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rabbit_nick
01-01-2016, 07:11 PM
Hello,

I recently bought a mini lathe 7x14" (180x350mm) for my workshop and I have to say that I should have bought a lathe it much earlier.
The machine is a small China import lathe (nothing special) with 550 Watts motor and metal gears and as you can tell I am really excited about it.

The only problem I found so far is that the tailstock is not very accurately aligned with the headstock center.
As I am new to lathes I searched on YouTube and I found 2 or 3 ways, using a dial indicator, to align it but my lack of experience does not allow me to fix my problem...

After a small online research I found out a tailstock alignment tool called MT2 to MT3 Buddy Bar. This "Buddy Bar" has one end MT2 Morse Tapered and the other end MT3 Morse Tapered.
The MT2 end fits into the tailstock and the MT3 end fits into the headstock and that "fitting" makes the alignment.

Do you think that this tool does cover my need?
Is it as easy as it sounds or I will have issues?

Thank you very much
Nikos

mars-red
01-01-2016, 07:31 PM
Do you have a set-over tailstock? If so, that tool might be useful if you plan on changing the alignment regularly. Otherwise, you can use a piece of card pinched gently between centers to roughly judge alignment, then fine tune it by making test cuts between centers on a piece of thick stock and measuring the amount of taper along the cut.

darryl
01-01-2016, 07:36 PM
I'm assuming that the tailstock will need shimming and re-tightening to get it to hold that position- the challenge will be to make sure it's still aligned once it's tightened down. I like the idea though- and presumably you would carefully check to see that the exposed MT2 part rotates precisely on axis without wobble beforehand. You would also need to know that the head stock is aligned previous to aligning the tail stock.

I have thought of using such a device, but I also thought that a good way to maintain the alignment would be to use a filler of some kind between the base of the tail stock and the upper part. You would lay on the filler, then bed the tail stock upper onto it, then carefully squeegie out the excess filler while aligning with the jig. Once the filler is hardened you can add the hold-down bolts or whatever it uses, and it won't shift out of position.

daveo
01-01-2016, 07:37 PM
I turned a "flat" on two morse taper to jacobs drill chuck adapters. With the flat being the SAME EXACT diameter. So you put one in the headstock, one in the tailstock, then run a indicator between them.

Its the same as having a test bar between centers but you can move the tailstock back and forth.... I will post pictures if needed.

darryl
01-01-2016, 08:00 PM
One of the chores with tail stock alignment is getting the bore aligned in all three axes. The buddy bar seems excellent for that. It's nice to be able to run the tail stock spindle in and out without losing alignment.

elf
01-01-2016, 08:19 PM
Normally, the headstock should be shimmed to match the height of the tailstock, however, the OP doesn't say which way the tailstock is out of alignment.

Baz
01-02-2016, 05:06 AM
Seems like a bad idea as it will be too rigid and trying to force the tailstock into place but it will spring back after removal. The starting point is to put a soft centre into the headstock and skim it as it turns so it must be dead true. ( you can also just put a bit of bar in the 3jaw and turn it to a point) Then put a good clean sharp hard centre in the tailstock not one that came out of the rusty bin at a yard sale and gently bring them almost together. this will show you coarse alignment which you can improve. Then you gently bring them together with a thin flat shim in between like a razor blade. Any miss-alignment twists the blade. You will understand as you try it. You seldom need better alignment than this and since things can move over time when you do need real good alignment use improved methods.
If you can post a link to a picture of the lathe or equivalent we will have a better idea of what the options are and perhaps people with the same one will recognise it.

drmico60
01-02-2016, 05:27 AM
Hi Nikos,
You do not say whether you have a Sieg or a Real Bull minilathe.. The tailstocks are quite different for the two lathes.
I have a Sieg lathe and I made a number of modifications to the tailstock to permit alignment. If you are interested then see:
http://mikesworkshop.weebly.com/tailstock-modifications.html
Mike

rabbit_nick
01-02-2016, 06:40 AM
Hello guys!

Thank you all for your tips!

