# Arrggh...aligning minilathe tailstock



## compressor man (Mar 27, 2010)

Not that long ago I aligned the tailstock on my minilathe. It has since lived in the cabinet under the lathe. Maybe it got bumped or something but...I was turning some small pulleys yesterday and it eventually came time to bore the axle holes. I started with the center drill and could tell that it was not exactly in the center of the shaft but it didn't seem so bad. But then, when I drilled it out with a 1/4" bit I actually saw the drill bit "spring" back into straight when withdrawing it from the workpiece. Puzzled, I cranked the bit back into the bore hole and saw it bend as it entered!! :wall:

Could someone please describe to me their "fairly simple since I am not a machinist" method of aligning the tailstock on this machine? I had considered centering a piece of shaft in my 4 jaw chuck , then sliding the tailstock up and (with loose alignment bolts) chucking the other end of that shaft into a drill chuck which would of course be inserted in the tailstock. Would this give me a nice alignment which would upon tightening give me good results?

Help!


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## rake60 (Mar 27, 2010)

It may not have been bumped Chris.
Ambient temperature differences can cause the same problem.

I don't know that it is the "best way" but this is what I do.

Chuck up a long piece of stock that will fit through the spindle with just enough out of the 
chuck to center drill that end. Move it out and engage the center. Take light cuts until
the entire length is cleaned up. Mic it for taper. If it's .010" bigger at the tail stock end,
than at the chuck, move the tail stock toward the compound side .005" Clean it up again
then take another light cut. It may take several attempts but you can get it perfect.
That doesn't mean it will be perfect tomorrow. There are just too many variables.

Rick


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## Maryak (Mar 27, 2010)

Chris,

My way with a test bar, (accurately machined and centred steel).







Hope this helps.

Best Regards
Bob


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## compressor man (Mar 30, 2010)

Thanks for the help guys. Rick, I might try your idea. It certainly is better than the method I have used (which I will not describe due to the laughter and raised eyebrows that would result if I did).

Bob, I love your method but alas I have no test bar and cannot turn one with my currently inaccurate lathe!


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## rake60 (Mar 30, 2010)

A combination would be best.

Once you get that tail stock set so the test piece has no taper in it,
*SAVE THE TEST PIECE!*
Then use it as Bob suggests for future adjustments.

I have never saved that test piece myself, but I will the next time!

Rick


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## Omnimill (Mar 31, 2010)

rake60  said:
			
		

> It may not have been bumped Chris.
> Ambient temperature differences can cause the same problem.
> 
> I don't know that it is the "best way" but this is what I do.
> ...



Nice one Rick! I must try and remember that.

Vic.


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## prof65 (Mar 31, 2010)

A good source for "cheap" test bar is an old printer; the steel bars are perfectly straight and round, and the diameter has a very small tolerance.

Roberto


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## rudydubya (Mar 31, 2010)

Chris, hopefully you've resolved your alignment issues by now. But if you haven't, you may want to check your alignment with the quill extended _*and*_ with it retracted. I had a terrible time recently trying to align the tailstock on my 7x12. It was out of alignment when I bought it, but I didn't realize how much until I was almost finished with my first project. Alignment seemed to be a function of how far the quill was extended. I could get it aligned with the quill fully extended, but then when I retracted the quill it would be out of alignment, and vice versa. No manner of twisting or moving the tailstock side to side seemed to help. I even checked the quill to see if was bored straight. It appeared to be OK. 

I finally checked the tailstock bore. I wondered if maybe it was curved or out of round or tapered somehow, so I removed the quill and checked the inside of the bore along its length with a coaxial indicator (bought during a moment of weakness), from the bore opening to the bore bottom (about 4.5 inches), along the back (back side of the lathe), top, bottom, and front (front side of the lathe) to see if I could find anything grossly wrong.






The back side of the bore was straight. The top side of the bore was straight. The bottom side of the bore was straight. But the front side of the bore looked like it had a deep gouge or scoop along its length. I took a lot of measurements along the length at different angles around the bad part to see if the gouge was just a deep scratch or something worse. The diagram below shows what I found. The red lines show where the bad part of the bore was, and of course it's not drawn to scale. The actual maximum deviation was about 0.011" about a third of the way into the bore. The problem area is only on the front side of the bore.





I took a picture of the inside, but it didn't turn out very good with my old camera. If you look closely at the right side of the bore about half-way down you can see what looks like a rough area. It felt a bit rough along that side to my finger, and I think it corresponds to the bad part I measured. (That light area on the inside at the bottom is just light coming through from the hole where the quill lock fits.)






