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Gunsmithing leveling lathe
- Thread starter smithy308
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Re: leveling lathe
I have a set of them yes they are and they make a big diff. if you have to turn a dia or bore a hole very far like say 5 to 6 in.
I have a set of them yes they are and they make a big diff. if you have to turn a dia or bore a hole very far like say 5 to 6 in.
Re: leveling lathe
I think that depends on the size of your lathe. In my experience, small lathes with short beds are normally okay. Lathes with longer beds are the problem. A lathe could machine standing up as long as the bed is true to the headstock.
I think that depends on the size of your lathe. In my experience, small lathes with short beds are normally okay. Lathes with longer beds are the problem. A lathe could machine standing up as long as the bed is true to the headstock.
Re: leveling lathe
the problem is that even a minor offset can create a twist in the bed. It can cause the tailstock to be out of alignment and can create taper as said above. Just had a buddy borrom my precision level, he was having trouble when he would start a drill bit after taking out a live center and the drill would shift on him ever so slightly... he leveled with a precision level and this problem went away. I agree with scout, but the problem is lathes are built to have the bed true to the headstock when they are sitting on the ground and leveled properly... Perhaps it is only a heavier lathe that this makes a difference with, but I think it is good practice to make sure everything is as close to perfect as we can make it, afterall that is the name of this game anyway, what kind of tolerance can you hold? What is acceptable for you? If you are worried about the cost of the level to get it right, you will have an eye opening experience tooling up for any actual work. I wonder how much run-out people have that could be adjusted out with a good level?
Anyway that is my two bits
Dave
the problem is that even a minor offset can create a twist in the bed. It can cause the tailstock to be out of alignment and can create taper as said above. Just had a buddy borrom my precision level, he was having trouble when he would start a drill bit after taking out a live center and the drill would shift on him ever so slightly... he leveled with a precision level and this problem went away. I agree with scout, but the problem is lathes are built to have the bed true to the headstock when they are sitting on the ground and leveled properly... Perhaps it is only a heavier lathe that this makes a difference with, but I think it is good practice to make sure everything is as close to perfect as we can make it, afterall that is the name of this game anyway, what kind of tolerance can you hold? What is acceptable for you? If you are worried about the cost of the level to get it right, you will have an eye opening experience tooling up for any actual work. I wonder how much run-out people have that could be adjusted out with a good level?
Anyway that is my two bits
Dave
Re: leveling lathe
if your doin precision work then yes it is , when i have my shop built i will have seperate footings for my machines so theirs less chance of the moving over time
if your doin precision work then yes it is , when i have my shop built i will have seperate footings for my machines so theirs less chance of the moving over time
Re: leveling lathe
I have the starret levels you need to do it right pm me maybe we can work something out.
I have the starret levels you need to do it right pm me maybe we can work something out.
Re: leveling lathe
Just remember the "GIGO" term.
Garbage In = Garbage Out
It doesn't matter what you're working with. Computers, machines, children, whatever.
You'll only get out whatever quality that you put in. So the better you put into (preparation) the better you'll get out.
Definitely applies here, too.
Just remember the "GIGO" term.
Garbage In = Garbage Out
It doesn't matter what you're working with. Computers, machines, children, whatever.
You'll only get out whatever quality that you put in. So the better you put into (preparation) the better you'll get out.
Definitely applies here, too.
Re: leveling lathe
Lathes have to be square on the ground but perfect level doesn't mean anything. They use lathes on ships with no ill effects.
As long as the bed is not twisted, and is sitting perfectly square, your good.
Starting with a good, hard, flat, concrete floor is important. If it's slightly off level but perfectly flat, your good. Can't have any stress or twist on the bed. Different floor sections for each machine helps keep vibrations from transfering from machine to machine
Lathes have to be square on the ground but perfect level doesn't mean anything. They use lathes on ships with no ill effects.
As long as the bed is not twisted, and is sitting perfectly square, your good.
Starting with a good, hard, flat, concrete floor is important. If it's slightly off level but perfectly flat, your good. Can't have any stress or twist on the bed. Different floor sections for each machine helps keep vibrations from transfering from machine to machine
Re: leveling lathe
how do you ensure the bed isn't twisted?
Also, I doubt lathes on ships are rigged conventionally, and I doubt they are used for the utmost precision machining, more like fabbing parts, where close is good enough to get you home.
how do you ensure the bed isn't twisted?
