Just bought a Starrett 6" machinist level (lathe leveling)

benmychree said:
A Starrett 6" level is nowhere sensitive enough to level any lathe, the grads are .005" per foot; the level used for machinery leveling and alignment is 10 times more sensitive, .0005" per foot, a #98 level is not going to do the job.
Click to expand...
Well, I hear ya, but here is a Starrett 18” Machinist level and it is only accurate 0.005” per foot. For about $350 give or take.

98-18 Machinists Level with Ground and Graduated Vial

The Starrett 98 Machinists Level with Ground and Graduated Vial includes a cross test vial and a single plumb vial. 450mm (18") size, without case.
www.starrett.com www.starrett.com


So to get the 0.0005” per foot you need to spend $900.

199Z Master Precision Level

The Starrett 199 Master Precision Level provides the ability to ensure a level machine setup, which in turn increases the efficiency of modern, high speed machinery. Master Precision Level, 15" (380mm).
www.starrett.com www.starrett.com

Seems to me for home Hobbyists the lower cost levels at 0.005” will be fine. If I was a machine shop with customers then I would want to be as level as possible.
 
If one watches e bay, high quality levels do come around occasionally for reasonable prices, that is how I got the Pratt & Whitney precision level that I use. As many people have advised, for smaller machines, level does not matter, alignment does, and it can be accomplished by the two collar method at little expense or trouble. BTW, there are precision levels listed at the bottom of the Amazon page that are priced lower than the Starrett level, 12" .0005 accuracy ----- (claimed)
 
Does .005 per foot mean that the most accurate I can get the lathe if I level is with this is at .005 per foot?
 
Not necessarily, it just means that it is not accurate enough for machine alignment purposes; lots better than a carpenter's level, but not nearly accurate enough for alignment purposes; if you had it dead on the mark at each end of the lathe bed, it could have a considerable twist in the bed, resulting in the lathe cutting a taper in a chucking mode.
 
benmychree said:
Not necessarily, it just means that it is not accurate enough for machine alignment purposes; lots better than a carpenter's level, but not nearly accurate enough for alignment purposes; if you had it dead on the mark at each end of the lathe bed, it could have a considerable twist in the bed, resulting in the lathe cutting a taper in a chucking mode.
Click to expand...
Which is why you need to cut a piece about 12-16” long and at least an inch in diameter and see if it has a taper. The taper is what you want to avoid. Get it level best you can then you have to make a cut. Spot on is no taper. There are a number of videos on YouTube that discuss this. Joe Pi is one of the best.
 
I guess I can start with the level to get it close and start turning a large diameter rod, then adjust the lathe accordingly to the taper.
 
For a relatively small lathe, 12 -16" long is way too long, especially if it it=s small diameter, sag and spring will negate any useful info. A test bar that is perhaps 1 1/4 diameter and 6 -8" long will tell the story, with most of the length turned undersize except the ends, perhaps 1/4" long, a very light cut at fine feed on each "collar" carefully measured will indicate if taper is present, then the bed is slightly twisted to negate that taper, adjustments made until the cut is straight. There have been very many posts on this subject, try to find them, there is a lot of good information there.
 
Last time i saw a lathe being levelled was by my father in the shed on the farm
He used a plum bob

There was a plate that had been machined to sit on the ways and it had a very long rod sticking up in the air to hang the plum bob of .thinking about it the longer the rod the more accurate it would have been .It had the rod monted on a hinge set up with an adjuster bolt .You could place the unit on the lathe then adjust the rod to get the plum bob to line up with the make on the base for the first reading at chuck end and then move it down the bed to look at other readings .
It worked quite well from what i can remember however it needs to be in an enviroment were wind or breeze factor could not upset the string
 
You must log in or register to reply here.
Back
Top