[4]

Scraping in all bearing surfaces on my Wards/Logan 10"

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I've been working on my lathe off and on over the past several weeks or months, but I've been hesitant to start a thread documenting my progress (or lack thereof!) for fear of embarrassing myself.

I'm increasingly confident that I'm going to end up with a very precise lathe rather than a very large pile of cast iron dust and tears, so I'm finally willing to share my progress.

After creating a new cross-slide for my lathe some time ago, I'd already spent a lot of time scraping in the compound and cross slide. But I decided to tackle a far larger project.

I've taken Richard King's class twice now (and I'm about to help out with a third) but I know full well there is no way to really learn something without actually doing it (and even better, trying to explain what you're doing to others). So, despite my old Wards/Logan being in perfectly (well ... "acceptably") useable shape to begin with, I decided to scrape in the bed ways, headstock, saddle, and tailstock. I rationalized that this was "my first lathe" and even if I ended up with an expensive and shameful pile of worthless cast iron, I'd learn something in the process.

As expected, it's been a terrific learning experience.

I decided to attempt the inner ways and tailstock first before tackling the outer ways and carriage. I thought this wise because in case I totally screwed up, the tailstock is less critical than the carriage. It took an embarrassingly long time for me to realize that the headstock also rides on the inner ways, though, so if I screwed them up I was still pretty much SOL.

Anyway, I'm happy to report that after a LOT of work, I've got the inner ways and tailstock base scraped in to about 0.0006" with decent bearing over the entire 42" length of the bed:


If I'm reading Connelly correctly, I think the standard for this test is under less than 0.0008". The width of the tailstock base is only about 4" and the level is calibrated to 0.0005"/10" so, if my math is right, each division on my level shows about 0.0002" of deviation. Three divisions max deviation is under the standard. Whoopee. :cool:

Actually, I've still got just a bit more fine tuning left. I'd like to get a little bit more bearing points on the far side of the rear fee way, as well as a few more on the bottom of the tailstock base (it's bearing across the entirety of all three surfaces, but I'd like to get a few more PPI). I'm pretty sure I can improve 0.0006" slightly but I'm pretty satisfied already (considering the stack of tolerances).

Interestingly, the far side of the inner inverted-fee way needed the most scraping. Not sure why this would be unless it was out a bit when it left the factory.

I'm leaving out an awful lot of things that I didn't document, but here's the rough outline of getting to this point. I'll try to update this thread with more thorough details as I tackle the outer ways, headstock, tailstock top, and carriage.

Step zero was to scrape in a 36" straightedge. It's slightly shorter than my bed, but there's no way I'd have been able to manhandle a larger straightedge. As it was, I really wish I'd acquired a plain casting without the angled edge for large dovetails. The additional weight of the dovetail feature put it right at the edge of what I can manage by myself (my straightedge weighs about 70 pounds if I recall correctly).

Another (critically important!) preliminary step was to determine what to use as the "datum plane." I'd heard from Scott Logan himself that the flattened tops of the inverted vee ways on Logan lathes were ground at the factory at the same time and with the same setup as the ways themselves. Since the tops of the vees receive no wear, this eliminated a lot of what Richard calls "detective work." After a good stoning to remove the raised burrs from 70+ years of nicks and dings, I had an excellent (and convenient!) reference plane waiting for me.

Connelly calls this a secondary reference/datum. For other manufacturers, you'll have to look for unworn edges on the flat ways, or use the bottom of the rear way to determine the original datum plane. After just one lathe job I'm convinced that if I ever work on a lathe that doesn't have the tops of the vees pre-ground to be coplanar with the real datum (the ways themselves) the very first thing I'd do on a refurbish job would be to make the tops of the vees a secondary datum. It's incredibly convenient to be able to just lay something flat across the ways to indicate from instead of having to balance/clamp 1-2-3 blocks and parallels.

The datum plane is everything when it comes to precise alignment and an accurate lathe. Literally everything on the lathe is adjusted relative to this plane. It's worth spending an awful lot of effort ensuring that all points on this plane are as coplanar as possible. Many years ago, I tried to level my lathe using shims. Trust me, screws/nuts (or paired wedges) are the only way to go for the level of precision required. You'll drive yourself insane trying to get things level (planar) with shims.

While it's only necessary to ensure the datum plane is truly flat, and not to align it with any particular plane, trust me that it's worth the effort of making the datum plane truly level. It's awfully convenient to be able to just throw your level onto things to see if they are parallel to the datum plane.

It's also worth calibrating your level instead of always ensuring you have it oriented in the same direction (something I try to do anyway, but am bound to screw up occasionally). The process is easy and satisfying (and likely documented elsewhere on this site).

I carefully re-leveled the bed at the start of each day's work (and often once or twice during a session, especially after jostling the bed or causing heavy vibration from rough scraping things nearby. Just the tiniest movement of the nuts on the leveling feet is enough to move things out of level by a couple tenths. I have the whole thing supported by a massive maple workbench, but temperature and humidity variations are definitely enough to move the bed out of alignment slightly from day to day.

