four hundred dollars and they bring it to me (and it's not messed up too bad). All machining and parts are extra. Cross slides can go from $400 to who knows what. I can usually do a cross slide and compound for about $2500 if I don't have to make wear plates or Moglice it. Spindle bearings can be tighten up a couple times, so don't worry too much about that. There's no easy fix for a tail stock, but I've rebuilt several that were junk (you need a jig bore and a good external grinder for starters). Reason I wrote all this was to help you buy a good used lathe, and not get socked with repair costs you can't live with. So do be picky and even more carefull!

gary

 

[Trickymissfit]

I started out on a old South Bend Lathe, 3/4" hole in spindle so you know what thats like. I then bought a new lathe, Enco 13x36" with 1.375" spindle, so I was in heaven. I must of done hundreds of barrels and many other projects for local shops. It got tired and needed some re building. I saved up my $ and started to look for a larger lathe. I researched the Grizzley's, talked to people that own them and got good reports. I ended up with the larger of the two
gunsmith lathes, 5200 or somthing like that. It is amazing on how smooth it runs and so many gunsmith options built in, this lathe makes my old one seem like a meat grinder. I needed a lathe that i could work on 2" dia barrels and the Grizzley has the 2" bore through the headstock. Only draw back for me was the 3 phase power it required. Where I live there is none so I had to go the Converter route, just an added expense. My advice is spend the extra cash and get a good lathe, you will be happy in the long run. I now have two lathes and two mills in my shop. Newest addition is a Bridgeport Series 1 CNC mill with 4th Axis.

Dave

if you can program the Bridgeport (not exactly my favorite), then look at the small lathes from Southwest Trac. Not too bad, and a very flexable system. Just don't wreck it, and like all Asian equipment, they're good for one hard wreck
There's a company that makes a Bridgeport clone that everybody should look at. It uses #40 taper tooling! Quill diameter is a little over six inches, and way area is about 40% greater. Uses hard steel ways and Turcite; thus making a rebuild a piece of cake. The head on the machine is much like a variable speed Bridgeport (P.I.A.), but on steroids. Is setup for an internal coolant system, and comes with ball screws and Nikon scales. You can also buy it in single phase electricity models!! Just the #40 tool holder setup alone puts this mill out in front of the others! They are at the Chicago Tool Show every time it's put on, and I highly recommend a look see at this beast. (you can buy it for about the same price as a Bridgeport without the scales and CNC box, and it has the Prototrac box as an option!)
gary

 

[jarnold37]

I started with a 12x36 benchtop lathe and thought it was all I needed. Didnt take long to see it was not what I really wanted-what can you expect for $1900 brand new.

I discovered that I didnt want to chamber between centers and my spindle was to small inside diameter to put bigger barrels through. W ith barrel through headstock one can indicate in zero if enough time is taken and can indicate in on throat area which you can not do that in a steady rest.

Either way, I think you should get a bigger machine, I bought a 14-40 Nardini and would rather have a 15-50 due to a 2 1/16" spindle hole. You may want to chamber a 2" barrel. The Nardini is very good but kind of expensive. However I think the old saying of getting what you pay for does hold true to machine tools. I could only afford 3 to 4 thousand and ended up paying 12 thousand without much tooling( most of the better machines come with little or no extra tooling)

 

[Trickymissfit]

I started with a 12x36 benchtop lathe and thought it was all I needed. Didnt take long to see it was not what I really wanted-what can you expect for $1900 brand new.

I discovered that I didnt want to chamber between centers and my spindle was to small inside diameter to put bigger barrels through. W ith barrel through headstock one can indicate in zero if enough time is taken and can indicate in on throat area which you can not do that in a steady rest.

