Fixed Bearing Support Block.

[Connor9220]

I've assembled everything for my ball screws.. I noticed that after I tighten down the lock nuts on the fixed end, that the ball screws are very hard to turn.. Looks like the lock nut might be rubbing the seals.. Also, on one of mine, after I tighten it up, there is some play.. I can move the screw back and forth.. almost as if the bearing inside had play. What can I do to make sure the screws turn freely without the added friction of rubbing up against the seals, and what's the best way to take out the play in the other ones?

Thanks, Billy

[PaulRowntree]

Do you use thrust bearings to seat the shaft?

[Connor9220]

Do you use thrust bearings to seat the shaft?

No thrust bearings in the mix.. It's a bushing (that the seal goes over) then two bearings, and then another bushing/seal)..

These are blocks from linearmotionbearings2008 guy.

[Connor9220]

No thrust bearings in the mix.. It's a bushing (that the seal goes over) then two bearings, and then another bushing/seal)..

These are blocks from linearmotionbearings2008 guy.

Like this..

Lock Nut
Spacer One
Bearing One
Bearing Two
Spacer Two
Shoulder of Screw

[PaulRowntree]

I am not an expert, but when I cut my bearing blocks I closed the outside ends except for a reduced-down shaft, and had a thrust bearing running between two matching super-flat washers. Then came the radial bearing, which fit tightly into the bearing block without a setscrew. The inner-most washer pressed against the moving inner diameter of the bearings. With these on either end of the shaft, I can apply as much axial compression onto the lead screw as I want (can?) with no evidence of binding or sticking.

Like this ..

Back of bearing block
flat washer 1
thrust bearing
flat washer 2
axial bearing

The shaft has a step that applies the axial force to flat washer 2

[RICHARD ZASTROW]

If Connor9220 is using angular contact bearings, they perform both radial and axial functions. These are usually 45-60 degree bearings intended as mostly thrust bearing assemblies that locate themselves radially. Very common set-up.

What is locating the bearings outer races within the block? Often there is a locating shoulder in the block and some other removable device that secures the bearings axially.

The locknut pushes the inner races together until all gap is removed. This provides the preload designed into the bearing pair (set).

After the locknut is tightened, the bearings/screw should rotate easily with no end play (no axial movement).

Dick Z

[Connor9220]

If Connor9220 is using angular contact bearings, they perform both radial and axial functions. These are usually 45-60 degree bearings intended as mostly thrust bearing assemblies that locate themselves radially. Very common set-up.

What is locating the bearings outer races within the block? Often there is a locating shoulder in the block and some other removable device that secures the bearings axially.

The locknut pushes the inner races together until all gap is removed. This provides the preload designed into the bearing pair (set).

After the locknut is tightened, the bearings/screw should rotate easily with no end play (no axial movement).

Dick Z

That is my exact understanding of how it "should" work. However, in my case.. If I tighten the lock nut down any more.. it rubs against the Rubber seal, causing excess friction, and in the case of the one that has axial movement, it might be I just don't have the lock nut tight enough..

Thanks, Connor