Hot Spindle on V2XT Bridgeport

[Spin]

I am a Newbie here,
I recently purchased a v2xt, as a hobby for now.
I have only milled one aluminum part and a mockup part for my vacuum
cleaner, to repair it.
I have noticed that the spindle near the nose gets to hot to touch. I can hold my hand on it for a few seconds.
Under no load it gets warm.
Does anybody have any ideas as to what it could be?


Any help with this is appreciated
Thanks in advance

[Mcgyver]

its the bearings, next challenge is to figure out 1) if they are toast or 2) it sat around for so long it is just in need of lubrication, 3) work was done on the spindle and it was over tightened. I'm less sure of the applicability of the last one, but with lathe spindles overheating can be an indicator you've loaded the bearings too much. I've had lathe spindles apart, but never a vertical mill - Hopefully you don't need new bearings because they will be expensive.

Any recourse with the vendor? any chatter or other symptoms? do you know if (or does it look like) any work was done on it lately? how’s the bearing lubricated? do you have a manual, exploded diagram, etc? those are some things you can start on.

Maybe someone here has more direct experience with that spindle

[machintek]

If you have the maintenance manual, you are that far ahead of the game.
Probably you have a bad spindle. There are two results to a bad spindle. One is heat caused by bad bearings, high friction (no oil or too tight a preload). The other is a bad finish (tool and spindle loose in bearings). Hopefully someone tried to put new bearings into the spindle and did not know what he was doing.
The spindle comes out as a assembly. Lower the table all the way. Lower the quill about an inch and remove the set screw in the back of the quill (1/4 X 20). spin off the quill nose (right hand thread). Knock the assembly out (down) using a broom stick from the top. Examine the spindle. There is a stack up of inner bearing race spacers and one outer bearing race spacer on the two precision (class 7) bearings on the bottom. Yes the top bearing outer race is very loose. It is there to prevent rattle.
The bottom two bearings if set up correctly will have their outer races turn together, very smoothly and will have some sort of marks for their correct alignment. As they wear eventually turning one race will not turn the other. The quill nut puts pressure on the outer races and keeps them together and prevents up and down movement of the spindle inside the quill. Therefore when installed in the quill, the quill nut should NOT BOTTOM OUT on the bottom of the quill. You should have some sort of gap there. I do not care if this gap is .002 inches or .040 inches. I usually spot drill the quill nose through the set screw hole so the set screw is below flush (important).

George

[Spin]

George,

If I remove the spindle, will debris fall inside?
If it does, any way to prevent it?

Regards

[Spin]

Thanks George(machintek) for the info.
George,

If I remove the spindle, will debris fall inside?
If it does any way to prevent it?

Regards

[machintek]

Negative. The top of the quill is covered by a piece of felt. Therefore when you put the spindle back in, you have to feel your way with it so it goes through the hole in the felt and then you have to get it through the spilned gear hub. Not as bad as it sounds.

George