Either way, I think you should get a bigger machine, I bought a 14-40 Nardini and would rather have a 15-50 due to a 2 1/16" spindle hole. You may want to chamber a 2" barrel. The Nardini is very good but kind of expensive. However I think the old saying of getting what you pay for does hold true to machine tools. I could only afford 3 to 4 thousand and ended up paying 12 thousand without much tooling( most of the better machines come with little or no extra tooling)

If you can find a solid state drive Monarch Double E for less than $1500 and runs OK; BUY IT! The ways are hard, and the apron and slides are an easy rebuild. Tailstock is a little harder to rebuild, but not rocket science. One with scales will usually position within .0003" on a heavy cut. Spinde bore is just under 2.125". To rebuild the apron all you need is about $200 worth of Moglice and a new screw & nut. The compound will have be scraped (they all do by the way). Assuming the ways are in fairly good condition, I can rebuild the slides in about a week, and another day and a half for the compound.. If the tail stock is pretty bad it may take another week (mostly in machine work)

I once rebuilt a LeBlond for an old man I used to grouse hunt with. This was a WWII war finish machine! that actually was in fairly decient shape. I hand scraped the slides and compound in about ten days, and made wear plates for the tail stock (bore was just fine). Tightened the spindle bearings, and was cutting metal in about three weeks. With Moglice I could have cut 33% of the labor out of it, but it didn't exist at the time. Was a 14" x 48" lathe that had a special frame casting for a female operator. Sat about six or eight inches lower to the ground than a standard model! When it came time for a coat of paint I told him to paint it pink! Made a lot of race car parts on that machine.
gary

 

[screech]

I run a south bend heavy 10 and I like it. The headstock is short enough to chamber through the head stock and they're pretty simple. I also worked on a sharp 1340vs. If I had the cash for a brand new lathe I would probablly get one of those or a Haas TL1.

 

[Trickymissfit]

I run a south bend heavy 10 and I like it. The headstock is short enough to chamber through the head stock and they're pretty simple. I also worked on a sharp 1340vs. If I had the cash for a brand new lathe I would probablly get one of those or a Haas TL1.

have never seen a Haas lathe, but have been around their machine centers a bit. Not too bad a machine, but they won't run with the big dogs when your looking at machine centers. A K&T MM600 is similar in size, but easilly the top of the heap. Still I think they are as good as the offshore stuff (cast iron frame and fairly good drives). The one to watch for is an older Burgmaster horizontal MC (325 to be exact). I've seen old ones go for less than a grand. Have an extremely ridgid spindle group, and use knob retention tooling. It's not uncommon to see one position in the .00035" range when making short moves. Nice thing about them is that they are very easy to rebuild and even easier to upgrade to the latest specs. They'll flatly smoke anything out of Japan. Ball screws can be had out of Michigan, and can be refitted for AC Pulse Code motors
gary

 

[Centre Punch]

Hi trickeymissfit,
It sounds to me like you are a machine tool fitter? without meaning to sound disrespectful are you a master machinist as well?
The reason im asking is that even though i agree with your description of how lathes should be set up, in my experience it hardly ever happens.

I spent most of my working career over here in the UK making high precision components on clapped out machinery, operator skill playing a big part on knowing how to get the best results from machines that should have been thrown on the scrap heap years ago.
I did for a few years have the luxury of working on swiss Schaublin toolroom lathes which were a joy to use and are still regarded as the finest lathes in the world

My employers business was specialised valving for the gas turbine and petro-chemical industries, so precision had to be guranteed, over a period of 23 years i learned from the old boys, techniques of getting precise results from less then precise machines

What i am basically saying is that IMO you dont need super accurate and well set up machinery to produce quality but it certainly helps, this has put me in good stead to get excellent results from my 1960 13x40 Colchester Master i have at home.

Concentricity on my chamberings has never been more then .0002"out (using the steady rest method) and thats locating the reamer with a dead centre and holding it with a modified tap wrench.

Cutting speed is 85rpm and the reamer is plunged .100" at a time, withdrawn, chamber blown out, reamer cleaned re-oiled with high grade neat cutting oil and another cut taken i reduce the amount of cut as the reamer its finished depth and final finish to depth rotating the tap wrench by hand generating pressure with the tailstock quill, once again sorry to the Op for going off on a tangent but i just wanted to get my point across.

Ian.

 

[Trickymissfit]

Hi trickeymissfit,
It sounds to me like you are a machine tool fitter? without meaning to sound disrespectful are you a master machinist as well?
The reason im asking is that even though i agree with your description of how lathes should be set up, in my experience it hardly ever happens.