There was also a lot of clearance between the quill and the bore on my lathe (0.870" diameter at the bore opening for a 0.866" diameter quill), but I always figured a little pressure on the quill lock would push on the quill and keep it straight against the side of the tailstock bore. I think that might be true if the bore had been in good shape. But with the bad bore, my assumption is that the quill lock was pushing the side and bottom end of the quill into that bad area as the quill was extended or retracted, causing it to move around and giving me poo poo for overall alignment.

Don't know what might have caused a flaw in a bore like that, maybe a bad casting? I ordered a new tailstock, and turned a test bar like Rick suggested above, and got the new one aligned to my satisfaction.

Hope this is of value to you or others who might have the same problem.

Regards,
Rudy


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## zeeprogrammer (Mar 31, 2010)

Thanks Rudy.
Tailstock alignment has been a recent issue/topic for me.
I'd been questioning whether extension made it better/worse.
When I get a chance I'll take a look at it.


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## compressor man (Mar 31, 2010)

Wow Rudy, talk about worse case scenarios! You have given me new things to lay in bed and worry about :-\ . I havent yet had the time to align my misbehaving tailstock. But I have begun to work on it, today I was able to get a little shop time in. While lining it up I have been dealing with one very aggravating trait of this particular type of tailstock. Of course the bottom screw must be loosened to allow the tailstock to be adjusted. This forces one to depend on the (crappy) rear screw to hold the tailstock in its new alignment. Well, once you slip it off the lathe and begin to tighten the bottom screw, that same bottom screw actually slides it out of alignment while tightening. Now that is frustrating. After seeing this happen once I used a pair of vicegrip pliers to hold the to parts together while tightening the bottom screw. Seems to work pretty well. I also extended the tailstock quill to its maximum length and ran a DI down it. I got a .005 difference from one end to another  A shim took care of this but I then had to come inside and take care of household duties. I really hope that tomorrow I can get out there (I took the day off) and get this thing straight (no pun intended!).


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## Blogwitch (Mar 31, 2010)

Rudy,

I think you have raised a couple of good points there.

The first concerns these cheapish lathes, and how they make them down to a price where they represent good value for money for the new machinist. 
I am sure a lot of 'what the eye doesn't see, the heart doesn't grieve about' goes on. That is if there is a small fault, and it isn't obvious, they do let it pass inspection, hoping that it doesn't rear it's ugly head for a fair while.

The other point, and a very valid one was your mention of the ram lock. How many people put on a bit of pressure to stop things wobbling about, then leave that pressure on, or just part of it, rather than taking the lock fully off. If the parts aren't too well lubricated, that minute bending of the ram will wear away the inside of the casting in no time, and looking at the where your wear pattern is, directly opposite to the lock, which is about 1/3rd back, just as you mentioned. I would say that is the major contributor to that wear pattern.

The same sort of wear pattern occurs where jib locks are fitted on sliding faces. If the pressure isn't removed after you have finished the job, either the gib will get a wear patch where the lock is, or the dovetail will get the same fault, depending which material is the softest. In the situation where your gibs need a tweak, reset the gibs rather than trying to compensate with the gib locks, otherwise wear like this will and does happen. 

It isn't usually how the lathe was built that is the fault, but how it is handled during it's lifespan. Lots of lube and regular maintenance will prevent most nasty wear patterns forming.


Bogs


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## ariz (Apr 1, 2010)

very interesting thread here, and many things to remember to avoid premature wear of parts (thanks bogs)

compliments rudy, not many people would had find that fault


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## rudydubya (Apr 1, 2010)

*Chris*, I agree with you about that cap screw at the bottom of the tailstock. I found it almost impossible to hold the base sections together to tighten that screw without losing alignment. I finally replaced the bottom screw with one that I could tighten from the top. (Not my original idea, I found the idea at http://myweb.tiscali.co.uk/silkstone/minilathe/minilathe01.htm down toward the bottom of the page, probably at other sites as well. And there also some other interesting mods at that website.)

I drilled out the threads in the top section of the base, all the way through so I could slip a cap screw in from the top.



Then I ground down a nut so it would fit in the existing slot in the bottom section of the base without turning, and ground down the end or the cap screw so it was flush with the bottom of the base and wouldn't interfere with the ways.




I used a cap screw so I could use an allen wrench to tighten the two sections together, but you could use a hex head bolt. With the cap screw I still had room to get a wrench on the locking nut.




*Zee*, your tailstock is probably much better than my original. The replacement I got wasn't perfect, but much better.

