Hafco AL900A lathe, is anyone able to identify what it really is?

Doug, well done, it would appear that it has been out of alignment for some time. and It will take time to get it back, each time you make a major adjustment, you need to let the main castings relax again, because old stresses have been relieved and new ones applied.

If you're having trouble getting the headstock to move and stay in position as you tighten the bolts. maybe over time a lot of crud has filled the clearances around the bolts and won't allow things to move properly. Is it possible to lift the headstock off the lathe and check the mating surfaces, yes I know it's a big job, and must be done with extreme care.

Actually before you attempt that, completely remove the holding bolts, one at at time, and remove any crud that has accumulated in the holes. I expect you will get quite a bit of crud out. Replace each bolt before moving on to the next one. Then you will find that it will move better and stay moved as you tighten it up. If That is successful, you may not need to lift it.

One thou per inch is still quite a lot. but one thou per foot is pretty good and many people will accept that, but you should be able to get it to within one thou over the full length between centers. You make the call how good do you want it. think about the things you are going to machine, if you are making a bush that is one inch long an it has a taper of one thou, is that a problem, no not really.

Enjoy.
 
Bob, I am chuffed to get it to this point. It has been a multi-day (2 to 3 hours per day) to evaluate and then test then adjust it. As you say, it appears to have been out every which way for a long time.
At my measure point 1" out from the chuck there is a 50 to 70 thou spring back when I cinch down the right front cap screw. I tried using the 2 adjustor screws in a controlled fashion and it was just a hiding to nowhere. So then resorted to moving
the headstock by hand (easier than I expected) and just left the adjustor screws loose.

When I had it at 1 thou per inch I then refreshed the centre point on the homemade mild steel centre as per your instructions and zero'ed
the tailstock. As mentioned, there is a consistent 1 thou per inch taper with and without the tailstock. That in itself is encouraging as it is one
less complication.

By the way, the tailstock moved the opposite direction to what logic dictates would happen when turning the cap screws, is that normal?

I will do the de-gunking as you advise and then tackle the headstock again when time permits, perhaps tomorrow or the weekend.

Change of subject. I see on ebay there a SECO CNXG carbide tips which should suit my tip holders. I want to replace all the chipped tips that came with the lathe but cannot find a listing for the properties of these particular ones with the "X" code.
I would like medium <-> fine, would these be suitable?

Regards
Doug
 
Bob, I am chuffed to get it to this point. It has been a multi-day (2 to 3 hours per day) to evaluate and then test then adjust it. As you say, it appears to have been out every which way for a long time.
At my measure point 1" out from the chuck there is a 50 to 70 thou spring back when I cinch down the right front cap screw. I tried using the 2 adjustor screws in a controlled fashion and it was just a hiding to nowhere. So then resorted to moving
the headstock by hand (easier than I expected) and just left the adjustor screws loose.

When I had it at 1 thou per inch I then refreshed the centre point on the homemade mild steel centre as per your instructions and zero'ed
the tailstock. As mentioned, there is a consistent 1 thou per inch taper with and without the tailstock. That in itself is encouraging as it is one
less complication.

By the way, the tailstock moved the opposite direction to what logic dictates would happen when turning the cap screws, is that normal?

I will do the de-gunking as you advise and then tackle the headstock again when time permits, perhaps tomorrow or the weekend.

Change of subject. I see on ebay there a SECO CNXG carbide tips which should suit my tip holders. I want to replace all the chipped tips that came with the lathe but cannot find a listing for the properties of these particular ones with the "X" code.
I would like medium <-> fine, would these be suitable?

Regards
Doug
Doug, it's hard to comment on some of the problem you are having, without being there and seeing it myself.
I'm pleased that you have come so far at this point.

The tailstock screws on mine appear to move it towards you as you screw. them in, At least that is what the drawings would indicate, I have no idea what others do. I haven't as yet tried to adjust mine, as I haven't found the need.

In fact I have not yet made any attempt to test the squareness of my lathe since buying it and setting it up in my garage. I'm beginning to suspect it is out, a bit, but not as much as yours, but I was doing a job today and became aware that the headstock is not square to the cross slide. as it happens it is not critical to the job in hand, but none the less I shall have to attend to it, but it will have to wait until the job is finished

Unfortunately you are asking the wrong person for advice on carbide tips, I struggle to make sense of the codes. So far I have only bought few tip holders that came with a packet of tips, and that is what I use. I grew up on HSS as carbide was quite new and most of our machines were not fast enough, The lathe I worked on during may apprenticeship had a top speed of only 350 RPM. Most of the time I'm using my Diamond tangential tool holder from Eccentric Engineering, Never used one before, but had heard lots of good stories so bought a couple when I bought my lathe, and so far so good.

I suggest you start a new post asking for advice on tips, many of our members appear to be quite knowledgeable on the subject, but be prepared for some conflicting opinions, as choice of tip has many factors, including personal preference
 
Pierre and Bob

Using Pierre's idea of a ground rod from a printer, I sacrificed a printer I had that was past its best and managed to get a rod whose ends are about 5/16" diameter but the body looks to be around 1/2" diameter.

It took me about 6 goes before I got the 3 jaw chuck to grip it true according to the dial indicator. The result was impressive, very gently turning the chuck showed no deflection at all!
Not believing what I was seeing and wondering if the pressure of the spring in the dial indicator was deflecting the bar, I presented the cutting tool to the bar and did some tests - turning the chuck using the key as a lever and doing so gently.
There is a 1 thou difference on the cross slide vernier between no contact and a tiny curl coming off the tool. So that would be a diameter runout of no more than 2 thou.
However I think it is less due to having to back off through the slack of the cross slide worm and then touch back on the rod again.
So I am calling it a 1 thou diameter run out at the bar length of 10" from the chuck jaw.
Unless I am barking up the wrong tree, I am very happy with that?

