Twist? Lol, you would never be able too even detect a machine bed has a twist in it with a machine level , only a laser could be accurate enough for that , millions of lathes in shops all over the world making lots of precision parts are just sitting on the floors with just a rough level job, besides if you where turning a bolt say that was 6 inches long and you wanted it too be parallel too within tenths of a thousandths you would polish it anyway to size after you cut it close, no lathe will cut zero over a foot , I don't care how good operator is
Finally got a lathe
- Thread starter SkytopBrewster
- Start date
Wood, you are the polar opposite to the machinists of old..... And thankfully very much in the minority.
What you state is impossible is standard practice for PROPER machinists. Hell, I've done better than what you say is impossible for a couple of your examples and I'm just a hobbyist.
It may not be possible to detect a twist even with a precision level. That I'll grant you. But the level is only the basic starting point. From that point the test cuts I've described previously along with a few others can be used to check and fine tune to whatever degree of accuracy the user can measure. Lasers? They aren't any better than the precision level. It's what a micrometer or a good dial indicator tells us that counts.
What you state is impossible is standard practice for PROPER machinists. Hell, I've done better than what you say is impossible for a couple of your examples and I'm just a hobbyist.
It may not be possible to detect a twist even with a precision level. That I'll grant you. But the level is only the basic starting point. From that point the test cuts I've described previously along with a few others can be used to check and fine tune to whatever degree of accuracy the user can measure. Lasers? They aren't any better than the precision level. It's what a micrometer or a good dial indicator tells us that counts.
True. And with smaller machines a very wise way to go. But my rather sturdy and heavy machine does OK with the direct push knurls.
To the newbies a knurling hint or two.
First off angle the tool so it sits a couple of degrees off square with the knurls towards the chuck UNLESS you are using a top and bottom clamp style such as tiriaq suggests. If you use the clamp type it should be dead on square to the work.
When you start the knurl only engage the first 1/3 of the width on the steel. This makes it far less of a load and a much cleaner start with less chance of a double strike by one or both of the knurls.
Flood the section to be knurled with a heavy cutting oil for steel or a good aluminium fluid if appropriate. There is a LOT of friction involved in knurling and a heavy cutting oil or proper fluid for the metal goes a huge way to getting clean surfaces. Generally anything intended for threading will work well for knurling.
Cross knurling is great for stuff you push and turn or pull and turn. For twisting only a "coining" tool or two is nicer and gives that slick looking longitudinal pattern. You can see a coining tool in my pictures above.
I'm a dying breed, learned from the old timers , and there is no way you can tell me you can see a difference in the way a lathe cuts by adjusting the level , true a moron could clamp a lathe down too a floor and slightly twist it but even them you could never tell difference, level it using 3 level points is the best bet,
fingers284
CGN Ultra frequent flyer
- Location
- Alberta Cowboy Ranges
One of the considerations nobody has mentioned concerning Lathe line-up is that no "entry level" lathe will have chucks that are accurate. Run-outless chucks & jaws, either 3 or 4 jaw, that are good enough to utilize the line-up tooling & testing being sugested are very very expensive. Chucks that don't have some run-out won't be present on any hobby priced lathe (If they are that accurate you are a very lucky dude).
The same thing aplies with C toC testing, unless the tailstock/live center are absolutelly balls-on lazer lined up with the spindle, a 0 runout test will be imposible.
Spend a few minutes leveling, and a few minutes measuring your lathes limitations, and a lot of minutes practicing to get the best you can out of your lathe and yourself.
The same thing aplies with C toC testing, unless the tailstock/live center are absolutelly balls-on lazer lined up with the spindle, a 0 runout test will be imposible.
Spend a few minutes leveling, and a few minutes measuring your lathes limitations, and a lot of minutes practicing to get the best you can out of your lathe and yourself.
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Agree re: 3 jaw chucks. But I use them a lot, all the same. They are either good enough for what I am doing, or I use something else, or find a workaround.