Here's what level looks like:


I started by scraping the inner flat way. The first blue ups showed more wear in the middle than on the ends, unsurprisingly. Because the area under the headstock is fixed and has no wear, I first tried to leave that area alone as much as possible. I thought I was being smart by "tipping in" the scraping and doing most of the scraping at the tailstock end. Naturally, this ended up with the way angled downward toward the tailstock relative to the datum plane. No bueno. So I ended up needing to remove a bit of metal at the headstock end anyway.

Note that the flat way needs to be coplanar with the datum plane in both dimensions (left to right, as well as fore and aft). It's very easy to confuse yourself when indicating in one direction if you're also out in the other.

In case it isn't obvious, here's how I indicated to ensure things are parallel to the datum plane:

IMG_0361.jpg

In this image, I've got a piece of precision granite across my datum plane. Just rest the the base of your surface gauge or indicator stand on this, and use a small parallel or side of a gage block to average out the points on a scraped surface.

I discovered a pretty significant nick in one corner of my mag base, by the way, that was causing me no end of grief trying to get repeatable results. A quick stoning fixed the problem, but for a while I thought I was losing my mind.

As I mentioned it's important to realize you may have tipped the flat way in one of two dimensions. At one point I was trying to determine how far the flat way was tilted toward the tailstock after my initial scrape, but I just couldn't seem to get repeatable results. After several attempts, lots of head scratching, walks, and countless cups of coffee, I finally realized the way was also tipped over a thou toward the back of the lathe as well as left to right. Because I wasn't always measuring in the precise middle of the way, my results would vary.

So I rigged up this ghetto King-Way to at least perform this one measurement reliably:

292410

I just super glued a couple washers on a flat bar to create a two point reference, and clamped it to the granite square or level I placed across the vees. This photo is a bit of a lie. I only used this setup to measure the flat way (and ensure I was indicating at the same offset from the edge of the way). I didn't actually use it for the vee ways. The front edge of my lathe is not precision ground (you can still see the rough abrasive grinder/saw marks). It's not flat enough for anything super critical, but it was enough for me to figure out how much I needed to correct left to right.

Hope this all makes sense. I've learned quite a bit in the process, and doubt I've covered half of it, but I hope this is at least somewhat interesting and useful.

Doubtless I'm still making other boneheaded mistakes, but I'll continue to share. Please don't hesitate to correct me if I'm doing something wrong or if there's some easier way.
 

Comments

That Richard King is a pretty smart fellow:

293189

I still need to scrape the back in for a nice sliding fit, but I successfully added material to remove the slop. Richard's suggestion worked a treat. You can see that I'll have to remove just a tiny bit of material on the back (left in the photo) edge for the top half to fit.

It's fairly inconspicuous from the side (even more so when I clean and paint the thing). Here's the gory innards, though:

293190

Before doing any work I also followed Rich's suggestion to just lightly kiss the front edge with an end mill after indicating it in as best as I could. I followed that with an extremely light scrape for penultimate alignment with the test bar as before. It literally only took 3 or 4 scrapes for perfect alignment along the length of the test bar.

Next I wanted to ensure that the tailstock mini-way traveled perpendicular to the bed ways (like the cross-slide) albeit just for an inch or so. It's possible that the taper in the quill is aligned parallel to the bed ways, but the front edge of the step or way on the tailstock base might be angled such that the whole top half moves toward or away from the headstock as you adjust the step over. (This is hard to explain in words without diagrams and hand waving).

So I took stuck a mag base and indicator on the tailstock base and swept in a granite square:

293191

First I swept in the short edge of the square by moving the tailstock left and right along the ways, knocking the square (very, very lightly!) with a wooden handled screwdriver until I got zero deviation along that edge. Then I repositioned the indicator as shown to bear on the long edge of the square and moved the tailstock toward and away from the operator. It was a little tricky to because I had to push against the leading edge of the step way on the base by hand, but I'm confident it's well under a single division (certainly good enough for a tailstock).

Finally I got curious to see how the headstock looks before I do any scraping on it. I placed it on the ways for a few quick and dirty initial tests (really tests will come after at least a single scraping pass and clamping the headstock down).

The first thing I did was to indicate the runout on the nose, face, and internal taper of the spindle while rotating the spindle. Far more deviation than I'd hoped. IIRC just slightly less than a half thou TIR.

Then I stuck a test bar like the one I used on the tailstock (but with an MT3 end) and checked the runout at both ends (near the spindle and at the end of the bar). Unsurprisingly it was around a half thou near the headstock (same as when I measured the internal taper directly). It was a good 0.006 or 0.007" TIR at the end, though. Clearly I scraping in the bottom of the headstock will help, but I'm concerned about the runout right at the spindle (I hope it's just a preload issue with the bearings).

Finally, I stuck a dead center into both the headstock and tailstock for a quick visual check of how much lower the tailstock is now:

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Scraping in the headstock will lower it somewhat, but clearly I'm going to need that phenolic stock I ordered! Visually, the tailstock is about 1/32" lower almost exactly.

