View Full Version : Need suggestions for repairing ways

08-12-2006, 02:45 AM
Last October I got a great deal on a large Polamco lathe (21x70) it has normal wear and tear and overall is in good shape except the front way close to the chuck, about 24" of the way is scored. I really haven't used the machine a lot but I'm assuming the front way wiper is bad and chips got under the carriage. Is it possible for a HSM to repair this or do I need to tear down the lathe and have the bed rescraped or ground? I don't know anything about scraping ways and these are about 84" long overall. The tailstock rides on it's own set of ways and they are in great shape. The rear carriage way is also in great shape and the tail stock end of the front way is perfect. I'm planning on doing some long work over the winter and I just know that bad section of the way will cause me trouble, any suggestions? Approx what does it cost to have a bed of this size reground?

08-12-2006, 04:00 AM
I'm not sure the details, but I've heard more than once "a couple of hundred dollars" thrown around. Of course, depending on how the head stock is mounted this may mean shimming up the saddle and reseating/scraping the head stock. Certainly doable, but finding a place close by to do the work may be the hardest part, otherwise you add shipping along with the accompanying delays and risk of it getting lost or ruined.

Fortunately, my new lathe seems to have a fine bed, but the cross slide ways turned out to be very badly scored on the bottom side. I’m currently investigating getting them ground and scraped, or possibly laminating with Turcite, or building up with Moglice which are low friction synthetic polymers that have become very popular for VERY low friction ways in the last few years. I think I prefer grind/scrape, but if it turns out to be too bad for that, then the others become more attractive. These are also options for the main bed ways that you might look into...

08-12-2006, 04:32 AM
Could I fill up the scoring with moglice or something similar? I haven't really looked under the headstock covers but I know it's complicated in there. The total bed length including the area under the headstock is about 10 feet, still think "a couple of hundred dollars" is possible? Fortunately I'm in Ohio so i have to think with all the machine shops and tools around there must be a refurbisher within reasonable driving distance and I do have a flat bed trailer that I hauled the lathe on when I bought it. I'd love to get it professionally done but I can't spend much more than $1000 at this time. The upside is that while the machine is torn down I could clean it all up, attend to some details and repaint the machine.

I really like this lathe and it has served me well when I have used it, nothing like taking 0.500 off the radius of 303 stainless in one pass! I had to make a stepped roller for a coating machine at work, it was a shame to make all those stainless chips but the roll had to be solid.

Hmmm wonder who has a 10' surface grinder :D

08-12-2006, 05:03 AM
No idea on how the cost compares, that's just some numbers people threw out talking about having a bed reground.

I also don't know details on the Moglice as I'm only beginning to sniff around in that direction. But here is a link to their web site (http://www.moglice.com/newsite/pages/applicpages/rebuildframe.html) that shows examples of where Moglice has been used to repair various machines...

08-12-2006, 08:19 AM
The first question is does the lathe provide the accuracy needed? If it is working within the requirements of your application, repair is not needed. Scoring does not necessarily affect accuracy.

Make sure the lathe is installed on a solid surface and properly leveled. If it was leveled at installation, recheck it. It can change. Make some test cuts and determine the accuracy of the lathe. There is no point in fixing it unless the problem warrants it.

If it is scored from trash under the carriage. Clean it and the carriage well, and lightly stone the ways to remove any high spots. It might be a good idea to remove or at least raise the carriage to make sure nothing remains to cause farther damage.

Install new wipers and keep the ways well lubricated. Unless there is wear in the ways, the scoring will not affect accuracy.

Scraping is not cheap, and with the size of the machine, you will have to have someone come to you to repair or incur shipping costs which will add even more to the expense. It can be done by the HSM, but experience, lots of practice and some specialized tools are needed.

08-12-2006, 11:27 AM
Jim's reply was spot on. Make sure that the ways or saddle are actually worn enough to affect accuracy before going into the grinding and way material process. And a 'couple hundred dollars" won't get you far along that path once you're moving, it'll be more like a thousand before you're finished with just the ways. Generally, if you find that much wear on a lathe there's going to be other problems that'll pop up in the process of fixing the ways.

I went though this with a Monarch 10EE - stripped the lathe down and took the bed, saddle and cross slide to Commerce Grinding in Dallas. The were able to clean up the bed with .007" grind and reground the cross slide dovetail ways on the saddle and squared up the cross slide and top of the saddle (the latter simply cosmetic). After remounting the bed I had to scrap the tailstock into contact with the bed, use that as a gage to scrape the headstock back into alignment and contact with the bed.