I have Burnerd Grip-Tru chuck on my Myford, that can be adjusted to very close tolerances on a particular diameter, but is a royal PITA to adjust, so mostly I don't bother.
If you put a piece of stock into the chuck to make a part that needs to be concentric, you pretty much need to plan around making it in one set-up, then parting it off and cleaning up the end.
Otherwise you are better off learning to use a 4 jaw chuck (another source of scary mumbo-jumbo!) or a collet system of one form or another for some form of acceptable repeatability when the part is removed and reinstalled into whatever is in use.
Repeatability and repeat concentric accuracy is a great big deal to a guy that has to make a run of second op parts, but a fella that has a bit more time on his hands can work around a crappy chuck.
Cheers
Trev
I have Burnerd Grip-Tru chuck on my Myford, that can be adjusted to very close tolerances on a particular diameter, but is a royal PITA to adjust, so mostly I don't bother.
If you put a piece of stock into the chuck to make a part that needs to be concentric, you pretty much need to plan around making it in one set-up, then parting it off and cleaning up the end.
Otherwise you are better off learning to use a 4 jaw chuck (another source of scary mumbo-jumbo!) or a collet system of one form or another for some form of acceptable repeatability when the part is removed and reinstalled into whatever is in use.
Repeatability and repeat concentric accuracy is a great big deal to a guy that has to make a run of second op parts, but a fella that has a bit more time on his hands can work around a crappy chuck.
Cheers
Trev
Yeah some fine work can be done on imperfect equipment if the operator knows how to work it.
On a side note, Horace Kephart noted in "Camping and Woodcraft" Fifteenth Printing, 1951:
"When you get into the real wilderness far away from rich men's preserves and summer hotels, you will find there some mighty hunters who make mighty kills with guns that would only bring the price of scrap-iron in New York."
Truly, the operator.
Decent equipment with proper maintenance and set-up does make quality work a lot easier though!
On a side note, Horace Kephart noted in "Camping and Woodcraft" Fifteenth Printing, 1951:
"When you get into the real wilderness far away from rich men's preserves and summer hotels, you will find there some mighty hunters who make mighty kills with guns that would only bring the price of scrap-iron in New York."
Truly, the operator.
Decent equipment with proper maintenance and set-up does make quality work a lot easier though!
Beautiful lathe my friend. Now what to get her?... Pretty much anything she wants bud. Just makes sure what ever she wants doesn't involve you so you can play with the lathe. As for set up of the lathe this will be good practice for you. Set it down on the ground and build yourself so screw jacks. Then lift up the lathe and set it on he jacks and fine tune the levelling. I had to do that at work when we moved a bunch of the lathes around.
Got it as level as I could for now, dont have proper level yet. Just been playing, got some 1'' 4140 to pizz around with, did my first practice muzzle brake today, threads were a tad sloppy but will keep practicing on scrap before even thinking about touching one of my guns. Also mage a couple hitch pins for the truck. Still need a fishtail for threads. Bought a bunch of brazed carbide bits today and some HSS blanks at EMS tools. Overall happy with the lathe so far, it only takes about 2 minutes to change gears for different threads.
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Was going to order one of those GTR action trueing fixtures for aligning barrels in the 4 jaw from PTG, anyone use that fixture, how do you like it? I think it's like $250
I'd suggest just building your own fixture. I wouldn't say it's to hard. Face both ends, bore it out and if you don't have the rest of the stuff just take it to a machine shop to drill and tap your holes in their 4 axis mill. Should only take an hour of machining or less to get those holes drilled and tapped properly
Sounds like you're doing fine.
A word of advice,...ignore all the internet drivel from experts who can't even turn a lathe on let alone run one. Everyone's an expert on the 'net.
Don't worry about it being perfectly level, there are bigger issues with lathes than being level. If it's within a few thou from end to end you'll never see an issue.
Threading isn't hard after someone walks you thru it. Don't think you have to thread with a very slow spindle speed. Sometimes more speed is better.
It's all hand/eye coordination. If you can drive a stick shift, play a musical instrument, shoot a bow or walk and chew gum you're halfway there. It's not rocket science.