Also, I doubt lathes on ships are rigged conventionally, and I doubt they are used for the utmost precision machining, more like fabbing parts, where close is good enough to get you home.
Re: leveling lathe
They have no problem holding the same tolerances gunsmiths do.
I'm not saying to cant the thing at a 30 degree angle. I'm saying your only focus should be on square.
Eyeball level and square is what u want. Trying to get it perfectly level, you might twist it slightly.
This was a recent question on one of our machine shop tests. Half the class put yes, it has to be level, the other half put no. Most of the time, it will get leveled without really trying because theyre normally put on a flat, level floor. But if
They have no problem holding the same tolerances gunsmiths do.
I'm not saying to cant the thing at a 30 degree angle. I'm saying your only focus should be on square.
Eyeball level and square is what u want. Trying to get it perfectly level, you might twist it slightly.
This was a recent question on one of our machine shop tests. Half the class put yes, it has to be level, the other half put no. Most of the time, it will get leveled without really trying because theyre normally put on a flat, level floor. But if
Re: leveling lathe
When leveling it only level off of three feet this keeps from twisting it as bad when you get it level then snug the other feet down and recheck every thing. I have only leveled a couple Manual machines but that is the way we always leveled CNC's where I worked. Level off of the two outside front ones and the one middle one in the back running the tool post back and forth checking long ways of the ways and across them. After you get it level swing the tailstock in and put a pieces of stock in it about 20" long or so like an old barrel and take a straight cut if its a new machine there shouldn't be more than a couple thousands over 20" and you can take that out with the tailstock if you get it that close you've done good. Some you get lucky and you can get right in 30 minutes but I fought a CNC lathe that would swing 36" and was 12' chuck to tailstock 8 hours one time some times you are fighting yourself tho. One way we would check to see if the spindle was inline with the ways is take a piece of stock pretty big like 6"diam and say 12-16" long and chuck it up and take a straight cut on it measure about every half inch and that will tell you the taper without using the tailstock some times you can adjust this out by releveling and some machines you have to tram the spindles in. The shop I worked at moved machines around alot so we got to level our machines own alot. Your work depended on and was alot easier depending how good a job you done so you learned to do it right.
When leveling it only level off of three feet this keeps from twisting it as bad when you get it level then snug the other feet down and recheck every thing. I have only leveled a couple Manual machines but that is the way we always leveled CNC's where I worked. Level off of the two outside front ones and the one middle one in the back running the tool post back and forth checking long ways of the ways and across them. After you get it level swing the tailstock in and put a pieces of stock in it about 20" long or so like an old barrel and take a straight cut if its a new machine there shouldn't be more than a couple thousands over 20" and you can take that out with the tailstock if you get it that close you've done good. Some you get lucky and you can get right in 30 minutes but I fought a CNC lathe that would swing 36" and was 12' chuck to tailstock 8 hours one time some times you are fighting yourself tho. One way we would check to see if the spindle was inline with the ways is take a piece of stock pretty big like 6"diam and say 12-16" long and chuck it up and take a straight cut on it measure about every half inch and that will tell you the taper without using the tailstock some times you can adjust this out by releveling and some machines you have to tram the spindles in. The shop I worked at moved machines around alot so we got to level our machines own alot. Your work depended on and was alot easier depending how good a job you done so you learned to do it right.
Re: leveling lathe
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AZPrecision</div><div class="ubbcode-body">They have no problem holding the same tolerances gunsmiths do.
I'm not saying to cant the thing at a 30 degree angle. I'm saying your only focus should be on square.
Eyeball level and square is what u want. Trying to get it perfectly level, you might twist it slightly.
This was a recent question on one of our machine shop tests. Half the class put yes, it has to be level, the other half put no. Most of the time, it will get leveled without really trying because theyre normally put on a flat, level floor. But if</div></div>
Still wondering how you determine if it is perfectly square? Are you speaking of a lathe where you can adjust the spindle?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AZPrecision</div><div class="ubbcode-body">They have no problem holding the same tolerances gunsmiths do.
I'm not saying to cant the thing at a 30 degree angle. I'm saying your only focus should be on square.
Eyeball level and square is what u want. Trying to get it perfectly level, you might twist it slightly.
This was a recent question on one of our machine shop tests. Half the class put yes, it has to be level, the other half put no. Most of the time, it will get leveled without really trying because theyre normally put on a flat, level floor. But if</div></div>
Still wondering how you determine if it is perfectly square? Are you speaking of a lathe where you can adjust the spindle?
