While I’m waiting to find a 3 phase transformer, I’m continuing to clean up the Fritz Werner mill.
I found another cover to pull off. It is on the gear box that adjusts the table’s feed speed. Everything in there looks pretty good and I didn’t see any broken teeth. On a side note, there is a port to add oil into the gear box that was missing the correct cap. While digging through the sludge in the cutting oil reservoir I happened to find the actual cap. Yes, I could have made a replacement but all the correct caps have a little oil can stamped into the top dripping oil.
The machine also has a handful of these recessed zerk fittings. I can’t get to them with a normal grease gun.
Not to fear though. A quick trip to the lathe solved that problem. Well, it was multiple trips because I was trying to take off as little material as possible. Eventually I got it though. From what I’ve read online, most milling machines use oil to lubricate everything as opposed to grease. One of the reasons this is done is because grease will trap chips which increases wear on the machine. From what I’ve seen on my machine, the zerk fittings on it are for grease. The one on the spindle also has a tag that says “Grease”. I’m going to switch over to oil on the zerks that feed the ways and slides though. Comparing grease and oil, I think the oil slides better anyways. The zerks that feed the thrust ball bearings and other unknown parts will still get grease though.
At some point, someone whacked the Y axis hand wheel that sticks out of the front of the machine. To fix this I first had to remove the lead screw for it. While removing it, I noticed there was a lot of grease with chips in it around the “nut” that the lead screw runs in. That needs to be cleaned up and requires removing the table. More on that in a few. As you can see, it’s a little bent.
To straighten the lead screw, I mounted it in the lathe and miked the end of the screw. This was all unpowered. I was turning the spindle by hand. The lead screw was rotated until I found the low point and marked it with a piece of tape.
I took the lead screw over to the arbor press and used it to gently push on the screw. Then it was back over to the lathe to see how I’d done. I kept going back and forth from the lathe to the press until the run out was around 0.01″. I figured this was good enough for a hand wheel.
Here’s the straightened shaft. I’d like to point out that the thread on the lead screw has a 20mm major diameter with a 5 TPI pitch. It’s also left handed. This is a mix of metric and UTS. It isn’t a standard thread I’m likely to find stocked somewhere.
Back to the machine, I noticed that what I’d previously though was some kind of plug was actually a smashed zerk fitting. It had to come out and be replaced. After I’d removed it, I measured it and discovered that it is a 6mm press in zerk. I’ll be ordering some of those soon.
I’d mentioned earlier that the table would need to come off and here we are. To remove it I had to remove the lead screw shown above and remove the gib. I also had to remove the studs the gib fits onto and the drive shaft that controls the table movement. After removing a few more small parts Chris and I were able to tilt the table and remove it. Unwiring it didn’t seem easy and I wasn’t planing on going very far with the table. So, it is still tethered to the mill. If you look in the middle of the pic, you’ll see a couple bevel gears. The one with the hole that points down is where the lead screw goes.
I moved the table from side to side so I could remove more chips. It also gave me a chance to look at the grease/oil passages that feed the slides. They look pretty good and I took the opportunity to push oil through them to purge any grease.
Above I’d mentioned the studs that hold the gib in place. Here’s the three regular studs. There’s a fourth that is used to lock the table in position and isn’t shown. I guess at some point someone tightened one the nuts down to tightly, broke the stud, and said “Oh well”. That won’t do.
With one of the good studs in hand, I headed back over to the Hendey lathe. After a screw up, I manged to reproduce the part. This little stud has M8 x 1.25 threads on both ends. Since my lathe only does SAE threads, I used a steel (12L14) I could run a die over to make the threads.
Shown below is the assembly that houses the “nut” and the bevel gear for the lead screw. The piece up top is the “nut” and is made out of brass. It’s made from brass so that it will wear instead of the lead screw since it is cheaper to replace. The assembly has a couple alignment pins that for some reason have threaded ends. They’re metric threads too.
Shown below is a close up of where the assembly from above sits. You’ll notice a bunch of holes in the surface. The two smaller holes are to get grease into the assembly which is supposed to lubricate the lead screw by seeping out of a hole I think. The lubricant being grease then traps chips as you can see on the bevel gear. The two medium holes are for the alignment pins and the largest holes are for the bolts that hold the assembly on. One of the bolts was gone and the other was very loose. To top it off, they’re UNC 3/8-16 threads. I checked multiple times and compared the bolt to a metric bolt that was almost the same. In the end though, they were UNC. Odd and annoying.
Remember I was talking about wear and how the brass “nut” is meant to wear instead of the lead screw? Here’s a pic of it. The internal thread here should have nice wide flats on the crest of the thread like the lead screw. Instead it has almost worn always leading to slop in the lead screw I can feel. While I had this part out, I made a dimensioned drawing of it. One day I’d like to make a replacement. I think I’ll need to practice a bit before then though.
That’s the latest update. I plan to get it put back together soon while crossing my fingers that I’ll find a used transformer.