Hf 7x10 Spindle, Bearing, & Transmission Gear Replacement

I have not installed this particular bearing, so I am not expert here, but I have installed others. Maybe, hopefully, this is helpful-

The idea is that you are squeezing the two bearing halves together to remove slop. The amount of pressure squeezing them together is the “load”. The bearing half opposite the nut must obviously be fixed or you could not load the bearing by tightening the nut and squeezing the two bearing halves together. I suspect you are thinking, duh!

The only reason I mention this is because:

"It seems like one bearing that slides on the shaft would be enough”

This is true, as long as the bearing half opposite the nut (outer half) is all the way on the shaft and is firmly seated against the shaft flange or whatever stops its movement on the shaft.

If for instance the outer bearing was difficult to slide onto the shaft and it stopped sliding on the shaft due to friction rather then pressing against a flange or whatever stops its movement, you could load the bearing by tightening the nut and think everything is OK. Over time, pressure from the nut could overcome the friction holding the outer bearing half in position on the shaft, causing the outer bearing to slide further down the shaft, away from the nut and inner bearing half, resulting in decreased load pressure between the two bearing halves, resulting in slop.

So your understanding is correct, just be sure the outer bearing is all the way on the shaft.
 
Thanks guys, that confirms what I was thinking.

Now if only my hands were in sync with my brain I would be in better shape :rolleyes:

I have been sanding the spindle (mounted on my wood lathe), and I think I took it a tad too far. The bearing fit is not bad, just a little looser than I had planned. I think it's OK though, so I am going ahead and putting everything back together.
 
“I think I took it a tad too far.”

Haha. :). Been there, done that! (More than once). In fact, I just did that on one of the bearings when I did the slide screw upgrade. One of the bearings just drops in, not really loose, but not a firm hand press fit. It’s fine. I just took it a tad too far. Doh!

I suspect that if you think that it is OK, it is. I think you pretty much get the idea. From what I can gather from the thread, it should be a firm press fit by hand.

If both bearing halves can actually wiggle on the shaft, or if they just drop on over the shaft with no pressure, then it is probably just a little too loose. If one bearing half is perfect and the other is a bit loose, you can probably get away with it because both haves are squished together with the preload. Depending on the application, if things are too loose, it might result in slight vibration, or runout. If it does not seem to affect operation it’s probably fine, but vibration could cause premature wear to it and closely related parts in the long run.

I saw the term “palm fit” in your post. What is that anyway? I’ve been around machines like forever, but have never run across that term. I know friction fit, press fit, hand press fit, etc., but not “palm fit”. New one for me. Press it with your palm?
 
“I think I took it a tad too far.”

Haha. :). Been there, done that! (More than once). In fact, I just did that on one of the bearings when I did the slide screw upgrade. One of the bearings just drops in, not really loose, but not a firm hand press fit. It’s fine. I just took it a tad too far. Doh!

I suspect that if you think that it is OK, it is. I think you pretty much get the idea. From what I can gather from the thread, it should be a firm press fit by hand.

If both bearing halves can actually wiggle on the shaft, or if they just drop on over the shaft with no pressure, then it is probably just a little too loose. If one bearing half is perfect and the other is a bit loose, you can probably get away with it because both haves are squished together with the preload. Depending on the application, if things are too loose, it might result in slight vibration, or runout. If it does not seem to affect operation it’s probably fine, but vibration could cause premature wear to it and closely related parts in the long run.

I saw the term “palm fit” in your post. What is that anyway? I’ve been around machines like forever, but have never run across that term. I know friction fit, press fit, hand press fit, etc., but not “palm fit”. New one for me. Press it with your palm?

That's a term I had used. When a mechanic is replacing king pin bushings in a straight front axle, the fit of the pin to bushing desired is called a "palm fit" The king pin is large enough that you would need to push it in with the palm of your hand.
It's an old time mechanics term. Most likely not used any more. Here is an example of another person referring to the term (I just googled that hoping to get a better definition of the term):http://www.jalopyjournal.com/forum/threads/kingpin-spindle-bushing-setup.239133/

I probably shouldn't be using such old terms in this modern world. It probably gets confusing. Sorry Guys.

Roy
 
"I probably shouldn't be using such old terms in this modern world."

Not a problem! You know.., learn something new every day. Nothing wrong with "old terms"! Dwell on this: I understand and know how to set dwell. :)
 
"I probably shouldn't be using such old terms in this modern world."

Not a problem! You know.., learn something new every day. Nothing wrong with "old terms"! Dwell on this: I understand and know how to set dwell. :)

I haven't used a dwell meter in the last 25 years. I sold both of my dwell meters about 15 years ago. Nice to know you understand dwell. That pegs you as not a millennial.
 
Got my first car early '70's. My current phone is a flip phone. 30 years in the IT industry. I use to hand hone cylinder walls! :eek 3: Nope, not a millennial.
 
I knew that as a push fit. Which is a little tighter than a slip fit but not as tight as a light press fit.
 
Outstanding, Billh50! A very fitting reply. Should be added to the master glossary.

Cavediver, let us know how it works out!
 
The headstock is (temporarily) reassembled and mounted. I bought an extra spacer to turn down to make up for the added bearing thickness, so hopefully that'll get done this week. I also noticed that the hi / low gear on the spindle (not the gear on the drive input axle) has a bit of room to move left and right. That seems a bit odd, though I don't think it will hurt anything. I didn't look for that sort of play when I disassembled everything, so I have no idea if it's a by-product of the different bearings, something else, or if it's supposed to be that way. In any case, I'm thinking about turning out a couple of additional spacers for the spindle to help keep that movement to a minimum.

The fit between the bearing and the spindle was a little looser than I wanted at the chuck end, but like I said, I doubt that'll be any worse than the natural play inherent in the lathe. My cheap dial indicator doesn't read any radial motion, so I guess I need to get a test indicator and see if it's messed up or not.

Thanks again for the help!
 
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