Re: leveling lathe
About the only way to determine it it's square is to turn something with some length to it and that is pretty good size around that will not want to droop on you. Cut a skim pass after you have the stock cleaned up about .001 along the diam and the face and then run a test indicater along it. This will show you the taper but everything has to be in really good shape like new for a machine not to taper some and it has to be a pretty good quality machine if you can get it down to a couple thousands over a couple feet and a thousanth across the face of a 6" piece you are doing very good.
About the only way to determine it it's square is to turn something with some length to it and that is pretty good size around that will not want to droop on you. Cut a skim pass after you have the stock cleaned up about .001 along the diam and the face and then run a test indicater along it. This will show you the taper but everything has to be in really good shape like new for a machine not to taper some and it has to be a pretty good quality machine if you can get it down to a couple thousands over a couple feet and a thousanth across the face of a 6" piece you are doing very good.
Re: leveling lathe
thanks! I will do this with my lathe soon. I am wondering how much wear there is in it anyhow... How would you determine which way it is twisted? Just by trying to go one way and rechecking first?
Dave
thanks! I will do this with my lathe soon. I am wondering how much wear there is in it anyhow... How would you determine which way it is twisted? Just by trying to go one way and rechecking first?
Dave
Re: leveling lathe
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DebosDave ©</div><div class="ubbcode-body">how do you ensure the bed isn't twisted?
Also, I doubt lathes on ships are rigged conventionally, and I doubt they are used for the utmost precision machining, more like fabbing parts, where close is good enough to get you home. </div></div>
You obviously haven't served in the Navy.....
The only "special" thing done is they are fastened to the deck ( you know, "stowed for sea")
but they have jacking screws for adjustment...
guess it depends on your definition of "accurate"
they aren't on the micron scale, but I haven't seen too many places that are outside of where I work now.....
I was on a "sub-tender" and parts were routinely kept within .0005" underway or at the pier....
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DebosDave ©</div><div class="ubbcode-body">how do you ensure the bed isn't twisted?
Also, I doubt lathes on ships are rigged conventionally, and I doubt they are used for the utmost precision machining, more like fabbing parts, where close is good enough to get you home. </div></div>
You obviously haven't served in the Navy.....
The only "special" thing done is they are fastened to the deck ( you know, "stowed for sea")
but they have jacking screws for adjustment...
guess it depends on your definition of "accurate"
they aren't on the micron scale, but I haven't seen too many places that are outside of where I work now.....
I was on a "sub-tender" and parts were routinely kept within .0005" underway or at the pier....
Re: leveling lathe
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: chpprguy</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DebosDave ©</div><div class="ubbcode-body">how do you ensure the bed isn't twisted?
Also, I doubt lathes on ships are rigged conventionally, and I doubt they are used for the utmost precision machining, more like fabbing parts, where close is good enough to get you home. </div></div>
You obviously haven't served in the Navy.....
The only "special" thing done is they are fastened to the deck ( you know, "stowed for sea")
but they have jacking screws for adjustment...
guess it depends on your definition of "accurate"
they aren't on the micron scale, but I haven't seen too many places that are outside of where I work now.....
I was on a "sub-tender" and parts were routinely kept within .0005" underway or at the pier....</div></div>
Roger that, my appologies. I was making some assumptions there
You are correct, never been in the Navy
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: chpprguy</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DebosDave ©</div><div class="ubbcode-body">how do you ensure the bed isn't twisted?
Also, I doubt lathes on ships are rigged conventionally, and I doubt they are used for the utmost precision machining, more like fabbing parts, where close is good enough to get you home. </div></div>
You obviously haven't served in the Navy.....
The only "special" thing done is they are fastened to the deck ( you know, "stowed for sea")
but they have jacking screws for adjustment...
guess it depends on your definition of "accurate"
they aren't on the micron scale, but I haven't seen too many places that are outside of where I work now.....
I was on a "sub-tender" and parts were routinely kept within .0005" underway or at the pier....</div></div>
Roger that, my appologies. I was making some assumptions there
Re: leveling lathe
No apologies...
just wanted to let you know,
there are some large repair ships with fair sized machine shops....
and some darn fine machinists (a few, not all)
No apologies...
just wanted to let you know,
there are some large repair ships with fair sized machine shops....
and some darn fine machinists (a few, not all)
Re: leveling lathe
Level the lathe the best you can and then make test cuts to see if there is any taper present. You also need to check the tail stock alignment for taper as well. Test cuts are the only way to determine if taper is present and the only way to see if you've removed it. That's what's important if doing precision work, zero taper in the work piece.
