Hardinge HLV-H: Variator Sheave operation / removal / servicing

I am helping one of the maintenance guys resurect a mid-70's HLV-H which was has been sitting, un-loved, for at least 20 years as I understand.

Something was definately wrong with the vari-speed assy when it was last used (perhaps why it became un-used) as the whole pulley assembly seemed to have walked towards the tailstock, and one end of the shaft had come out of the (headstock side) bearing on the drive support frame.

The parts manual just points to the pulley, and calls it out as "pulley assembly" with no cross-section or other description. I am sure that if I have this right in my mind, the middle part of the pulley should move from side-to-side relative to the (fixed) outer pulley parts - induced by the position of the support frame from the screw-drive...
The middle element on this unit is seized solid, and perhaps explains how when someone tried changing the speed, it walked the whole pulley sideways.

So, am I correct thus far?

If so - what is the procedure to remove the belts and then remove the varidrive pulley? Reading the manual, it looks like I need to move the brake to the side, lift the motor, allowing me the get the belt off the motor - but the actual removal of the belts from the varidrive pulley "assembly" in the support frame is not clear.

Finally - what is the cost for a pair of new belts. The headstock drive belt doesn't look too bad, but the motor drive belt is defiantely past it; but if we are in this deep - may as well replace both....

Thanks

1. Remove the brake.
2. Loosen the pivot screws between the speed control motor/gearbox and the variator frame, get that out of the way.
3. Remove the nut and washer on the jacking/adjusting screw at the front of the motor base-plate.
4. Raise the base plate up far enough to get the lower belt off. Use a colleague and a pry bar or a pry bar and chocks if working on your own.
5. Undo the set screws under the variator shaft on one/both sides of the variator frame (sound's like it's already gone!)
6. With the tension off the belts, the centre shaft should drive out fairly easily (if it's not bent in this case).
7. Work the belts off the pulleys.

This is approximately extrapolating from the Earlier HLV. There should be an HLV-H maintenance manual somewhere out there on the Web, but I don't know where, since it's not the model I've got.

People that actually know what they're talking about will hopefully correct my mistakes, but this should be enough for you to work it out.

You might find the centre sheave of the variator moves freely once you get it out.

Dave,

Just finished doing that job on my 1975 HLV-H; Mark is mostly correct, but I don't know that you need to do steps 2 & 5; may be on an HLV, but not on an H.

There is a bit more to removing the spindle belt; you need to read the maintenance manual, as it is confusing trying to explain it here.

That manual can be found by clicking on "Forums" at the top of this page, go down to "Machinery Manuals", go to page 3, and it's the 6th title down on that page, unless you already found it.
It's a bit of work, but not difficult to replace the spindle belt.

I assume you want to remove the pulley assy., to see what is wrong with it, and check the bearings for damage.
That's where you'll have fun. The pulley shaft can only be removed by sliding it to one side, pulling up on the free end, and pulling it out. In order to do this, you'll have to remove the bearings, which are prevented from coming out by a circlip.,
There are 2 circlips on each bearing, but you only need removing the "outside" ones. It took me an hour, and finally I had to use an ice pick to pry the end up, and stick another pick under, and work it out, while trying to keep the mirror and light from moving around; the bearing can then be tapped out; mine had a shim between the bearing and the "inside" circlip. Once out, the assy. comes out nicely.

When you go to re-install the circlips, which is a pain, this is what I did: gently sqeeze the circlip in a vise until the ends just about touch. Then use a small wire .020-.030" and twist the wire in the holes to heep the circlip almost closed. Present the circlip to the groove, make sure it's engaged, hold it there, then cut the wire with side cutters. That took no time!!!

As for prices, I got my spindle belt from HCI Supply, Jackson, TN. Phone: 731-427-7725; talk to Jenny Cobb, nice person.
Price was: 32.95, plus shipping. The motor belt won't be far off. I found this on E-bay, by typing the p/n: 1626-V-597

Good luck,
Tbird

Mark / TB
Thanks for the response. I looked at the link for the manual - couldn't justify the $9 of my own money to print it off, so just used the print-screen option LOL.

Looking at the machine, and that we are going to replace both belts, it looks to me like it might actually be easier to undo the two socket screws on the front of the support frame (at the speed screw), then undo the reasr of the frame, and bring it out through the back access panel as a complete assy. This will also need the speed indicator rod wihdrawing, and to cut through the headstock drive belt - but it will give me access to this big hunk of metal on the workbench.
Obviously, I'll need to re-fit it without the sheave or bearings in place before I fit the belts; but it just feels like when dealing with something that has issues (the sheave pulley assembly is rusty all along the shaft so getting bearings to come off it might be difficult in itself) removing it as a bigger piece and looking at it on the workbench is a better option - if it can indeed be done.