Once the headstock was in place I made little jackscrews for the corners of the saddle to work out the alignment. It needs to be a particular height for the apron to have the appropriate height for the leadscrew, feed rod and switch rod and you want the cross slide to be perpendicular to the spindle. Once that was done I could use feeler gages to get the existing clearances (wear and the bed grind) and calculate the work. I had to mill the ways on the bottom of the saddle to give clearance for Moglice (minimum thickness is .032") about .012 on the leading edge and .019 on the trailing edge. After putting tape (oil grooves) and release compound on the ways I was able to mount the saddle with Moglice putty on the bed, and in testing the result it came in better than .001 on height and .0001 on cross slide alignment.

I then had to measure the wear on the cross slide, I'm not sure if there was an easier way but I simply measured the height from the top of the cross slide to the cross slide screw, and subtracted the thickness of the cross slide. That should have given the distance from the top of the nut to the screw centerline, and it's what I used to calculate how much material to take off the bottom of the cross slide to get it to the proper height for the screw, taking into account the .032 for way material and .004" for glueline. It came in .001" low when all was said and done, but no scraping was required. The repair of the drop eliminated a makeshift fix on the gib with a .007" shim, so if the cross slide gib is loose the cause is likely wear on the bottoms of the cross slide ways.

The rest of the work was pretty straightforward repair stuff (but a lot of it), I just wanted to summarize the way work. Since the Moglice is using the work as a master in the molding process it really does need to be straight and clean, something very freshly scraped might work but all the examples I've seen have used ground surfaces. You can't use a thin layer of it anymore than you can use a thin layer of glue to build up an exposed surface, and that's all it is - very brittle glue at that. It worked very well on the saddle but would not have worked on the cross slide, so I used way material for the latter.

Harry Bloom has written a couple of articles for HSM on the process of reconditioning a lathe, with a focus on scraping the bed and other bits into alignment. It might be a good idea to read all that to have a good grip on the process before jumping in.

08-12-2006, 02:40 PM
Well I suppose it only makes sense to determine if the accuracy is being effected before fixing something that might not need fixing. I'll get a long piece of stock and make so test cuts to determine if there is a problem before proceeding.

08-12-2006, 03:55 PM

You might also look up the machine tool reconditioning book, read about way checking procedures and do some indicator tests comparing the unused portions of the ways with the scored ones. This would tell you whether the geometry has changed and by how much.

Jan M.

08-12-2006, 06:40 PM
it has normal wear and tear and overall is in good shape except the front way close to the chuck, about 24" of the way is scored. I really haven't used the machine a lot but I'm assuming the front way wiper is bad and chips got under the carriage. Is it possible for a HSM to repair this or do I need to tear down the lathe and have the bed rescraped or ground?

It depends. If the ways are just scored (and not depressed from wear), then you can just (very) lightly scrape the raised scores back into the trough and stone everything flat, and use the lathe as-is. However, since the front way close to the chuck is the area of most use (and swarf), it's more likely that it's just worn more on that side from use. If this is the case, then the cross-slide and compound will be worn more on that side as well.

Note that Moglice, Turcite-B, Rulon-142 et al are meant for the female bearing slide. The most common use for these PFTE bearing materials is to insert under the saddle of a lathe or mill, which wears a lot faster than the male ways if you have hardened (or chromed) ways.

As RKlopp mentions, Harry Bloom (who is a poster on PM, and possibly here as well) has an outstanding article on rebuilding a Monarch lathe with worn ways. I don't know how experienced you are, but Harry's restoration involved extensive scraping with a Biax power scraper -- i.e., it was a heroic effort, and not something a newbie would want to attempt.

First thing you're going to want to do is clean up those scores with a scraper, file, or india stone, and measure the alignment of the ways, carriage, etc.

As others have suggested, Connelly's Machine Tool Reconditioning is highly recommended, but it's not for the faint of heart :)

08-12-2006, 06:55 PM
I don't mean to hijack, but since it seems we are dealing with similar problems and questions, I'll link some pics of my problem scoring for comment, and perhaps it will help Christian as well. If nothing else, maybe it will make him feel better about his damage? Or comment that his is better/worse for discussion? :D

The first is the bottom of my slide. The next 2 are a side angle shot of the saddle for perspective and a close up shot of the details of the same area.

Edit: Oh, and my expectation was that the saddle would be surface ground smooth and then Moglice/Turcite the cross slide.




