Need help in aligning a cheap lathe

[Gloworm5]

I made a trade recently which included getting a 14 x 41 Central Machinery (Harbor Freight) wood lathe. I have been using it to begin making pens. The good news is that I have found a hobby that I really enjoy. The bad news is the lathe just will not cut concentric. I have tried many different ways but the closest I have been able to get the headstock aligned is +/- .004. Is this the closest that I should expect or is there a method that will do a better job. I am using a dial indicator to check my measurements. I have been successful in getting it close a couple of times but it does not want to stay. This lathe uses flange mounted bearings. This means 4 bolts hold each of the two bearings in place.

I guess it goes without saying that you get what you pay for. The problem is now I am on disability and funds are pretty tight. Any suggestions would be greatly appreciated. Hopefully I can make and sell enough pens to afford a new lathe soon.

 

[Pen Maker]

Since I'm a newbie too..... Have you just put the mandrel in without anything on it.. Spin it up and check to see if it's slightly bent.? you should be able to tell by putting your tail stock very close without inserting it in the mandrel. I would check that first and then we'll be able to go from there.

 

[JimB]

More experienced folks will chime in but they will want to know more precisely what the mis-alignment is. Is the headstock higher/lower than the tailstock or are they side-by-side? I assume you know it is mis-aligned becuase you put dead'live centers in both headstock and tailstock and they when brought together the tips don't match.

Oh, and welcome to the site.

 

[Gloworm5]

Yes, I have brought the tail stock up to the head stock and also to the end of the mandrel shaft. Visually they look pretty close. Especially with just the head stock and the tail stock. When I back the tail stock off with the mandrel mounted, I can see a slight mis-alignment but not really that much. I used my dial indicator on the mandrel adapter at the headstock and measured +/- .004" for a total of .008" OOR. I have ordered a new mandrel shaft. But, I have been very careful not to over tighten the mandrel. The tail stock has a bearing with a live center. The bearing was a little sticky at first but it spins freely now. I was thinking I might have to build a steady rest to support the middle of the mandrel when turning 7 mm pens. That seems to be a little extreme but maybe I will need it. I have never used any of the mini-lathe from PSI or anyone else so I have no bench mark to measure from. I don't know and cannot find any specifications for any of the PSI lathes or for mine. So, I don't know what is considered within design tolerance.

Thanks for the fast reply and the warm welcome.

Larry

 

[Gloworm5]

I am sure there is some slight bend in the shaft but very little. I have been very careful about that. I have ordered a new replacement just to be safe and to make a very careful alignment with the new mandrel.

Thanks
LK

 

[rherrell]

Try one of these.......

OR, if your dial indicator has a magnetic base just use that. Rotate the lathe by hand to find the high (or low) spot and then tap it with a small hammer until you get it to within .001". It only takes a few seconds.
To line up the TS and HS with each other try these......
http://tinyurl.com/cuuxjn.

 

[jackrichington]

If you don't ever succeed, try it as a boat anchor..it ought to work fine

 

[Rifleman1776]

We need more information to know exactly what is happening.
However, all mandrels will flex. Minimize the flex by using a 'pro' type mandrel. Shorten and turn only one half of the pen at a time.
For larger (non-7mm) pens, use the 'no mandrel' turning methods. Makes a world of difference.

 

[Paul in OKC]

That is close enough for alignment. I would follow what has been suggested on checking run out on the mandrel, or that the headstock itself is running true.

 

[mostangrypirate]

Can't help you on staightening out your lathe, but I wanted to encourage you. my wife bought me a grizzley lathe and pen start up package for father's day. 200$ total. I sat cross legged on my front porch, with my hand drill, hand saw and my lathe. (which ALSO ran out of round). I have been able to sell enough pens, that I now have a Jet and a SHOP 10x12, AND a shop full of tools. this is the best addiction I've ever had.

 

[Gloworm5]

Wow! so many great suggestions here.

Rick
Yes, I have the magnetic base and dial indicator. The out of round is the headstock shaft. The +/- .004" is the measurement at the headstock shaft. The shaft is supported by two flange mounted bearings using 4 bolts each. I have literally spent hours and hours trying to get it down right but it never gets any better than that.

Frank

I not sure what you mean by pro type mandrel. I bought mine from PSI. The problem does not seem to be the mandrel. The headstock has a 3/4-10 TPI shaft. PSI advised I put an adapter that would bring it to a 1"-8 TPI. That way I could use a standard mandrel. It works well when the lathe is close to correct alignment.