I spent most of my working career over here in the UK making high precision components on clapped out machinery, operator skill playing a big part on knowing how to get the best results from machines that should have been thrown on the scrap heap years ago.
I did for a few years have the luxury of working on swiss Schaublin toolroom lathes which were a joy to use and are still regarded as the finest lathes in the world

My employers business was specialised valving for the gas turbine and petro-chemical industries, so precision had to be guranteed, over a period of 23 years i learned from the old boys, techniques of getting precise results from less then precise machines

What i am basically saying is that IMO you dont need super accurate and well set up machinery to produce quality but it certainly helps, this has put me in good stead to get excellent results from my 1960 13x40 Colchester Master i have at home.

Concentricity on my chamberings has never been more then .0002"out (using the steady rest method) and thats locating the reamer with a dead centre and holding it with a modified tap wrench.

Cutting speed is 85rpm and the reamer is plunged .100" at a time, withdrawn, chamber blown out, reamer cleaned re-oiled with high grade neat cutting oil and another cut taken i reduce the amount of cut as the reamer its finished depth and final finish to depth rotating the tap wrench by hand generating pressure with the tailstock quill, once again sorry to the Op for going off on a tangent but i just wanted to get my point across.

Ian.

I'm a machine builder by trade, and also have a journeyman's card as a machinest repairman. Thru the years I got a mechanical engineering degree as well. The latter degree was just something my boss pushed me into, and looking back I wish I'd gone after the degree in metalurgy

I could have been a tool maker, but just never found it all that interesting. Besides I hate being locked into a certain location. My father was a master tool maker (he even had his papers from the department of labor). I learned and learned from him in conversations, and wasn't against calling him up in the middle of the day to run a question or two by him. But I also had access to a couple of metalugical engineers that were well known in their fields.

I loved building machinery. I mostly built CNC machine centers and delved into super precision measuring devices alot. Robotics was something I had dumped in my lap about 20 years ago, and found it interesting, but nothing I wanted to stay with (I did build the world's largest robotic cell that had a two hour and forty minute cycle time). I guess I'm a guy that has to keep opening new doors all the time. The most interesting equipment I built started out with a basic machine frame, and built entirely new machines off of existing castings.

I seem to remember seeing that Swiss made lathe at the Chicago Tool Show a few years back. I was going to order two Colechesters for finish work in the Model Shop. We wanted something like Monarch EE's (mostly for their small foot print as well as accuracey). I didn't get to spend as much time with them as I'd liked to have, but ended up buying three of them. I was looking at their threading abilities more than anything else. Anyway I had a list of eqipment to look at that would have taken a full week to see! And machine centers and FMS stuff was what I was after. I did fly back up there the last day to look at the "new" slantbed Hardingh CNC lathes for a buddy located in Michigan. He wrote the check for one while I watched (still the largest check I've ever seen hand written!) Still the best CNC lathe I've ever seen by a wide margin, and why these guys I worked for bought Okumas I'll never know as they were cheaper and built better.

Your reamer process seems about right if you have a good spindle line. The tailstock must be close to being perfect. I used have have several drums of "Trim Coolant" that I never mixed with water. Just painted the slimey mess on the reamer or tap and cut. The finish was a satin (perfect), and holes were very round. Trim has a good lubricity, and it takes a lot of tool pressure to wipe it off the cutting surface. I (this is a personal thing) liked to run the rpm down around 40 to 60 rpm, and the last few thousandths I often turned the chuck by hand (I never trusted the spindle bearings on any lathe). If the hole had to be very close I used a floating adapter that fit inside the tailstock quill (it was one that was bought just for reaming holes. You sound like you do nice work when I hear you speak of .0002" numbers! Do you use a roughing reamer and a finish reamer? How do you deal with chatter?