I will post a few photos of my lathe later so you can see it :)

@mars-red I am not planning to change the alignment regularly but who knows in the future.

@Baz I tried something like that but.... I will do it again :(

@drmico60 My tailstock is simular to Sieg. As I can see Real Bull is better...

rabbit_nick
01-02-2016, 09:29 AM
Hello again,

I am posting a few photos of the mini lathe and the kind of alignment I did...

This is the mini lathe 7x14" (180x350mm)
http://s27.postimg.org/il4uk87lr/Mini_Lathe.jpg (http://postimg.org/image/il4uk87lr/)

This is my alignment way...
I inserted a linear bearing shaft in the headstock chuck then I inserted it in the tailstock chuck and then I inserted the tailstock in the tailstock chuck morse tapered shaft...
http://s13.postimg.org/jbqwqptsz/How_I_aligned_it.jpg (http://postimg.org/image/jbqwqptsz/)

And the results!
I tested the tailstock shaft from one side to the other with the dial indicator and I found that the difference is less than 0.05mm.
Does this mean that I am parallel to the lathe ways ?
http://s30.postimg.org/ibiyskcu5/Align1.jpg (http://postimg.org/image/ibiyskcu5/)
http://s3.postimg.org/hyjnd621b/Align2.jpg (http://postimg.org/image/hyjnd621b/)


Thank you
Nikos

Old School
01-02-2016, 11:56 AM
I agree with Baz as this is the easiest way I have found to check alignment as well. Unless you want to really get cared away it works well and is simple to do. To me easy is always better. !!

rabbit_nick
01-02-2016, 12:34 PM
I think Baz solution is good but I am a newbie so I dont know if I am going to do it right but I will try :)

danlb
01-02-2016, 01:09 PM
Welcome to the site Rabbit.

You are not really doing it right. Here's why Baz's suggestion is more valid.

First; some facts;
1) The 3 jaw chuck is not very accurate. It may be off by several thousandths of an inch.
2) A drill chuck is extremely inaccurate. It may be off by 10 thousandths of an inch or more.
2a) The rods you are using are not necessarily straight and consistent diameter.

3) If you stick a bar of aluminum in the 3 jaw chuck and then use the lathe to make a point on the end, the point will be centered in the exact center of the chuck's rotation (also known as the lathe's axis).
4) If you stick a short, stiff drill in the tailstock and drill into the end of an aluminum bar, the hole may be oversize, but it will be centered with regard to the lathe's axis.
5) What you want is for the tailstock to be at the same height as the lathe's axis, parallel to the axis and lined up with the axis front to back. In other words, lined up in both dimensions as well as parallel.

Using Baz's suggestion will give you two known good points (the pointed rod in the chuck and the pointed center in the tailstock) to compare. Anything pinched between the two points will tilt if the points are not perfectly aligned. A razor blade is often used for this.

When you have the points aligned, then you move the tailstock and extend the ram an inch or two. If they are still aligned, the tailstock bore is parallel with the axis in all directions.

The real test is to make two test cuts on opposite ends of a 6 inch bar that is mounted between centers. The diameter of the test cuts will be the same if everything is aligned.

Dan
( yeah, I realize that now you have to look up terms like "mounted between centers", but machining is an endeavor that is benefits from doing a lot of reading as well as watching videos. The more you know, the easier it is to use the tools)

rabbit_nick
01-02-2016, 01:20 PM
Hi Dan,

I will try to make a pointed center and do the Baz way. I also saw it on a youtube video so I think I know what to do (short of...)