Level the lathe the best you can and then make test cuts to see if there is any taper present. You also need to check the tail stock alignment for taper as well. Test cuts are the only way to determine if taper is present and the only way to see if you've removed it. That's what's important if doing precision work, zero taper in the work piece.
Re: leveling lathe
I still think that it dependes on what machine you have. A good small lathe should be fine setting securely to a work bench. Larger and longer machines need adjusted to make sure that isn't any twist. But perfectly level is not the only way. Normally, I level one slightly off level to aid in coolant return to the drain. Twist is the problem not level. As for the headstock and cutting tapers, Normally, you can adjust leveling screws at the end to remove any twist. But, some lathes actually have adjusting screws to move the headstock from side to side to remove taper. But is an alignment problem then not twist. The adjusting screws simple align the headstock to the ways of the bed. On some machines, the bed ways actually go under the headstock to insure headstock alignment. I have four lathes in my shop and the one with the 10 foot bed is the only one that I have ever had any trouble with twist. The others are short enough that I have never had a problem. To each his own, but in my opinion precision levels are not the only method.
I still think that it dependes on what machine you have. A good small lathe should be fine setting securely to a work bench. Larger and longer machines need adjusted to make sure that isn't any twist. But perfectly level is not the only way. Normally, I level one slightly off level to aid in coolant return to the drain. Twist is the problem not level. As for the headstock and cutting tapers, Normally, you can adjust leveling screws at the end to remove any twist. But, some lathes actually have adjusting screws to move the headstock from side to side to remove taper. But is an alignment problem then not twist. The adjusting screws simple align the headstock to the ways of the bed. On some machines, the bed ways actually go under the headstock to insure headstock alignment. I have four lathes in my shop and the one with the 10 foot bed is the only one that I have ever had any trouble with twist. The others are short enough that I have never had a problem. To each his own, but in my opinion precision levels are not the only method.
Re: leveling lathe
As close to the chuck as most of the gunsmithing work is done a machine would have to be way out of level,square, and so on to make alot of difference. Don't get me wrong you want it as close to right as possible. I'm new to the gunsmithing and hope to get more involved but there is a big differences from what i'm use to doing and what you guys are accomplishing and the taper gets worse the farther you get from the chuck. I hope I can accomplish some of the fine pieces of work you gunsmiths do some day but right now everything i'm use to turning is 6' long between centers with a dog turning it and about 10 different journals ranging from 6"-30" with a +-.0003 tolerance and no taper. So this is a whole new realm of learning for me. I just wish i could afford a CNC for my basement.
As close to the chuck as most of the gunsmithing work is done a machine would have to be way out of level,square, and so on to make alot of difference. Don't get me wrong you want it as close to right as possible. I'm new to the gunsmithing and hope to get more involved but there is a big differences from what i'm use to doing and what you guys are accomplishing and the taper gets worse the farther you get from the chuck. I hope I can accomplish some of the fine pieces of work you gunsmiths do some day but right now everything i'm use to turning is 6' long between centers with a dog turning it and about 10 different journals ranging from 6"-30" with a +-.0003 tolerance and no taper. So this is a whole new realm of learning for me. I just wish i could afford a CNC for my basement.
Re: leveling lathe
Thanks everyone for your input.. I will go ahead and get a machinist level.. I think I will be OK because my lathe is brand new and it is sitting on 2 cast iron pedestals on a concrete floor.. I haven't even had the time yet to even turn it on, so I have to go through a checklist of things to get it going..
Thanks again..
mtnsmith
Thanks everyone for your input.. I will go ahead and get a machinist level.. I think I will be OK because my lathe is brand new and it is sitting on 2 cast iron pedestals on a concrete floor.. I haven't even had the time yet to even turn it on, so I have to go through a checklist of things to get it going..
Thanks again..
mtnsmith
Re: leveling lathe
Remember to level several times during the year, after large changes in temps the expansion/contraction of the concrete can change your level.
Always check tail stock alignment too. I check it when I level.
Remember to level several times during the year, after large changes in temps the expansion/contraction of the concrete can change your level.
Always check tail stock alignment too. I check it when I level.
