Leveling and aligning a new 1440 - New guy dumb questions.

LVLAaron

LVLAaron

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After setting up my 1440 (https://www.hobby-machinist.com/threads/pm1440gt-is-in-the-shop.97814/page-8) I'm now working on leveling and aligning.

* Tailstock alignment was fairly easy.
* Spindle runout was barely measurable with a 10ths indicator. Maybe just under half a tenth. Maybe less.

To level the bed I used this level (https://www.mscdirect.com/product/details/69017267?rItem=69017267) and just placed it on top of the V ways on both ends and worked the leveling feet until I got it dead nuts on both ends. Let it sit for a while, got it dead nuts again.


I put a 12" 1.75 round bar in the 4 jaw and turned 10 inches (2 inches in chuck) - Taper as measured with my Mitutoyo QuantuMike from one end of the cut to the other is .0008 (small end was at the chuck)

Should I be happy with 8 tenths over 10 inches? Will I end up chasing my tail in circles if I try and make it better?
 
LVLAaron said:
After setting up my 1440 (https://www.hobby-machinist.com/threads/pm1440gt-is-in-the-shop.97814/page-8) I'm now working on leveling and aligning.

* Tailstock alignment was fairly easy.
* Spindle runout was barely measurable with a 10ths indicator. Maybe just under half a tenth. Maybe less.

To level the bed I used this level (https://www.mscdirect.com/product/details/69017267?rItem=69017267) and just placed it on top of the V ways on both ends and worked the leveling feet until I got it dead nuts on both ends. Let it sit for a while, got it dead nuts again.


I put a 12" 1.75 round bar in the 4 jaw and turned 10 inches (2 inches in chuck) - Taper as measured with my Mitutoyo QuantuMike from one end of the cut to the other is .0008 (small end was at the chuck)

Should I be happy with 8 tenths over 10 inches? Will I end up chasing my tail in circles if I try and make it better?
Click to expand...

You should be ecstatic over 8 tenths in 10 inches!! I don’t think you should touch anything else.
 
erikmannie said:
You should be ecstatic over 8 tenths in 10 inches!! I don’t think you should touch anything else.
Click to expand...

OK I will be! haha. I've waited a long time for this machine and have been really stressing out over getting it set up. I'll have a beer and a nap now!
 
Depends on the work. Most work that is good, very few old lathes with wear would have issues doing better. I would use the lathe, and learn. Typically things break in and need adjustment again with some use. Put it on your calendar for 6 months from now and do it then

Also many things, like tail stock ridgidity and center style/quality can impart issues with getting it dead nuts..

The key to adjusting push pull screws for offsets is to get close (like under a .001) with lite to moderate pressure on each of the screws. Don't loosen the opposing screw at the point of taking out .0001's , just apply more pressure to the other one.
 
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Firebrick43 said:
Depends on the work. Most work that is good, very few old lathes with wear would have issues doing better. I would use the lathe, and learn. Typically things break in and need adjustment again with some use. Put it on your calendar for 6 months from now and do it then
Click to expand...

Ultimately it's for chambering rifle barrels. I am sure I have 6 months of just learning the machine and tooling before I expect to make anything that doesn't go in the recycle bin.
 
You should be able to take much of the .0008 out with the tailstock. Your numbers are very good. The chuck itself could cause more variation even if the spindle was -0-. Dave
 
You should be quite happy with those numbers. Normally you do a double ring test (one cut near the chuck, one cut near the tailstock), as a long and continuous cut warms things up, and you can read a small shift due to thermal expansion. You may discover that your actual accuracy is higher than 8 tenths.
 
addertooth said:
You should be quite happy with those numbers. Normally you do a double ring test (one cut near the chuck, one cut near the tailstock), as a long and continuous cut warms things up, and you can read a small shift due to thermal expansion. You may discover that your actual accuracy is higher than 8 tenths.
Click to expand...

That's what I was aiming to do, I was going to put a gutter down the shaft. But after my last cleanup pass (was some nasty cutoff I got on ebay) I measured 8 tenths and came inside for a lunch break. Good info though!
 
LVLAaron said:
Ultimately it's for chambering rifle barrels. I am sure I have 6 months of just learning the machine and tooling before I expect to make anything that doesn't go in the recycle bin.
Click to expand...
Well, I assume by the lathe you have you are going to chamber with the barrel in the headstock(ie spiders and a ground bore rod) If so, with good chambering reamers and a floating holder what you are seeing is immaterial
 
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