The Sherline's gettin' some love

[ddmckee54]

Over 10 years ago I purchased a used Sherline from a gentleman that was downsizing his shop and decided the Sherline could go. I got not only the lathe, I also got the tooling for the Sherline and every accessory he purchased for the Sherline. The box it all was shipped in had to be pushing the limit that the USPS would allow. To my shame all of it sat in that box, unused and un-loved until I retired at the end of September last year. At that time I started on one of my numerous retirement projects, radio control conversions for Bruder construction toys. While I MIGHT be able scratch-build something, converting the Bruder toys will get me to a usable point quicker. I've got a shelf in the basement that's filled with toys waiting for conversion.

What's this got to do with the Sherline, glad you asked. At least 5 of the models on the shelf are trucks, trucks that will require at least 2 differentials per truck - 3 per truck if I go with a 6x6 drive configuration. Do you know how much a differential for an RC truck costs? Let me put it in perspective for you, I paid less for my first full-sized car - granted it wasn't much of a car. I decided to fabri-cobble the differentials out of cheap Chinese clones of 1/10 scale RC car differentials using a little machining and some 3D printing - I've got the tools to do both.

To do the machining I needed the Sherline, now where'd I put that box? I found the box and started setting things up, unsurprisingly almost nothing wanted to work, all the oil and grease had turned to glue. That's when the Sherline started gettin' some love.

I took apart the carriage and the cross-slide and cleaned the glue that used to be oil off the dovetails, lead-screws, and lead nuts - then oiled everything and put it back together. The carriage and cross-slide work MUCH better now.

The headstock is another matter. The motor works, but sitting in one position for years didn't help the headstock bearings any as they are rough and noisy. I suspect that the grease in the shielded bearings has dried out and hardened. I've been dousing the bearings with light oil in hopes that will re-constitute the original grease, but so far other than slinging dirty oil everywhere it hasn't done much. I suspect that new bearings will be required.

I started using the lathe, but was constantly losing track of where the cutting tip actually was when I moved the hand-wheels. My hat's off to anybody that can use a manual machine and make usable parts with just the hand-wheels. I cannot, I am much too digitally inclined. So that was the next lovin' that the Sherline got, some digital scales with remote readouts. I knew that I could totally botch this up, so I got the cheapest scales I could find. I didn't want this to hurt the piggy-bank too much if I totally hosed it. (They appear to be a Shahe/Igaging DigiMag scale clone.)

And it worked, kinda/sorta/mostly. I installed the scales in the simplest manner I could think of using mostly the supplied hardware. ,That hardware is mostly bent sheet metal brackets. This installation wound up having the scale strips facing up which is not good to begin with, but it also burns up a lot of real estate on and around the lathe. This is a shot of the cross-slide scale.

And this is a shot of the carriage scale from the headstock end.

I also have an intermittent glitch with the carriage scale, it will sometimes forget where it is and starts over from 0. I have been doing a little research into this problem and found these scales are sometimes vulnerable to electrical noise. There are several things you can do to fight this problem: 1) Shorten the cables, this is do-able but not really worth the effort. 2) Replace the existing non-shielded cables with shielded cables, again not really worth the effort. 3) Don't loop the cables - Whoopsie, wish I'd have known that before I got bit by the Cable Management bug.

Would I do this again? I am doing this again, just not like this.

I'm not going to use the Shahe clone scales again, I'm going with the Igaging EZ-View Plus scales. The EZ-Views are only a few dollars more that the equivalent Shahe scales, but they have better resolution, they use shielded cables between the read head and the display, and most importantly - you can get an AC adapter for them. The Shahe scales are strictly battery fed, and mine do not have an Auto-Off feature.

I am also going to rotate the scales 90 degrees, so that the scale strip is facing away from the spindle. That way the hot chips should bounce off the metal scale support bar and not embed themselves into the scale strip. That hasn't happened yet, but it easily could. In addition to rotating the cross-slide scale I will probably move it to use the existing T-slot as an anchor point for the scale. The carriage read head will be driven back and forth along the scale that is fixed to the lathe base. The cross-slide read head will be fixed in position and the scale will be driven back and forth through it. I am currently planning on 3D printing one bracket that will do double duty. First it will fix the carriage read head to the carriage, and second it will fix the cross-slide read head in position. That single bracket will probably have to be in several pieces so I can align the read heads to their respective scales. It's yet to be designed.

I almost forgot, I ordered and installed an OXA QCTP on the Sherline, even though it is a little big. I really would have liked to get a Tryally QCTP, but not at that price. (Even though it's probably worth every penny.) I also set up 4 tools for the OXA in their tool holders.

Don

 

[trlvn]

The headstock is another matter. The motor works, but sitting in one position for years didn't help the headstock bearings any as they are rough and noisy. I suspect that the grease in the shielded bearings has dried out and hardened. I've been dousing the bearings with light oil in hopes that will re-constitute the original grease, but so far other than slinging dirty oil everywhere it hasn't done much. I suspect that new bearings will be required. ...

Congrats on starting the journey!

