Tree Vertical Mill knee screw fix?

Hey everyone. I have an old(er) Tree 2UVR milling machine with a knee that I believe I knocked the lead screw adjustment out of whack. I was raising the knee up to a part I was machining when the table reached the end of the threads and dropped. I was able to thread the knee screw and the table will lower and raise but it is way too tight for my own personal comfort. I fear that I will cause undue wear or further damage if I don't get in there and adjust it. The manual I downloaded doesn't go into much detail on this topic so I'm hoping one of you can help.

Happy Thanksgiving everyone! NAES

That happens a lot on turret type miils...because someone removed the end of traver block...It's a pretty easy repair...get a bottle jack and put it under the knee make sure the knee is unlocked and you have the Z axis gib loosened a turn o gib screw. Wipe off the chips and dirt...remove the Z axis way wipers...then jack up the knee...I can't exactly recall what a tree down therelooks like...but the nut probably is inside a pedestal..(like Bridgeport) The first lead on the brass nut is bent over and possibly on the steels screw. But after it is high enough pull out brass nut and put it in a vise and grind the bent lead thread out then file the steel screw and try to screw it back on....lube the screw..and let the knee down,tighten the gib, instal washed wipers and go to town. You should also make a dead stop bracket so it doesn't happen again....Good luck :-) Rich

Wow Rich thank you for the quick reply! As I've been looking around I see I'm not the only guy with this problem in the past. Your description sounds easy enough so I'll have a go at it.

And the stopper is a great idea! Thank you! NAES

I did the same on my Test 2U last weekend (the repair, not the unscrewing...) see "mystery mill" a few posts down the page...

For the dead stop I used a couple of thick penny washers with a roller thrust bearing between (ID 20+, OD 35mm, 4mm thick - it was in the "misc bearings drawer and exactly right...), had a bit of difficulty getting the snapped 10mm SHCS out of the end of the screw (Sidecutters!) and also had to grind out about 60 degrees of the first turn of the thread where it had rolled over under the weight of the knee.

Dave H. (the other one)

On the top of the vertical knee way on the column there is a dowel to stop the knee from raising to much and over extending the screw and nut to disengage! After you repair the screw and nut on knee you have to lower this dowel to prevent knee screw from disengagement from nut again! I would assume your dowel is missing but hole should locate where it was. The knee way wiper is what hits the dowel stopping upwards movement
After you repair screw and nut engage both to check repair, this will leave knee lower and you will have to drill new hole to insert dowel lower than original placement to prevent disengagement from repeating again.
This is the way my 2uvr was built, yours should be the same!