Tailstock Alignment?

[MarkM]

This is just my opinion and I know I beat a different drum then most. Why would you even consider to buy something you can easily make and it will be another project under your belt to improve your ability to truly understand the relation.
I think there is too much thought into this when the proof is in the pudding. What you are getting as a result of the cut is what needs to be addressed. To set up an intentional taper To compensate for tooling flex is just a recipe for grief down the road with a tool change or even a different batch of material.
Turn your own 60 degree centre so you don t have to remove your chuck and install the Mt centre. You have to take a 60 degree cut everytime you remove and put it back in your chuck to be concentric.
Make a bar say ten inches long and press on two bushings on each end. Grind your tool with no radius so it is free cutting. Your not worried about surface finish here. Set up an indicator on your tailstock body where it moves with your screw settings. I use no lathe dog just friction turning. Take a cut of a thou. Or three. Move apron over to the other bushing and take the same cut. Measure then compare then move your tailstock over half the difference. Repeat until they measure the same.
In my opinion deflection is something to be dealt with spring cuts, a file and emery cloth and to work within the machines capabilities.

 

[seasicksteve]

IME tailstocks are generally a bit high so traversing a bar will not give a perfect setting for tailstock alignment. If tailstock height is perfect then traversing the bar would work. I use a bar about 1.75" in dia and 24" long I have 4 bosses about 1" wide on the bar one on each end and two equally space along the length. I rough turned the shaft to create the bosses undercut about 25% of the dia. I simply mount the bar take a cut off the boss disengage the feed crank the carriage to the next boss reengage the feed.... repeat. Just be sure not to move the compound or crosslide. Mic the bosses adjust the tailstock accordingly.
I have had a number of lathes various manufactures and all of them to some degree have inaccuracy in the tailstock. I have seen variation depending on how far the tailstock ram is extended. I have also witnessed variation based on how hard I draw down the clamping device on the tailstock
Jut some food for thought YMMV

 

[jwmay]

Not to hijack this highly active thread, but in three years of playing with machine tools, I’ve needed to align my tailstock once. How often are people finding it necessary to do this? I don’t see the ROI on this device. Are you all in business or something? Working to tenths? What’s the point of chasing this type of perfection? Stick a center in both ends, hang a steel rule between them, and adjust until the rule is perfectly vertical with no lean in any direction. Done. I’m probably being too simplistic, but it probably depends on what you’re making. At any rate, everything I’ve made worked just fine, and if it was wrong it had nothing to do with tapering. I just think this is a problem we as hobbyists aren’t really dealing with that much. I’ve heard it referred to as “slaying the wrong dragon”. I’d save the money for something else. But I’m sure the thing can be useful to the right person.

 

[pontiac428]

To set up an intentional taper To compensate for tooling flex is just a recipe for grief down the road with a tool change or even a different batch of material.
...
In my opinion deflection is something to be dealt with spring cuts, a file and emery cloth and to work within the machines capabilities.

It's hard not to agree with this. My little Atlas is adjusted to the gnat's tail, so with a dial indicator a test bar looks good, but under real world cutting, deflection induces a little bit of a taper when checking the work with mics. If I take those spring cuts, taper nearly goes away... nearly. Part of it is knowing and verifying your machine, but the "art" is in the operation, where compensations can be made for those effects.

 

[mikey]

Not to hijack this highly active thread, but in three years of playing with machine tools, I’ve needed to align my tailstock once. How often are people finding it necessary to do this? I don’t see the ROI on this device. Are you all in business or something? Working to tenths? What’s the point of chasing this type of perfection? Stick a center in both ends, hang a steel rule between them, and adjust until the rule is perfectly vertical with no lean in any direction. Done. I’m probably being too simplistic, but it probably depends on what you’re making. At any rate, everything I’ve made worked just fine, and if it was wrong it had nothing to do with tapering. I just think this is a problem we as hobbyists aren’t really dealing with that much. I’ve heard it referred to as “slaying the wrong dragon”. I’d save the money for something else. But I’m sure the thing can be useful to the right person.

I don't know about anyone else but I actually check my headstock and tailstock alignment at least several times per year or after I machine something that is big/heavy/off balance. Alignment and leveling affect every single thing you do on your lathe and it takes only a few minutes to confirm everything is right. Better that then finding out after a project that everything you did was off by whatever its off.

I think hobby guys can get really anal about some things. Well, okay, most things. But alignment is at the root of good work and confirming that things are right is not being anal; its being smart.

 

[projectnut]

After I bought spiral flute and spiral point taps, my old straight flute hand taps just sit on the shelf gathering dust.

Ken

Not to hijack this highly active thread, but in three years of playing with machine tools, I’ve needed to align my tailstock once. How often are people finding it necessary to do this? I don’t see the ROI on this device. Are you all in business or something? Working to tenths? What’s the point of chasing this type of perfection? Stick a center in both ends, hang a steel rule between them, and adjust until the rule is perfectly vertical with no lean in any direction. Done. I’m probably being too simplistic, but it probably depends on what you’re making. At any rate, everything I’ve made worked just fine, and if it was wrong it had nothing to do with tapering. I just think this is a problem we as hobbyists aren’t really dealing with that much. I’ve heard it referred to as “slaying the wrong dragon”. I’d save the money for something else. But I’m sure the thing can be useful to the right person.

