List of known design issues.


Issue #1: Carriage Translation Safety Issue. Raised by David G Levine.
Status: Open
David says:
"It also raises a BIG safety issue.

chain_drive.jpg
Might I suggest a different means of translating the carriage might be wider?"

Suggestions:
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An adjuster needs to be added to keep chain tight


- 8.19--.11

Add to the bottom of the front page so that the viewers will have an idea of where we are coming from
Add these links from the wiki intro
  • Yeoman’s Shell Turning Lathe Patent
  • Yeoman’s New Method for Building Lathes
  • A more detailed look at the shell making machine technology

"We had to scale it down and make it a general purpose lathe with a movable tailstock and threading capability.
We wanted to make it buildable in primitive conditions but we tried to keep as close to the original design as possible." (poorly worded but you get the idea


bed length. The bed length shown is the bare minimum. It is easy to make it longer.



For a 8"
lathe (page 8) , (replace with 12" swing lathe with ways 8" between centers) ways 32 to 38mm diameter should be fine.

some of the drawings show the cross slide hold down bolt heads not imbedded deep enough in the concrete



Need to finish the carriage clamp drawing

Pdf load speed. Could we increase the size of the drawing text and dimensions and then compress the PDF more? Lat night my web was slow and caused problems.



Need to put hubs on the thread follower sprockets

Need to say Open Source often

8/29

Fix backgrounds on concrete bed page 2


carriage_8.,27_7pm.jpg


round_shoes_hold_down_bolts_9.7.jpg

Alignment

Shining a light between the ways as 1 is turned against the other, correct by lathe work or the 3 rounds method
check the spindle against a straight and smooth way

The ways before grouting

A bar between the ways to get accurate way separation
A glass plate to get the ways in the same plane
glass plate and ball bearing to make them level

carriage shoes clamped in place and then cemented put the carriage in alignment

Spindle is aligned by using a dial indicator alternately mounted on the left, center and right side of carriage

Cross slide parts are made parallel by the 3 flats method

Cross slide is aligned by tramming from the spindle

Tailstock MT socket is aligned by a drill bit held in the chuck

  • Use a 15-0-15 DTI, not a long stroke indicator
  • Use a straight, accurately ground test rod of constant diameter
  • To measure spindle axis vertical error:
    • Set the DTI finger horizontal and in contact with the top of the test rod, near the chuck end of the test rod
    • Carefully adjust the cross slide for maximum DTI deflection (center of rod)
    • Rotate the chuck by hand and adjust the DTI vertical position for equal DTI needle deflection above and below zero, e.g. +1.5 and -1.5 -- this makes the "near end average distance" equal to zero.
    • Without disturbing the vertical or horizontal settings for the DTI, move it to indicate near the far end of the test rod.
    • Rotate the chuck by hand and record the minimum and maximum DTI readings
    • Algebraically add (i.e. account for the signs) the minimum and maximum readings and divide by 2. The result is the vertical spindle axis error.
  • To measure spindle axis horizontal error:
    • Set the DTI finger vertical and in contact with the side of the test rod, near the chuck end of the test rod
    • Carefully adjust the vertical position of the DTI for maximum deflection (center of the test rod's side) See Note
    • Rotate the chuck by hand and adjust the cross slide for equal DTI needle deflection above and below zero
    • Without disturbing the vertical or horizontal settings for the DTI, move it to indicate near the far end of the test rod.
    • Rotate the chuck by hand and record the minimum and maximum DTI readings
    • Algebraically add the minimum and maximum readings and divide by 2. The result is the horizontal spindle axis error
List of alignment techniques



Formulas to figure stress on the ways
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