Lathe Alignment

[ShopShoe]

I just posted my opinion on another thread regarding sorting out a problem with a lathe.

Now I feel the ball is in my court to provide input to those who may be stymied by such an issue.

I know there are accepted reference works out there and many sources for problem solving. I have Connelly myself and lots of bookmarks in my browser. I also feel that some sort of checklist could be put together in short form here. Perhaps yes or no?

--ShopShoe

 

[goldstar31]

ShopShoe

The chart showing the series of tests together with where to put the dial mikes etc are probably clearest in Schlesinger.

OK, he posts several other tools others than lathes but I've just checked and I got the pdf free from the 'net.

I went through 'several' books and this was possibly the simplest whilst Moore caused insomnia and Connelly the best for propping up the 'gammy' leg on my bed.

Years ago, I saw the 'test sheet' for the Boxford lathes so somebody might add the details- which I cannot now

Norm

 

[Lloyd-ss]

I think it would be very helpful to have a readily available reference for how to check out lathe alignments.
Just from my own perspective, I have a tailstock alignment issue that has stymied me for too long. Or maybe its a tailstock chuck issue. It is difficult for me to tell because I am not even sure I am checking it correctly. But the point is, a general reference for checking out a lathe would be appreciated.

 

[goldstar31]

I think it would be very helpful to have a readily available reference for how to check out lathe alignments.
Just from my own perspective, I have a tailstock alignment issue that has stymied me for too long. Or maybe its a tailstock chuck issue. It is difficult for me to tell because I am not even sure I am checking it correctly. But the point is, a general reference for checking out a lathe would be appreciated.

Lloyd, the addition of a chuck in this scenario is merely adding to your difficulties.

Armed with a clock gauge on a magnetic stand, I would turn the diameter of the tailstock poppet/barrel in a chuck and set the clock gauge on the saddle and then wind it up to the tailstock and adjust the tailstock to the same recording.

The lazy man's rough way is to insert a true centre in the spindle and the tailstock and attempt to hold a safety razor blade between the two points. Probably doing a rough setting this way will avoid a lot of adjusting as described above.

Does this help?

Norman

 

[ShopShoe]

Norman,

I think you are right about Schlesinger over Connelly. You also remind me that years ago when I was starting I didn't believe the business about using razor blades and 6-inch rules for quick checking, thinking I needed expensive gages for testing. I think where I am going is that it should be possible to determine a general location on a machine for a particular problem and then narrow in to the real issue with tests of increasing precision.

Of course, I have a "scientific" mind where there is no "perfect": Everyting has a tolerance. Going out from there, an individual must determine what level of tolerance is acceptable for their own type of work and the resources to hand.

--

(Mildly OT below)

If you like videos: David Richards's Steam Powered Machine Shop provides an example of setting up work in a 4-jaw chuck without a dial Indicator, as it would have been done in the 1920s. About 15:55 on the following video:



--ShopShoe

 

[Lloyd-ss]

Lloyd, the addition of a chuck in this scenario is merely adding to your difficulties.

Armed with a clock gauge on a magnetic stand, I would turn the diameter of the tailstock poppet/barrel in a chuck and set the clock gauge on the saddle and then wind it up to the tailstock and adjust the tailstock to the same recording.

The lazy man's rough way is to insert a true centre in the spindle and the tailstock and attempt to hold a safety razor blade between the two points. Probably doing a rough setting this way will avoid a lot of adjusting as described above.

Does this help?

Norman

Norm, Yes that does. I will try the simplified preliminary check (euphemism for lazy man, LOL) first with a pair of hard centers, with tailstock fully retracted and fully extended to note any differences. My tailstock only has an adjustment for "X", i.e. across the ways or for taper turning. It has no adjustment for height or parallelism to the bed. I suspect (but could be wrong) either a bad chuck or bad Morse-Jarno adapter that is on the chuck.
Lloyd

 

[goldstar31]

Norman,


Of course, I have a "scientific" mind where there is no "perfect": Everyting has a tolerance. Going out from there, an individual must determine what level of tolerance is acceptable for their own type of work and the resources to hand.

--


--ShopShoe

I actually found the Boxford chart mentioned in Madmodder back in 2012 when a un-certain Fergus O'more- who shall be blameless( Moi) was contributing on someone who was raising 'dished facing problems' on his lathe. Philf- a modeller of great experience produced the even simpler Boxford test chart.

I might not like Boxfords but the charts are very useful. Correction, I have a Boxford dial gauge for their grinding machines. The 0.0002" variety. Very tasty!

Norm

 

[goldstar31]

It has no adjustment for height or parallelism to the bed. I suspect (but could be wrong) either a bad chuck or bad Morse-Jarno adapter that is on the chuck.
Lloyd

There's thing about adding several errors and another about compensating ones. I think that yours comes into the first category. Sorry!

Norm

 

[Lloyd-ss]

There's thing about adding several errors and another about compensating ones. I think that yours comes into the first category. Sorry!

Norm

Agreed. Remove all of the suspect accessories first so that the "machine" can be checked and corrected (if necessary), and then start adding the accessories back in, one variable at a time.
Lloyd

 

[hanermo3]

Everything depends on everything.