The wonderful folks at McMaster assure me the stuff I ordered should be here before I head up to the class Tuesday night (can't believe they replied to my email on Easter Sunday — love that company). Looking like I should have Rich and the entire class watching over my shoulder as I glue in and scrape the phenolic shim. Perfect timing!
 
I sent a vintage used Challenge brand 36" plain (no angle) camel back that will need to be touch up out via UPS, so your club has it for the next lathe bed.
Hey, Rich, that's awesome. Thanks! Dunno how I missed this comment. That'll be great. Not sure if there will be a large enough plate at the class to touch it up, but I'll definitely do so on mine after the class if not. Every single aching muscle in my back thanks you profusely! <laugh>
 
Hey, Rich, that's awesome. Thanks! Dunno how I missed this comment. That'll be great. Not sure if there will be a large enough plate at the class to touch it up, but I'll definitely do so on mine after the class if not. Every single aching muscle in my back thanks you profusely! <laugh>
Tell Jon that as he said you had a 36" already and figured I was dumping it on you. He also suggested we could cut it in 1/2. I told him, no way and I would ship it home before allowing that. I wrote him and told him about your heavy one was made for doing dovetail ways and not lathe beds. gave Jim a de-mag for him to keep. He didn't know we were writing. I am in Dixon now and will drive down to Jim's place this afternoon to unload my tools. Thanks
 
Rex Walters, what brand & model is your precision granite angle? Any issues with it?
Pretty sure I bought it from Shars (but possibly on ebay). I’ve been very happy with it. It’s as accurate and square as I’m able to measure (within a tenth over the long side).
 
"Pretty sure I bought it from Shars (but possibly on ebay). I’ve been very happy with it. It’s as accurate and square as I’m able to measure (within a tenth over the long side)."

Thanks for the feedback. I've been debating about getting one of them from Shars. Would prefer an angle granite from Rahn but can't justify the $$$$.
 
I clamped that granite angle plate to my scraping project angle plate..
We clamped it up high and ran a test indicator along it's horizontal edge to check square.
Came in very handy. Someone said the error factor of that plate is + - .0002.
That's exactly the variance we experienced when we checked for square.
I wondered what the hole was for. :)
I was very happy with it. I didn't know it was yours Rex.
Thank you for bringing it.
Jon had a Suburban Tool, cylinder square with the magnetic base. That came in handy also for the smaller pieces.
 
When we checked Jeff's angel plate he was scraping with the granite . With indicator starting near the iron and moving out the square it was zero for about 6" and the jumped .0002" for about the last 3 inches. At the time I figured it was the square, but maybe the plate under the square was bad. One way or the other Jeff did a super job on it. I was fun watching him get mad and start to step scrape. :)
 
Haven't posted an update in quite a while. Neither the family nor the few people still paying me money occasionally seem content to let me spend all day every day in the shop. Even the Giants keep insisting on extra inning walk-offs. Such problems!

Anyway, some progress since the last post: I've only (!!) scraped in the outer ways, headstock, and saddle. The headstock is now aligned to [kisses fingers] near perfection:


There was a whole lot of learning involved for me to get it to this point.

1. Attitude

The first thing was to "get mad" as Richard likes to say. I finally got tired of seeing my lathe in pieces, and stopped repeating check after check after check before actually doing anything.

I think it's a natural tendency for beginners like myself to pussyfoot around for fear of breaking things. Watching my dad try to use a computer used to drive me insane, for example. I spent my entire adult and professional life with computers and have zero fear of hurting the darned things. With the lathe I'm terrified of making a mistake that can't be corrected. Most mistakes just mean more scraping. Occasionally, they require gluing on some Rulon or phenolic and then more scraping.

I'm still being careful and trying to think things through, but mistakes are unavoidable the first time you do anything in life. So I quit messing about with the inner ways and tailstock, and moved onto the important bits. That definitely paid off, as I learned quite a bit more.

2. Vee Way Angle

Before the change in attitude, I was quite worried about accidentally changing the angle of the inverted vee ways (90 degree included on a Logan). Then I remembered mentioning it to Richard who just shrugged and said to remember that you scrape the saddle in to the bed anyway. A slight change in angle is no big deal.

I think that as long as each side of the vee is FLAT, it doesn't matter if one side is, say 47 degrees off of vertical and the other 51 degrees.

I think what matters most is that the vee doesn't get wider or narrower at the tailstock or headstock end of the way. In other words, what matters is the center of rotation for each plane. As long as those two lines are parallel with each other, it doesn't matter if one or rotates more than the other.

Put yet another way: Imagine a tiny little man wearing a pair of skis, and resting each one on the outside of the vee. It doesn't matter how much the man's knees spread apart or come together. What matters is that he doesn't go pigeon toed or duck footed — his feet just need to be parallel no matter how bowlegged or knock-kneed he gets.