*Bogs*, I agree, and appreciate your comments. Yes, even with their limitations, these imports have allowed lots of us to pursue our hobby on modest budgets. Even after replacing the defective tailstock, I've found that the new tailstock still requires a little quill-lock pressure to stabilize the quill while drilling. I've added a spring washer under the lock handle to allow me to fine tune and minimize the force. And as you suggest, I lubricate the quill and tailstock bore.

*Ariz*, thanks. As usual, the problem was at the last place I looked.  ;D

Rudy


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## compressor man (Apr 1, 2010)

Alright, I have an update on my lathe 

First of all...Rudy, thankyou for posting that truly excellent suggestion about putting the adjusting screw on top of rather than under the tailstock. I did this (it was quite simple) and it made things 1000% easier.

Secondly, I turned a rod according to Ricks method and began to get things into shape. I noticed that my adjustments were sort of hit-and-miss and what should help sometimes did not. Curious, I put my di on the base of the tailstock and noticed that even when locked down I could wobble it severel thousandths with firm hand pressure. With this new information in hand I set my DI against the side of the extended quill and took a reading. I then released the tailstock (homemade camlock) and slid the tailstock back down the ways and slid it back into position and locked it down again. Sometimes it would come back to the same setting as before but just as often it would be out of alignment a few thou or even 10 thou.

Here was my problem, how in the world can one align their tailstock if its setting is not repeatable when removed and put back on? Surely you cannot realign every time it is slid around!!? I wonder if my camlock simply does not hold firmly enough and would I be better off with the old style nut and wrench. Anybody else ever ran into this?


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## rudydubya (Apr 2, 2010)

Chris, glad the mod worked for you.

If your camlock is locking the tailstock down securely but you can still get some rocking movement, your tailstock may not be sitting flat on your lathe's ways. You might try putting some layout ink or magic marker on the bottom of your tailstock and slide it back and forth on the ways to see where your contact points are. That blue color on the bottom of my tailstock in the middle picture of my last post is layout fluid, and you might be able to make out some lighter areas on each corner where it's worn off from sliding on the ways. My tailstock wasn't sitting flat on the ways initially and would rock back and forth a little when it wasn't locked down. I got some aluminum polish and lapped the tailstock bottom on the ways with it, similar to the lapping shown on the mini lathe website at http://www.mini-lathe.com/Lapping/mt_lap.htm. It took me a few hours, IIRC, but I finally got rid of the wobble and a stable seat on the ways.

Rudy


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## keys (Apr 9, 2010)

After reading this thread I decided to check my mini-lathe tailstock out. I have never adjusted my tailstock, but I've known it needs to be done. As prof65 mentioned, I made a test bar out of a steel rod I took from an old printer. Side to side looks good, but the tailstock seems about 3 thousandths high. What is the best way to fix that problem?


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## rake60 (Apr 9, 2010)

I wouldn't mess with it keys.

High or low will have very little effect on the machines taper.

Rick


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## Maryak (Apr 9, 2010)

rake60  said:
			
		

> I wouldn't mess with it keys.
> 
> High or low will have very little effect on the machines taper.
> 
> Rick



Touche 

Best Regards
Bob


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## keys (Apr 9, 2010)

rake60  said:
			
		

> I wouldn't mess with it keys.
> 
> High or low will have very little effect on the machines taper.
> 
> Rick



Duhhhh! I guess high or low doesn't change the distance the work piece is from the cutting tool. I will just consider myself lucky that I don't have to adjust it yet. It looks like a lot of fun with the locking screw on the bottom and all.


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## Blogwitch (Apr 10, 2010)

I would have to disagree with Ricks' statement just a little.

All would be well and you wouldn't notice much of a difference if it was only a couple of thou high or low, but any more than that can have a pronounced effect on the cutting action of the lathe tool.

Say your lathe tool was set to height by the chuck as is usual, if the tailstock is high (unusual) then as the tool begins to cut, the tip is lower than centre height of the job, and would most probably cut OK, but you would get a slight taper from the larger diameter at the tailstock to the smaller at the chuck end.

The main problems begin when the tailstock centre is low (normal condition). Again, with the tool at centre at the chuck, the position of the cutting tool tip will in fact be higher than the centreline of the piece being cut, and will not cut correctly, but rub against the side of the job, depending on depth of cut, it would be more pronounced the shallower the cut, and wouldn't start cutting correctly until the tool was back to correct centre height as it neared the chuck. This would be liable to give you a rubbish finish towards the tailstock, and yet again a tapered cut.