DAVE_C
I have completely overhauled the variable pully assembly on my HLV-B. I assume the sheaves etc are the same on B and H variants, just operated differently. Loosen the motor to allow the lower belt to be removed from the drive pulley. On the variable pulley system, there is a pivoting rectangular frame that holds the solid central spindle, this is held in place by piggyback grubscrews on the right hand underside of the rectangular frame (viewed from rear access aperture) the first grubscrew holds the shaft, the second grubscrew is tightened onto the first grubscrew to lock it into position. Remove them both, the solid spindle (20mm Dia) should drift out towards the tailstock end. With the spindle clear of the sheaves, there is enough clearance to pull the assemble clear of the belts and out of the lathe. The assembly in front of you should be simply two outer fixed cones held together on a tube and between these, a double sided cone on a larger integrally machined tube that slides left and right over the bearing tube, I would suggest initially that you soak the whole assembly in penetrating fluid and ease the assembly along the shaft and hope that this frees off the central cone. If you have to disassemble, inside the fixed tube at each end is a sealed bearing held in posiotion by a circular plate with 3 socket head screws (bolts), Remove the caps and drift out the bearings, replacements are readily and easily available ( 60042RS). Next stage is the difficult bit. make a support frame that will fit either side of and into the larger of the belt pulley openings, support each end of this frame so that the pulleys are horizontal (the tube vertical) and 25mm clear of the work bench, with a suitable size brass drift drive the central tube off the outer pulley, you only need to do one end, you should now be able to slide the central cone off the shaft, there should be a keyway in the pulley and along the tube shaft. clean both assembies , put them back together and check the movement between the two, if they 'rattle' then you will need to recondition them, reassembly is the reverse etc I used bearing lock when I pressed the tube shaft and outer pulley together.
If your assembly need refurbishment, contact me and I will explain how I did mine for not a lot of money.

That should also apply to the HLV-H assembly.


Unfortunately for me and owners of other older lathes, the earlier ('52 in my case) HLVs had the assembly welded together instead of the caps and screws of the later ones. Wonder why they changed that...

If your hlvh is anything like my hlvh, the upper belt is effectively captured by the spindle gear and the
gear that rides on it. There's a tiny hatchway in the back of the headstock that permits the shaft
that the gear rides on, to be withdrawn.

I seem to recall puzzling about how this shaft in a blind hole is extracted, till I realized there was
a tapped hole on its end. The screw that secured the shaft was simply threaded into that hole
and it acted as an extractor.

I need to replace the motor belt on my HLV-H-1590, can one of you tell me the number belt to order?
I see tbird listed the upper belt number, but I need to get the lower one.

Thanks,
Jim

The more things change.... the more they remain the same. Yawn. All that you seek is here:
http://www.practicalmachinist.com/vb/bridgeport-hardinge-mills-lathes/changing-belts-hvl-h-179821/

Much good advice here,I would add a few points learnt the hard way doing three of these on a HLV! DSM and HC, firstly, leave the cradle in the machine if you can, it is heavy and difficult to put back on your own, secondly, when you get the shaft out and on the bench you will have a big bronze bearing with the two cones on each end with the third double one between them. The faces of the cones want polishing in the lathe and the bore of the middle moving one cleaned up.
You now turn up a new bronze bush to fit the new bore of the moving cone and with steps down on the end to fit the fixed one with above to suit the shaft.
You then drill a few radial holes in the bush in the area covered by the moving cone and on assembly fill these with grease.
When it is all back together you adjust the level of the cradle so the cones run in the middle of the cradle and not try to get to one end, this will reduce the load on the end races on he shaft.
Done this way my first one (hlv) has done over 10 years without trouble.

Hi Dave_C,
I have a vibration problem with the variator pulley on my HLV-B. Ihe bearing surfaces on which the center pully disc slides are worn to the point that it wobbles and causes excessive vibration. For another member you offered to ouline the rebuild process - I would greatly appreciate it if you could foreward same the information to me.
Thanks,
Michael deltastarcanada1

I have an HLV-BK and am getting vibration in the belts at high and low speed. Still has the original belts. Are the belts changed the same way?