Saturday, November 26, 2022

Feast your eyes on the exploded diagram of the Logan cross slide (LA-747) and the pivoting part of the compound slide (LA-746).  Of particular interest to our proceedings today is the pin (LA-744).  There are two, one each side.


While I have some time today, I'm gonna get some idea of what the pins need to look like.  I gotta make two to replace the two I murdered trying to remove them.

 The plug on the bottom of the pivoting part has a complementary angle for the plug to push against, effectively locking it into place.  Logan calls part LA-746 the swivel.

Part 19 - bottom view

Angles on the ends, length and diameter of the old pins.


60° ends


Length is 28/32" = 7/8" = 0.875"

Caution!  PARALLAX ERROR!!!!


Diameter is 0.252" in a 5/16 - 18 tapped hole.  Tap drill size is F or 0.257" leaving 0.005" clearance.

Uh... no, I won't make it that big again

After these are made, there will be a bit of fitting to make sure they work right.  Then assembly to see what else I need to make to finish up the taper attachment.  Hooooboy, this is getting exciting.


  1. Can you make a brass button for the end of the pin where it jams into the taper?
    It would be sacrificial, softer and grab better.
    Just a thought. Otherwise you could probably just go buy a couple of hardened pins and grind down the ends.

    1. Now that you mention it, I have some brass rod I could make the tips out of... Hmmmmm..... I really want the tips to come out with the set screws that hold them in. I don't like that they float with no way to retract. But they didn't need to be removed in 80 years, so I may just be over thinking it.

  2. Go to about 6;20 in this video and you will see what I'm talking about with the brass buttons.
    This guy modified his Mini lathe.