Keeping the angle of each side exactly 45 degrees off of vertical is hard (nearly impossible) because each side is only about half an inch wide. As long as both sides are flat, though, it's relatively easy to tell if one end or the other is narrower. One way is simply by feel and by sound: move the (roughly scraped in) saddle to each end test for play. A slightly more precise way is to blue up the ways, slide the saddle to the two ends and examine the resulting marks on the ways (each end should see roughly the same amount of streaked/wiped away ink).

The job of an inverted vee is to keep the saddle from rotating on the horizontal plane. As long as the saddle has full bearing, the precise included angle just doesn't matter (unless someone convinces me otherwise).

3. Headstock alignment

EVERYTHING
on a lathe references from the center of rotation of the spindle in the headstock (more specifically, the center of rotation of the Morse taper at the chuck end of the spindle). Unfortunately, it's a purely imaginary line.

You can't indicate an imaginary line! Nor can you throw a level on it.

3.1 Test bars

The way you find the center of rotation is interesting. It requires a test bar: a precision ground bar about 12" long, with centers bored at each end, a morse taper at one end, and a precision ground cylinder for most of the length.

I bought a surprisingly inexpensive pair of test bars shortly after taking Richard's class for the first time (from India on ebay, I think). One MT3 and one MT2 to fit the headstock and tailstock tapers of my lathe.

The right way to validate a test bar is to put it between centers and check for runout. Since I, ahem, currently lack a fully assembled and precisely aligned lathe, I had to use a matched pair of vee blocks on my granite plate. Testing the cylinder portion was easy: just find top dead center with a tenths indicator, and carefully rotate the cylinder. Repeat at each end and in the middle of the bar.

I was shocked at how accurately ground the cylinder portion was. The needle on my tenths indicator barely moved. Total indicator runout of like 0.00005". Amazing.

You basically test for runout on the Morse taper portion the same way. Unfortunately, because I couldn't put it it between centers it was much harder to test. Even a tiny amount of movement axially while rotating the test bar will move the needle on a tenths indicator significantly. I tried sandwiching a small ball bearing between the center in the far end and a heavy block to push against while rotating. Using this method I measured about 0.0003" to 0.0004" TIR, but I'm not confident in the result — it may actually be better than this. Tenths indicators are unbelievably finicky beasts.

The last test for the test bar is for the taper itself. You ink a stripe down the length of the taper, insert it into a matching taper in the spindle, twist, then analyze the resulting smear.

The taper in my spindle was pretty grody from decades of misuse. There is a bit of surface rust, quite a few scores, and lots of "character" from use since 1947.

I cleaned it as best I could, then took a MT3 hand reamer (one of the most expensive cutters I've ever purchased) and very carefully removed any remaining burrs and crud, twisting the reamer purely by hand. I did NOT insert the reamer fully and turn it with a wrench to cut a new taper, of course, as there would be no (easy) way to precisely align the taper with the spindle axis. I just removed the burrs.

I then inserted the test bar with a stripe of spotting ink, and couldn't have been happier with the result:

IMG_0769.jpg

That's an excellent fit. And a very well made test bar. The wider unstreaked areas were due to worn grooves in the spindle taper, not anything with the test bar.

3.2 Testing the spindle

Next, I needed to ensure the spindle and spindle bearings themselves were reasonably precise.

First I indicated for runout on the spindle itself. A little less than 0.0002" TIR. Honestly, not as good as I was hoping for (hey, even I can scrape to a few tenths) but probably as little as could be expected from a very old hobbyist lathe:


Logan's use a screw-on chuck. I also tested if the surface the chuck references against had any cam action going on. Again, the surface quality is far from perfect, but I'm still quite satisfied with the results (and some careful stoning should eliminate the one little bump you see):


3.3 Finding lines on the same vertical/horizontal planes as the center of rotation

Finally we get to the thing I found most interesting in the whole process.

I've now validated that the test bar is astonishingly accurate, and that the spindle itself is in reasonably good shape. Time to actually use the test bar for its intended purpose.

There is nothing like a tenths indicator and a 10-12" lever arm to reveal the tiniest little bits of dirt, inconsistent pressure, etc.

This is the very best result I saw with the test bar inserted yesterday:


That's about 0.0001" TIR at the chuck end, and 0.0009" at the tailstock end.

That's the best result, that I was never able to repeat. Results vary every time you remove and re-insert the test bar. Sometimes it would move as much as 0.005" TIR at the tailstock end!

No matter what, the spindle and test bar tapers aren't perfect. Minute specs of dust will invariably kick things around a bit. It doesn't matter how carefully you re-insert the test bar, the end is pretty much guaranteed to show some runout, and the bar will basically circumscribe a cone.

Here's the thing, though: it really doesn't matter too much! With one little trick, that cone can still reveal a line in the same plane as the axis of rotation.

Here is possibly my favorite passage in all of Edward F. Connelly's fantastic book, Machine Tool Reconditioning:

"To nullify the effect of eccentricity error, the mean position is located at the vertical diameter for this portion of the test."

That is some seriously opaque technical writing, especially for something so important to understand. It's impossible to read that without your eyes glossing over! I must have read it two dozen times without understanding until the penny finally dropped.