Alistair Hosie
08-12-2006, 07:31 PM
What Jim Hannun says is a good point(as always with JIM ) might be better to clean up and leave alone if the accuracy is good enough.I wouldn't like to take my lathe to pieces to do this but then maybe my being unwell doesn't help still it needs a guy with a big heart to undertake such a re grinding task good luck whatever you decide I hope it all turns out well for you kindest regards Alistair

J Tiers
08-12-2006, 09:18 PM
If the score is a depression, and most of the surface is OK.....

Then you really DO need to fix it, as it will continue to tear up the saddle as stiff gets in the score, and then under teh saddle.

The good news is, you can stone down the edges.....

Then give that area a really good bath in solvent, wiping and re-applying, until all oil is gone.

Then, get any un-filled epoxy that suits you, and fill in the score. Get it all teh way full, and above.

When hardened well, use a burr file and cut it down flush. A stone will just fill up, and a regular file may damage the surface.

Did it a couple years ago, all is still fine and dandy, way oil has not caused any trouble. I used 5 minute epoxy.....

08-12-2006, 11:09 PM
The scoring on my ways looks similar to the above pictures. Filling the scores with epoxy sounds like and option if the machine is still accurate enough. I won't know much more until I take a long cut on the machine.

08-12-2006, 11:25 PM
Right now I think you should take a test cut on a long piece, to see if you have a problem that you can't live with
The next thing you can do now is to obtain a copy of Connelly's book "Machine Tool Reconditioning", if for no other reason than to see what is involved in leveling and checking the lathe out. There are nuances in the book that only experience teaches, and that Connelly was able to put into words.
One way to check the bed is with a Master Precision Level. It is one of the ways I verified the Monarch's bed in the article. The way I did it is quite involved, and is detailed in the article. In short I checked the front way against the other 3 ways. I then did the other 3 ways in the same manner. That was for the transverse direction. I also checked the ways longitudinally. I recorded all the readings and then did a comparison. When I got done I had an excellent idea how "good or bad" the bed was.

08-13-2006, 11:33 AM
HI! 20 years ago we were charged $ 100.00 a foot. That's the cheap part...By the time you re-scrape in the saddle and tail stock plus re-shim the tail stock to proper height will take hundreds of hours. A complete re-build without much headstock work would be 1/3 to 1/2 the cost of a new machine.It's a real big job and a challenge time wise. Hope this helps...If you need more info, feel free to ask...

08-13-2006, 10:40 PM
to rkepler: I saw you had work done at commerse grinding in dallas. They were also recommended to me for gringing the ways on my 19 x 54 LeBlond. I have about .015 of wear near the headstock, but none back further. The tracks are removable, and I could remove them to have them ground. I could then shim them up by the amount taken off to get the saddle the correct height. The saddle binds some with certain movement and jib adjustments.

Did you like the work they did for you, and was it for a reasonable cost?


08-14-2006, 12:20 AM
Did you like the work they did for you, and was it for a reasonable cost?

They did excellent work at a very reasonable cost. I saw the last of the work being done - they were grinding my taper slide on the same grinder on which they'd run the lathe, and it looked like it would have been good for a lathe up to about 16' or so. Grinding a bitty taper slide weighing a few pounds on that looked a bit funny. They knew what they were doing with a lathe bed, too.

They weren't quite done when I arrived to pick things up, and the owner gave me something of a tour and a lesson on hammering a 1/2" thick circular saw blade flat. the blades were used in mills to cut channel, big suckers.

08-14-2006, 11:18 AM
By the time you re-scrape in the saddle and tail stock plus re-shim the tail stock to proper height will take hundreds of hours...

That's a very good point -- I was going to say something about shimming the headstock, saddle and tailstock after grinding the bed, but I think we discouraged Christian enough as it is :p

By the way, Machine Tool Reconditioning doesn't believe in shimming -- Connelly indicates that after you get the ways straight (either by scraping or grinding), then you scrap the tailstock and headstock to compensate.

On the other hand MTR is pretty extreme, and shimming the Headstock (and tailstock) after grinding the bed is very common.

08-14-2006, 01:02 PM
Shimming the headstock I can understand. But how do you shim the tailstock when it needs to slide around? Same for the saddle...

Shimming or scraping the head stock into alignment though is pretty obvious.

Seems the tailstock would then need scraping to align the axis with the spindle axis in height, and parallel to the ways. It would also need a decent bearing surface but even 40% would seem like more than enough since it does not slide under load.