Thank you
Nikos

PS. I know what "mounted between centers" and "turning between centers" is :)

CarlByrns
01-02-2016, 03:24 PM
I found that the flat setscrews that lock the tailstock don't really grip very well and the tailstock can shift. I replaced mine with cup points.

rabbit_nick
01-02-2016, 03:30 PM
Mine has allen setscrews and they can hold it very good.
Has 2 at the back and one at the bottom

Edited: The photo is a little bit dark...

http://s9.postimg.org/ws17y2vmn/Camera_ZOOM_20160102144630820.jpg

Mike Burch
01-02-2016, 04:50 PM
Rabbit, your lathe is a Sieg C3 with different lipstick. I have the older Sieg C3 model, which came with centres for both ends. IIRC, the headstock alignment and height cannot be adjusted.
The tailstock's lateral adjustment tends to wander as you tighten it, but with patience you can get it lined up. Baz's method is easiest.
Having to tighten and release the bolt that tightens the hold-down on the tailstock every time you want to move it along the bed will drive you mad in short order, so the first mod you make to the lathe should be to replace it with a lever-and-cam arrangement.
Do NOT be tempted to fit the factory DROs, by the way, they are rubbish; the batteries go flat even when they are turned off, and they prevent the compound from being turned to an angle for easier thread-cutting.
And if I am interpreting your photos correctly, you may be a bit adrift in your reading of your dial gauge. Each division is 0.01mm, and the difference between the readings in the two photos is about half a division, i.e., 0.005mm, not 0.05mm.

rabbit_nick
01-02-2016, 05:42 PM
Hi Mike,

Yes it is a Sieg C3 clone. I bought it from MTP Poland and is made by Wellmach Tools in China.

Mine unfortunately came only with the tailstock dead center so I am planning to go and buy an MT3 dead center on Monday to fit it in the headstock.

Yeap! As you say the bolt tightening on the tailstock makes me mad. Sometimes I forget if it is locked and I double check it for no reason.
Really !*&@$#!@ disturbing :)

And yes I wrote it wrong before. The difference was 0.005mm as my dial indicator has 0.01mm resolution.

Now.. as for the DROs...
I cut a piece of aluminum with my CNC and I glued an old digital caliper on it.
After that I screw the aluminum piece in the hole that the lathe accepts the traveling steady and I used a magnet to hold the caliper on the lathe carriage.
It is pretty accurate I have to say and I will post photos tomorrow to see my mod.

The reason I did it is that the divisions in my lathe handles are 0.001" or 0.025mm and is it very difficult for me to make measurements with that.

Thank you
Nikos

rabbit_nick
01-02-2016, 05:49 PM
PS. A while ago I saw a kit that you buy and make the tailstock camlock your self.
Do you guys know anything about that?

Thanks you
Nikos

danlb
01-02-2016, 06:10 PM
PS. A while ago I saw a kit that you buy and make the tailstock camlock your self.
Do you guys know anything about that?

Thanks you
Nikos

Yep. Available from little machine shop. (littlemachineshop.com)
I have one installed on my small lathe. It works just as it should. Easy to install. IIRC, just one hole to drill.


Dan

rabbit_nick
01-02-2016, 06:12 PM
Yep. Available from little machine shop. (littlemachineshop.com)
I have one installed on my small lathe. It works just as it should. Easy to install. IIRC, just one hole to drill.


Dan

Thank you very much!

Nikos

jdunmyer
01-02-2016, 07:33 PM
Almost as good as the cam-lock arrangement is this:

Get a 15mm combination wrench at a flea market, cut it in half with an abrasive wheel. Use the box end (ring spanner for the Brits) to tighten the clamp nut. The angle of the end is about perfect to just let it hang on the nut, with the 'handle' sloping downward. If you're lucky, you won't have to even lift the wrench to grab another flat.

(I think that nut is 15 mm, I no longer have that lathe, the one I have now has the cam lock T.S.

Mike Burch
01-03-2016, 03:59 AM
PS. A while ago I saw a kit that you buy and make the tailstock camlock your self.
Do you guys know anything about that?

Thanks you
Nikos

This is the one, Nikos - but you could very easily make your own. It's a nice wee project.
http://littlemachineshop.com/products/product_view.php?ProductID=2018&category=1687114045

rabbit_nick
01-03-2016, 04:38 AM
@jdunmyer I was thinking something similar with a pipe wrench...

@Mike Burch As I can see it is not very difficult to be made.
I will try to design it at first place and then try stuf...