Re: leveling lathe
The best way to install a lathe to be true is to set it on blanched and ground soleplates that are grouted into the concrete floor already precision leveled with each other. Then you use shims or jack bolts to level it with precision levels, or if you know an optical alignment guy, you can optically check each foot for level to remove most of the twist from head-to-tailstock. Since most of us cannot do soleplates, we just anchor to concrete. Personally, I would use epoxy-set all-thread anchors and nust/washers under the feet to level, then put shims to hard-level the feet. Grout with a good epoxy grout and you should be set.
Then, as said above, make cuts on a long piece of stock and check for taper.
The best way to install a lathe to be true is to set it on blanched and ground soleplates that are grouted into the concrete floor already precision leveled with each other. Then you use shims or jack bolts to level it with precision levels, or if you know an optical alignment guy, you can optically check each foot for level to remove most of the twist from head-to-tailstock. Since most of us cannot do soleplates, we just anchor to concrete. Personally, I would use epoxy-set all-thread anchors and nust/washers under the feet to level, then put shims to hard-level the feet. Grout with a good epoxy grout and you should be set.
Then, as said above, make cuts on a long piece of stock and check for taper.
Re: leveling lathe
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: chpprguy</div><div class="ubbcode-body">No apologies...
just wanted to let you know,
there are some large repair ships with fair sized machine shops....
and some darn fine machinists (a few, not all) </div></div>
We even had lathes on the submarines. When the guys from Colt-Pielstick came to work on our diesel, the re-trued our lathe when they were cutting some gears. They got it true for the entire length between centers (48") within .0003". I wish I had been back there to see how they did it.
I agree with the comment about tenders and machines/machinists....most were pretty damned good.....a rare few sucked. We had some pretty good MRs at the sub repair facility I was on shore duty at.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: chpprguy</div><div class="ubbcode-body">No apologies...
just wanted to let you know,
there are some large repair ships with fair sized machine shops....
and some darn fine machinists (a few, not all) </div></div>
We even had lathes on the submarines. When the guys from Colt-Pielstick came to work on our diesel, the re-trued our lathe when they were cutting some gears. They got it true for the entire length between centers (48") within .0003". I wish I had been back there to see how they did it.
I agree with the comment about tenders and machines/machinists....most were pretty damned good.....a rare few sucked. We had some pretty good MRs at the sub repair facility I was on shore duty at.
Re: leveling lathe
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Thanks everyone for your input.. I will go ahead and get a machinist level.. I think I will be OK because my lathe is brand new and it is sitting on 2 cast iron pedestals on a concrete floor.. I haven't even had the time yet to even turn it on, so I have to go through a checklist of things to get it going..
</div></div>
We've used 3 levels while leveling a lathe. One at the headstock, one at the tailstock and then one on the bed (long way). That way you can see how the whole bed reacts as you adjust the jackscrews (eliminates twisting the bed). Place the level on precision rolls, not directly on the ways.
. Make sure you don't have a soft foot when done or else you'll experience viabration which will show up in the finish of the part.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Thanks everyone for your input.. I will go ahead and get a machinist level.. I think I will be OK because my lathe is brand new and it is sitting on 2 cast iron pedestals on a concrete floor.. I haven't even had the time yet to even turn it on, so I have to go through a checklist of things to get it going..
</div></div>
We've used 3 levels while leveling a lathe. One at the headstock, one at the tailstock and then one on the bed (long way). That way you can see how the whole bed reacts as you adjust the jackscrews (eliminates twisting the bed). Place the level on precision rolls, not directly on the ways.
Re: leveling lathe
When I got an engineering degree and got a job, I made less than half what my little brother made as a machinist.
He, and 10 other machinists, worked for a company that paid each guy half of what the company got for the parts each made. They specialized in parts that were for Boeing that few other machine shops would bid on the job, because the parts were so hard to make.
That shop did not, and still does not level machines.
The machines are on felt pads that are on concrete.
I have a 1938 Atlas lathe 12x36 that is so light that I can lift it.
I have a 2009 Precision Matthews lathe 12x36 that weighs 1250 pounds.
Neither are leveled. Neither are on felt or rubber pads.
Both are on caster wheels.
If the unleveled Atlas can make a cut accurate enough for any gunsmithing, then a heavy 12x36 should be 10 times as stiff.
When I got an engineering degree and got a job, I made less than half what my little brother made as a machinist.
He, and 10 other machinists, worked for a company that paid each guy half of what the company got for the parts each made. They specialized in parts that were for Boeing that few other machine shops would bid on the job, because the parts were so hard to make.
