VN 21 worn head

Hi,

The VN 21 or 2I that I've been using for the past 8 years has some wear in the head. I feel this is going to be a problem for boring an accurate hole. I haven't taken the head apart, but I have tried to adjust it. It appears there is a tapered bushing that the spindle is drawn into. The problem is, if I don't have a little bit of slop, then it starts to bind up. Or, if I attempt to drill a hole the spindle gets pushed into the taper and stalls the machine. The only way to prevent stalling is to constantly pump oil into the oil cup to create oil pressure to hold the spindle from locking into the bushing. Is this bushing restorable? Is there a bearing type head that can be mounted on the ram?



thanks,
Mark

Read the posts on Hendey lathes with similar tapered plain bearings - most either have this problem - or will have this problem - or used to have this problem but have been fixed.

Here is just one of them:

http://www.practicalmachinist.com/v...ead-spindle-thrust-problem-205770/index2.html

Get your spindle out and see if it has features similar to the Hendeys with their removable thrust ring that can be shimmed behind to correct the problem

Thanks for the reply and links John. I took the head apart tonight, it does not appear to have any shims. Although it looks like it could use some. I took a few pictures, but don't have time tonight to upload them. It appears the end of the bushing is worn allowing the tapered shaft to lock in the bushing. It would be nice to upgrade this with some tapered roller bearings on each end. But, if it were shimmed properly it would probably last another 80 years. Perhaps there are shims in there I didn't see. Maybe next week I can take another look. I'd do it sooner but, I need to get ready to pick up a Norton U-4 10x20 cylindrical grinder this weekend.

thanks,
Mark

The VN 21 worn spindle head has been apart for about 2 weeks.



Here is the upper bushing:


Here is the lower bushing:


I had an idea. Instead of using shims to raise the step, I decided to hone the taper. Honing worked surprisingly well. Increasing the inner diameter of the bushing allowed the tapered shaft to sink further into the bushing permitting the shoulder to rest on the end of the bushing before the taper locked. What I used was a cheapie three stone hone from the auto parts store.



The stones are free to rock on the end of the hone arms so they conformed to the angle of the tapered bushing. It really worked great.
Here is the honed lower bushing:




After reassembling the head the spindle would move free and had no side to side play. Plus, it held the oil better. Back when the spindle was loose, I'd constantly have to pump oil into the cups. Or, it would risk locking-up.
I'm pretty happy with this repair and have much better confidence in the precision of this old Van Norman.

Oh, and here is a quick pic of the Norton U-4 10x20 that I picked up. I hauled it behind my 68 Colony Park.



The wagon's gvcw was at the limit, but it drove and handled the load very easily.

....and yes, the hydraulic tank of the Norton "was" full.

Haha I did that to!

Not fun when you pull over and see oil everywhere!

Family car when I was a kid was a 1970 Colony Park with a 429.

Q? I have a VN 22LU.
Does my head have bushings or bearings??
It has 2 grease nipples on the head, maybe
they are for oil. I have really not got
to using my mill yet, just want to make
sure I lube it properly before I use it.
Thanks.

--Doozer

Doozer said:

Q? I have a VN 22LU.
Does my head have bushings or bearings??
It has 2 grease nipples on the head, maybe
they are for oil. I have really not got
to using my mill yet, just want to make
sure I lube it properly before I use it.
Thanks.

--Doozer

Click to expand...

The spindle bearings are tapered roller bearings.
I would use something like Mobilith shc-100 grease for the zercs. There is oil in the reservoir under in the big cover on the side of the cutter head. You'll want to drain that, flush with kerosene and refill with Mobile DTE Heavy-Medium oil (which you can get from MSC, Grainger, McMaster-Carr, etc.). Use the same oil in the ram gearbox, which you will also want to drain and flush. The drain plug is on the bottom of the ram, probably hidden under a layer of grease, should take an Allen key to remove. Note, there is a hole for the profile guide in the bottom of the ram, the drain plug is (IIRC) behind that hole.

Cal