Thank you
Nikos

rabbit_nick
01-03-2016, 07:07 AM
Well...

I made a pointed corner from a steel shaft I had on my workshop
http://s28.postimg.org/i4y5dhvt5/1_Point_to_Point.jpg (http://postimg.org/image/i4y5dhvt5/)

Then I used a razor to do the alignment
http://s9.postimg.org/ewbnpzafv/2_Razor_1.jpg (http://postimg.org/image/ewbnpzafv/)

I noticed that my tailstock's center is a bit higher than the headstock center. I don't know if this has to do with my chuck but it probably is not a very good thing...

The good thing is that I managed to align the tailstock from to the left-right origin with the chuck center :)

Do you guys think that I should spend my money on a new and better tailstock?


Thank you
Nikos

PS. This is the DRO/Caliper mod I was telling you about yesterday
http://s30.postimg.org/ysimefunh/Caliper_Mod.jpg (http://postimg.org/image/ysimefunh/)

RichR
01-03-2016, 12:24 PM
I noticed that my tailstock's center is a bit higher than the headstock center.
Before jumping to that conclusion, I would pull the tailstock. Make sure the sliding surface is absolutely clean and has no high spots
due to dings or other damage. Then check the ways for dirt and damage. Either one can make the tailstock appear to be high.

rabbit_nick
01-03-2016, 12:46 PM
I clean the lathe after every use.
It was clean like a new mirror :(

Thank you
Nikos

Carm
01-03-2016, 02:18 PM
"I noticed that my tailstock's center is a bit higher than the headstock center. I don't know if this has to do with my chuck but it probably is not a very good thing..."

Many's the lathe came from the maker with a high tailstock, and many fitters do the same when refurbishing.
Make some parts and see if you have error.
Setover adjustment usually cures taper unless there are other factors, like severely worn ways.
The setover screws on your lathe look to be a PITA.

rabbit_nick
01-03-2016, 05:51 PM
Maybe I will try to realign it tomorrow with more attention this time and see if this happens again.

I drilled a few holes to aluminum round bars and I didn't notice any big problems.
I made a 10mm hole in an aluminum bar and when I measured it it was exact 10mm.

Are there any other ways to measure if there is any alignment error?

Thank you
Nikos

RichR
01-03-2016, 09:31 PM
Are there any other ways to measure if there is any alignment error?
Check this out:
http://www.frets.com/HomeShopTech/QuickTricks/TailstockAlignment/tailstockalignment.html

rabbit_nick
01-04-2016, 04:46 PM
Niceee...!!

Doozer
01-04-2016, 06:09 PM
http://i288.photobucket.com/albums/ll168/TexasTurnado/P9110034.jpg

Blue up the base of the tailstock
and check it's bearing on the bed.
I bet it is 10 to 20% at best.
Fix that first.

--Doozer

rabbit_nick
01-05-2016, 05:55 AM
Can I use a marker?

How you blue it? With liquid ink ?

Thank you
Nikos

Carm
01-05-2016, 09:05 AM
Can I use a marker?

How you blue it? With liquid ink ?

Thank you
Nikos

No, not if you mean a quick dry marker.
You want what is called high spot blue, Prussian blue or any slow dry (if ever) pigmented contrast that can spread very thinly, else a thick film yields error.
There is a fellow that posts here, Richard King, read his posts for the gospel. There are brand names but may be hard for you to obtain.
A quick dry marker works for experienced eyes, but here's an old saying:

A little knowledge is a dangerous thing. Drink deeply or not at all from the spurious spring.

rabbit_nick
01-05-2016, 10:24 AM
Can you suggest any ebay link for that to see what it looks like?