That shop did not, and still does not level machines.
The machines are on felt pads that are on concrete.
I have a 1938 Atlas lathe 12x36 that is so light that I can lift it.
I have a 2009 Precision Matthews lathe 12x36 that weighs 1250 pounds.
Neither are leveled. Neither are on felt or rubber pads.
Both are on caster wheels.
If the unleveled Atlas can make a cut accurate enough for any gunsmithing, then a heavy 12x36 should be 10 times as stiff.
Re: leveling lathe
Might not be an issue with the smaller/lighter lathes. You can bend/twist the bed easily on the bigger stuff which will cause taper issues when boring holes or reaming holes oversized. If you think aircraft work is critical try working with gaging equipment. Splitting tenths (.0001") the norm.
Might not be an issue with the smaller/lighter lathes. You can bend/twist the bed easily on the bigger stuff which will cause taper issues when boring holes or reaming holes oversized. If you think aircraft work is critical try working with gaging equipment. Splitting tenths (.0001") the norm.
Re: leveling lathe
I was specifically told NOT to attach the lathe or mill to the floor by a very experienced machinist/instructor. Temperature changes are so extreme here that the floor moves too much. It also varies with the distance from exterior walls.
I use a machinist's level to check for twist. I don't worry about level (the floor is pretty close to level). I mostly work close to the chuck.
If you are going to machine on a lathe, you are gonna have to pony up for a machinist's level.
Machines are cheap compared to the tooling and instruments, as I have come to find.
I was specifically told NOT to attach the lathe or mill to the floor by a very experienced machinist/instructor. Temperature changes are so extreme here that the floor moves too much. It also varies with the distance from exterior walls.
I use a machinist's level to check for twist. I don't worry about level (the floor is pretty close to level). I mostly work close to the chuck.
If you are going to machine on a lathe, you are gonna have to pony up for a machinist's level.
Machines are cheap compared to the tooling and instruments, as I have come to find.
Re: leveling lathe
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: scout67</div><div class="ubbcode-body">I still think that it dependes on what machine you have. A good small lathe should be fine setting securely to a work bench. Larger and longer machines need adjusted to make sure that isn't any twist. But perfectly level is not the only way. Normally, I level one slightly off level to aid in coolant return to the drain. Twist is the problem not level. As for the headstock and cutting tapers, Normally, you can adjust leveling screws at the end to remove any twist. But, some lathes actually have adjusting screws to move the headstock from side to side to remove taper. But is an alignment problem then not twist. The adjusting screws simple align the headstock to the ways of the bed. On some machines, the bed ways actually go under the headstock to insure headstock alignment. I have four lathes in my shop and the one with the 10 foot bed is the only one that I have ever had any trouble with twist. The others are short enough that I have never had a problem. To each his own, but in my opinion precision levels are not the only method. </div></div>
Amen
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: scout67</div><div class="ubbcode-body">I still think that it dependes on what machine you have. A good small lathe should be fine setting securely to a work bench. Larger and longer machines need adjusted to make sure that isn't any twist. But perfectly level is not the only way. Normally, I level one slightly off level to aid in coolant return to the drain. Twist is the problem not level. As for the headstock and cutting tapers, Normally, you can adjust leveling screws at the end to remove any twist. But, some lathes actually have adjusting screws to move the headstock from side to side to remove taper. But is an alignment problem then not twist. The adjusting screws simple align the headstock to the ways of the bed. On some machines, the bed ways actually go under the headstock to insure headstock alignment. I have four lathes in my shop and the one with the 10 foot bed is the only one that I have ever had any trouble with twist. The others are short enough that I have never had a problem. To each his own, but in my opinion precision levels are not the only method. </div></div>
Amen
Re: leveling lathe
Straightness of machine, matters more than level.
Matters more with big, old OD grinder, setting on three different concrete pads!
Jim is right.
Straightness of machine, matters more than level.
Matters more with big, old OD grinder, setting on three different concrete pads!
Jim is right.
Re: leveling lathe
I work for an Lockheed Martin (well new contractor,same tools)all of the tools that cut flight hardwear are attached to their own pad which is 18" thick and just big enought o hold the tool , the slabs are leveled prior to tool install and the tool is leveled then grouted on place. They are first leveled then lazer aligned to ensure they are true (just cause its level don't meen its square), this goes to for everything from a couple 15x30 LaBlonds to 10 million dollar CNC centers , some of these parts are held to micron finish so every possible weak link is minimized even though the enviroment is kept pretty consistand not varying more than 8-10 deg.
