Re: LHT-25B - Small Turret Lathe

On 2/4/2025 5:33 AM, Jim Wilkins wrote:

"Bob La Londe"  wrote in message news:vnrjpm$1gfoa$1@dont-email.me...
 On 2/3/2025 4:20 PM, Jim Wilkins wrote:

https://www.amazon.com/Lathe-Dividing-Plate-Indexing-Dividend/dp/ B0D5NF5T8Y

  I'd want to index most on my 14x40 which has a D1-5 Spindle nose.  I
can't put anything between that and the adapter plate.  Technically I
could put something between an adapter plate and a chuck, but I would
prefer to index at the back of the head where it is completely out of
the way.  I need to make a spider for it someday as well.  Probably make
both setups at the same time.  I'd just CNC the indexing plate on one of
the mills for whatever I needed.  I am sure it will be "close enough."
If I need to try to chase decimal plates I might make it on the big
manual knee mill with the DRO instead.  I don't know how I would QC it
though.  I guess the end part would have to be the QC.
 -- Bob La Londe
CNC Molds N Stuff
 -----------------------------------------
 I seriously considered drilling index holes in the rim of the backplates if I could mount them on my dividing head accurately enough. The 4" and smaller chucks on 5C mounts can index in milling fixtures. A larger diameter index disk with an alignment recess could be screwed to a D1-5 backplate.
 5C chuck mounts, listed under 5C instead of backplates:
https://littlemachineshop.com/products/product_view.php? ProductID=5479&category=-199764519
 The spiders I made clamp onto only the work piece, not the spindle, which makes them simple and non burring on the spindle, though possibly dangerous on a faster lathe. One slips over the spindle end, the other into the collet closer tube. The collet closer spider is a self- centering bored-out 1/2" Multicraft chuck. The nose end fits into the tube and pins pressed into the key holes allow tightening. Shafts larger than 1/2" don't whip at the low speed of my 60 year old lathe .
 I needed to index 68 for a steering sector gear and 13 for a motorcycle drive sprocket, neither matching an index disk. I used a 52 tooth change gear from the AA lathe for 13, and cut the spline slots slightly too narrow so the hardened sprocket shaved them to a snug press fit.
 I think the QC process for an index disk is to turn two pins to a light press fit in the holes and measure across adjacent pairs of them with your best mike, similar to using toolmakers buttons for jig boring accuracy. Only the differences between measurements matters.
 

I don't see why it would any any harder to indicate in than anything else you put on it.  Face up, and indicate in center of rotation of disc.  Face right (or left) and indicate in perpendicular to travel. Indicate center with half function.  Drill, ream, rotate, Drill, ream, rotate,Drill, ream, rotate... it wouldn't be hard.  Just tedious.
USE A STUB (screw machine length) DRILL.
You have an Indicol (or clone or home made holder) and a test indicator right?
--
Bob La Londe
CNC Molds N Stuff
--
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