Mostangrypirate...thanks for the encouragement. That means a lot to me. Some time when you have a spare moment send me a note on how you got started selling yours. I enjoy hearing all the different ways people get going.

Thanks to all for taking the time to answer. And, I am not quite ready to use it as a boat anchor yet but if all else fails!!
Larry

 

[Randy_]

How old is the lathe and how much use has it seen. A possibility that has not been mentioned is that the bearings are worn and a little loose.

And another possibility is that you just won't be able to do any better. If this is your lathe, you really can't expect much more than what you are getting for $80.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=38515

 

[Gloworm5]

Progress is being made on the alignment

We need more information to know exactly what is happening.
However, all mandrels will flex. Minimize the flex by using a 'pro' type mandrel. Shorten and turn only one half of the pen at a time.
For larger (non-7mm) pens, use the 'no mandrel' turning methods. Makes a world of difference.

I have spent several hours taking all these suggestions and working each one at a time. I have found the headstock has some movement horizontally. There is a clip ring that should be holding the shaft in position but there is no groove for the ring. I have located a locking collar and ordered it which should solve the problem.

Next, I found the shaft is very close to tolerance when it is held in position. But, when I put the adapter to change the shaft from a 3/4-10 TPI to 1-8 TPI, I pick up a total run-out of another .007" - .008". That seems to add up to the total mis-alignment. It must have been there from the beginning. I wonder now if I can get PSI to exchange the adapter.

With the adapter and mandrel removed, I can put the center back on and pull the tail-stock up to the headstock. I can't see any noticeable alignment problem. I am having problems finding a way to measure the difference because the headstock center is made from hex material.

Like you said, all the mandrels have some run-out. I suspect this is probably true. I pulled everything up as tight as I could without the collar and I still see run-out but it seems to be greatly reduced. I am hoping that adding the collar will close the gap. Or, at least close enough to where I can make enough pens to sell so I can afford to buy a better lathe. :doctor: Guys, I am disabled and on SS disability. This makes funds a little small for hobbies. The wife says I can only buy another lathe if I sell enough pens to buy it. :frown: That sounds reasonable.

As Randy mentioned, the bearings may be worn as well. And yes Randy, the link you provided is very close to the model that I have. Mine is model number S36066 which does not show up now. The manufacture date is 081501 which I would say was August 15, 2001. The lathe doesn't show much wear from what I can tell. The serial number and manufacture date are printed on paper labels and they are still clear and intact. There are very few scratches on the lathe overall. But, all in all it is still a cheap lathe as mentioned in the title.

Frank, can you point me in the right direction to explain what you are referring to as a 'pro' type mandrel?

All of you have been a great help and I appreciate each and every comment and suggestion. I really mean that!

Thanks
Larry

 

[Gloworm5]

We need more information to know exactly what is happening.
However, all mandrels will flex. Minimize the flex by using a 'pro' type mandrel. Shorten and turn only one half of the pen at a time.
For larger (non-7mm) pens, use the 'no mandrel' turning methods. Makes a world of difference.

Frank

I have managed to refine the adjustments enough until I have the lathe working well enough to get me by for a while. I will wait for the collar to see if it is really ready to make lots of pens.

Here is a pen that I turned today after making several adjustments and checks. The wood is Black and White Ebony. The pen kit is a Woodcraft Wall Street II. I also cut another pen barrell which by looking at the ends seems to indicate that improvement has been made. I thought everyone might enjoy seeing that the efforts have paid off.

Thanks again to everyone.
Larry

 

[ldb2000]

Larry , the Pro mandrel that Frank mentioned is for a MT2 spindle shaft . You never said if this lathe has MT capable spindle or if's a solid shaft . I have a HF lathe similar to the one in the link and it has a solid spindle .
Thats a great looking pen by the way .

 

[Gloworm5]

Larry , the Pro mandrel that Frank mentioned is for a MT2 spindle shaft . You never said if this lathe has MT capable spindle or if's a solid shaft . I have a HF lathe similar to the one in the link and it has a solid spindle .
Thats a great looking pen by the way .

Butch
The spindle in the headstock is a solid shaft with 3/4-10 TPI. The tail-stock seems to have a Morse MT2. But, I have not confirmed that. The current model of this lathe does have the MT2 according to the manual for it.

Thanks
Larry

 

[Randy_]

After being away from this thread for a couple of days, I went back and reread all of the posts and comments and have to say there is still a bunch of missing or confusing information.

Before asking for additional information and clarifications, Larry, maybe you could give us an update of where you are in your effort to get the lathe to turn true?