These tools are first leveled
Is it realy needed , probaly not but theirs no sense in not doing it right. Kinda like blue pringting an action , for the most part the factroy setup can shoot as well as most men but trueing the action is just eliminating any possible weak points.
Do it right the first time and only cry once.
I work for an Lockheed Martin (well new contractor,same tools)all of the tools that cut flight hardwear are attached to their own pad which is 18" thick and just big enought o hold the tool , the slabs are leveled prior to tool install and the tool is leveled then grouted on place. They are first leveled then lazer aligned to ensure they are true (just cause its level don't meen its square), this goes to for everything from a couple 15x30 LaBlonds to 10 million dollar CNC centers , some of these parts are held to micron finish so every possible weak link is minimized even though the enviroment is kept pretty consistand not varying more than 8-10 deg.
These tools are first leveled
Is it realy needed , probaly not but theirs no sense in not doing it right. Kinda like blue pringting an action , for the most part the factroy setup can shoot as well as most men but trueing the action is just eliminating any possible weak points.
Do it right the first time and only cry once.
Re: leveling lathe
The reason they make machines so stout is so they won't flex.
The heavy machine can make a deeper cut.
If you had a long light weight machine, you would still not be able to measure any advantage from leveling for gunsmithing.
Leveling does have the advantage of being able to measure a taper with a level.
What does it all mean?
Bench rest shooters are not the only ones with superfluous accuracy rituals, machinists have them too.
If you think chasing the threads in an action will make the rifle shoot more accurately, we have some land to sell you
The reason they make machines so stout is so they won't flex.
The heavy machine can make a deeper cut.
If you had a long light weight machine, you would still not be able to measure any advantage from leveling for gunsmithing.
Leveling does have the advantage of being able to measure a taper with a level.
What does it all mean?
Bench rest shooters are not the only ones with superfluous accuracy rituals, machinists have them too.
If you think chasing the threads in an action will make the rifle shoot more accurately, we have some land to sell you
Re: leveling lathe
Mills and lathes installed on USN vessels are set on pads which are precision ground to be level after they are welded in place. The machines are then set on the pads and shimmed if needed. After time the decks can twist enough to throw the machines off but thats a timeframe of 20 years or so. Machines used for critical repairs (Level 1 Nuke type stuff) have a scheduled overhaul required to maintain the needed criteria for such work.
Mills and lathes installed on USN vessels are set on pads which are precision ground to be level after they are welded in place. The machines are then set on the pads and shimmed if needed. After time the decks can twist enough to throw the machines off but thats a timeframe of 20 years or so. Machines used for critical repairs (Level 1 Nuke type stuff) have a scheduled overhaul required to maintain the needed criteria for such work.
Re: leveling lathe
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Clark</div><div class="ubbcode-body">If you think chasing the threads in an action will make the rifle shoot more accurately, we have some land to sell you </div></div>
Prove it
If the barrel threads are not concentric to the action's bolt centerline, chasing the threads to bring them into concentricity will indeed make a measurable improvement in accuracy. Geometric tolerances matter 10x what dimensional tolerance do when it comes to building a precision rifle.
-matt
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Clark</div><div class="ubbcode-body">If you think chasing the threads in an action will make the rifle shoot more accurately, we have some land to sell you
</div></div>Prove it
If the barrel threads are not concentric to the action's bolt centerline, chasing the threads to bring them into concentricity will indeed make a measurable improvement in accuracy. Geometric tolerances matter 10x what dimensional tolerance do when it comes to building a precision rifle.
-matt
Re: leveling lathe
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: monteboy84</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Clark</div><div class="ubbcode-body">If you think chasing the threads in an action will make the rifle shoot more accurately, we have some land to sell you </div></div>
Prove it
If the barrel threads are not concentric to the action's bolt centerline, chasing the threads to bring them into concentricity will indeed make a measurable improvement in accuracy. Geometric tolerances matter 10x what dimensional tolerance do when it comes to building a precision rifle.
-matt </div></div>
The center of mass, or as my father, the great gun designer says, "the center of percussion", is off more due to the attachment of an asymmetrical scope, stock, and trigger that are off center, more than due to any amount of off center action threads.
Threads clamp longitudinally, and may initially locate radially on assembly, but the axial alignment and rigidity are geometrically controlled by the large ring and the shoulder.