As usual, the underlying concept is critically important (and actually kind of cool):
  1. Place the indicator tip at roughly top dead center at the end of the test bar.
  2. Rotate the spindle to find a high point and a low point.
  3. Set a zero at the low point, then rotate to find the high point (which should be 180 degrees away). Let's say the high point reads 0.0016".
  4. Now rotate the spindle to find the halfway point precisely between those two values (rotate until the indicator shows 0.0008").
Since the test bar circumscribed a cone, the line formed at the top of the test bar is now on the same horizontal plane as the axis of rotation.

That is, the line formed between a point at top dead center at the headstock end, and one at the tailstock end will be twisted fore or aft around the vertical axis, but it doesn't tip up or down at the headstock or tailstock end — it's precisely aligned with the axis of rotation.

If you now sweep an indicator mounted on the carriage along the length of the test bar, with the tip at the top of the bar, you can measure exactly how much the spindle axis is tipped up or down.

The test then needs to be repeated once with the vertical plan, and once with the horizontal plane (once with the indicator on top, and once with it on the side of the test bar). In both cases you just rotate to the halfway point to find the true axis of rotation.

That is what I'm showing in the first video of this massive post: the outer ways of the bed are guiding the carriage along a path precisely aligned with the axis of rotation of the spindle.

Whew! I hope someone finds this as interesting as I do. (laugh)
 
Rex, I can't imagine how difficult scraping in your lathe must be to a hobby guy.
Scraping a flat bar is one thing, to correct a worn lathe and bring it back to better than factory specs is incredible.
Scraping both sides of a v way alone is daunting to me.
Well done sir.
We missed you last Saturday.
See you at the scrape fest.
 
Rex, I can't imagine how difficult scraping in your lathe must be to a hobby guy.
Nah, like anything I think it gets easier the more you do it. Now that the outer ways and carriage are a reliable reference, it’s easier to see just how poor a job I did with the first things I worked on.

It took me a month of pussyfooting around and fretting to get the inner ways and tailstock rough scraped. Maybe three or four days to do the more critical outer ways, saddle, and headstock. And they came out far better!

I like the puzzle of it. Everything you touch affects everything else.

If only Connelly had learned to write readable English! It’s all in there, but the man was clearly incapable of using the active voice.

Anyway, I’ve got a little more progress still to post, and I can see the light at the end of the tunnel.

I debated with myself whether or not to (shudder) paint the dang thing since I’ve already got it apart. After mulling it over in the back of my brain for a few days I convinced myself just to get the darn thing finished and put back together. Having a working lathe again is more important than making it pretty, right?

Yet somehow I seem to have just ordered some expensive gray enamel paint ....
 
Sounds like RDM. I find it very interesting.
RDM?

In my day job, RDM stands for raw device mapping storage to VMware.

Google also turns up “remote device monitoring” and, my favorite, “random death match”.

Suspecting you don’t mean any of those, though the last seems somewhat appropriate.
 
RDM?

In my day job, RDM stands for raw device mapping storage to VMware.

Google also turns up “remote device monitoring” and, my favorite, “random death match”.

Suspecting you don’t mean any of those, though the last seems somewhat appropriate.
Rollie's Dad's Method.
 
Rollie's Dad's Method.
Ah! I should have figured that out. And I think you're right, what Connelly described is basically the same idea as RDM.

I wasn't a fan of RDM, mostly because it uses a chuck rather than the taper and you don't need a straight bar. Now that I re-read it, though, I see it is pretty close to the same idea. I'm far less critical of it now, but still prefer Connelly's method.

Connelly's method that I've described requires a verified, very straight and concentric test bar inserted carefully into the spindle taper. It depends on the high points and low points being the same everywhere along the bar. It also suggests removing and reinserting the test bar until you get a minimal difference between high and low readings at the headstock end (indicating a good fit).

Since RDM uses a chucked part that doesn't even need to be straight, and performs no cutting to create cylinders concentric to the spindle axis, I was skeptical that it would tell you much. Especially considering the inevitable bell mouth of any chuck.

After re-reading (and after actually DOING something similar) I now see that it's saying that the outermost points of even a twisted part will sweep two circles at each end of the part that are concentric with the axis of rotation. Since RDM requires a part that has the same diameter at both ends, it sweeps two circles at each end (one with a larger radius indicating the high reading). If the midpoint between high and low readings with the indicator tip on top of the part is the same, then the headstock isn't tipped in the vertical plane — even if the part is inserted such that it's sweeping a cone rather than a cylinder (which is pretty much guaranteed).

That's exactly the same as what Connelly describes, but Connelly wisely (I feel) prescribes a straight, precision ground test bar.

As described in the "Common Errors" section at the end of the RDM document I linked to above, RDM doesn't give you an actual line you can sweep with an indicator. It gives you two points and an imaginary line between them. If instead you use a straight, precision ground test bar as with Connelly's method, you can sweep an indicator anywhere along its length once it's rotated to the midway point. With RDM you must consistently indicate at precisely the same two locations along the bed, and rotate the part to find the midpoint independently at each end, every time.

