Lifting a lathe versus force on spindle bearing

From quite a bit of research on this some years ago it turns out a LOT of manufacturers lift lathes by a sling under the chuck and another around the tailstock end of the bed, even on very large lathes. If holes for bars in the bed or stand are provided then may as well use them or a lifting plate that lifts from under the ways. With regard to stresses think about this. A 1/4" UNC bolt grade 5 has a tensile strength of 1.35 Ton, a 3/8" bolt 3.3 Ton - one bolt. Think about the forces acting upon a turbo-charged Diesel engine under full load. A plate,(essentially what a headstock is),bolted down can withstand more force than the individual bolts restraining it can. Then think about the hammering an axle bearing on the average car or pickup truck takes, not only rotational but shock loading as well.
That mover probably did know exactly what he was doing, especially if he moves a lot of machinery.
I'd stop worrying and start turning.
 
Well, we’re not really talking about breaking off the chuck here. When I aligned my headstock and tailstock i was measuring and setting to tenths of thousandths. It you lift a 2500 pound lathe by these components, you know that there is at least some amount of elastic deformation. And the stress is not applied completely evenly to all fasteners. Could there be even a small amount of plastic deformation, so it does not return exactly? Tenths, remember.

Recall how important leveling is to removing any twist in the bed. This is from the its own weight, and very small adjustments! This means the whole bed can move! You think picking up from the chuck is not going to affect accuracy?

So please move your equipment how you like. I will go with the manufacturers recommendation, which for Takisawa is to use a sling with lifting bars through holes specifically provided.
 
NortonDommi said:
Then think about the hammering an axle bearing on the average car or pickup truck takes, not only rotational but shock loading as well.
That mover probably did know exactly what he was doing, especially if he moves a lot of machinery.
I'd stop worrying and start turning.
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As i stated above, it could probably handle the load but what you say here is comparing apples to oranges. I think the Biggest concern is that lifting from the chuck will have a Negative effect on the tools accuracy more so then breaking a bearing.
 
It does not point down, it points towards the operator. Many pages have been typed on other forums detailing My attempts to discover where the error is coming from. I have been given a few ideas to try they will have to wait for winter before I have time. It's not a common error and so far I have no answer. Rollies Dad's method gives the problem but nothing changes the result.
 
Tim9 said:
As per Clausing manual. Steel flat bar under lathe bed. Once up off ground carriage gets moved either left or right to balance. Works perfectly. To load on truck I used a forklift with 2x6 laying on forks between bed and forks to prevent contact with lead screw .
View attachment 299346
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I do not agree with Clausing on that method either. Its putting the opposite forces on the bed, then it normally would bear.

It would be interesting if someone could measure the distortion caused by the various methods. If someone has a lathe they are going to part out, it would make a great experiment. Put an indicator under the chuck, and put some lifting force on the chuck, then the head stock, and see what happens. Then find a way to measure the bed bending, and apply some force to the center.
 
mcostello said:
It does not point down, it points towards the operator. Many pages have been typed on other forums detailing My attempts to discover where the error is coming from. I have been given a few ideas to try they will have to wait for winter before I have time. It's not a common error and so far I have no answer. Rollies Dad's method gives the problem but nothing changes the result.
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Ah, okay, so the spindle itself isn't bent, which would have caused the chuck to "orbit" like a spinning top. What you're describing sounds like simple head alignment, but it appears that this issue has already been beaten to death and left you rather unhappy. Didn't mean to kick the beehive again.
 
My lathe came with holes in the base casting to use for lifting by putting steel bars through. Lacking the bars, I lifted it with straps under the bed & a 5000# fork lift. 2700# lathe. I doesn't seem like that would cause any harm.
 
I watch professional riggers put three guys on the back of a forklift to counter balance a huge gang drill Assy. 4 separate columns on one huge cast base with large tables for each one. There was not a lot of professionalism going on. No safety chains all the cribbing they had was busted up 2x4 material standing them on edge:oops: they looked like cheap labor with a forklift operator. The whole time I was there like 4 hours they were loading a flat bed semi with 2 CNC lathes these gang drills and a sharp mill and figured out when loading the mill they had to much space between the equipment and had to reposition everything to make room for the mill. Luckily my end went smooth and I got out of there without loading fees so I was happy.
 
kb58 said:
This is the OP. I agree that the equipment mover should have lifted it the correct way, but at the same time, the blanket statement that the machine is ruined isn't valid either. The weight, how much of the lifting strap was on the headstock versus the spindle, and how heavy duty the spindle shaft is are all unknowns. Will the spindle deflect to some degree, yes, but the question is, will it spring back. All we know for sure is that it was a unnecessary risk of unknown magnitude. Guess I'll find out when a test piece is put in place, but even then, if there's an issue, it'll never be known whether or not it was due to previous abuse.

