Aligning Lathe Tailstock

[Ken I]

I came up with a new method - probably been done thousands of times but it's new to me.

Every attempt I have made using gauges etc. has to date not satisfied me so I came up with this.

Put a small diameter rod in your 4 jaw chuck (as small as it will go) clock it up as best you can get, drill a centre and give the OD a lick so the two are concentric. (I used a 3mm rod in a drill chuck/shank held by my 4 jaw).


Now move the rod out a few inches from the chuck and clock up the OD.

Once you are happy it's rotating dead true. then bring your tailstock in and measure the deflection of the shaft with your dial gauge as you engage the centre. (The thin shaft flexes front to back if your tailstock is off center.)

Adjust your tailstock until there is no deflection as the centre goes in - QED.

By rotating your centre you can check for errors in your centre, you can also check parallelism errors by using differing stick out from your tailstock (errors here are not adjustable or easy to fix - but at least you know.).

Back to front errors are adjustable, up down is generally by shimming.

I found this a lot easier than rotating dial gauges etc.

Regards,
Ken

 

[don-tucker]

That's a good idea to me,tell you what i did i bought a No 2 MT reamer with a 2mt shank,held it in the mandrel and re reamed the tailstock barrel,mainly because the barrel taper was a bit rough,the ML7 is 2mt both ends.
Don

 

[AllThumbs]

How do you know the thin rod is straight to begin with?

 

[jonesie]

if you have an indicator with a shaft in the center of it you can make a small holder for it the put holder in for 4 jaw indicate it in and then can use it to tram the tail stock hole. i do this with my interrapid indicator . get the hole in the center of the holder and put in a small set screw to hold it. jonesie

 

[Ken I]

if you have an indicator with a shaft in the center of it you can ...

I tried rotating a dial gauge - its a PITB - and I was never satisfied - In the past this is the method I have used - this method seemed a lot easier - hence the post.

How do you know the thin rod is straight to begin with?

It doesn't matter if the rod isn't straight as you reclock the end diameter (which you trued up when you made the centre hole) by readjusting your 4 jaw after you pull it out aways. You clock it dead true - if it moves when you insert the centre then something is out.

re reamed the tailstock barrel,mainly because the barrel taper was a bit rough,the ML7 is 2mt both ends.

Re-reaming the taper is a bit brutal but if it needed it anyway ....

Regards,
Ken

 

[doc1955]

I use a method pretty close to what you are doing.
I have a straight shaft with a center in each end (I insured the shaft was straight on the surface plate) and put a center in the head stock and a dead center in the tail with the shaft between. Then run the indicator back and forth and adjust the tail stock.

 

[fcheslop]

As a quick check I nip a razor blade between centres and you can see very easily the direction you need to move the tail stock

 

[digiex-chris]

As a quick check I nip a razor blade between centres and you can see very easily the direction you need to move the tail stock

Assuming your bed isn't worn. My Unimat was too far gone for that to work well.

 

[doc1955]

As a quick check I nip a razor blade between centres and you can see very easily the direction you need to move the tail stock

Hey now that is a good way of a quick check nice tip!

 

[Bill S]

Here is a nice method from Frank Ford.

http://www.frets.com/HomeShopTech/QuickTricks/TailstockAlignment/tailstockalignment.html

Bill

 

[Ken I]

Thanks fcheslop and Bill, that's two more methods I hadn't heard of before.

When I was a student a cleaner removed all the tailstocks from 6 identical lathes and put them back on willy - nilly.

Various people fiddled with them before it became apparent what had happend. Silly sod here got volunteered to unscramble the omlette.

The hights varied from machine to machine (I presume originally line bored or machined to suit) - so it was a mission.

Regards,
Ken

 

[Mastermaker]

A question/idea about re-reaming the tail-stock.

Wouldn't it also work to do this with a straight shank Morse reamer held in a lathe chuck?
I mean, even if the chuck has run-out it would only mean that the reamer would cut on one edge but the result should be the same...Right(provided your 3-jaw chuck jaws aren't out of parallel(holds the reamer at an angle relative to the lath bed)) ?

 

[LX Kid]

Here is a nice method from Frank Ford.

http://www.frets.com/HomeShopTech/QuickTricks/TailstockAlignment/tailstockalignment.html

Bill

Thanks Bill for the tip. As a newbie to latheing your idea really seems to make sense to me and quite easy. Thanks

 

[Noitoen]

Don't how to link directly to the page but on page 181 there are some neat tricks

http://books.google.com/books?id=H98DAAAAMBAJ&printsec=frontcover&hl=pt-PT&source=gbs_atb#v=onepage&q&f=false

 

[Metal Butcher]

Don't how to link directly to the page but on page 181 there are some neat tricks

http://books.google.com/books?id=H98DAAAAMBAJ&printsec=frontcover&hl=pt-PT&source=gbs_atb#v=onepage&q&f=false

You can click on 'indice'. Scroll down to page 180 (design drilling in perforated hard board) and click on that. Then scroll down to Shop short cuts: 'Checking Lathe centers'.

-MB