Hardinge threading lathe calibration

[ccarlsen]

I have a Hardinge HLV-H threading lathe that has seen some abuse. The spindle is misaligned by a degree or two from the bed and various components no longer work. Does anyone have a ball park estimate for having a tech come out and (at least) realign the rotor?

Thanks

[BillTodd]

The spindle is misaligned by a degree or two

Oh dear! that's a serious problem. (Are you sure the spindle is that far out?)

The head is held in place by four bolts in the corners, but is dove-tailed to the bed. There is a clamping screw in the rear to pull the head over to the front of the bed (like the tail-stock).

You could try loosening the four bolt and tweeking the clamp bolt in the hope it'll square up a little, but if it's really move that much it might have damaged the head or the bed or both.

If you want it fixed properly go to someone like Paul Babin - you better be sitting down when they quote the price !

[ccarlsen]

Thanks for the information. It looks like it is actually on the order of minutes, I will know the exact amount when I find my dial gauge. Currently I can not use a live center or drill small diameter holes correctly because of it.

There are many things wrong with this machine right now, including a non-functioning break and broken lubricant hoses, so I am in the process of trying to fix that. I will give your suggestion a try, and hopefully it will work.

[BillTodd]

There's a parts manual on the hardinge yahoo site

http://groups.yahoo.com/group/Hardin...LV-H%20Manual/

[ccarlsen]

Thanks, that manual is a big help.

Its going to take me several days just to get this machine sorted out enough to see what needs to be fixed. The old lead machinist left about 10 years ago, and this lathe has not been cleaned since. I just finished draining the old oil and pulling about a cubic foot of fine aluminum curls out of the oil pan...

[ccarlsen]

So far, I have found a few problems with this unit. The dove tail wiper is horribly damaged, which has probably caused additional problems with the way lubrication (which does not seem to be feeding correctly). Its not worth it for us to send it out for repair and refinishing, but if I can buy the parts and just replace what is damaged I will.

Does hardinge still sell parts for this model?

The spindle does not seem to have any run out (as far as i can tell right now), but I am getting an angular deviation that causes 0.0000 offset at the collet, but about +/- 0.0005 variation 1.25 inches from the collet. I am using a 1/2 inch collet and 1/2 inch gauge pin to do this test, so there should be no deviation for the stock, but this may indicate a problem with the collet itself? I am going to try this with a few different collet as well as measuring the inside of the spindle for any deviations.

[BillTodd]

Does hardinge still sell parts for this model?

Some parts are still available (ensure a comfortable landing area before calling about prices!)

The spindle does not seem to have any run out (as far as i can tell right now),

That's about right the spindles are ground in place to impeccable precision.

I am using a 1/2 inch collet and 1/2 inch gauge pin to do this test, so there should be no deviation for the stock, but this may indicate a problem with the collet itself?

Yes. Unless you know the collet and closing mechanism is perfect.

A better way to test is to take two test cuts on a length of stout bar. Use say a 6-10" long Bar of aluminium 1-2" diameter. Relieve a section between two areas (like a waist) near and away from the chuck (so you can take the two test cuts with out moving the cross-slide) then measure the diameter of the cuts. My 50 year old HLV-H is better than 0.0003" over a 6" length.

You may find the bed is worn, corroded or just plain filthy near the head-stock, throwing off the alignment.

[ccarlsen]

I made a cut over a 3" length and found a deviation of 0.0009


From what I can tell from the shape of the machine, at several points, a previous shop idiot took the large chuck with tool steel fingers on it and crashed it at highspeed into the crossfeed table.

Edit: Nice work by the way, I had come across your documentation earlier.

[BillTodd]

Time to boost the confidence in your machine

Reviewing what you have reported, I do not think the head has moved at all.

A crash that would move the head would have killed the bearings and the zero TIR and the fact that you are not complaining about spindle noise, suggests that the bearings are OK.

HLV's are incredibly robust machines for their power, it is easy to stall the spindle by taking too big a cut on a large diameter - they don't mangle themselves when stalled like a gear head lathe . If the bed scrapper has been mangled in the crash it probably absorbed most of the chuck/spindle's kinetic energy so, another reason to be cheerful

1 thou" over 3" is not great, but really there are a number fixable of reasons why it could be cutting off by that much. It could easily be tool/part flexing for instance.

(put a DTI on the test piece, push it with your thumb and I bet you'll be able to move it)

I don't want to teach granny to suck eggs but, to be accurate for this type of test

First, clean the back edge of the dove-tail bed (that's the reference, so it should be spotless). Apply way oil (mobile vactra 2) to the bed if the oiler is not working). The HLV's carriage weighs as much as I do (yes really!) yet it should move like silk along the bed - it should easy to position the carriage a thou" at a time without sticking.

If the carriage gib is a bit loose you may need to drag the carriage lock a bit - make should you back-up the carriage a few inches away from the test, so it has time to settle before it starts cutting. (once you are happy that the lathe is still straight - you can adjust the gibs accurately)

The tool has to be absolutely bang-on centre height - use both the HLV's power feeds to cut a needle sharp centre and set the tool height to match.

Use a razor sharp tool - HSS honed to polished finish

Take a 1thou" cut to get the test areas to match, then the final test cut should be 1/10,000" (set the top-slide to an angle of 5.75° to parallel so a 1thou" feed will equal a tenth") You could put a dti on the final cut to check for any spring back.


It would be well worth changing the apron oil while you at at it - use Automatic Transmission Fluid - Do not over fill - the bloody thing will start dripping from the carriage handle and you'll not be able to stop it - Dragging or slipping feed clutches are often caused by using the wrong oil.

The non functioning brake could be just a worn cork (I just spaced my one out by wrapping it in a piece of paper). Make sure the brake is lightly oiled (I use a drop of ATF).

[ccarlsen]

I removed the collet clamp and cleaned it and the spindle out, as well as tightened up the ways and did a bit more cleaning. My gauge pin test read +/- 0.00025, and the rest I FWAH (fixed with a hammer). It is now reading near spot on, for any more accurate measurement I will need a better TDI, as I am now just reading between the lines.

I haven't tried your suggested test cut, but I will tomorrow. I expect it will yield fairly good results.

I have a question about your tool post. I bought the same model a while back, and had to grind down the blank T-nut to fit my HLV-H. About six months later the nut stripped out, forcing me to change back to the original tool post. How did you attach yours?

[BillTodd]

I have a question about your tool post....

I used to have a miniature Dixon type post, but it wasn't really up to the job (a size too small). [edit] come to think of it, I remember drilling it out to take a larger fixing bolt so I could use an Indexing handle instead of a nut.

This one from RDG -http://www.rdgtools.co.uk/acatalog/MYFORD_LATHE_USERS_NEW1.html


I replaced it with a home-brewed copy of the Hardinge tool post. It is held down with a length of M12 threaded rod - one of those things I was going to replace, but doesn't work badly enough to warrant doing immediately (i.e. within a decade).

I made a close fitting T-nut - peinning the end of the tread to ensure it does not screw through and damage the top-slide.

The odd looking offset fixing holes seem strange but work fine in practice.