Any questions send me a PM, I've run a lathe a couple times....and I do go thru Rocky MH once in a while.
After reading thru some of the posts you might do well to listen to wood800,...he sounds like my kind of machinist...
.....take his advice and don't listen to the "armchair machinists"...
there's very little that will go wrong with one of these small lathes if it's looked after. Don't worry about Modern Tool and service, I've known Brian and Jesse over there for a while. They are a 5 min drive from me.
....and don't waste your money on high speed steel tools.....
A word of advice,...ignore all the internet drivel from experts who can't even turn a lathe on let alone run one. Everyone's an expert on the 'net.
Don't worry about it being perfectly level, there are bigger issues with lathes than being level. If it's within a few thou from end to end you'll never see an issue.
Threading isn't hard after someone walks you thru it. Don't think you have to thread with a very slow spindle speed. Sometimes more speed is better.
It's all hand/eye coordination. If you can drive a stick shift, play a musical instrument, shoot a bow or walk and chew gum you're halfway there. It's not rocket science.
Any questions send me a PM, I've run a lathe a couple times....and I do go thru Rocky MH once in a while.
After reading thru some of the posts you might do well to listen to wood800,...he sounds like my kind of machinist...
.....take his advice and don't listen to the "armchair machinists"...there's very little that will go wrong with one of these small lathes if it's looked after. Don't worry about Modern Tool and service, I've known Brian and Jesse over there for a while. They are a 5 min drive from me.
....and don't waste your money on high speed steel tools.....
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I agree that a hobbyist running a Chinese lathe will not see the benefits of fine leveling, but your statement is plain wrong.
Getting the machine correctly sitting on the floor (the best way is to level it) has a massive impact on the ability of a machine to make precise straight cuts. It also has an impact on the cutting harmonics of the machine.
I originally learned that from the "Old Timers" and have found it true on countless occasions. But i guess we came from different schools of thought.
When I machine to ten-thousandths I cut on size. If the machine is turning taper I adjust the machine.
Getting your machine dialed in is part of the trade!
I agree with this Guy 110 percent, align and level lathe or mill to a perfect setting is not as necessary to manual as to CNC, in CNC everything is more precise and rigid, running these Quarter of Million dollar machine to hold 2/10 of a thousand and achieve repeatability, it is necessary to level it to the best that you can do, but in a Manual Chinese made machine, it not necessary, the tail stock is not perfectly alignment to the chuck, the leveling of the chuck is not perfectly align to the way, is not precise as a more expensive CNC, per-have this is what make bad harmonic. I would suggested to the new lathe owner to read the manual.
fingers284
CGN Ultra frequent flyer
- Location
- Alberta Cowboy Ranges
One sugestion I will make is, on any Chinese lathe, to check the gear mesh and set screw tension inside the spindle gear box before too much use. Very simple to do...pop the lid off and watch the gears change as you manipulate the gear change knobs. I have done three of them and every one of them had at least one or more gear engagements contacting less than half the width of the gear. Very easy to chip a gear tooth if you ever jam or lock-up a cutter under power...it happens.
Another thing I have read on this forum is to check for casting sand left in the housing in these lathes, do it while you have the lid off to check gear clash, I haven't found any but others apparently have.
Another thing I have read on this forum is to check for casting sand left in the housing in these lathes, do it while you have the lid off to check gear clash, I haven't found any but others apparently have.
- Location
- inside a huge cloud of MOSQUITOS
I'm just chiming in here but I believe I read back there somewhere someone suggesting using a tail stock to steady up the work when parting off.
Bad idea in my opinion.
YMMV
Cheers, YC
Bad idea in my opinion.
YMMV
Cheers, YC
Fingers makes some good suggestions in his last post. My own Chinese lathe came with the assembly oil on all the parts having a very gritty feel to it. This lead me to delve deeper and I found that it was well worth taking the whole machine apart, clean all the parts and re-assemble. It turned into a week long project where I filed off the razor like edges and generally "blue printed" a lot of the stuff as it went back together.
