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Hardinge BB-2V Spindle Bearings

Shiseiji

Aluminum
Joined
Sep 15, 2014
Before I head into a bearing store, want to ask if there is any experience to share. Old MAC number is 206RF0, and marked "Thrust"

Best I can tell current number is 6206R, can't find a reference to match the "F" to, likely a MAC designation probably lost to time. But I only know what I've read in catalogs.

Matched/duplex. Metal shield on one side, outer facing on both, synthetic rubber on the facing sides.

Ideas?

TIA

Ron
 
Before I head into a bearing store, want to ask if there is any experience to share. Old MAC number is 206RF0, and marked "Thrust"

Best I can tell current number is 6206R, can't find a reference to match the "F" to, likely a MAC designation probably lost to time. But I only know what I've read in catalogs.

Matched/duplex. Metal shield on one side, outer facing on both, synthetic rubber on the facing sides.

Ideas?

TIA

Ron

By MAC, do you mean MRC? I have had my BB2V for over 40 years and never ran or repaired it, so I know nothing about the spindle bearings. The word "thrust" indicates you have an angular contact ball bearing. I have had the bearings out of some old Hardinge lathes and recall that they used MRC brand.

All Categories On MRC Bearings

Current number still looks like 206R. I suspect the F0 may be a precision/preload modifier or maybe a shield code. You could ask the factory for help.

Item # 206-R, 200-R Series Single Row Angular Contact Ball Bearings On MRC Bearings

Larry
 
By MAC, do you mean MRC? I have had my BB2V for over 40 years and never ran or repaired it, so I know nothing about the spindle bearings. The word "thrust" indicates you have an angular contact ball bearing. I have had the bearings out of some old Hardinge lathes and recall that they used MRC brand.

All Categories On MRC Bearings

Current number still looks like 206R. I suspect the F0 may be a precision/preload modifier or maybe a shield code. You could ask the factory for help.

Item # 206-R, 200-R Series Single Row Angular Contact Ball Bearings On MRC Bearings

Larry
Thanks Larry! The hand etched number bit me, and I was too dumb to note the difference on the other one. The poorly etched one is the clearest, so here we are. The MRC catalog is pretty comprehensive! I'll be contacting them.

One bearing had a definate grab in it, or else I wouldn't have pulled it apart. But glad I did as all three had almost no lube left. I have a 2nd BB-4. The table on the BB-2V is in pretty, I'm considering that maybe a good 2 & 4 is better than two BB-4. If you have the vise for yours, that's a pretty rare item.

Thanks again for sharing your knowledge, exactly what I needed to know!

Ron
 
Hardinge was sneaky and used their specially made bearings with their own thrust settings compared to off the shelf bearings. Before installing them, stack the old bearings up (with the spacers) on a surface plate and note the heights with a height gage and tenths indicator and then stack up the new ones. carefully mic the ID and OD. Also use some Mobil # 32 red grease to pack them 30% full. Or some Kluber isoflex 20 to 25 % We've Got Kluber Isolflex NBU15 - 50g Tubes - CNC Specialty Store
 
Hardinge was sneaky and used their specially made bearings with their own thrust settings compared to off the shelf bearings. Before installing them, stack the old bearings up (with the spacers) on a surface plate and note the heights with a height gage and tenths indicator and then stack up the new ones. carefully mic the ID and OD. Also use some Mobil # 32 red grease to pack them 30% full. Or some Kluber isoflex 20 to 25 % We've Got Kluber Isolflex NBU15 - 50g Tubes - CNC Specialty Store
Thanks Richard, any idea what the pre-load is? Allied Industrial was able to talk to MRC and get the angular contact bearings for me. $163 each, they had 9 on the shelf. The upper bearing was $26. Quill is in the freezer. People don't want to believe Logan did the same, had to their spec bearings made, for their 800 series lathes and scream Scott is just ripping them off, or that "xyz" is just as good.
Ron
 
Yes, Logan did spec an internal preload bearing and nothing else will work right. You need to get this right for the machine to work like it did new. OTOH, I've had no problem with used bearings that I could get sufficiently clean and that had no roughness, clicks or defects. Pay attention to Richard's fill percentages- don't overfill.
 
Angular contact precision bearings have the preload set during manufacture of the bearings. The bearing part number will have a preload code for light, medium, etc. preload. All the machine designer has to do is specify the bearings and make sure the inner races and the outer races are tightly clamped together, which makes the preload match the bearing company's spec. Pairs of bearings mounted together at the collet end of the spindle will have a single radial bearing at the opposite end of the spindle with the outer race free to move axially in the headstock.

Some Hardinge machines have only two spindle bearings, both angular contact. On those, the bearings are mounted far apart and precisely equal length spacers separate the inner and outer races to make the preload match the bearing company's spec.

There is no adjustment of preload during the machine assembly process.

Larry
 
No adjustment unless you have a surface grinder, setting fixtures, and real good indicators.

Bridgeport (sneaky again) used standard off-the-shelf radial bearings in their M heads, run in approximation of angular contact mode, by grinding the faces of the outer races and using equal length ID and OD spacers. Anectotal evidence that Hardinge did 'something special' to the stock HLVH bearings and replacing those with non-hardinge parts (of nominally correct size and preload level) does not work out well.
 
Thanks everyone for their contributions. Richards comment on grease has me wondering if I've extended too much trust to MRC. The old bearings were metal shielded on both sides, re-lubricating them would have been challenging. These are open on both sides so warm lube will just drip away. The machine has no provision for lubricating them. The pulley nut put pressure on the bearing stack but apparently not enough to consider it preload.

I do volunteer work at a bicycle coop. Few people know/understand that the wheel leaver lock is quite capable of overpowering the inner race (cone nut in the bike trade) lock nut and changing the preload. Literally the first thing I cover in teaching how to remove/reinstall wheels.

Ron
 
Took the old bearings with me this time, yea, little brain fart, and returned the open annular contact bearings. To be determined what the re-stock fee is. I mentioned that while I didn't say if they were shielded, I was also very clear I was a hobbyist and wasn't asked. The top replacement bearing is shielded. To be continued . . .

Ron
 
Can you pull out all the bearings, spacers, and the spindle, lay them out for a photo?

You can use a radial bearing pair in approximation of angular contact if you set the spacers up properly.
 
Jim, I missed this, sorry. I had to start packing up for a move. I need to dig out the box.
 








 
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