Sheldon (Vernon) Model 0 Horizontal Mill Restoration.

[Aukai]

Nice writeup, and pictures.

 

[wayback machine]

Following this, as I have one of these mills also - I found a B&S 9 ER40 collet chuck for it.

 

[RebelJD]

Update #2
It has been too cold outside to sandblast the base and column, so I've been working on cleaning and inspecting things. If you are not intimately familiar with this machine here is a drawing of the moving parts from the parts manual.


As I mentioned the spindle bearings are in good shape, so I'll be retaining them. These bearings and races sit in bearing houses that are pressed in the column casting. The lubrication chart above indicates they are to be lubricated with bearing grease but I'm not quite how that is to be done. There are 3 holes in each housing but on mine the holes were completely full of a hard material, not sure what it was. I cleaned these holes and used a punch in each hole to push the races out. I decided I would tap each for 1/4-28 and install grease zerks. This should make it easy to grease after it is assembled. The grooves you see in the back of the housings I believe are called "Labyrinth seals".


Here is the spindle assembly cleaned ready to go be re-assembled. The pulley is not shown. You can see a grease zerk in the front bearing housing.


Here is the counter shaft parts ready to go back together. Since I'll not be using the mechanical speed adjust mechanism and installing a VFD, I'll need to change one or more of the pulleys to get an adequate top speed on the spindle. The original Vernon documentation calls for a top spindle speed of 1100 RPM so I'll try to get somewhere near that. With the VFD I'll be able to adjust for any speed up to that.


I've spent quite a bit of time accessing the condition of the ways. I can see oil flaking on most of them, but I don't know if it is original or did someone add them at some point during its near 80-year life. Using my surface plate, straight edge, machinist square etc. I've determined the worse wear is about .0015 to .0020 over any length of travel. For my intended use as a hobby machine, I think I can live with this, at least for now. If I find it is an issue after I start using the machine, I may do something about it. It is not easy or cheap to resurface dovetails and once you do it you have to deal with the proper alignment of the leadscrews, just adding to the complexity.



Everything else has been bagged and tagged. I've started working the leadscrews, hand cranks, etc. and will have update on those next.


Happy Holidays.

Jim

 

[TomKro]

It must have been a heck of a job getting all that dried grease cleaned up.
Moving along nicely.

 

[RebelJD]

Update #3
Still have not been able to sand blast the base and column outside. If it's not too cold the wind is too high. Sand blasting is my least favorite activity. I did however use a needle scaler and cleaned up the base a little so I could repair the big wound in the cast iron. I used a piece of 3/8" x 1" hot rolled along the bottom and some 1/8" cold rolled to fill the gap. I used stainless steel filler rod and a tig welder to do this. A little body filler and it will look fine. This technique works ok for cosmetic repairs like this, but I would not do it for a structural or safety related repair. It is hard to avoid cracks along the weld as things cool down.


I did finish cleaning all the lead screws, hand cranks, etc. All the lead screws are in decent shape with just a little wear in the middle where most of the use is. There are grease zerks on Y and Z leadscrew nuts, which I think helped reduce the wear. The X axis leadscrew nut does not have a direct method of lubrication, so I'll try to figure one out.

Sorry about the orientation of the photos, I can't figure out how to rotate them when I pull them off my iPhone. If anyone knows how to do this please let me know.

I had a few requests to provide some details on the inner workings as I go so here are some pictures. The left pic is the X axis leadscrew and associated parts. The crank handle was bent so I had to heat is up to straighten it which is why it is discolored. I'll polish it later. The picture on the right is the Y axis, I did not get a picture of it before I assembled it.



Here is the Z-axis, or knee elevation leadscrew. There were a few .003 shims in the assemble which I think are used to set the gear mesh.


I decided to polish the hand cranks rather than paint them and also polish the dials to improve the visibility.


I've still got a lot of misc parts to clean up and get the base, column and tray sandblasted and painted. As I mentioned I'm going to be replacing the mechanical spindle speed control with a VFD and install an Electronic Feed Drive on the X-axis. I have finished the electrical design and have ordered the parts that I need. I'll provide some details on those efforts a little later.

Happy Holidays everyone.
Jim

 

[TomKro]

Very nice progress, and great pics too.

I'm curious as to how much backlash exists in your crossfeed nut, and how much it changed between the heavily used positions in the middle and the ends of screw travel. It's been a long time since I touched my machine, but I do recall that the crossfeed was pretty sloppy. I didn't notice your crossfeed nut in the pics of the cleaned up components. I'm guessing the inside of mine will look more like a V thread nut than a power screw nut. It sounds like yours is in a lot better shape.

Thanks for sharing.

TomKro

 

[RebelJD]

TomKro,
Once I get all the nuts cleaned, I'll take some pictures and some measurements and post them next. My initial inspections showed the crossfeed had the most backlash, which is to be expected. I'm guessing it is around .020 to .025. The leadscrew doesn't show much wear so its likely in the nut. I'll decide later if I want to do anything about it. I don't have an acme tap and I'm not sure it's worth the investment to buy one to use once. We'll see.

 

[frugalguido]

Nice work on this mill. You probably wish you started this before winter.

 

[Dabbler]

Pretty machine and a very worthy restoration you have going!

 

[RebelJD]

I Did get a chance to measure the backlash in the X axis Lead Screw. It was .011 on the ends and .014 in the middle. Not great but for my intended use, which will mostly be feeding, it will be fine. The Y axis and Z Axis are in much better shape, and I'll measure the backlash once I start the re-assembly.

We did have a couple of nice days recently but---- there was too much football on TV to do sandblasting outside. Pretty soon I'll run out of excuses, and I'll get the sandblasting done.

I also mocked up the electrical and fully tested the VFD for the spindle motor and the feed drive for the X-axis. Everything works as it should and I'm working on documenting the electrical drawings. I'll provide more details on that later.

Just a few more misc parts to clean and then I'll be working on the paint.