And speaking of .0002" numbers, I once had an indexing plate on a SIP jig bore. Hole location was extremely tight, and the bores were to be held under .0004" total. The guy used a Unimic to measure each bore, and it wasn't good enough. After he removed the plate (about forty holes) he discovered that the bores were actually about .0002" undersize! Boss had another plate started for me, and I just looked at it thinking there had to be away. I made a phone call, and found found carbide ball bearings that were used in ball drifting. Jumped in the car and went over to the store and bought all they had. Pressed a carbide ball thru each hole, and never looked back. Handed the plate to the boss and said here it is! Each hole looked like a mirror finish, and he bugged me for two weeks wanting to know how I did it! I finally let up and told him (the credit card bill would have spilled the beans anyway). Funny thing was that when they went to check the plate the guy called back and wanted to know how we managed to get each bore exactly the same right down to about 50 millionths. We never told them how! The kid on the SIP never made that mistake again, and was an extremely good operator. The guys in the tool room never heard of ball drifting processes, and when I started they knew I'd flipped out all the way this time!
gary

is a Colechester Master their best quality lathe? The ones we bought didn't have the "Master" on them. They are very fine lathes

 

[Centre Punch]

Hi Gary my spindle line is pretty good at 30" from the chuck hence i use the steady method, but i have wear in the bed resulting in .003" drop of the saddle in front of the chuck and .002" of the tailstock.

I have a floating reamer holder but was concerned about it maybe presenting the reamer on a slight tilt, so my thinking was at least if i located it with a dead centre it could follow the bore of the barrel without inducing any stress on the reamer.
I dont use a roughing reamer and i dont pre-drill as i am not trying to make money so i am not worried about the time it takes unlike a lot of smiths here in the UK.

Even if i was doing this professionally i would still take the time to do the chambering how i like to do it, a buddy of mine who i mentored before he set up his own business regularly phones me telling me how quick he chambered his latest barrel, i am alarmed each time!
I must say holding the reamer in the toolpost mentioned by nesika chad looks an interesting option, i shall have to get a morse taper tool-holder for the quick change and see how it works with the floating reamer holder.

I have only had chatter in one barrel and that was a Lother Walther i chambered in .257 Weatherby, the chatter came about half way through the chambering and i eliminated by upping the speed to 120rpm and pushing the reamer in at a much higher rate of feed, this trick has always worked for me when reaming bores at work.
I have played around with Trefolex and Rotol cutting fluids brushed onto the reamer but neither seems to produce results any better then the neat gutting oil, which is cheaper and cleans up better anyway.

I dont know if you have the same in the US but most of the people i ever worked with had the skills to produce high quality work but could never be bothered to do anything more then what was needed to pass quality control, a small percnetage had genuine pride in their work (myself included) and got a buzz out of producing a good job, i still do, my own standards are very high and nothing goes out the door unless it has reached them.

Did you know that once you have become a Registered Firearms Dealer here in the UK it gives you open licence to produce firearms even if you have no engineering or gunsmithing experience at all, in other words once a RFD a baker could become a rifle builder/gunsmith overnight!

Lathe nomenclature is slightly different here, we go by centre height x distance between centres, ie 6x24 and 6 1/2x40, they then get assigned a name according to the centre height, in this case, Student and Master respectively.
Have a look at this link it will explain things much better:

Page Title

The carbide ball trick was great success, it sounds like one of those eureka moments that always puts a smile on your face

Ian.

Ooh! forgot to ask, please can you explain what you mean by journeyman

 

[Trickymissfit]

Hi Gary my spindle line is pretty good at 30" from the chuck hence i use the steady method, but i have wear in the bed resulting in .003" drop of the saddle in front of the chuck and .002" of the tailstock.

I have a floating reamer holder but was concerned about it maybe presenting the reamer on a slight tilt, so my thinking was at least if i located it with a dead centre it could follow the bore of the barrel without inducing any stress on the reamer.
I dont use a roughing reamer and i dont pre-drill as i am not trying to make money so i am not worried about the time it takes unlike a lot of smiths here in the UK.

Even if i was doing this professionally i would still take the time to do the chambering how i like to do it, a buddy of mine who i mentored before he set up his own business regularly phones me telling me how quick he chambered his latest barrel, i am alarmed each time!
I must say holding the reamer in the toolpost mentioned by nesika chad looks an interesting option, i shall have to get a morse taper tool-holder for the quick change and see how it works with the floating reamer holder.