One thing that I found was that the front apron box on the carriage was bone dry inside. Not a hint of oil or grease. I ended up making up a "one spot oiler" system from small brass tubing that lets me inject some bed oil and it drips down on all the internal gears.
Another thing that I found on mine was that the bed wipers on the carriage and tail stock were useless. They didn't even contact the bed fully. I ended up making my own of the "old school" manner. A set of 1/4 inch thick felt boot liners and some 1/8 metal compression plates were made up and do a much better job of keeping the small swarf particles from getting between the bed and carriage ways and tearing things up. Here's a picture that you can use as a guide if you find the same thing on your machine. Either way you most certainly want to ensure that you do have GOOD wipers on the carriage and tail stock because if harder bits of tough alloy steel get in the ways it'll gouge the hell out of the bed over time and lead to a hollow area over the most frequently used portion of the bed.
The way these wipers are "cleaned" is to dribble some oil on the bed and run the wipers into the oil for an inch or so. Then back up and the dirt and particles held by the wipers come away in the oil. Wipe and repeat 6 to 8 times and you'll see that the amount of crud coming away becomes minimal.
Making up your own tooling and accessories is a great way to learn your lathe skills. It'll take a lot longer but you're learning instead of buying so the time is well spent. So when it finally gets to where you chuck up some gun parts you'll have a lot more background to avoid some issues and a much better sense of what is important and needs to be adjusted or compensated for and what is fairy dust and rumour.
Do look at those book titles I mentioned earlier. I've run lathes since I was in my teens some 45 years back. But when I got my own and took a more serious interest in machining as a hobby some 20 years ago I found those books were priceless for their information and techniques. They filled in a lot of the holes in my knowledge.
One thing that I will grant to the guys above that are saying that it's less important to align a Chinese lathe is that these machines are built to a price point. So they do not come with the factory adjusted assemblies that you get on the big name machines costing 10 times the price.
BUT! With some knowledge and thinking you can measure, adjust, shim and otherwise check and set all the critical points of the headstock, carriage and tail stock so that it becomes as true as the high priced options. The only limit is in YOU and your ability to think about the basic principles and to use the tools you have to perform the checks. That test bar I mentioned before is one such trick. And there's other things you can do for aligning a tail stock both horizontally and vertically to get to where you can set up work between centers and know that the machine is not going to end up tapering your work.
Contrary to what some say you CAN do work on this machine to high standards. VERY HIGH in fact. But it will only get to that point if it's well set up and aligned. The good news is that you don't need to set the machine up to that sort of standard for now. It's worth getting it somewhere close but keep in mind for the future that it might still need to be fine tweaked as your skills and requirements for precision become more demanding.
One last comment on the whole HSS vs Carbide war going on in your thread and which is constantly repeated in other threads. It is well worth getting a couple of HSS blanks and grind out a cutter or two and actually try them. Then make up your own mind on the issue.
But do get the books or read about the various angles that go into shaping the cutter so you give the HSS a fair test. I went that way and found that for probably 95% of my HOBBY machining that HSS actually does a BETTER job than carbide. But I'm not a production shop. For a number of very valid reasons carbide inserts are the way to go for production. But for my home use I found that I get a better finish and have more control over the very light 1/4 and 1/2 thou "impossible" cuts as described by wood and others with a HSS cutter over carbide.
One thing that I found was that the front apron box on the carriage was bone dry inside. Not a hint of oil or grease. I ended up making up a "one spot oiler" system from small brass tubing that lets me inject some bed oil and it drips down on all the internal gears.
Another thing that I found on mine was that the bed wipers on the carriage and tail stock were useless. They didn't even contact the bed fully. I ended up making my own of the "old school" manner. A set of 1/4 inch thick felt boot liners and some 1/8 metal compression plates were made up and do a much better job of keeping the small swarf particles from getting between the bed and carriage ways and tearing things up. Here's a picture that you can use as a guide if you find the same thing on your machine. Either way you most certainly want to ensure that you do have GOOD wipers on the carriage and tail stock because if harder bits of tough alloy steel get in the ways it'll gouge the hell out of the bed over time and lead to a hollow area over the most frequently used portion of the bed.
