Spindle bearing preload

[Pevehouse]

Here’s a few pics of my spindle and bearing system

 

[extropic]

I will post some pictures of the bearing system in just a bit. To sum it up , it’s your typical quill with taper roller bearing top and bottom. There’s really not much else to add. There’s two taper bearings and the spindle,lol.

As you mentioned earlier, the preload on tapered roller bearings is commonly set by measuring torque.
The question is, how much torque for your bearings?
Try searching "what preload torque for XXXXXXX (your bearing number(s))?".

If you identify the make/model of your machine, maybe someone with previous experience will step up.

Edit: If all else fails, I might just wing it. What I mean is tighten the nut to zero clearance - plus a bit tighter. check the bearings for excessive heat when running. After all, that is not a Moore Jig Borer spindle.

 

[Pevehouse]

Here’s a couple photos of the gear that failed in my Z axis power feed setup. This gear was part of the hand crank setup that raised and lowered the head of my mill. Had to remove the entire head assembly from the column and remove the gear for the manual feed. There’s no way to source a gear, therefor I’m going to leave the gear out and make a bushing to go in its place. This will allow me to raise and lower the head using the power feed only. Which is how I prefer to raise and lower the head anyway. I’m also replacing the cheap Chinese bearings with Timken bearing while I have it down. Just figured you guys would like to see some carnage

 

[Pevehouse]

As you mentioned earlier, the preload on tapered roller bearings is commonly set by measuring torque.
The question is, how much torque for your bearings?
Try searching "what preload torque for XXXXXXX (your bearing number(s))?".

If you identify the make/model of your machine, maybe someone with previous experience will step up.

There’s where I run into issues with this particular machine. It’s labeled as a Bolton tools ZX45A, which from what I can tell, there’s not that many out there. So finding anyone else with a like machine has been hard to do. This would definitely not been the machine I would have purchased if I were shopping for a mill. I just ended up with it through a trade so I figured I would make do with it till something better came along. In doing that I figured I may as well fix it to as good a shape as possible with it being a Chinese piece of ****. I really have zero dollars in the machine so putting a little money in it is no big deal. However back on subject, I have not found anyone out there with a machine that’s similar as of yet. And getting any information or specs from Bolton tools ,lol, is a no go too. I guess I can try looking for specs for the bearing numbers and see what I can find that way. Other than that I’m on my own with the exception of any help I can get from the guys on here. I do appreciate your input and your response, thank you

 

[Ischgl99]

Download the Timken engineering manual, it has a ton of good information on tapered roller bearings that will help you as you rebuild the spindle. Page 77 starts talking about installation.

https://www.timken.com/resources/timken-engineering-manual/

 

[Pevehouse]

Download the Timken engineering manual, it has a ton of good information on tapered roller bearings that will help you as you rebuild the spindle. Page 77 starts talking about installation.

https://www.timken.com/resources/timken-engineering-manual/

Will do, Thank you