Thank you
Nikos

dian
01-05-2016, 01:04 PM
rabbit, dont overthink this. your tailstock looks just fine. if you want to play around with this, centerdrill a 30 x 200 mm aluminum bar, chuck it up using the tailstock and turn it down a little. then measure the diameter in the middle and on both ends. whats the difference? do you care about the difference? i bet not. enjoy the mashine, learn to use it and make some parts. a fun project is to make some "air springs" maybe 40 mm long by boring out some stock and making a close fitting rod. really easy in aluminum. put some grease on there and if the part is still springy after a few days you lathe is as good as it will get. you can use a sharpie for blueing just fine, btw, at least to get a first impression. good luck.

rabbit_nick
01-05-2016, 02:43 PM
Hi dian,

I did a test today like the one you just wrote with a 25mm 6063 aluminum rod.
I was not able to measure any difference with my dial indicator so I suppose my alignment is pretty accurate :)

Thank you

dian
01-05-2016, 03:22 PM
you mean micrometer, right? (a digital caliper would do.)

danlb
01-05-2016, 03:51 PM
If you measure with a dial indicator mounted to the carriage, you are duplicating the path of the tool. Because of that, you will not detect a taper.

If it did cut a taper, one end would be bigger than the other. That's what you want to detect, so use a caliper or micrometer to measure the diameter.

Dan

rabbit_nick
01-05-2016, 04:08 PM
I just mounted the dial indicator on the carriage and I moved back and forth...

I got it now. I will do it again and I will measure with my digital caliper :)

Thank you

dian
01-06-2016, 04:31 AM
also be aware that every quill will be tilted left/right and up/down (which doesnt matter that much) to a certain extend. place the indicator on the carriage/toolpost and find out how it is in the horizontal plane, so you know what your doing. then find the quill exstention, that gives best results. mark the quill and whenever you need precision, work at that extention. in a way this is not bad at all, because you can dial in a very sligt taper into the work by extending or retracting the quill from that mark.

rabbit_nick
01-06-2016, 02:51 PM
Thank you for your suggestions dian :)

darryl
01-06-2016, 05:54 PM
One could make his own morse taper alignment bar if you can set up your compound to give an exact angle. Turn the mt3 taper first, then fit it into the spindle, marking the rotational position of it in the spindle so you can re-insert it the same at another time. Then turn the mt2 taper on the remaining end. This will eliminate any wobbly error you might potentially get with a purchased product. Mounting the tailstock onto this will ensure that the bore is aligned in all axis, and you would deal with the gap between the top of the tail stock and its base in whatever way suits you. I'd still use a filler, making sure the top of the tail stock is clean and the base is prepped with a mold release. To me it seems like the best option because you are actually mating the two pieces and won't have to dick around with adjustment screws, etc.

Just my opinion of course. But there is the possible issue of the tail stock bore not being parallel to the quill. If this is the case, you'll still get an error when you move the quill in and out. And if the quill's bore does not end up parallel to the ways it could become a compound error. Before doing too much dicking around it might be good to check whether the mt2 bore is parallel with the quill.

If you had an mt2 stub adapter, it will give you a straight section of metal to indicate against, and you would arrange to turn the quill in its bore (by removing a locating pin or whatever) to find any possible runout. Of course this assumes that the stub adapter is machined true-

rabbit_nick
01-07-2016, 08:06 AM
Thank you for your tips!

What is the use of a stab adapter?

dp
01-07-2016, 10:43 AM
Can you suggest any ebay link for that to see what it looks like?

Thank you
Nikos

It is common in any decent artist's supplies store if you're lucky enough to have stores near by. Otherwise, Amazon.com (which is why there are fewer stores near by). Look for Prussian Blue oil paint. Also look for a brayer as you'll probably need one sooner or later. It is a small roller used to apply the blueing.

darryl
01-07-2016, 07:53 PM
Stub adapter- it has a Morse taper on one end and a stub on the other. The ones I get are MT3 and the stub is 1 inch diameter, and maybe a bit more than an inch in length. You can machine the stub to do anything you want. One of mine has a small faceplate on it which is drilled and tapped in a 3 and 4 bolt pattern. Useful for holding certain things. Because my mill has an MT3 spindle, I've used them for making custom boring tools, end mill holders, one is a custom centerless hole saw holder, another holds a drive gear which mates with a bevel gear in a right angle adapter.

rabbit_nick
01-08-2016, 10:17 AM
I see...

Thanks