Milwaukee No2 Help, Backlash adjustment

Courier250 · Nov 3, 2017

Picked up my Milwaukee No 2 vertical mill last week, runs great. Down loaded a manual for the horizontal version; it's what I could find for free and the lower half of the machine is the same. Backlash in the table screw is about .060, causes the cutter to bounce around when cutting starts. (or more accurately, the table bounces around. The spindle is solid as a rock!)

I'd like to take up some of the slop if I can. The thrust bearings at either end are ok, no movement there. I found the acme nut in the book and in the machine. It looks like I'm going to have to take the table off, adjust the nut and put the table back. Anyone care to confirm or deny the accusation?

Paolo_MD · Nov 4, 2017

You're likely correct about the procedure to adjust the backlash. However, I don't think the backlash is necessarily what is causing your problems.

First: are you sure you're cutting in the proper direction and you aren't climb-milling?

Second, before adjusting the nut, you should make sure all the gibs are adjusted correctly, by testing for lost motion perpendicularly to the axis of the gib that you're adjusting. If you cannot adjust the gib in order to have no more of .002-.003" lost motion in one place without the table binding somewhere else, your problem is, at least in part, too much uneven wear in the table/saddle/knee ways.

Paolo

johnoder · Nov 4, 2017

Pdf pages 27 and 28 appear to show a spacer - part 82 - between two sections of nut

http://vintagemachinery.org/pubs/2098/6562.pdf

Courier250 · Nov 4, 2017

I think the gibs are adjusted correctly as the table slides with effort. Maybe a little tighter than when I set B-port gibs. Not climb milling either. The T-nuts for the clamp kit I bought were .060 too wide, so I cut them down with 7/8 end mill cutting on the face, offset to the correct side for down hill cutting. The tool chatter is only the first half second as material makes contact, then quiet as a mouse with great finish. I tried holding a little back pressure on the table screw crank handle, no change in results. Indicating the screw, I get .060 in the middle and .050 at one end. That's a classic indication of light wear on the screw and a loose nut. When I look at where the nut is, there is a big web in the saddle with a hole for the screw...and about 1/16 clearance. There's no way to get two tools in there to hold the nut and tighten a jamb nut. I figured the table would have to come off, just wanted to ask someone that knows more than me. I'll get 'er done and let you know how it goes. Thanks to John and Paolo, much appreciated.

Mine is a 3 hp machine, made prior to 1951, that is as far back as my lots are listed, 11-3385. Manual for the 3 hp shows a one piece nut, probably with a split. I have seperated the OEM nut on many Bridgeports, don't expect this will be any different. Still have some quality 1/4 felt left over from a SBL overhaul.

johnoder · Nov 4, 2017

Yep, yep 2HL parts different than 2H. 3385 in lot book is not a mill, says "Special Boring Machine for Rock Island"

Here is that section of the lot book

Kearney & Trecker Co. - Publication Reprints - SERIAL NUMBER REFERENCE - Lot 15 - 3835 | VintageMachinery.org

Courier250 said:
I think the gibs are adjusted correctly as the table slides with effort. Maybe a little tighter than when I set B-port gibs. Not climb milling either. The T-nuts for the clamp kit I bought were .060 too wide, so I cut them down with 7/8 end mill cutting on the face, offset to the correct side for down hill cutting. The tool chatter is only the first half second as material makes contact, then quiet as a mouse with great finish. I tried holding a little back pressure on the table screw crank handle, no change in results. Indicating the screw, I get .060 in the middle and .050 at one end. That's a classic indication of light wear on the screw and a loose nut. When I look at where the nut is, there is a big web in the saddle with a hole for the screw...and about 1/16 clearance. There's no way to get two tools in there to hold the nut and tighten a jamb nut. I figured the table would have to come off, just wanted to ask someone that knows more than me. I'll get 'er done and let you know how it goes. Thanks to John and Paolo, much appreciated.

Mine is a 3 hp machine, made prior to 1951, that is as far back as my lots are listed, 11-3385. Manual for the 3 hp shows a one piece nut, probably with a split. I have seperated the OEM nut on many Bridgeports, don't expect this will be any different. Still have some quality 1/4 felt left over from a SBL overhaul.

Courier250 · Nov 10, 2017

Well, I got her done and she runs great. Backlash is about 0.009, minimal tool chatter, cuts smooth and quiet.

As for the adjustable nut, I neglected to consult the manufacturer before opening my mouth. The nut has no backlash adjustment feature what so ever and to make it adjustable would require a donor nut to cut up (IMO the easiest way to do it). I couldn't find a used one at all, but did find a factory new part on someone's shelf. I kept the old one to revisit the topic when the new one runs out so bad I can't stand it.

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Milwaukee No2 Help, Backlash adjustment

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