The body is currently covered in a soft brown foam like sponge - so I need to be able to get that off somehow without scratching the rod, which appears to be mild steel. I will try petrol and if that doesn't work then paint thinners.
The problem being I am very reluctant to take it out of the chuck now that I have it so nicely sitting true.

I am now confident of being able to set the Dial Indicator up at the RHS of the rod and turn the headstock to hopefully obtain almost no taper -
aiming for a lot less than 1 thou per inch!
Providing I can get the foam off and whatever glue, being able to run the carriage back and forth with the dial indicator
rubbing on the rod body should then tell me how well the carriage is behaving.

.
20180629_110457.jpg
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Doubtless, I will then have to do a fresh centre point and re-zero the tailstock.

Regards
Doug
 
Well, as of this arvo it was all down hill. No matter what I did, the final sit of the headstock could not be predicted when the 4 anchor cap screws were tightened. Every time this would draw the headstock towards the apron and induce a taper.

In the end, I backed them all off and left it sit like that till I get back to it tomorrow arvo.

The screws all seem to want to rotate the head to the right for some strange reason.

Sigh.
 
Hopefully the shaft is not knurled to grab the rubber coating. Seems you are getting handle on the lathe.
 
Pierre

It is not knurled, but does have a spiral like roughness on it. However, that is consistent so I can allow for it when using it as a parrallel test tool.

The thought occurred to me overnight that the adjuster screws could be part of the problem with the head. I will try backing them right off and see if that makes a difference.

I will also move the headstock multiple times through all of its travel. Hopefully that may make it relax and move any grit etc that could be causing the issue.
 
Pierre and Bob

SUCCESS! :courage:

After quite a few hours of perseverance I am pleased to report that I now have 1 thou in 5 1/2" (length of my unsupported alloy turning bar) taper.

So, I will be content with that. Trying to attain perfection would be an exercise in futility!

The printer rod was a huge help in that it gave me a reliable reference. Due to the spiral mark from the sponge coating, which was not going to come off without being aggressive, I chose 2 reference points and retracted the dial indicator probe when moving back and forth between the 2. It can be done accurately if you are gentle. The reduced diameter RHS end gave me a handy cross-check that the bar hadn't deflected with all the dial indicator probing that happened countless times today as I could gently revolve the chuck by hand and verify the runout had not altered.

It was a very frustrating experience due to the spring in the headstock. In the end I put a washer under the cap screw closest to the operator. This helped reduce the spring/unpredictable movement effect. Until I did that, I was on a hiding to nowhere!

Initially the other 3 cap screws were also having an effect on the spring back too, but after much moving of the headstock left to right whatever was causing the issue with them disappeared from the equation and it was just the front right cap screw that was the problem.

But I was still faced with 40 or so thou spring when backing the screw off to move the headstock. I discovered that if I left the other 3 loose and cinched down this one (front right) all the way I could then predict the end reading give or take a couple of thous, so had to keep at it until is landed at the the desired tolerance. Then a case of gently cinching up the other 3 in a regimented order every time. Bit like doing up the wheel nuts on your car in that set pattern.

Running between centres was not so successful as I have a 14 thou runout even after re-zeroing the tailstock using the razor blade method and a freshly turned centre point in the 3 jaw chuck.
The live centre point does not seem quite right - I think it is giving me a false zero - I need to take a very close look at it and even with 2 pairs of magnifying glasses on I can't focus on it - the joys of getting older!
So will need to find a magnifying glass.

I knew that bedding down a lathe was a precise affair but never imagined it could by this finicky. However, I do think there is a back story to the history of this lathe that I will probably never know.
 
G'day Doug, I'm back again, we went away for a quick trip, but back now. Looks like you are making progress, Tat one screw pulling it over all the time I'm wondering if I didn't have a depressed wear mark under the head and it was pulling in to that, however it appears that by putting a washer under it you fixed it, seams to prove a point.

One thou over 51/2 inches isn't bad it will do for now.

Time to move on and start using your new lathe, getting to know it and brushing up on turning skills.
 
Bob, thanks.

Wondered what happened to you. Thought I would give it a bit longer before getting worried.

A good training job for me will be to make the height setting devices that go on the quick change tool holders.
For some bizarre reason, all 4 of my ones are missing.

On 2 of the holders there is a running thread with an allen key recess, but no cap screw head. These look too short to me to do the job as there would not be enough thread to project above the height device for a back nut to lock it.
On the other 2 the running thread is missing altogether along with 2 square head cap screws on each holder.

See here for what I assume they should look like.
<http://www.bison-bial.com/spare-parts-and-accessories/u-6876/0>
Why buy them when I have a lathe and can make them!

So, do you have any idea of how tight a fit the skirt on them is in the 2 cam like fingers that rotate out from the head?
<https://www.cromwell.co.uk/shop/spi...ts/t-00m-quick-change-toolpo-st/p/IND4454800K>
I would assume that they don't have to be a tight fit, because the lower finger would support the skirt, but, there is an upper finger and I doubt it is there for decoration?

Also, I went all over the QCT head trying to find any markings at all. There are none, likewise on the tool holders. You asked me about that quite a while back and I did not get to check it out till today.

Regards
Doug
 
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