I think Connelly's method and a precision ground test bar is superior to RDM if for no other reason than it gives you a physical line you can sweep (like my first video in comment #44). It also shows you directly if the taper in the bore of your spindle is ground on-axis.

I see test bars from India on ebay right now for $25 for 2MT, and $45 for 3MT. Cheap enough that I'd still recommend Connelly's method over RDM.

Regards,
--
Rex
 
Back onto the tailstock, and I realize it's kind of a mess.

After my umpteenth nap^h^h^h re-reading of Machine Tool Reconditioning, I noticed it suggests using a custom scraped "template" to check if the top of the tailstock base is flat and co-planar. Basically what you need is a surface plate with a hole in the middle (something I now recall Richard suggesting is a useful thing to have around).

The problem is that the bottom half of the tailstock has two independent surfaces that need to be scraped coplanar, with these annoying lumps of metal sticking up in the middle ( the set-over ways and the thing the set-over screws bear against):

IMG_0394 2.jpg

I'd been making do with straightedges, just scraping each surface (top and bottom in the photo) independently then carefully indicating on the lathe bed. This sorta worked, but wasn't ideal.

I toyed with the idea of milling a big hole in my cast iron surface plate (something I still might do) but then realized I had just the thing: a cast iron box square or "transfer block" I'd scraped in long ago.

So, with a big lump in my throat, I decided to mill out a portion of one side:

IMG_0779.jpg

I thought I was being clever by leaving most of the webbing in place. "It won't move that much with that much metal remaining all the way around the hole," thinks I. "That hole should provide plenty of room to mark up the part, even if I have to angle it a bit to get all surfaces."

Wrong on both counts. After milling the hole, I was surprised to see how badly the surface moved. A markup and hinging showed it had sort of bubbled up like a volcano: it was only bearing on the surfaces around the hole. I forgot to take a photo or actually measure how much it moved, but I'd estimate the outer edges were as much as 0.0001" lower than the areas immediately around the hole.

So I spent an hour or two re-scraping the surface (now surfaces) flat. I studiously ignored the little voice in my head telling me the remaining five sides now also need to be re-flattened and re-squared.

Stupidly, only after I did the scraping did I try to actually mark up the part. That's when I discovered that there still isn't quite enough room to move the tailstock base around and get a good markup. Sigh.

I need to remove the remaining portions of the webbing on either side. That's my task for today. Once that's complete, I think this tool will be even more useful.

Even with the obstructing webbing, I was able to at least mark up the tailstock base enough to see that things weren't as coplanar and well-scraped as I thought:

IMG_0782.jpg

I've got more work ahead of me.

Onward!
 
Rex you are a perfectionist, but my God your working on a lathe. How many hours do you have in it now? 500 or 1000? If someone had me quote an Atlas I would have said at tops 100 hours plus parts and planning or grinding the bed. If I were to scrape the bed. Maybe an extra 20 hours.. The spindle test bar would have been so simple if you had used plastic shim under the head to get it straight then relieved the middle and only scraped where the head bolts to the bed. Scrape the opposite side of the shim. Then leave out the shim. I would swear I showed everyone this technique in the classes. You would have to use the math to figure out how many time you needed to blue and scrape using the blind / step cut method that Jeff used and also learned the hard way to figure out on his angle block.

You have to learn how to relieve the middle and pre check surfaces like the tail stock bottom (base) with a straight-edge. Trying to follow and then quote the Connelly book on such an easy thing to me is insane. You could have called or written me. Remember Connelly was not a scraper, he was a organizer of thoughts from several craftsmen, much of that book is wrong in my opinion and one has to say...now is the best way before following that advice. My Dad said to never follow whats in the book, but for a beginner he might read it like the bible verse by verse.

Your doing a service showing and writing about your machine, but your giving examples of bad examples. Next time you start a thread or a You Tube show I would suggest you do a couple machines to learn from your mistakes before teaching others all the mistakes along the way. I love you as a student, but please don't give a step by step and assume it is right on your first attempt rebuild. Like you using the angled camelback SE when I told you you would regret it. You have a lot to learn young man. It would be like me hiring a first year college grad to program a Cray computer.
 
Wow, Rich. Glad I know you or I'd take offense. I'm a full grown 57 year old man, it's been a while since anyone laid the "you've a lot to learn young man" line on me. <laugh>

I DO have a lot to learn, about many things. With all due respect, I hope you think so too. The day we stop learning is the day we die.

Rex you are a perfectionist, but my God your working on a lathe. How many hours do you have in it now? 500 or 1000?
I think we've had a fundamental misunderstanding.

This is a hobbyist forum. I'm a hobbyist, you're a professional.

I've no idea how many hours I've put in scraping the lathe specifically, nor do I care. At all. Think of me like a teenager spending every weekend lovingly washing and waxing his cherished piece-of-junk car. Or the rich guy doing the same with his Ferrari. This lathe is my pride and joy and my absolute favorite toy.

As a hobbyist, this is FUN for me, not billable hours. I cherish every day I get to spend a few hours in the shop. I expect to make mistakes, and I value the learning and the doing every bit as much, if not more than, the final result.