All points of the compass, when it comes to the tailstock centreline, has some bearing on how the job will proceed, not just side to side. It all depends on how accurate you want things to be.

Bogs


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## compressor man (Apr 15, 2010)

Ok, I know everyone here has been on the edge of their seats waiting for an update on this continuing saga so here it is...

After deciding that one literally could not align one of these tailstocks and minutes before casting it with great force out of my shop I had an idea. You see, when one loosens the bolts that allows the tailstock to be shifted from side to side to align the silly thing, everything and I do mean everything becomes loose. If you are lucky enough to adjust it pretty close to what you feel is accurate then the whole thing is apt to slide around a bit upon retightening throwing it back out of whack. After doing this oh...about a thousand times it occurred to me to make a type of adjusting rod system for it.

I merely took a small piece of key stock and milled out a groove in the center to allow it to sit flush on the tailstock base. I then fastened it with screws to that base and then bored to oversized holes in its vertical face to allow two screws to go through it and then thread into the tailstock. This allows me to screw the thing back and forth whenever it is loosened rather than the tapping and banging I was doing before. This allowed me to finally align the tailstock with some accuracy. 

I used Ricks method (thanks Rick!) of turning a shaft and then measuring the taper of that shaft. I was finally able to get my shaft to only 4 thou difference from one end to the other (it was 5.5" long) I know that there are many that will tell me that this is not good enough and I have no doubt that you are correct but I have spent a great deal of time on this and this is as good as I was able to get it.

Yes, I could try some more but once you loosen it back up it goes all ahoo and you are back at square one. I have a fear that I will never get it this close again!!! Anyway, I hope that this little adjusting system will help somebody else that has the same troubles that I have had. Anyone that works in heavy industry may notice that it is almost a miniature version of the system used to align large electric motors on motor bases


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## rudydubya (Apr 16, 2010)

Nice solution Chris. I like your adjustment system much better than others I have seen. Next time I have to align, I'm going to try it out. Thanks for sharing and thanks for the update.

Regards,
Rudy


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## TarheelTom (Apr 16, 2010)

You might want to take a look at youtube. 

Tryally, in Brazil, wasn't satisfied with the alignment on his tailstock. So he first cut (if memory serves me) a double ended taper shaft, that would fit into his headstock, then he could slide the tailstock into position around the other end of the taper.

He then cut the top of the tailstock loose from the bottom, and made a new intermediate part which allows him to put the tailstock where ever it needs to be for alignment, then tighten up four screws and nuts to hold it in that position.

Making the morse taper
http://www.youtube.com/watch#!v=P8LkfC_xiZQ&feature=related

Part 1
[ame]http://www.youtube.com/watch?v=opt7whN4Y3o[/ame]

Tom


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## radfordc (Apr 16, 2010)

keys  said:
			
		

> After reading this thread I decided to check my mini-lathe tailstock out. I have never adjusted my tailstock, but I've known it needs to be done. As prof65 mentioned, I made a test bar out of a steel rod I took from an old printer. Side to side looks good, but the tailstock seems about 3 thousandths high. What is the best way to fix that problem?



Mini-lathes typically come from the factory with the tailstock a little high. This ensures that there is some material available for fine tuning. You can easily remove material to lower the ram, but it's harder to add material to raise it. Some judious filing of the bottom casting will bring the ram centerline down a few thousanths. 

Charlie


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## zeeprogrammer (Apr 16, 2010)

radfordc  said:
			
		

> Mini-lathes typically come from the factory with the tailstock a little high. This ensures that there is some material available for fine tuning. You can easily remove material to lower the ram, but it's harder to add material to raise it. Some judious filing of the bottom casting will bring the ram centerline down a few thousanths.



Aha! Thanks Charlie.
Now I just need to develop my judicious skill. ;D


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## compressor man (Apr 16, 2010)

Interesting that you post this video Tom, because I was thinking of doing something very much like this. I would like to make a new base for my tailstock. A base that would allow it to be bolted securely to the ways with bolts 1 & 3 yet still allow adjustment of the tailstock with bolt 2. Just like a "real" lathe allows one to do. I made a quick sketch with paint so everyone can see what I am talking about. My one real problem would be how in the world to machine the aligning groove that runs down the bottom of the base. I have a mill but have had it only for a very short time and have only done 2 very, very simple jobs with it. To be honest I really would not begin to know how to do it. Anyone?