I have only had chatter in one barrel and that was a Lother Walther i chambered in .257 Weatherby, the chatter came about half way through the chambering and i eliminated by upping the speed to 120rpm and pushing the reamer in at a much higher rate of feed, this trick has always worked for me when reaming bores at work.
I have played around with Trefolex and Rotol cutting fluids brushed onto the reamer but neither seems to produce results any better then the neat gutting oil, which is cheaper and cleans up better anyway.

I dont know if you have the same in the US but most of the people i ever worked with had the skills to produce high quality work but could never be bothered to do anything more then what was needed to pass quality control, a small percnetage had genuine pride in their work (myself included) and got a buzz out of producing a good job, i still do, my own standards are very high and nothing goes out the door unless it has reached them.

Did you know that once you have become a Registered Firearms Dealer here in the UK it gives you open licence to produce firearms even if you have no engineering or gunsmithing experience at all, in other words once a RFD a baker could become a rifle builder/gunsmith overnight!

Lathe nomenclature is slightly different here, we go by centre height x distance between centres, ie 6x24 and 6 1/2x40, they then get assigned a name according to the centre height, in this case, Student and Master respectively.
Have a look at this link it will explain things much better:

Page Title

The carbide ball trick was great success, it sounds like one of those eureka moments that always puts a smile on your face

Ian.

Ooh! forgot to ask, please can you explain what you mean by journeyman

A Journeyman is a term that came out of the craft guilds in Europe. (there are still a few Guilds in the USA even today) Basicly it says that you went thru an accredited apprenticeship that came under supervision of the U.S. Department of Labor. I've done two and about 3/4's of a third one. I'm not sure if the system still exists, but in any certified trade there was a procedure to get a "Master's" card. I never tried to get one, but know it ends up be a ten year process. Most of the better places these have the off site schooling done on college campuses, and you start picking of credits fast. I found myself going to school about 25 of the 40 years I've been in the field.

Try and find a good six in machinest level (two would be much better). Remove the tail stock from the lathe, and give all the ways a very light stoneing with a hard Arkansas stone. When you feel a bump just mark it with a red felt tip pen. Also look the bottom of the tail stock over while you have it removed. You may see some bumps here as they seem to always be getting beat up. Now remove all the tooling from the compound (good time to stone it as well). Get yourself some modeling clay, and put it under the two levels with the cross slide cranked into the center. Now with the table as close to the chuck as you can get it zero the levels (one should be 90 degrees to the other in a tee fashion, with one inline with the cross slide lead screw. now cranl the table (apron or carriage) towards the area where the tail stock was resting. Stop over the leveling screws and see if there is a change in the levels. If so make an adjustment in the leveling screws. Now move over to the next pair of screws and to the samething. (note: you may need to tighten the lag screws if things are high). Now with the carriage somewhere near the chuck (not all that important) go around and check each leveling pad to see if it's tight. If you can move it you need to put pressure on it (this is where it's nice to have a second pair of eyeballs to watch the level as you move the screws). Now repeat the samething with the carriage again, and adjust till the levels quit moving. If the levels quit moving you probably have everything pretty close to being strait (but not always!). I'm assuming that your chuck jaws are strait & true (few are). Find a piece of steel tubing (5 to 10mm wall) that you know is strait and true (as well as smooth!), and about 50mm or larger in diameter (you only need about 40 cm in length). Chuck it up with about 30cm hanging out, and setup two dial indicators to read ontop and on the side easiest to see. (Oh yes I forgot to tell you to true it up as close as you can). This check is not for the lathe frame, but to see if the centerline of the spindle follows the Z axis of the lathe. If you see much more error than .001" in 10" (too lazy to convert it) you need to make an adjustment in the headstock. Two ways to do this:

1. you can break the headstock loose and reseat it after pulling the dowl pins out. (normally you can just loosen the bolts a little bit and reinstall the dowls). By reinsterting the dowl pins and then retightening it should come right back. But not always!

1a. If it didn't realign itself when you did the above you got a problem! I've seen lathes (usually out of Asia) that never would realign after a wreck. Sometimes you actually have to shim the headstock to get in back strait. Try to avoid doing this if possible.