Honestly, though, since I rarely get to spend more than 2-3 hours in the shop any given day for any project, I'd be shocked if I've spent more than a hundred hours on the lathe specifically.

The spindle test bar would have been so simple if you had used plastic shim under the head to get it straight then relieved the middle and only scraped where the head bolts to the bed. Scrape the opposite side of the shim. Then leave out the shim. I would swear I showed everyone this technique in the classes. You would have to use the math to figure out how many time you needed to blue and scrape using the blind / step cut method that Jeff used and also learned the hard way to figure out on his angle block.
Apologies, but I've no idea what you're talking about. The aligning the headstock with the test bar in the spindle ws by far the absolute easiest and trouble-free part of the process so far. The near perfect result in the first video of comment #44 took very little scraping to achieve.

You did indeed show us the "shim to remove any rock" then step scrape as much as you needed to shim technique in your classes. Possibly even with my lathe at the last class (I didn't get to spend much time working on it at the class).

I didn't have to use that with the headstock when I got it home, though, because at no point was there enough rock to insert even a 0.001" shim.

You have to learn how to relieve the middle and pre check surfaces like the tail stock bottom (base) with a straight-edge.
Again, I don't know what you're talking about. The headstock on my lathe only bears at four points, two vees and two flats, there is nothing to relieve. Here's the bottom view.

IMG_0794.jpg

If you're talking about the bottom of the saddle, that I did relieve when I did the rough scraping with a straightedge prior to fitting it to the bed.

Here's how the underside of the saddle marked up before I fit it to the ways:

IMG_0795.jpg

As you can see, I'd already relieved the vees in the middle and the flats are separate on this lathe.

For the record, here it is after some light scraping to fit it to the ways. Still not perfect, but quite a bit more bearing, and good enough in my opinion. I did start to see a few bearing points in the relieved section after a couple passes of fitting, so I relieved it a bit more:

IMG_0800.jpg

Trying to follow and then quote the Connelly book on such an easy thing to me is insane. You could have called or written me. Remember Connelly was not a scraper, he was a organizer of thoughts from several craftsmen, much of that book is wrong in my opinion and one has to say...now is the best way before following that advice. My Dad said to never follow whats in the book, but for a beginner he might read it like the bible verse by verse.
I'm extremely appreciative of your willingness to take questions of me and others, but as a beginner I often don't know what the right questions even are! I've got hundreds of questions, and most are too big and vague to ask. "How do you scrape in and align a lathe?" takes Connelly most of 500 pages to answer — I doubt you'd want to put it in email.

My way was to take your classes, read up on what's available (your handouts, Connelly, Moore, Schlesinger, youtube, this site and others like it, etc.) then try to do it, definitely making some mistakes along the way. I'm only now starting to understand what some of the better, smaller questions might be. If you've a suggestion for a better way to learn, I'm all ears, but, respectfully, I'm not going to stop documenting my journey.

If I was truly a perfectionist, and all I wanted was to have my little Logan "perfectly" reconditioned, I'd have definitely asked you for the name and contact info of a good reconditioned, then paid to have it done.

My goal, though was to have some fun learning how to do it myself. So far I'm succeeding in this goal.

Please don't take it as a personal affront when I quote Connelly or anyone else rather than you. It's only because your handouts are about the mechanics of scraping, not machine tool reconditioning.

With all due respect, "much of that book is wrong" is a cop out without specifics about what is wrong and why. You've mentioned to me in person that nobody in practice actually uses the water leveling methods he describes. What else is wrong?

Your doing a service showing and writing about your machine, but your giving examples of bad examples. Next time you start a thread or a You Tube show I would suggest you do a couple machines to learn from your mistakes before teaching others all the mistakes along the way. I love you as a student, but please don't give a step by step and assume it is right on your first attempt rebuild.
There's a lot to unpack there.

Firstly, I've tried hard to make it clear to anyone reading my posts that I'm a hobbyist and a beginner, that I'm figuring things out as I go along, and to talk to professionals like yourself if you want to know how to do it right. I create these posts for just two reasons:
  1. To document my own progress and learnings for myself. This site provides a nice way to include diagrams, photos, and videos inline with the text) — much more useful to me than greasy and ink-stained scribbles in a shop notebook. That I can share it with others is a bonus.
  2. Several people have expressly indicated that, like myself, they enjoy reading the play by play and actually like reading about the mistakes as they are caught. In my very strong opinion, you learn more from making and correcting mistakes than you do just watching a professional do it perfectly.
In short, I think showing mistakes is a service (as long as I or someone else catches the mistake).

Secondly, please correct me if I ever assume or even appear to assume that I'm "doing it right on my first attempt" or giving a bad example. But pointing out what specifically is wrong/bad is a lot more helpful (and less likely to create ill will) than just saying "that's a bad example".

Finally, it may not be obvious, but my youtube videos in this thread have always been unlisted. The only way to find them is from the links in this thread. I've done this intentionally in case I post something flat wrong (fewer places to chase down and correct the error).