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## Blogwitch (Apr 17, 2010)

If you look at this picture of the tailstock off my old Atlas lathe, it shows that you can fit a gib strip in there to allow you to get a perfect fit into the casting slot.

http://i202.photobucket.com/albums/aa102/bogstandard_photos/Tailstock14.jpg

Bogs


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## Twmaster (Apr 17, 2010)

Interesting solutions. It's amazing that the mini-lathe does not have a more 'in control' means of adjustment. Even my creepy old Craftsman 109 has opposing screws to adjust the TS.

The only thing I can think of that might be wrong with that dude from Brazils method would be if the taper cut into the barrel of the TS ram was not aligned with the central axis of the ram.


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## Lew_Merrick_PE (Jun 2, 2010)

All,

One of the "kids" I went to college with has ended up fairly high up the food chain in the Indian _Ministry of Industry & Trade_. He sent me a prototype minilathe back in the early 1990's. I wrote up an evaluation/critique of it for him and consigned it to a corner of my shop for general deburring type work. My situation changed and it has become my primary lathe as my shop space declined from 2500 sq ft to 880 sq ft. (I have to drive 20+ miles to access a larger and sturdier lathe.) As a result of this, I have:

A) Made a gauge bar and reset the alignment of my tailstock. I also "nailed it down" with screws and dowels to prevent misalignment. I wrote this up for Chris at _The Little Machine Shop_.

B) Added a camlock driven by an "back side" handle to replace the screw. I have also written this up as a "how to" document.

C) I am in the process of adding a taper turning attachment to the beast. This will almost certainly wait until I have replaced the bed casting with one of the longer ones from _The Little Machine Shop_. It will also entail rebuilding much of the cross-slide. As my *paying* work load has picked up, I am unlikely to complete this until the end of the summer.

However, I have PDF's of the gauge bar and camlock operations in hand. Is there a way to post them to the files area here that won't leave them being merely another undifferentiated file in a long list of files?

Irrational minds want to know....


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## GailInNM (Jun 2, 2010)

Lew,
The Uploads/Downloads section is not very user friendly in this forum's software.
An index to it has been created and I am trying to update during the first week of each month. It is available as an attachment to the message at:

http://www.homemodelenginemachinist.com/index.php?topic=9161.msg99164#msg99164 

This message is the first one in the Plans section of the forum. It is organized as an alpha sort on the title that the poster gives the download and the description of the message is also shown. A better method is being looked at but for now that is the best we can do. So, the best thing to do is to make the title descriptive, like "Minilathe Camlock" or something that tells what it is. 

I plan to update th index by the end of the week.

Gail in NM


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## Lew_Merrick_PE (Jun 2, 2010)

GailInNM  said:
			
		

> This message is the first one in the Plans section of the forum. It is organized as an alpha sort on the title that the poster gives the download and the description of the message is also shown. A better method is being looked at but for now that is the best we can do. So, the best thing to do is to make the title descriptive, like "Minilathe Camlock" or something that tells what it is.
> 
> I plan to update th index by the end of the week.



Have you heard from the Vatican about your nomination for Sainthood yet? I have managed several files libraries over the years. *My* rule is to force the people uploading them to fill in an "about" form and fill in all the index categories -- and delete their files if the do *not* do so...

It was so much easier in FidoNet days...


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## bazmak (Aug 27, 2014)

Hi,read this thread with interest.Did the tailstock alignment first when i got the lathe.Under BAZMAK diary.Its much easier if you bed the tailstock first,then do the forward/backward alignment.Yes the vertical alignment does not affect
taper turning BUT will affect centre drilling Regards Barry


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## AussieJimG (Aug 29, 2014)

If anyone is still interested, here is the simplest method I have found to align a tailstock: http://www.frets.com/HomeShopTech/QuickTricks/TailstockAlignment/tailstockalignment.html

Jim


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## chucketn (Aug 29, 2014)

When this thread came up today, I tried to find the webpage I used to mod my 7x tailstock for easier allignment. 
My problems started when I accidently knocked the tailstock off the bench while it was removed for what, I can't remember.
The sight had great pictures and writeup on turning the base clamp screw upside down as shown earlier in the thread, but also added adjustment screws on the headstock side and opposite side of the TS base to clamp on the wedge. As I remember the lathe in the article was yellow (Clarke?). I was not Mikey's site, at least it's not there now if it was. 
I know I have referred other mini lathe users to that site, but if I saved the info, I can't find it now.
Best I can do is take pictures of my Tailstock, if needed.
Chuck


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## bazmak (Aug 29, 2014)

Hi, i did some mods on the lathe under Bazmak diary of a mini lathe
which included the Tailstock.Sounds similar to what you mentioned
Lots of pictures perphaps it may be of help. Regards Barry


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