2. (I told you there was another way to cheat!) Assuming the dial indicator is reading pretty good at the 9 oclock position, but is showing a few tenths at the twelve oclock position (no more than .0035" max). Now goto the leveling screws farthest away from the rear of the chuck body (headstock end), and with the indicator reading the max reading adjust them so remove about 25% of the error with each screw so in the end you have taken half of it out. Check everything again, and adjust the headstock leveling screws again.

In the end this will put the spindle line strait with the ways (you may have to tweek the other screws slightly). The final confirmation to how strait things are is a .010" cut, and then measure the tube to see how strait it is. If everything is strait and it cuts strait; put a lock on the machine to keep your buddies from messing it up!

I recommend a search for a copy of the "Machine Tool Rebuilders Handbook" This book covers most everything you'll ever encounter. (appears to be no ISBN #). The book is old, but still upto date (tools are much different), and really gets into precision equipment.

I served my first apprenticeship at a place that did ball drifting processes, and this process is the most accurate form of sizing a hole out there even to this very day. If done right you end up with a round mirror finish that will usually be about .0001" smaller than the ball bearing.

Now adays in this country (probably Canada as well) they are using a form of gauging called Statisical Process Controll on production lines. It monitors the deminsions on every part, and is done via an automated gauging process. The operator keeps charts on size variations and the gaugeing system will automaticly send it's data back to the machine(s) to make a size adjustment. As the operator plugs the numbers into his charts he is also keeping track of tool life. He operats in a window that is roughly 2/3's the total tolerance allowed in the part. This gives him a chance to assemble to needed tool to swap out; thus creating far less down time. If it's a machine center (place I came from had hundreds of them), there will often be several pieces of redundent tooling in the magazines (usually 200+ tool magazines). The machines probe their own work automaticly, as well as do a broken tool check (usually a drill or a tap). If it finds a broken drill (or whatever) it will note the part as bad, and change the tool on it's own for the next part. They also have a tool pressure back feeding system that will alert the operator that something's wrong or going south before it happens. But alas the tool room is a different story. Usually it's one or two pieces, and the guy running the machine has to stay ontop of it. Plus they often get stuck with metals well known for their low quality machineability (Hestalloy being my alltime favorite!). In my job I co-ordinated getting the parts flow thru there, and had to stay ontop of about twenty jobs going on at the sametime. Plus I had to go out and make measurements all over town, and had a laptop PC with a CAD program in it that allowed me to make drawings right onsite. My work days felt like they were about two hours long. but most often were twelve hour days
gary

 

[Centre Punch]

Hi Gary,
Your Journeymans ticket is very similar to our Indentured Apprenticeships which alas are no more here in the UK, all so called "apprenticeships" now are basically government trainings schemes, which as far as i am concerned are worthless.
i was taken on by an engineering company at 17 to do a 4 1/2 year apprenticeship. i was an employee and the company payed for all of my training but they did get government support

For the first part i did a years off the job training at a technical college to learn basic bench and machining skills, you know the stuff, fitting tests and turning and milling tests which had to reach a certain standard.
The other 3 1/2 years was spent in the training area back at work with one day a week at college studiying maths, physics and engineering technology.
After which there was a sort of graduation ceremoney where i was presented with all my certificates and all my indenture papers.

I then became an Improver and went to work in the toolroom.
After an initial apprenticeship there is no longer any encouragement to better yourself from my employer, they now wanted their monies worth of work out of me.
Anymore qualifications you wanted would have to be done off your own back, i did certificates in Welding and QC. but i enjoyed machining so much thats what i kept on doing.

I joined my last company in 1983 eventually taking over as No1 machinist after 17years, having my own section where i had a Colchester Bantam 5 1/2 x20, a Colchester Student 1800 6 1/2x40 with Ainjest high speed screw cutting attachment and a Bridgeport.
I did all the one offs and developement work and was not timed i also set up and did all the electron beam welding as well as sectioning, etching and testing samples of all the welds i did, like i said previously i get huge job satisfaction from what i do.
I can see from the way that you enthusiasticly put into words, that like me you truly enjoy what you do, it makes a change to correspond with someone with this frame of mind.