I have experimented with replacing the threads with solder on a cylindrical barrel shank in cylindrical receiver, and it still shoots sub moa.
I have experimented with welding a lug for a Browning 1911 type link on a 308 bull barrel in a ribbed pistol type lock up, and it still shoots.
I have put a 6mmBR barrel on an old 1918 Sav 99 take down, with loose old square interrupted threads, and it shoots well.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: monteboy84</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Clark</div><div class="ubbcode-body">If you think chasing the threads in an action will make the rifle shoot more accurately, we have some land to sell you
</div></div>Prove it
If the barrel threads are not concentric to the action's bolt centerline, chasing the threads to bring them into concentricity will indeed make a measurable improvement in accuracy. Geometric tolerances matter 10x what dimensional tolerance do when it comes to building a precision rifle.
-matt </div></div>
The center of mass, or as my father, the great gun designer says, "the center of percussion", is off more due to the attachment of an asymmetrical scope, stock, and trigger that are off center, more than due to any amount of off center action threads.
Threads clamp longitudinally, and may initially locate radially on assembly, but the axial alignment and rigidity are geometrically controlled by the large ring and the shoulder.
I have experimented with replacing the threads with solder on a cylindrical barrel shank in cylindrical receiver, and it still shoots sub moa.
I have experimented with welding a lug for a Browning 1911 type link on a 308 bull barrel in a ribbed pistol type lock up, and it still shoots.
I have put a 6mmBR barrel on an old 1918 Sav 99 take down, with loose old square interrupted threads, and it shoots well.
Re: leveling lathe
Wow, after all this I still need to add my .02. Most of the answers are here, just hard to pick out.
Way twist and soft foot are all you need to worry about, they are important. You do need a precision level to remove twist.
Pads are fine unless you will be doing heavy interrupted cuts with a light machine. In that case epoxy/weld studs into/onto the deck.
Machines with hydraulic operating systems should be pretty close to level. If it's gear or belt driven it could be upside down or on the wall (chips fall out better).
In fact, if you'll be running large volumes of coolant, set the machine up so it drains to your advantage.
Check for soft foot and twist if tolerances go bad or if shop conditions dramatically change.
A straight taper between centers is caused from the tail stock being off. It is normal to have to adjust the tail stock according to the length of work. A non-uniform taper is caused from twist in the ways.
Shane
Wow, after all this I still need to add my .02. Most of the answers are here, just hard to pick out.
Way twist and soft foot are all you need to worry about, they are important. You do need a precision level to remove twist.
Pads are fine unless you will be doing heavy interrupted cuts with a light machine. In that case epoxy/weld studs into/onto the deck.
Machines with hydraulic operating systems should be pretty close to level. If it's gear or belt driven it could be upside down or on the wall (chips fall out better).
In fact, if you'll be running large volumes of coolant, set the machine up so it drains to your advantage.
Check for soft foot and twist if tolerances go bad or if shop conditions dramatically change.
A straight taper between centers is caused from the tail stock being off. It is normal to have to adjust the tail stock according to the length of work. A non-uniform taper is caused from twist in the ways.
Shane
Re: leveling lathe
What Shane said about soft foot is paramount. There's essentially no way for 4 or more feet to come from any factory, all on the same plane.
Find the soft foot first, accommodate for it, then move on. Doing all this now will save you grief in the future.
I regret not saying anything sooner about that, and my apologies.
Most people don't get into the detail of this type of thing, and I should have known better with the members of this site.
What Shane said about soft foot is paramount. There's essentially no way for 4 or more feet to come from any factory, all on the same plane.
Find the soft foot first, accommodate for it, then move on. Doing all this now will save you grief in the future.
I regret not saying anything sooner about that, and my apologies.
Most people don't get into the detail of this type of thing, and I should have known better with the members of this site.
Re: leveling lathe
In setting your machine....an old timer machinist offered this advice to me and it seems to be good. I use lead strips for shims to level my lathe. I recheck in a week or so to see how much the lead has squished and adjust as needed. He told me the lead helps isolate the machine to a small degree from vibration caused by being directly bolted to the concrete floor with say a steel shim material.
In setting your machine....an old timer machinist offered this advice to me and it seems to be good. I use lead strips for shims to level my lathe. I recheck in a week or so to see how much the lead has squished and adjust as needed. He told me the lead helps isolate the machine to a small degree from vibration caused by being directly bolted to the concrete floor with say a steel shim material.
