HLVH rack question

[HWooldridge]

I came across a '68 Hardinge HLVH in very good overall condition. The previous owner's father purchased new, and it was primarily used with a tool post grinder to produce small carbide gages. It was well maintained so is in pretty good shape for its age.

The only two issues I've found are:
- Both the gear range setting and the thread/feed knobs are very hard to move (I have to use channel locks). I'm assuming it's because the shop probably never/seldom used the threading option. Is it normal for these knobs to be so difficult to turn? I opened the side cover and everything appears to be covered in grease from the factory, and of course, it may be pretty hard by now - so I doused everything I could see with penetrating oil. I am able to move the selectors to the right positions but the effort seems excessive.
- The rack has four damaged teeth about 3" back from the spindle nose, so any manual travel over this area makes the carriage jump. I know that normal feeding is done by the motor and threading is done on the leadscrew so I'm thinking the rack is not so important as on other types of machines, but I'd like to make it right. That being said, I was thinking about milling out the damaged area and dovetailing an insert there, then recutting the threads. Or would it be easier to just look for a rack in better shape?

Thanks in advance.

HW

 

[jperrin]

I went through the thread/feed knobs being stuck/hard to turn issue with my HLVH. When I first got it the grease had become more tacky/hard than like grease. What I did was use a mix of WD-40 and Kerosene in a spray bottle and took off both of the insepction plates on the back of the gearbox to spray everything down. Then a combination of toothbrush, scrapers, and towels I cleaned up most of the old grease. In hindsight I should have removed a few of the gears as outlined in the maintenance manual to make cleaning them easier which I later did when putting in new belts. My knobs are very easy to turn now. Make sure to try and work them back and forth as you clean and get the portions of the rods that go into holes in the casting.

As for the rack, I don't know off hand, can it be flipped around so that the damaged teeth are at the last three inches towards the tailstock? Might be a quick fix if possible.

 

[HWooldridge]

@ jperrin:
Did you remove the gearbox or do everything through the inspection ports?

 

[jperrin]

I did everything through the inspection ports (which is what i called the inspection plates). I put a pigmat under the opening in the bottom of the gearbox and just took my time. Spray some wd40+kerosene and walk away, come back later spray some more, go at it with the toothbrush/rags, spray some more, repeat. I think I used an airgun at one point near the end to blow hard to reach bits out the bottom. I'm sure it would have been easier to clean everything taking the gearbox off but when I first got the lathe I was not that confident in my ability to put everything back together correctly.

There are steps in the maintenance manual about removing just the main engagment gear (the gear that connects the gearbox to the spindle using the thread/feed knob) that would give you more access to reach in and clean things.

The two knobs also come off with a set screw, be careful though, there is a ball bearing that pops into a detent under the knobs, but you can take those off and clean underneath them as well and put a little oil in there.

I took a picture with the plates off when I was taking out the engagment gear to do the belt replacement. Also, somewhere on this forum someone said hardinge ok'd a moly-lube in the gearbox so thats what I used.

 

[HWooldridge]

My lathe only has the lower plate - no upper port - but it has a second one on the rear of the headstock. I may remove that one and see it anything else is visible.

Wouldn't surprise me that this machine was never used for threading so this may be the original settings from when it left the factory.

 

[car2]

The shafts and bushings in the selectors are very close fitting, and will gum up with extended non-use or lubricating.

The bushings are press-fit into the casting. On my HLVH, I removed the rear access plate (used for belt change too) behind the selector bushings, and removed the plastic selector knobs. This allows working the shaft axially a couple/few mm by pushing them from the inside(with a dowell) and outside, while squirting down the bushings (interior and exterior) with mineral spirits. After repeatedly doing this (over a day or two), the shafts will loosen up; afterwards apply some light oil. This does not require taking anything apart other than the plastic knobs.

