HLVH live center repair

co1859 · Jul 24, 2016

My HLVH was cutting a .002 tapper with no tapper attachment. After eliminating the Tru Adjust Chuck and Tail stock. I placed a indicator on the Live Center shaft and found .012 of up and down movement. Time to replace the Live Center Bearings

Somewhere on this forum I found a thread on disassembly of a live center. (Cant find in now to use as a link) once the aluminum cover was gently pried off. I found a threaded compression nut that needed a pin wrench to remove. WARNING: DRILL OUT PIN IN HOUSING BEFORE TRYING TO REMOVE COMPRESSION NUT. If you don't -You will gall the threads. It took about 1 hour to repair the threads. In the picture below the pick is at the pin location, Drill it out first. Just FYI and Pictures for reference.

The end bearings 2203H are shot. The center bearing has .125 gap in it. Checking on new bearings locally on Monday.

Jersey John · Jul 24, 2016

Thanks for posting this ... I've just received a Hardinge Live Centre and it needs bearings too ...

would welcome info on your bearing supplier and costs.

John :typing:

co1859 · Jul 24, 2016

I am going to check with Whisler Bearing here in Colorado Springs - I will let you know Thanks for the like!

Milland · Jul 24, 2016

co1859 said:
The end bearings 2203H are shot. The center bearing has .125 gap in it. Checking on new bearings locally on Monday.

Hi, just to clarify - the center pair of rings aren't bearings, but spacers meant to "pre-load" the actual bearing pair. If you measure the width of each ring you may find they're slightly different, this is to create the correct load/drag on the actual bearing pair for optimal stiffness and life.

When you get the new bearings you may have to do a trial assembly or two, and see if you got lucky and the bearing set works as-is, or if there's too much wobble at the center tip you may have to adjust one of the spacers to create the correct loading. This can be time consuming and requires great care to maintain parallelism of the two faces of the spacer in the ~.0001" range.

This will be a good learning exercise for you, but ultimately you may find that it was cheaper to buy a decent new live center. Good luck!

co1859 · Jul 24, 2016

Thank you for your clarifications they are well received. This is a learning experience. A New Live Center did cross my mind. The good thing is the old one is already broke, I may get lucky and find some replacement parts and take a gamble. I will direct my research to the cost of Matched Bearings vs. New live Center. Quick question. Who manufactures a quality live center.

Update;
Just read up on matched bearings sets, along with the importance of parallel. So I decided to check the outer and inner rings for parallel to .0005 needle did not move.

Milland · Jul 25, 2016

Right, you shouldn't see any needle movement on that indicator. On the bearings, check the ones you have and see if they have any markings on the rings that look like ">" or "<<", as these are alignment marks. If the OEM bearings are angular contact types, they should have something like this to show how they face one another, and you should reinstall the new bearings in the same relationship. And after final assembly, you may find the 60 degree taper is not running true (even if stiff/stable), so may have to regrind it on the new bearings for optimal concentricity.

A good brand for new live centers is Royal, you can sometimes find good deals on Ebay for them in the right taper. Others include Riten, Rohm, Skoda, Bison - the last two being cheaper but usually acceptable. Very cheap Chinese brands may or may not work out for you, but for light/occasional use should be fine.

JRIowa · Jul 25, 2016

Look at Concentric centers, owned by Riten.
JR

co1859 · Jul 25, 2016

Milland

My two bearings have a hand scribed C on the outer race and a B in the inner race. The article I read did talk about the alignment marks and mentioned the possibility of scribe marks. When I price the new bearings, I now know what the marks are used for. Regrinding the center with the new bearings makes a lot of sense now that it was explained. Thank you.

JR

Checked out the web site, I like it. Looks like quality stuff. I really like that they offer rebuild services just incase. Thanks for that lead.

co1859 · Jul 25, 2016

Jersey John said:
Thanks for posting this ... I've just received a Hardinge Live Centre and it needs bearings too ...

would welcome info on your bearing supplier and costs.

John

Update.. The stock Bearings are Barden 2203H, The cross reference is USA Made Brand SKF 7203CD/P4ADGA precision ground ABEC-7 matched set with install markings only $457.86 from local supplier.
I may need to rethink this.