If one has a test bar with taper,
or a near perfect steel cylinder,
all sorts of verifications become easy.

MT builders and support engineers spend little time on checking the mechanicals, because they have the tools to do so efficiently.

 

[IanN]

I think it would be very helpful to have a readily available reference for how to check out lathe alignments.
:
:
.... the point is, a general reference for checking out a lathe would be appreciated.

Hi,

I have three excellent descriptions of the correct sequence and recognised methods to use for accurate lathe setup.

1) The article in Model Engineer magazine by Tubal Cain (T. D. Walshaw) 21st Sept 1973

2) Pages culled from Machine Shop Technology Vol 1 (Author lost)

3) South Bend bulletin H3 (1946) "The Installation and Leveling of the Lathe"

As the first two documents are still in copyright I will not upload them, but if you would like to see them email me

All the best,
Ian

 

[packrat]

{If you like videos: David Richards's Steam Powered Machine Shop provides an example of setting up work in a 4-jaw chuck without a dial Indicator, as it would have been done in the 1920s. About 15:55 on the following video:}

I did enjoy that video, having your boiler inside the shop is nice. I have a steam engine much like his but it is vertical about the same size 5-6 HP. thanks for posting that.

 

[Lloyd-ss]

Hi,

I have three excellent descriptions of the correct sequence and recognised methods to use for accurate lathe setup.

1) The article in Model Engineer magazine by Tubal Cain (T. D. Walshaw) 21st Sept 1973

2) Pages culled from Machine Shop Technology Vol 1 (Author lost)

3) South Bend bulletin H3 (1946) "The Installation and Leveling of the Lathe"

As the first two documents are still in copyright I will not upload them, but if you would like to see them email me

All the best,
Ian

Thank you for the offer Ian. I found the South Bend booklet and read thru it and that search lead me to other articles, so I think I am all set. The last paragraph on the last page of the South Bend booklet showed a simple test to of turning a pair of diameters as a final check for the level of the machine. The test would even reveal which corner of the machine was low. Like so many things in life, its know the tricks of the trade.
Lloyd

 

[goldstar31]

Lloyd, I'm going to get a lot of flak, but please note that a badly worn lathe might exhibit the wrong results from this test.

If the lathe is worn, say classically 6" or so from the spindle end, none of this works. This why Schlesinger introduces a wire pulled taught between the two centres i.e. at the extreme ends of the lathe bed, s part of his tests

Sorry to possibly 'ruining the parade'

Norman

 

[Anatol]

ShopShoe

I went through 'several' books and this was possibly the simplest whilst Moore caused insomnia and Connelly the best for propping up the 'gammy' leg on my bed.

"Moore caused insomnia"
lol, or bad dreams

I'm just finding this thread in some downtime. Great, informative thread. Thankyou. Herewith a deluge of short responses.

re: Shopshoe's original suggestion - Some forums have ongoing FAQ files, very useful for newbies and reduces duplication of threads/themes. Could be a nice addition.
Or, more ambitiously, a wiki, where members could contribute to pages on specific topics. I think such a project could be a really important contribution to preserving knowledge. If pictures are worth a 1000 words, video is worth 100 pictures, so short embedded videos would be very useful - but not the sort of extended rambling examples common on youtube. There's a lot to be said for good editing

 

[Anatol]

I actually found the Boxford chart mentioned in Madmodder back in 2012 when a un-certain Fergus O'more- who shall be blameless( Moi) was contributing on someone who was raising 'dished facing problems' on his lathe. Philf- a modeller of great experience produced the even simpler Boxford test chart.
Norm

Does someone have these legendary Boxford charts to share ?

 

[Anatol]

Everything depends on everything.
.

"How true, how very true" (said in a pompous Peter Sellers voice
But then, does nothing depend on nothing?
Everything doesn't depend on nothing, doesn't it?
Perhaps I should take a nap.

 

[Anatol]

Norman,
I didn't believe the business about using razor blades and 6-inch rules for quick checking, thinking I needed expensive gages for testing.
--ShopShoe

I love these kinds of tricks, because they leverage basic geometry and logical reasoning - they also show the genius of the tradition. I'd love to find a compendium of them. I'd feel proud if I could master them. Dial gauges are still pretty simple, but they do put you in the realm of numbers as opposed to the realm of geometry. Of course, these days, reliance on DROs makes even dial indicators seem like magic to the born-digital generation.

 

[Anatol]

OT dept - Shopshoe, I loved the David Richards's Steam Powered Machine Shop vid, I hadn't found him before. Turns out there's about 50 since that one. I guess I'll be wasting a lot of time on his channel I went straight to the last one provocatively titled freestyle machining. .
At 22.45 he makes a single cylinder single acting wobbler with no plans and no dimensions.

 

[clockworkcheval]

Hi Shopshoe, we are taught that the easiest way to check whether headstock and tailstock are in line is to put a poupytaster in the headstock and let it run on the inside of the tailstock-cone. Left-right difference adjust; high-low difference tough luck. Clockworkcheval.