To clean the old grease from the gearbox, I remove the back plate, put a pan under the gearbox, and use a squirt bottle with mineral spirits, toothbrushes, and utility brushes to clean off the old grease; reapply grease with utility brushes (the metal ones can be bent into odd angles).

(a friend that has a machine shop has a late-model HLVH with vise grips on one on the selectors--pains me to see that and I offered to fix them...)

I've never checked if that's a standard rack gear (probably is), and in that case you could buy a piece of rack (from Mc-Master etc), and scab on a piece by milling out a section and brazing/pinning/epoxying in a piece (requires milling obviously). I've done that on an old tool and cutter grinder.

 

[HWooldridge]

Thanks for the info. 99% of this lathe is in almost new condition so it pays to be patient and work my way through the small nuisances.

 

[Chips Everywhere]

Thanks for the info. 99% of this lathe is in almost new condition so it pays to be patient and work my way through the small nuisances.

If you are sure its in great condition buy it and figure it out later. Do you have pictures? are you sure its not a HLV (model before the HLVH)?

 

[Mark Rand]

Another note:- Don't ever use vice grips, pliers etc to get more torque on the plastic knobs. They are surprisingly fragile and the side, where the grub/set screw is, will pop out if they see too much torque.

 

[HWooldridge]

If you are sure its in great condition buy it and figure it out later. Do you have pictures? are you sure its not a HLV (model before the HLVH)?

I already have the Hardinge in possession, along with a LeBlond Tool and Die Maker that came out of the same shop. Both are huge upgrades over my old lathes.

 

[HWooldridge]

Update: The Feed/Thread knob is locked up tighter than Dick's hatband, so I think something is jammed or binding. I removed the inspection cover and sprayed penetrating oil over everything for several days. The grease in the box is somewhat stiff but this feels mechanical and I don't want to force it, so I plan to pull the gearbox (carefully) and see what's going on. Wish me luck.

 

[alcro1998]

@HWooldridge

I have a very nice extra HLV-H rack. Send me a PM if you would like to purchase it.

 

[HWooldridge]

Well, I’m happy to report that I was able to free up both knobs without pulling the gearbox. I did have to remove the collet closer and hand wheel to get above all of the gears, so I could soak everything in penetrating oil. Lots of fiddling back and forth to turn gears by hand, followed by more oil, then the whole gear train finally turned loose and started sliding like it was supposed to. Several clods of hard grease fell out of the box, and it looked exactly like old Cosmoline. The thread/feed knob was also stuck solid, but a bit of the old in-out on the shaft made it start working.

The worn teeth on the rack are more of a nuisance than anything else - they don’t seem to affect turning or threading. I will probably fix it at some point but not a priority.

 

[Turbo442]

Well, I’m happy to report that I was able to free up both knobs without pulling the gearbox. I did have to remove the collet closer and hand wheel to get above all of the gears, so I could soak everything in penetrating oil. Lots of fiddling back and forth to turn gears by hand, followed by more oil, then the whole gear train finally turned loose and started sliding like it was supposed to. Several clods of hard grease fell out of the box, and it looked exactly like old Cosmoline. The thread/feed knob was also stuck solid, but a bit of the old in-out on the shaft made it start working.

The worn teeth on the rack are more of a nuisance than anything else - they don’t seem to affect turning or threading. I will probably fix it at some point but not a priority.

The carriage gear and gear rack is still available from Hardinge. The carriage gear is different depending on what year you HLVH is.
For your 1968 round door HLVH you will need

GEAR FOR RACK LH 0006655 $530
RACK FOR BED LH 0006634 $407

These prices are current as of July 2023.
You will also need to replace you carriage gear bushings front and back. Don't buy those from Hardinge just make them.
You can flip the gear rack front to back but the countersink holes will be on the wrong side. Some people use button head screws for clearance. If you dont plan to do any part replacement at the bare minimum check your carriage gear bushings for wear. Its a known weak point. Once they get worn they will rock to one side and start to wear the carriage gear and gear rack.