The way these wipers are "cleaned" is to dribble some oil on the bed and run the wipers into the oil for an inch or so. Then back up and the dirt and particles held by the wipers come away in the oil. Wipe and repeat 6 to 8 times and you'll see that the amount of crud coming away becomes minimal.
Making up your own tooling and accessories is a great way to learn your lathe skills. It'll take a lot longer but you're learning instead of buying so the time is well spent. So when it finally gets to where you chuck up some gun parts you'll have a lot more background to avoid some issues and a much better sense of what is important and needs to be adjusted or compensated for and what is fairy dust and rumour.
Do look at those book titles I mentioned earlier. I've run lathes since I was in my teens some 45 years back. But when I got my own and took a more serious interest in machining as a hobby some 20 years ago I found those books were priceless for their information and techniques. They filled in a lot of the holes in my knowledge.
One thing that I will grant to the guys above that are saying that it's less important to align a Chinese lathe is that these machines are built to a price point. So they do not come with the factory adjusted assemblies that you get on the big name machines costing 10 times the price.
BUT! With some knowledge and thinking you can measure, adjust, shim and otherwise check and set all the critical points of the headstock, carriage and tail stock so that it becomes as true as the high priced options. The only limit is in YOU and your ability to think about the basic principles and to use the tools you have to perform the checks. That test bar I mentioned before is one such trick. And there's other things you can do for aligning a tail stock both horizontally and vertically to get to where you can set up work between centers and know that the machine is not going to end up tapering your work.
Contrary to what some say you CAN do work on this machine to high standards. VERY HIGH in fact. But it will only get to that point if it's well set up and aligned. The good news is that you don't need to set the machine up to that sort of standard for now. It's worth getting it somewhere close but keep in mind for the future that it might still need to be fine tweaked as your skills and requirements for precision become more demanding.
One last comment on the whole HSS vs Carbide war going on in your thread and which is constantly repeated in other threads. It is well worth getting a couple of HSS blanks and grind out a cutter or two and actually try them. Then make up your own mind on the issue.
But do get the books or read about the various angles that go into shaping the cutter so you give the HSS a fair test. I went that way and found that for probably 95% of my HOBBY machining that HSS actually does a BETTER job than carbide. But I'm not a production shop. For a number of very valid reasons carbide inserts are the way to go for production. But for my home use I found that I get a better finish and have more control over the very light 1/4 and 1/2 thou "impossible" cuts as described by wood and others with a HSS cutter over carbide.
Sounds like you're doing fine.
A word of advice,...ignore all the internet drivel from experts who can't even turn a lathe on let alone run one. Everyone's an expert on the 'net.
Don't worry about it being perfectly level, there are bigger issues with lathes than being level. If it's within a few thou from end to end you'll never see an issue.
Threading isn't hard after someone walks you thru it. Don't think you have to thread with a very slow spindle speed. Sometimes more speed is better.
It's all hand/eye coordination. If you can drive a stick shift, play a musical instrument, shoot a bow or walk and chew gum you're halfway there. It's not rocket science.
Any questions send me a PM, I've run a lathe a couple times....and I do go thru Rocky MH once in a while.
After reading thru some of the posts you might do well to listen to wood800,...he sounds like my kind of machinist...
there's very little that will go wrong with one of these small lathes if it's looked after. Don't worry about Modern Tool and service, I've known Brian and Jesse over there for a while. They are a 5 min drive from me.
....and don't waste your money on high speed steel tools.....
I agree with you pretty much.
But I figure there IS a place for HSS, especially when starting out.
There are enough frustrations at the outset when learning to operate a lathe effectively, without seeing the dollar signs in your eyes every time you crunch a threading insert tip, for example.
And with the skill of grinding your own tools, you are never backed into the corner of not having a tool that will do what you need it to, whether it is a different thread form than what the insert makers offer, or something as simple as needing a groove of a particular width for, say, a snap ring on a screw.