Many thanks for the insight into getting my machine trued up and possibly curing my drop, i will aslo keep a sharp eye out for the book you mentioned.
Levelling machinery at work has only ever been a hap hazzard affair, time to do it weighed up against production time lost, hence it was never "allowed" to be done properly.

I am two minds whether to level my lathe in my garage that precisely as in the next few years, i intend to go into rifle-smithing fulltime and set up my own business.
I shall be purchasing better more modern machinery because i intend to build BR, Target and Varmint rifles with the occaisional traditional hunting rifle.
To get the best results i will want to get the straightest machinery i can afford but be sure that i will take all the time needed to level my new machinery properly.

Ian.

 

[Trickymissfit]

Hi Gary,
Your Journeymans ticket is very similar to our Indentured Apprenticeships which alas are no more here in the UK, all so called "apprenticeships" now are basically government trainings schemes, which as far as i am concerned are worthless.
i was taken on by an engineering company at 17 to do a 4 1/2 year apprenticeship. i was an employee and the company payed for all of my training but they did get government support

** it's similar over here, but the government is pretty serious about their standards, and the company sponsering it must often prove they are living up to their end of the bargin. More than once they came around to do on onsite inspection of our training. The real problem is not the kid in training, but who's training him! I was lucky as I worked with old men that knew their business like you couldn't imagine. They were extremely cranky, and at times a pure pain to get along with. But they made you learn, and learn it the right way. In ways these guys were as good if not better than anybody I worked with after that time frame.
A kid now taking the apprenticeship test almost needs a couple years of college! And in an electrician's apprenticeship most folks have a college degree! But the scope of work is much deeper than it was forty years ago.

For the first part i did a years off the job training at a technical college to learn basic bench and machining skills, you know the stuff, fitting tests and turning and milling tests which had to reach a certain standard.
The other 3 1/2 years was spent in the training area back at work with one day a week at college studiying maths, physics and engineering technology.
After which there was a sort of graduation ceremoney where i was presented with all my certificates and all my indenture papers.

** when I got my first card, the guys all took me to the local pub (where of course I had to buy). They then told me I was ready to start learning my trade! Been learning eversince

I then became an Improver and went to work in the toolroom.
After an initial apprenticeship there is no longer any encouragement to better yourself from my employer, they now wanted their monies worth of work out of me.
Anymore qualifications you wanted would have to be done off your own back, i did certificates in Welding and QC. but i enjoyed machining so much thats what i kept on doing.

** I think it's that way in most places. You reach a level and that's it unless you move into supervision. As I said I was a Machinest Repairman, and then went into Machine Building (another four years (actually closer to eight)). But I think the biggest step in my learning curve was in the first ten years.

I joined my last company in 1983 eventually taking over as No1 machinist after 17years, having my own section where i had a Colchester Bantam 5 1/2 x20, a Colchester Student 1800 6 1/2x40 with Ainjest high speed screw cutting attachment and a Bridgeport.
I did all the one offs and developement work and was not timed i also set up and did all the electron beam welding as well as sectioning, etching and testing samples of all the welds i did, like i said previously i get huge job satisfaction from what i do.
I can see from the way that you enthusiasticly put into words, that like me you truly enjoy what you do, it makes a change to correspond with someone with this frame of mind.

Many thanks for the insight into getting my machine trued up and possibly curing my drop, i will aslo keep a sharp eye out for the book you mentioned.
Levelling machinery at work has only ever been a hap hazzard affair, time to do it weighed up against production time lost, hence it was never "allowed" to be done properly.

I am two minds whether to level my lathe in my garage that precisely as in the next few years, i intend to go into rifle-smithing fulltime and set up my own business.
I shall be purchasing better more modern machinery because i intend to build BR, Target and Varmint rifles with the occaisional traditional hunting rifle.
To get the best results i will want to get the straightest machinery i can afford but be sure that i will take all the time needed to level my new machinery properly.

Ian.

I gotta run, but will answer the last couple paragraphs when I get back home.
gary