Jersey John · Jul 26, 2016

co1859 said:
Update.. The stock Bearings are Barden 2203H, The cross reference is USA Made Brand SKF 7203CD/P4ADGA precision ground ABEC-7 matched set with install markings only $457.86 from local supplier.
I may need to rethink this.

Thanks very much for the update - appreciated ... but no way am I spending US$457.86 on bearings.

A brand new Rohm or other quality one would be less .... drawing board here I come

John

Milland · Jul 26, 2016

co1859 said:
Update.. The stock Bearings are Barden 2203H, The cross reference is USA Made Brand SKF 7203CD/P4ADGA precision ground ABEC-7 matched set with install markings only $457.86 from local supplier.
I may need to rethink this.

Heh, yes, that's life with precision bearings. You may be able to find identically sized angular contact bearings on Ebay for much less, check that out. Universal style will work (not a matched set), you just may have to play with preloads as I mentioned before. Make sure the contact angle matches the specified bearings.

co1859 · Jul 26, 2016

Jersey John
Glad I could help. I am in the same boat, New is looking like a better deal

Milland
I did was check Ebay there was a new set for $179. However; The unit could still have other issues that may need $$ attention. So I am going to look for something new.

JR
I also check out the Riten Rebuild service is about 40% of a new identical unit. Being a Heavy duty Hardinge live center 40% could still be more the something new.

I will be looking for a quality 3000 rpm unit for home use.

Thanks for everyone's help.

co1859 · Aug 9, 2016

Last Update

My New Royal Live Center arrived today #10662 I found it at MSC with 35% off. The same cost of bearings. I did not waste any money on the old Center, the bearings were bad and the taper need grinding. Cheaper to buy new for my situation.

I machined the Plug cover so it would eject from the HLV-H Tail stock.

Plug Cover Size
.432 OD X .494 Length
.312 ID x .250 Deep counter Bore to fit over Plug. It is a snap fit works great. It would be nice to title this thread to HLV-H Live Center - Rebuild or Not?

Thanks for the help.

cinematechnic · Sep 17, 2017

I've got two "light duty" Hardinge live centers from a lot of tooling I got with my HLV-H. I'd be interested in seeing the rebuild thread if anyone can find it.

I've noticed that the HLV-H tailstock works best with live centers that actually have the MT2 tang at the end. My machine is just under SN 5000 - don't know if that makes a difference.

I got my nicest live center, a Nakane which has the standard round end, stuck in the tailstock (despite putting some oil on the taper) and had to pry it out. Fortunately no damage.

So... Is there a way to adjust the HLV-H MT2 tailstock to properly eject centers that do not have a tang at the end? Or is the best solution to make a plug cover as co1859 did (see previous post)?

cinematechnic · Sep 28, 2017

Found this P.M. thread from 2006 about rebuilding the Hardinge live centers. Some good info but it's certainly not a complete DIY:

http://www.practicalmachinist.com/v...dinge-live-center-bearing-replacement-116617/

I managed to get the cover (slinger) off, and pull the spindle with the bearings out.

I still have to get the rear threaded cap that holds the bearings to the spindle off. Hopefully I can find a source for for bearings that won't cost more than a new high quality live center.

The Hardinge Light Duty Center would be useful to me because it has a very small diameter tip, which is hard to find in live centers.

I searched and found Hardinge's PDF on the live centers, with a parts list and they cheerfully state:

"-Even though parts are available to repair the Heavy Dute and Light Duty Centers, we recommend the Center not be repaired by customers. We have found that many customers cannot repair the Center to their original accuracy and by the time parts are purchased and labor is applied to the repair, it would have been less costly to simply purchase a new Center.

-Hardinge does not repair the Centers. We know of no one who repairs them."

cinematechnic · Sep 30, 2017

Here's how I solved the HLV-H ejecting problem on my Nakane live center:

The original back cap is above, the new back cap placed right next to the back end of the MT2 taper.

The original O-ring was transferred from the original cap to the new one.

The plug is .4375" dia and .379" longer than the original. It ejects easily.

Now I need to make one for my Favor (a Swiss brand) bull-nose live center.

Also, I still want to rebuild the Hardinge Light Duty live center. If anyone has any info to contribute, please do.

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