It's up to the lathe operator to choose.
Cheers
Trev
Please have a look and see if I did anything wrong. Having problems getting nice threads, can't really see in photo but I keep getting very slight galling. Have been using Vipers Venom sulphur based cutting fluid and another type of aerosol cutting fluid called S00208 by sprayon,also just tried Rigid Dark thred cutting oil all with the same results. Last couple threads I cut I only took like .0002 per pass (it took a while). I redid my practice piece for muzzle brake (1'' 4140).
It's 24tpi, made the relief cut with part off blade.
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Did the crown with the tip of an inside 60 deg threader, then did 11 degree recess with PTG piloted crowning tool.
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Just chucked it up in the 3 jaw and checked run out was .0005, I know not proper for barrel work but this was just cutting practice.
All advice and help much appreciated. I have only been running lathe for 3 days and I know I am hooked.
It's 24tpi, made the relief cut with part off blade.
Did the crown with the tip of an inside 60 deg threader, then did 11 degree recess with PTG piloted crowning tool.
Just chucked it up in the 3 jaw and checked run out was .0005, I know not proper for barrel work but this was just cutting practice.
All advice and help much appreciated. I have only been running lathe for 3 days and I know I am hooked.
Pressure is removed just as it gets near center, hardly takes any pressure anyhow, if the part has no center hole an Acetal or AL disk with a center in it works great. It's the easiest, and often only way to get rid of chatter and rigidity issues when parting/grooving, mostly with smaller flimsy lathes, you just have to DO IT RIGHT. Any half decent machinist knows that and how to do it with success and efficiency. If you don't know, you don't know, doesn't make it wrong just cause you don't know.
NEVER assume that there is only one way to do something. Smart machinists do what has to be done to make good parts with the equipment at their disposition. The better ones actually manage to make money at it.
Gotta say there's always some really funny stuff in these threads...
HSS has its place, Carbide has its place, CBN has its place, and so does a hand file, a chisel and a honing stone, its about knowing when you should be using what to do a good job efficiently, some guys with 50yrs in this trade never figured that one out.
OP, looks to me like your threading tool is not cutting and flowing the chip very well at all, probably a brazed carbide 60° bit eh? soft steels at slower speeds tend to stick pretty bad and tear rather than cut, so it doesn't help the process.
Are you threading with compound set between 29-30°?
A properly ground HSS bit should do very nice threads but its important that it cut well and gets the chip out of the way.
I do most of my threading with carbide shaped inserts and certainly recommend it when it makes financial sense, vardex is common but there's a few other good to even better options.
For cutting oils CoolTool2 is still my favorite, works great and smells ok(made with tall oil so has a bit of a wood smell), tried a bunch and keep coming back to it as the best one overall for all applications have it be turning, drilling, tapping, broaching, and I don't usually work with much of the easy materials. A few other oils had some potential for smelled deadly and still didn't gain any performance.
3-wires and a bit of time learning to use them is very useful in making good threads on spec.
As to the crowns and so on, you have a lathe, it can cut the best ones out there. The reamers/formed tools and so on have their place, but when its setup in the lathe, use the lathe.
Are you threading with compound set between 29-30°?
A properly ground HSS bit should do very nice threads but its important that it cut well and gets the chip out of the way.
I do most of my threading with carbide shaped inserts and certainly recommend it when it makes financial sense, vardex is common but there's a few other good to even better options.
For cutting oils CoolTool2 is still my favorite, works great and smells ok(made with tall oil so has a bit of a wood smell), tried a bunch and keep coming back to it as the best one overall for all applications have it be turning, drilling, tapping, broaching, and I don't usually work with much of the easy materials. A few other oils had some potential for smelled deadly and still didn't gain any performance.
3-wires and a bit of time learning to use them is very useful in making good threads on spec.
As to the crowns and so on, you have a lathe, it can cut the best ones out there. The reamers/formed tools and so on have their place, but when its setup in the lathe, use the lathe.