It all depends on the type of work you do. I have moved the tailstock on both lathes more times than I can count. When turning a short taper it can be accomplished with the cross slide. When making a longer taper it requires either a taper attachment, or moving the tailstock. Neither of my lathes has a taper attachment, and I have no plans on investing in one or making one. The remaining alternative is offsetting the tailstock. I have turned a number of different style tapers from Jarno, to Jacobs, to Morse, and even a few B&S thrown in for good measure.

It only takes a couple minutes to recenter the tailstock with a test bar. It's already of a known tolerance so there's no need to cut, measure, and repeat. All you have to do is put a center in both the spindle and tailstock, measure, adjust, and be done. If you don't want to remove the chuck you can use a soft center and do a skim cut to be sure the point is on center.

I prefer to spend my limited time in the shop making parts rather than making the tools to be sure the parts I'm making are accurate. The truth be known a good machinist could probably make every tool needed in the shop. It's more a matter of time and resource management. Determining where time and money is best spent.

If you're only offsetting the tailstock on an annual basis or less it's probably not cost effective.

 

[stupoty]

Not to hijack this highly active thread, but in three years of playing with machine tools, I’ve needed to align my tailstock once. How often are people finding it necessary to do this? I don’t see the ROI on this device. Are you all in business or something? Working to tenths? What’s the point of chasing this type of perfection? Stick a center in both ends, hang a steel rule between them, and adjust until the rule is perfectly vertical with no lean in any direction. Done. I’m probably being too simplistic, but it probably depends on what you’re making. At any rate, everything I’ve made worked just fine, and if it was wrong it had nothing to do with tapering. I just think this is a problem we as hobbyists aren’t really dealing with that much. I’ve heard it referred to as “slaying the wrong dragon”. I’d save the money for something else. But I’m sure the thing can be useful to the right person.

Your

Not to hijack this highly active thread, but in three years of playing with machine tools, I’ve needed to align my tailstock once. How often are people finding it necessary to do this? I don’t see the ROI on this device. Are you all in business or something? Working to tenths? What’s the point of chasing this type of perfection? Stick a center in both ends, hang a steel rule between them, and adjust until the rule is perfectly vertical with no lean in any direction. Done. I’m probably being too simplistic, but it probably depends on what you’re making. At any rate, everything I’ve made worked just fine, and if it was wrong it had nothing to do with tapering. I just think this is a problem we as hobbyists aren’t really dealing with that much. I’ve heard it referred to as “slaying the wrong dragon”. I’d save the money for something else. But I’m sure the thing can be useful to the right person.

Theirs a lot to what you say that is totaly true, test equipment can be some of the most expensive and least used items of kit.

I like threads like this as they alow everyone to share their prefered methods of doing things.

The ruller method is as you say probably perfectly aceptable 99% of the time. I use ruler method for setting tool heights mostly.

I can see if you were setting the tailstock over a lot to do tapers then some way of easily and quickly reseting it could be helpful.

I hadnt realised how afordable the long ground test bars were, im personaly interested in getting one as my lath has seen quite a bit of use (1940's era leblond) and thought it would be handy for seeing which parts of the bed have high weare in adition to dialing in head and tail end quite quickly.

Also knowing what useful aids are out their is quite handy for when you see them for a couple of bucks at a flea market / car boot sale

Stu

 

[MarkM]

I kinda agree with jwmay. Unless theres a crash to upset things once things are set there may be wear to consider but like I said earlier proof is in the pudding. I know I ve leveled the lathe properly. My tailstock has been aligned. The pudding is checking my work head to toe as you should and if numbers start to wander I ll Investigate and go from there. Haven t had to.
It is good practice though to check your equipment! Maybe I should ? We all go about things in different ways.
For the o.p. I say make your own. You will be a better machinist after. Press fit a couple bushings, set up your indicator. Each setup has it s own merits and something gained. It s all experience. Maybe tackle an offset now you see the relation. Last but surely not the least! Too many other things to buy!!!

 

[Bob Korves]

The ruler method is a perfect way of roughly setting accurate centers for turning between centers -- for a zero length work piece! It is a great place to start, and close enough for lots of work. The problem is that lathes do not often have ways that are perfectly flat, untwisted, or unworn. They are also not manufactured perfectly, there are always deviations, and we need to know where the issues are to turn out good work in spite of them. A tail stock near the chuck, six inches from the chuck, half way down the bed, and all the way down the bed will give different results on all but imaginary and legendary lathes -- unless we are aware of the issues and work to compensate for them when necessary.

 

[Kroll]

Guys just to let everyone know the reason behind the question is I took this train wreak apart down to the last bolt/screw.I'm not far from being finish with it so when I'm finish I want to do a good tuneup.I just don't know how to go about doing a good tuneup so question then more questions as I go.My goal is to get the lathe best it can be for its age like the tail stock,head stock.Na no Nasa work here just want the parts to also be the best it can be.