Re the bearings, have you tried just leaving the lathe running for a period? You really don't have much to lose if they are bad. For some machines, the break in process is to run the lathe at 3 different speed setting for, say, 30 minutes at a time. For yours, I would want to monitor that the bearings aren't getting too hot. Hopefully the process should return your grease to a more suitable consistency. It might also be possible to pull the bearings, clean and re-pack.

Was the machine ever left to accumulate heavy rust? That would change things.

BTW, I don't know anything about "Bruder toys". Can you share a pic or two of your favs?

Craig

 

[ddmckee54]

Craig:

The lathe was stored in an unused, but still heated, room of my house so no rust. My first attempt at a bearing fix was to do just as you suggested. I ran the motor at about half speed for about 30 minutes. Nothing got hot, but the bearings never got any quieter. I bought the lathe on-line and never heard it run, the bearings might have noisy when I bought it.

The bearing part number says they are shielded on both sides, so the only way I could effectively clean and repack them would be to pop them out and rip off the shields. If I need to go that far, I'm just going to replace the bearings. The part number says the bearings I've got are just standard precision bearings, not high precision bearings. Standard precision bearings are cheap, I've got new bearings on the way.

This is probably going to be the first conversion victim, not because it's my favorite, but because the only control function needed, other than the usual forward-reverse and left-right controls, will be the mixing drum rotation.

Of the trucks I've got, this one is probably my favorite.

But it will take a whole bunch of functions to animate it.

 

[trlvn]

The bearing part number says they are shielded on both sides, so the only way I could effectively clean and repack them would be to pop them out and rip off the shields. If I need to go that far, I'm just going to replace the bearings. The part number says the bearings I've got are just standard precision bearings, not high precision bearings. Standard precision bearings are cheap, I've got new bearings on the way.

Just for curiosity, what type of bearings does the Sherline use? Tapered roller bearings? Is the preload adjustable?

Craig

 

[ddmckee54]

Sherline uses a 6004ZZ bearing, that's a deep groove ball bearing - the ZZ on the end tells you it's shielded on both sides. The standard replacement bearing from Sherline is an ABEC class 3 bearing and costs about $15-$20 US per bearing. ABEC class 5 bearings are available for about $40-$50 US each. Sherline uses an interference fit on both bearings which is why they don't recommend that the end user does a headstock bearing replacement. The bearings either need to be pressed onto the spindle, or you use the heat the bearing/freeze the spindle trick. Either way with that interference fit, unless you've got the factory jigs, you really only get one shot at getting the bearing location/preload correct.

My current plan for the headstock bearing replacement is to use HR32004XJ tapered roller bearings that are ABEC class 3's. These are about the same price, the same ABEC class, and most importantly the same size as the stock bearings. Here's a link to a video showing how it's done using the heat/freeze method. (He's going to ABEC class 5 bearings in the video.) Sherline tapered roller bearings

I plan on polishing the pulley end bearing location of the spindle with emery cloth to get a sliding fit between the spindle and the bearing. The Sherline spindle has a 10mm bore so I can use a piece of threaded rod as a mandrel for the spindle. That assembly gets chucked into my drill press, making it into a vertical lathe to polish the spindle. That polishing will allow the spindle to move back and forth in the bearing, and also allow me to easily adjust the pre-load on the tapered roller bearings. I plan on taking the polishing process very slowly, with many checks of the fit during the process. Too loose of a fit means the spindle can rattle around in the bearing - which is never a good thing. And that would mean ordering a new spindle.

 

[clockworkcheval]

Some of my collegue horologists who want to downsize purchase as replacement for their larger machines a Sherline or a TAIG. Interesting that it also works the other way around! Trying to put DRO on my TAIG I was faced with the same challenge of not wanting to limit the working space of the lathe. As a solution I put rulers and readers at the back of the crossslide. It required some funny components to get there, but it works out fine. I guess a similar solution is possible for the Sherline lathe. Some pictures are enclosed:

• Start picture: topview with protective covers
• Frontview of the lathe showing intact working space
• Block that holds the y-axis ruler and strip for reader
• Attachment of the strips that hold the readers
• Underside of the ruler- and reader-holders
• Bent fixture that connects z-axis reader with lathe
• View from headstockside without protective covers
• Rear topview of DRO assembly without covers
• Topview without protective covers.
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[ddmckee54]

clockworkcheval:

The gentleman I bought the Sherline from wasn't so much downsizing the size of the equipment in his shop, as he was downsizing the amount of equipment. You CAN work on smaller parts with a larger lathe, doing it the other way around on a Sherline - not so much.

With a couple of minor exceptions your set-up is what I intend to do with the Igaging scales for the Sherline. The carriage scale will be rolled 180 degrees so that the scale surface is facing away from the spindle. The carriage scale will also be fixed to the lathe mounting base, and its' read head will be fixed to the carriage. The scale being fixed does not require the free space at the headstock or tailstock ends for the scale to protrude into. It does require a longer scale though, I went from an 8" scale to a 12" scale. Like you, I'll also be using the same block that mounts the carriage read head to mount the cross-slide read head. Great minds think alike?

I've got some thin silicon sheet left over from making the seals for my dust collector rotary valve, I plan on using some of it to make wipers to keep chips/dust out of the read heads.