Like you using the angled camelback SE when I told you you would regret it. You have a lot to learn young man. It would be like me hiring a first year college grad to program a Cray computer.
I honestly think you've mixed me up with someone else sometimes. I own a Montgomery Wards branded Logan lathe, not an Atlas, and I bought that angled 36" straightedge expressly to rebuild the only two machine tools I own, the lathe and a Grizzly square column bench top mill. I simply reasoned it better to have the dovetail feature than not, didn't want to buy two 36" straightedges, and it was only chance that I chose to do the lathe first.

Anyway, I'm looking forward to using my angled straightedge someday to scrape in the mill, and I don't regret the purchase. I am extremely appreciative of the gift of the lighter straightedge to the group, of course. It has made scraping in the lathe much easier.

Peace.
--
Rex
 
I wasn't trying to hurt your feeling, just bringing to back to reality. Just so much info and writing it as if it's a novel. It's a long drawn out story and if you had waited and did this drama on your 2nd machine you could have had a shorter story. But hey ejoy the story. I am just telling the readers rebuilding is not this difficult. Especially a Atlas lathe. I have had students spend less time on a Monarch EE. I am suppose to be the senior rebuilder here. Your a young man and a student with what 3 years part time experience? Someday when you have say 10 years experience....come back and read this and you will see where I am coming from.
 
I’ve replied to Richard privately and won’t be posting any further updates until we’ve both had a chance to cool down and reflect for a bit.
 
I am sorry about causing an upstir here. I have tried to support you here, but when you made the fixture to scrape the tail stock I just had to say something. I consider you a friend and have knowledge. If I hadn't I would not have asked you to help at the CA class as my assistant. As I said, spending months rebuilding an Atlas is not something one needs to do. I understand you have a full time job, but I was starting to see your project scareing (I have seen this happen before) people away from rebuilding because you made it so complicated and the way you go so deep into experimenting on new ways that take hours and hours, weeks and weeks, months and months.. when it should take others a few weeks or a month. I had to say something. Rebuilding and scraping is easy and not so complicated. One your issue about filing the Tailstock key to get alignment I tried to be diplomatic about your guess or experiment. This plate to scrape the TS just set me off....way to complicated for a Sears or Atlas lathe. The saddle is relieved but was the tailstock top you blued up? I would have been checking that and normally the underside of the TS top is relieved.

You are doing a service but I had to step in and say to Joe Public rebuilding and scraping need not be this complicated. Please continue on, but to the others reading this. Rebuilding is a whole lot simpler then what Rex is showing you. I have been saying this for years "if I see something not correct no matter who says it I will say something" If that hurts your feeling, that the way it goes. The Industry has to come before friendship and feelings. Please keep writing your documentary. It's like the Connelly book...some great info, but don't read it in bed and you can't take it as gospel.
 
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when you made the fixture to scrape the tail stock I just had to say something.
Ah! So that's what set you off. I honestly had no idea what specifically made you mad. I wish you would have said so earlier.

Please, please call out specifically at least one or two instances of anything I'm doing wrong in the future, don't just say I'm giving bad examples and leave it for us to guess which of the things I've talked about are wrong. Hopefully they aren't all wrong!

Milling the slot in one side of my box square is just to make the marking and scraping cycles quicker and easier for the top of the tailstock base (or anything similar in the future that has a protrusion in the way like that).

I just finished epoxying phenolic to the top of the tailstock base. Once it dries, I'll need to scrape the phenolic and that will be pretty much the end of the scraping work.

If I hadn't milled the slot in the box square it would take longer and be more difficult to ensure both surfaces remain coplanar as I scrape away several thou of phenolic. You obviously hate the idea, but I had the box square just sitting around not doing anything useful, it was quick and easy to do, I find it a convenient tool to have, and I have a strong suspicion I'll find other occasions to take advantage of that slot in the future.

All that's left of the project is:

- Reassembly of all the precision bits and final alignment checks.

- Cleaning, sanding, and painting (which I hate, hate, hate, so will probably take me forever, but while I have it apart....)

- Final assembly of everything including gearing, motor, etc.

- Re-leveling, a two-collar test, and then start making chips.

Sorry to irritate you further with another long comment, but once its completely done I'll post one with my takeaways from the experience. Again, I'm doing it as much for my future self as anything, I find it useful to get things down while they are still fresh in my mind.

Regards,
--
Rex IAHNAPDTAISAG* Walters

* I'm a hobbyist, not professional, don't take anything I say as gospel.
 
I've painted old machines. Hated the whole process, from prep to paint, but was able to get a bit of a premium when the machine was sold. I don't paint anymore. Not as important as function and operating condition. And not a big enough premium to make it worth the hassle.

Ok, I understand that the purpose of reconditioning a machine is so you can then use it to make stuff. But also that, for us hobby guys, reconditioning is a journey. And the journey can be satisfying as well. Building skills and learning is part of what makes this hobby enjoyable.

Nothing but love for you guys. All of these posts are going to be really helpful for any of us who decide to take on a similar project.
 
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