Dumb question on R8 (i think) spindle

[r-mm]

Got it thanks. Similar prices (pre US shipping) as the auction I found.

 

[Ken226]

The price will have less to do with brand than with precision level. Nachi makes 20$ bearings and 1000$ bearings in the same size. So do all of the other manufacturers.

They all have factories in Japan, China, the US and many other countries. As long as it's a reputable manufacturer, it doesn't matter so much which manufacturer it is.

Choose the precision level your willing to pay for, then worry about the brand. FAG, NSK, Timken, SKF, Nachi all produce everything from the bearings in your blender, to the turbine bearings in a Leer45.

 

[Ken226]

@r-mm

Since budget is a concern, For the best bang for the buck, check out the FAG X-life line if bearings

They have a reputation for very often testing way better than their precision rating level in radial runout.

7207-B-XL-TVP FAG • SP

Buy 0167251310000 manufactured by FAG. Inner Diameter: 35, Outer Diameter: 72, Width: 17, Weight: 282. a.k.a. 7207-BE-P (SKF),7207-B-TVP (FAG).

www.sp-spareparts.com

 

[r-mm]

Thanks for the tip. I'll see if I can locate those domestically.

 

[r-mm]

There is a spacer between the two angular contact bearings. I cannot recall how these were when I dismantled them should they be pressed together so that the spacer is tight between the two bearings?

 

[Ken226]

Yes, that's the only thing that would make sense. If there were any space between the spacer and outer races, an outer race could slip, and your inner race would lose its preload.

Make sure you put the new bearings in the correct direction.

 

[Ken226]

I believe that in a spindle configuration like yours, the "back to back" configuration is correct.

The spacer gives them the correct seperation distance.

The back-to-back configurations means that axial forces acting upward on the spindle, such as drilling, puts the axial load on the lower bearing.

A force pulling downward on the spindle, would put the axial load on the upper bearing.



You can see how the axial forces would be transmitted at an angle from the inner race, through the rollers, into the outer race, by the shape of the raceways.

 

[r-mm]

Thanks guys. I have new bearings here and a press with larger working distance coming this week.

 

[mikey]

Just a couple of comments, r-mm.

• If you can get a new spindle with a known R8 configuration then that would be the best way to go. Given how important an accurate spindle taper is, why mess with boring or home-grinding it?
• You packed the bearings in post 195 with waay too much grease. Spindle bearings only require 25-30% of the bearing be packed with grease. During run in, the grease will distribute properly. Over greasing bearings will make them run too hot and may lead to premature failure.

I understand trying to save money but given that an accurate spindle will improve tool life, accuracy and finishes, it is poor economy to go with a wonky spindle and cheap bearings.

 

[r-mm]

Well that only took the purchase of a new press ha. Old bearings off, new ones will go on.

Can anyone tell me how I set the preload with the ring nut? eg: how much is enough?



Do I need to pack these (less full) with grease?View attachment 358237