And the saddle needs to be scraped to "fit" with high contact and the cross slide perpendicular to the longitudinal axis while also flat relative to the front and rear ways. Since it move under load, it would need a high contact bearing.

That's how I see it anyway. Am I mistaken?

08-14-2006, 01:41 PM
Shimming the headstock I can understand. But how do you shim the tailstock when it needs to slide around? Same for the saddle...

Good question. People usually shim the tailstock by putting the shim in between the tailstock base and the main tailstock casting. If you don't have a two-piece tailstock (like on the Hardinge), you're screwed.

Two other issues with shimming the tailstock: the nose of the tailstock is often shipped from the factory a tad high, to account for sag from the workpiece. Counter-acting that is that the front edge of the tailstock base tends to wear faster than the back half, front dragging the tailstock on the lathe ways. A lot of old-timers will tell you to lift up the tailstock when you're moving it around for this very reason.

Shimming or scraping the head stock into alignment though is pretty obvious.

Sure, but in Connelly's perfectionist world, he believed that you should scrape the headstock down to the ways, and not shim it.

Seems the tailstock would then need scraping to align the axis with the spindle axis in height, and parallel to the ways. Am I mistaken?

No, you're right. In fact Connelly's sequence of rebuilding a lathe is:

1. Scrape the ways.
2. Scrape and align the tailstock to the ways.
3. Scrape and align the headstock to the ways and the tailstock.
4. Scrape and align the compound slide rest
5. Scrape and align the carriage so it's parallel/perpendicular to the compound slide, and parallel to the ways.

The bitch with scraping the carriage is that by scraping the bed ways, you've effectively lowered the height of the carriage in a non-uniform way (each of the four ways is lowered by a different amount) and in order to prevent binding of the leadscrew in the half nuts, not only do you have to scrape the carriage back level, but you also have to raise it back to the correct height to center the half-nuts.

Nowadays, people usually just shim the saddle back to the correct height with Moglice or Turcite-B.

08-14-2006, 02:15 PM
Have a look at this one, especially his approach to the ways...



08-14-2006, 02:59 PM
Have a look at this one, especially his approach to the ways...

"Don't try this at home." :D

08-14-2006, 07:37 PM
Have a look at this one, especially his approach to the ways...



Actually there is a lot to learn there. My lathe is similar in that is has separate ways for the tailstock and they are in great shape. I suppose I could rig something up with the tailstock base to measure the main ways and see where I'm at.

I'm picking up metal tommorrow so I can make some long test cuts.

J Tiers
08-14-2006, 10:15 PM
I am slightly acquainted with the Picosystems guy... He is OK... and oriented towards getting things right, not a hack.

So, I wouldn't dismiss the info, although I might not have done exactly that in exactly that way.

08-14-2006, 11:06 PM
BadDog, did you look at this page (http://www.moglice.com/newsite/frames/wroteframe.html) on Moglice? Look at fig 29 or 30.

08-14-2006, 11:36 PM
Actually, no, I didn't see that one. But I think that would only work with "V" as opposed to inverted "V" of a typical bed or, as in my case, flat" for the cross slide. Mine also has the problem of being damaged on both sides AND being flat.

From what I've gathered, fixing mine will involve the following.

1) Setting up the top slide on a surface grinder to cut the bottom parallel to the top and deep enough to remove all wear. Estimated 0.030-0.040 material removed.

2) Set up the apron by tramming the top of the saddle level to the table. Then mill the entire top of the saddle enough to remove all wear. The current cross slide way surface was originally level with the top, now worn with scoring and galling below the surface. I am advised that if I just grind it down, being lower than the rest of the surface, it will be more inclined to collect trash, so it has to all come down. I'll also be taking a page from Moriseki in milling a small, maybe 0.030 trough with a 1/8" ball end mill to act as a "moat" along side the ways and hopefully reduce the trash getting in there.

3) Scrape the two for bearing surface, then spot for oil control.

Hmm, I suppose I could just grind and polish the top of the saddle on a surface grinder as described above, but save the “moat” for later (or eliminate). Then rough grind or mill the cross slide to clean it up and square it. Then build a dam on the apron to pour the Moglice after coating the apron with the release agent. And then settle the cross slide into place to let it set. Hmmm, and HMMMM some more... If the apron is very nicely finished/polished on the grinder, and the Moglice makes up the difference for the removed material, it wouldn't even need the dovetails or gib modified for the new height nor would it need the expensive hand scraping. Or maybe just have the dovetails scraped to bring them back in if needed?

