Improvements to a lathe tailstock

**tonyfoale** · Mar 26, 2019, 02:49 PM

I had a precision job coming up which needed the tailstock to be well centred. My tailstock has always been a pain in the neck to align. Tightening the cam lock would always screw up the alignment and of course I couldn't make the adjustments with the cam lock tight. On lathes that I have had in the past I modified the tailstock to help with this problem. Today I decided to do the same with my current machine.

I made a video as I worked and the best way to get an idea is to watch the video

It didn't take long to do and the alignment was considerably easier. I will follow up this post and video with another discussing the actual alignment.

Improvements to a lathe tailstock-aligning-tailstock-02.jpg

There are other tool making videos on my channel at
Motochassis channel

**marksbug** · Mar 27, 2019, 05:10 PM

a lot of people dont uderstand that the center may be in the right position for center but not realy moving the right direction to keep it there through the full trevel of the tailstock quill....or what ever it's called. it may be centered at the point hear or there but go up down or sideways or both when screwed in or out. these china lathes that are wacked with a chizzell to get close and....skeery!!!at best.and some rock... I was going to set mine up in my mill and square it up and machine it...but them I found with this 9x20 lathe...it wont help all that much, as the bed has oh so much flex in it.. I wish I had a 24" long x8" wide cast iron plate that I could use for a base and flip the bed over and mill it square& flat on the pads and bolt it good and tight so the flex is...almost eliminated... do the head stock too!!!but a better lathe would be better...perhaps someday if Im still screwing with this stuff. keep up the great work tony!!! and keep those ideas coming!!!

**Toolmaker51** · Mar 27, 2019, 08:52 PM

Originally Posted by marksbug

<snipped> . . .but them I found with this 9x20 lathe...it wont help all that much, as the bed has oh so much flex in it.. I wish I had a 24" long x8" wide cast iron plate that I could use for a base and flip the bed over and mill it square& flat on the pads and bolt it good and tight so the flex is...almost eliminated... do the head stock too!!!but a better lathe would be better...perhaps someday if Im still screwing with this stuff. keep up the great work tony!!! and keep those ideas coming!!!

Using a cast surface plate wouldn't be too hard; and they are heavily ribbed. Don't worry about milling the feet; shim or jack them with flat point, fine thread setscrews. They'll lock in position when bolts are secured.
Of the two, shims are more practical. Best if the shim encircles the bolt.

Alternately, aluminum tooling plate, or welding ribs to steel plate is how many fixtures are created.

**Toolmaker51** · Mar 27, 2019, 09:21 PM

Originally Posted by tonyfoale

I had a precision job coming up which needed the tailstock to be well centred. My tailstock has always been a pain in the neck to align. Tightening the cam lock would always screw up the alignment and of course I couldn't make the adjustments with the cam lock tight. On lathes that I have had in the past I modified the tailstock to help with this problem. Today I decided to do the same with my current machine.

It didn't take long to do and the alignment was considerably easier. I will follow up this post and video with another discussing the actual alignment.

There are other tool making videos on my channel at
Motochassis channel

Locking the slide to base this way is a fine, secure method, and Tony's solution could be accomplished by most anyone. Great presentation, Tony! I understand that some have few occurrences of taper turning.

My suggestion for those who may taper more would exchange cap screws for combination thread studs and nuts, making those fasteners endure the wear, instead of gray iron. Either way gray iron isn't suited to fine threads; proper studs will be threaded coarse on one end.

**tonyfoale** · Mar 28, 2019, 05:27 AM

Originally Posted by marksbug

a lot of people dont uderstand that the center may be in the right position for center but not realy moving the right direction to keep it there through the full trevel of the tailstock quill....or what ever it's called. it may be centered at the point hear or there but go up down or sideways or both when screwed in or out.

You are quite right on this point. It is very easy to clock that and I would advise anyone to do it. A way around that problem when you want it for turning between centres is simply to check and set your alignment with the quill close to the planned 'in-use' position and locate the tailstock at the planned 'in-use' position also. of course this does not fix that sort of problem when drilling but in most cases that is less critical.

My lathe has hardened ways and there is imperceptible wear on those but the base of the tailstock is worn thus lowering the centre, and I have shimmed that.

Originally Posted by marksbug

these china lathes that are wacked with a chizzell to get close and...

This is an elderly JET and is pretty well built, no complains there. When I had a business making motorcycle chassis for a living I had some 'brand' name lathes and although the JET is lightweight in comparison, I have few complaints with it.

I bought it from a poor unfortunate bloke who was restoring and modifying it for his upcoming retirement. He made quite a few nice modifications including fitting a larger headstock spindle and better bearings. I say that he was unfortunate, because his wife decided that on his retirement they would move to Florida to a house without a basement for his workshop. He was in NH at the time where everyone has a basement.
My wife has enough sense to know that she would be moving alone if she tried that.

**DIYer** · Mar 28, 2019, 06:38 AM

Thanks tonyfoale! We've added your Tailstock Precision Centering Method to our Machining category,
as well as to your builder page: tonyfoale's Homemade Tools. Your receipt:

Tailstock Precision Centering Method by tonyfoale

tags: centering, tailstock

**marksbug** · Mar 28, 2019, 08:36 AM

florida?? say it aint so.....I live in florida. you could harden the base to keep wear to a minimum and/or use a dry film coating too ( I dry film coat almost everything in my engines and ceramic coat also) that stuff is fricken awesome!!!! .and get the hight back at the slpit joint!!! I thought about cutting mine at a angle with a key way slot like some old hardinge's were and just turn a screw to go up or down.( basicly like sliding jack plate;s) I may do that if I ever add a inch or so to the head stock&tail stock for more clearance over the cross slide....but then there is that get a bigger lathe thing going on.... but I just got a new car...well a 12 year old sports car with 55000 miles looks like new inside and out...the leather even looks new!!!so...Im riding my new lathe for a while. I wish I could find a poor unfortunate soul...oh thats me!!!
back in the 90's I used a old jet, it was wore slap out...and still 5x what my new enco is...of coarse that old jet was probably a 14x48 or close to that. I shoud of bought it for $500 when I had the chance...probably could of got it for 250 delevered!! but I didnt have a place for it back then.