Spindle bearing adjustment

[Makintrax73]

40 year old RF mill drill clone. New to me. First cuts have half moon artifacts. Everything else seems tight so I checked the spindle with an indicator.



I'm getting no play on the quill, but when the spindle is checked I get .001" play in the spindle. Being a newb mill owner IDK if that is considered normal, or excessive.

The Enco manual refers to bearing preload adjustment. I see these collars are here for that purpose. Should I try that? Or is it simple more likely the bearings are worn and this will go no where without new quality spindle bearings?


Thanks!

ETA: I'm using an old end mill from a friend's grandfather who was a machinist 50 years ago.....possible its the cutter. I do have new ones on the way.

 

[Nutfarmer]

.001 play on a mill that old isn’t bad. How do the bearings sound? Check the tram of the head before adjusting the spindle bearings. If the head is out of tram it could cause what you are describing. Try turning the spindle by hand. If it is rough or grinding then worry about the bearings. Make sure and lub the mill. The bearings on the spindle may be sealed and not serviceable, depends on the mill. Above all have fun making some swarf.

 

[Makintrax73]

.001 play on a mill that old isn’t bad. How do the bearings sound? Check the tram of the head before adjusting the spindle bearings. If the head is out of tram it could cause what you are describing. Try turning the spindle by hand. If it is rough or grinding then worry about the bearings. Make sure and lub the mill. The bearings on the spindle may be sealed and not serviceable, depends on the mill. Above all have fun making some swarf.

They aren't making any noise, and don't seem rough. There is a grease zerk in the lower bearing area. The manual says "grease" so I gave it a shot, and dabbed some on the upper. The upper doesn't appear sealed.

I'll check the tram.

 

[markba633csi]

Try a new endmill

 

[matthewsx]

Yes, try a different cutter. Speed, feed, etc. But, if you’re getting uniform removal and the parts you’re making are as square as you need I wouldn’t worry about getting a perfect surface finish yet.

I bet if you examine the machine closely you’ll see some of those same half moon “artifacts” on it.

Check the tram, but realize tool marks are normal and can have many different causes.

Trying to adjust this mill so it’s “perfect” is more than likely going to end in frustration and potential damage to the machine.

Pick a project and start making chips, you will learn how to address problems as they arise.

John

 

[Canus]

Have you checked the TIR of the bore of the spindle?

 

[Makintrax73]

Have you checked the TIR of the bore of the spindle?

As near zero runout in the spindle as I'm able to measure. Perhaps 2 tenths.

I did tighten the spindle pre load 1/8th turn. That took the movement out of the spindle, or substantially out anyway.

Trammed the column, which after refining my technique I believe was out several thou. I'm showing .002" off over 8" now, and perhaps another .001" shim in the right place would work, or maybe go too far IDK.

New cutters are here, I'll try again.

I did discover .001" runout on avg in my cheap R8 collet set.