Aligning Tailstock

[Spokerider]

Guys,
Wondering....what are the methods I can use to align tail stock to spindle center?
I have a 6" Craftsman 101.0703 lathe. I have a live center for the tailstock, no 2MT dead center for the spindle, no face plate and no dogs. I do have 3 jaw and 4 jaw chuck/s. I do have a dial gauge with magnetic base / articulating arm.
Yes....I need to buy a 2MT dead center, I know.

Seems most alignment techniques involve turning a length of stock on the lathe and comparing diameters at each end.....done between centers. Pretty sure this requires the face plate, lathe dog, and a steady rest to drill 60 deg holes in the bar ends. Hummmm.

Thanks for your thots and ideas.

 

[Aukai]

My hack way to check mine was to turn an end mill around, or anything with an accurate center drill, and put in the chuck, then bring the live center to that. This only works for working close to the spindle, you will still need to check twist farther out.

 

[francist]

I was thinking something similar except chuck up a short piece of whatever in your three-jaw and turn your own centre point on it. It will be centred to the spindle rotation, just don’t remove it from the chuck before lining the tail stock up first. One shot deal, but fast and will get you close. After that it all depends on how fussy you want to be.

-frank

 

[mikey]

Easiest way is to turn a 60 degree dead center in your lathe chuck and without taking it out of the chuck, slap this in there. I much prefer to make my own but then again, I have the stuff to make it with. That ET bar will work just fine for you.

 

[Mitch Alsup]

step 1) get it close by inserting a live (or dead) center in the tailstock and closing the jaws of the 3-jaw chuck and position the tail stock so the point is touching the center of the 3-jaw. This will get you within 10 thou.

Step 2) insert a bar of stock 12" long. Drill a center in it. Now, extend the piece as far as possible, and turn the outside diameter a few thou. With a micrometer measure the diameter close to the chuck and close to the tailstock. When these reading are identical you are done. If the tailstock end is larger, the tailstock needs to move towards the tool (and vice versa). You can get the tailstock aligned to a couple of tenths using this method.

Step 3) when the tailstock is accurately aligned, take an exacto knife and a straight edge and make a mark from the moving part of the tailstock to the non-moving part so you can "get close" in seconds when subsequent needs arise.

 

[Mini Cooper S]

John Widmar, my high school shop teacher, taught me this technique back in the late 1960's. The trick, he said, was very light pressure so as not to damage the centers or dimple the scale. If the centers are misaligned, the scale tips on an angle. It is actually very accurate. You can also chuck up a piece of rod and turn a center if you don't want to puul the chuck or don't have a headstock center.

 

[Winegrower]

Doing this on the Takisawa was relatively challenging trying to get into the tenths of total taper. Cutting your own center in your chuck solves one end of the problem, but positioning the tailstock accurately is another. Take the time to put a tenths indicator on the headstock in a way that it survives moving the tailstock along the ways, removing the center, the test bar, etc. Note that if you have a .001 taper, you will have to offset the tailstock by 0.0005. And if as people say you can get into tenths, you have to control the tailstock to half that. I found that errors of that magnitude could be introduced by, for example, locking the tailstock to the ways, locking the tailstock quill, and of course trying to adjust the tailstock screws involves loosening and tightening opposing screws, and each operation can move the tailstock dramatically.

I got it to about 0.0008 over about 24”, which seemed good enough for bushings and washers.

 

[Bamban]

I found out on the ACER1236, the wear on the ways shows TS alignment is only good at the distance you aligned it at.

 

[Bamban]

I found that errors of that magnitude could be introduced by, for example, locking the tailstock to the ways, locking the tailstock quill, and of course trying to adjust the tailstock screws......

Thank you for bringing this up. Shiraz from Grizzly added torque wrenches to some of the gunsmith lathes ensure consistent lock up of the TS to the ways.

I am trying to figure out how to add one to
my PM1440TV.

 

[Ed ke6bnl]

Easiest way is to turn a 60 degree dead center in your lathe chuck and without taking it out of the chuck, slap this in there. I much prefer to make my own but then again, I have the stuff to make it with. That ET bar will work just fine for you.

I picked up a ground rod happened to have 3mt on one ens but has centers on both ends and make a 60* center for the Chuck side and center in tail stock and run a dti over the rod. I believe I paid about $35 on ebay.