Regardless, I agree that "next time", the mover won't be allowed to cut corners.
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I agree that there is no way you can prove the mover caused any damage... which unfortunately works to the movers benefit.

The key is your confidence in your knowledge of the proper way to perform a task. It is not enough to know the proper way to perform a task you have to know why it is the proper way and the consequences of doing the task the wrong way.

When the "Pro" is setting up to do the task inproperly you can yell at them and start a pissing contest in which no one will really come out ahead. Or you can explain, in this case, that you purchased this particular lathe because it has no slop or runout in the spindle and you would like the mover to to use the method the manufacture reccomends for this particular model of lathe to preserve its precision. You don't have to start by being an A&& and being confrontational... in doing so you are kind of asking for a bad outcome. Working with people is an art... just like working with machines.

Just because the "Pro" did it wrong the last 200 times doesn't make his way the proper way to do the job.



I had a situation somewhat recently where my 2 year old well pump stopped working. Every time the pump would run it would blow the overload breaker on the control box. I messed around with the pump for a couple hours and found the starting current was 4x the breaker rated current on one leg and practically nothing on the second leg... I concluded I couldn't do anything so I called the company that installed the pump. Some kid "Well technician" came out screwed around and declared there was a wiring problem and the pump was good. He called the electrician they use. Electrician came out. The first thing I told the electrician when he arrived was the pump guys say I have bad wiring but I am pretty sure the problem resides somewhere down the hole. The electrician spent a couple hours taking everything apart and putting it back together to run up his bill. At about the 3 hour mark he declared the the line from my house to the pump controller was bad.

"OK, I guess I am going to have to spend many thousands of dollars digging up the line to replace it". "That is going to take a while can you help me run a cable from my electrical panel to the pump controller so I will have water while the work is done". The electrician agreed... huh the problem didn't go away. Well it must be the line from the controller to the well head... ok, ran a temporary replacement... same problem. Swapped out the controller.... same problem. Huh it must be a problem with the pump.

I got the bill from the electricians company a month and a half later. I politely called him on his cell phone and told him that the 4 hour charge didn't seem right to me. He agreed and canceled the bill. I was confident in my knowledge of the problem and didn't even have to mention the mutiple wrong diagnosis to be treated fair.

The pump company... yeah that was a whole nother headache.
 
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Winegrower said:
Well, we’re not really talking about breaking off the chuck here. When I aligned my headstock and tailstock i was measuring and setting to tenths of thousandths. It you lift a 2500 pound lathe by these components, you know that there is at least some amount of elastic deformation. And the stress is not applied completely evenly to all fasteners. Could there be even a small amount of plastic deformation, so it does not return exactly? Tenths, remember.

Recall how important levelling is to removing any twist in the bed. This is from the its own weight, and very small adjustments! This means the whole bed can move! You think picking up from the chuck is not going to affect accuracy?

So please move your equipment how you like. I will go with the manufacturers recommendation, which for Takisawa is to use a sling with lifting bars through holes specifically provided.
Click to expand...
If you must know I agree with the manufacturer knows best most of the time and IF there are lifting points made available then they should be used. Different manufacturers have different methods and there is more than one way to skin a Possum. ANYTIME you move a large piece of equipment you will have to check its alignment that is a given and given that as long as no damage has been done and the move accomplished safely then it is on with the job. If a 2500 lb lathe is lifted by slings around the headstock then the load on any fastenings below the headstock is not 2500 lbs. The proof load for a single 1/4-20 UNC grade 5 bolt is 2700 lbs, grade 8 3800 and I can't recall ever having seen a 2500 lb lathe headstock held on with a single 1/4-20 bolt.
I have watched videos of very large lathes being moved around in factories while and after being made and I seriously doubt that most people would consider moving their equipment that way.
The point I was trying to convey is that kb58 need not worry needlessly about something that in the real world is unlikely to have occurred. The lathe was moved it now needs to have its alignment checked and corrected. Even using 'the correct method' this would need to be done.
 
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