Thread: AL960B level and alignment

G'day All,

I'm a new forum member and I'm also new to the hobby machinist world.

I apologise in advance. I know this threads been done to death and I have been reading some older threads. I'd feel better if I proceeded carefully with good advice from people with experience.

I bought my AL960B lathe new, early last year. I'm trying to set it up as perfectly as possible to cut parallel.

I've fitted some decent feet and using a 0.02mm/m precision level, I've levelled across the ways and the saddle with very close results. Having done the 2 collar test over approximately 9", I'm getting a .006" difference. Larger at the tail stock end.

I tried adjusting the feet to twist the bed and bring the cutter closer at the tailstock collar, but the best I can get is a .0015” difference, larger at the t/s end. At that the R/H rear foot is being lifted off the ground.
Twisting the bed to compensate for other misalignment doesn’t sound like a good idea to me anyway.

I reset the bed level again and bought a 5M parallel test bar for the head stock spindle. Sweeping the bar with dial indicator off the saddle proves that the spindle isn’t parallel to the ways.

What would you guys recommend as the next step?

Any advice is really appreciated.

Thanks, Denis.

My AL960 was out by several thou
and that was after I had levelled the bed.

I had to adjust the headstock to get mine to cut parallel. At the back of the head there are adjustment screws to do this.

Went over to mates house a fortnight ago, and he said his lathe (up two sizes on the AL960 but also from H&F) was cutting a 4 thou taper over 3inches with no tailstock support...as I had allready put the level on his lathe and levelled it some time back I put a his newly aquired test bar in and checked tailstock alignment..all good. Put a dead centre in headstock and one in tailstock and bought them together...and wow...didnt even need a magnifying glass to see how far out the head was pointing...showed him the adjustment screws, had a cup of coffee and left.

Couple days later I received message it was now cutting 0.0005" over 3 inches.

Thanks for chiming in Eskimo. Yours was a thread that I read amongst others and convinced me to buy the parallel test bar. I’m thinking that the head stock is not aligned correctly but I’ve seen a lot of people saying that adjusting it is more likely than not a mistake. I want to make sure that I’ve done all the relevant checks methodically and correctly before I interfere with the factory head stock alignment.
From a layman’s perspective, I think I have. I don’t think wear can be an issue being a new machine.

There are basically 2 tests to consider.

The first is taper/parallelism turning a round shaft. Yours is out by an unacceptable amount.

The second is facing. The lathe should face off *very slightly* concave. Acceptable amount in Schlesinger's book which is available as a PDF thanks to RC. Somewhere.

So you need to be careful in correcting for parallelism that you don't screw up facing, which tweaking the HS alignment may do.

I'm not saying don't do it; I had to do exactly this on my Chipmaster and I got it to 0.0004" in 8" which is good enough for me. Just - don't lose sight of the facing requirement as well.

Edit: You also need to check if the HS spindle is pointing uphill/downhill but this should be easy with a known good test bar.

PDW

Does this help?

Chris, thank you very much. Great to understand the allowable tollerances.

Welcome to the forum Denaar.

Ross

Thanks Ross. I bought a mill at the same time. I’ve really been enjoying learning to use the machines. Looking forward to gaining a lot from the good people of this forum

Denis

I’ve recalibrated the level which is perfect, I’ve re-levelled the ways again and the precision level is near perfect at both ends and across the saddle.
The below video is the result. Would you guys agree that mows the time to adjust the headstock?

https://youtu.be/X8AL2-RwEMo

Denaar you will need to check the alignment bar for run out at the end furthermost from the chuck, I am pretty sure that you will have some, maybe a couple of thou. If so I have found that a gentle strategic push on the end of the bar can correct this, it might take a few gentle pushes to remove the run out.
Now that you have no run out set your DTI on top of the test bar so that it just touching, maybe .005", find the top by moving the stylus back and forth across the top to find the high point of the test bar, zero the dial.
Now move the DTI down near the chuck and find the high point on the test bar, hopefully it will read zero.
If not, and the test bar is pointing up or down this could affect your reading when testing for taper (on the side of the bar) as you
might have the DTI set to the centre of the bar at the far end and as you return the DTI to the chuck end the stylus could now be sitting above or below the centreline of your test bar and this could be enough error to have you chasing your tail.
So in essence you need to check that the centreline of the spindle is parallel to the bed first.

cheers, shed

Hi Guys,

This is one reason to have and use an elephants foot

Thanks so much Shed, I’ll do these tests today. I did sweep the top of the bar yesterday and the DTI happily sat on zero the whole way. I haven’t checked for runout at the end of the test bar though.

Here's the South Bend lathe levelling guide Denaar. Sounds like you've already done the steps outlined, but it might provide some useful info.

I checked the run out at the end of the parallel bar today. The best I could get was almost .0015".

First test with the high side marked on the chuck and the parallel test bar.

https://youtu.be/CceB3I1_gUA

Second test with the parallel bar rotated 180 degrees.

https://youtu.be/T_GJrPLc3uA

The high point of run out stays with high mark on the chuck. So in my mind, that means that the morse taper hole axis is not true to the spindle axis. Its almost .0015" out at 12". The tolerance in the lathes manual is .00078 at that distance.

Do you guys agree?

I thought Taiwanese lathes were supposed to be OK.

Cheers again, Denis.

Hi Dennis,

That could easily be caused by dust, dirt, oil etc in or on the taper !