08-14-2006, 11:46 PM
BD, looks like this is getting overcomplicated. Never used Moglice, we did it the old fashioned way. If the machine was too large, we'd send it out to be rebuilt. Not sure which way I would go, without seeing it. Good luck

08-15-2006, 04:16 AM
Aint that the truth.

<Warning: My legs are killing me, can’t sleep, and bored. Rambling follows and has little or nothing to do with the original topic>

Thing is, people fall into groups in that respect.

Group A: Smart experienced people do things the “easy” way (or make it look easy even when it's not), because they know what they are doing and how things are done. They just do it, usually with little “production” to it, and lesser men (often called management) don’t even recognize what they are seeing because it went by so smoothly.

Group B: Ignorant people (those that know they are ignorant anyway) that none the less have some experience and common sense (they hope) make things overly complicated because they don't know what they are doing, much less have a clue what the “best way” may be (definition of “best way is often a task in itself AND subject to change). So they are trying to analyze every possible way to approach and solve the problem and hoping against hope that they don't miss something and screw it up (including spending more money/time than needed or getting insufficient results). Eventually, with a little luck, these ignorant people hope they can one day be among the “smart people” if only they can learn to understand things sufficiently.

Group C: Stupid people some times look like smart people because they “just do it” and it works. They then hold this out as proving that complicated things are actually really easy and everyone is just over-thinking it. In my other hobby, “rock buggies” we see this all the time when people “get lucky” with their first link suspensions and such, then have no clue why the second one is completely non-functional. But more often than not, they screw things up, and usually blame someone else if possible, or god/fate if they can’t find a convenient person to blame. :D They also sometimes look like ignorant people simply because they can’t grasp the problem and can’t even grasp THAT fact, so they churn and try to find an answer anyway. Eventually though, it becomes obvious that they are in fact in the stupid camp. Also note that some people are stupid in certain areas (or just ignorant, only time can make the truth known to the person or observer) while being quite smart in others...

Any guess which camp I fall into? :D There are 2 possible answers I’m afraid, and they are easily identified by process of elimination. Which of the 2 is the more accurate remains to be seen...

As said by others before (to paraphrase, artistic license, beat-to-fit-and-paint-to-match and all that), “It takes a truly brilliant/great man to make a difficult thing seem easy, an average man to make something simple into something hard, and an Engineer to truly screw things up” (I figured you would like that bit ;) I’m an Engineer of sorts by the way.)

I have an experienced friend who is primarily "old school" but also still kept up to date for the most part and continues to work in many facets of the machine work community. He urges me to do the grind/mill and scrape routine along with all the accompanying realignment of the various bits and pieces including dovetails and a new gib to make up for the changed dimensions and relationships. He’s also generously offered to “hook me up” with the “right people” and even let me use his personal Moriseki lathe and surface grinder. I hesitate to disregard his advice, but it is my nature to question everything until *I* understand. So I read about these marvelous (sorta) new technologies like Moglice and Turcite that are reported to provide previously undreamed of smooth operation while at the same time allowing things to be tighter (gibs and such) for less chatter and repairing worn out bearing surfaces. Seems be perfect as a part of the repair of the damage that I and the original poster are dealing with. One problem is that I don’t know anyone with real hands on experience in that area since most of my HSM friends are retired machinists and the like with no knowledge of this newish stuff. There are lots of resources on the net that cover these options to varying degrees, but we all know the value of such “resources” is questionable, and I have no way to gauge their accuracy or completeness. Are they really in “group C” and just got lucky? I also imagine (and have read accounts that seem to support even though generally low key and not really a warning flag) that these materials could be more easily damaged by grit and such. Since I do use my lathes for polishing and finish sanding with emery and the like (covering as much as possible), is this a problem? And what are the real total costs/requirements of all the varied options using Turcite laminate, Moglice, or traditional approaches? Moglice putty vs. Liquid? Grind vs. Scrape? To flake or not to flake? Longevity issues for HSM use? There seems no clear answer, so I find myself in a situation sometimes called “analysis paralysis” in my professional field. In that area, I know how to break through, in this area, I am either too ignorant or stupid to find a way other than “just do as I’m told” or flip a coin. One seems as viable as the other... :(

Sorry for the book...

08-15-2006, 04:54 AM
I currently work at a job shop and have seen an awful lot of damaged peices come through here. You might check with any local job shops and get a quote from them. Just an idea.

08-15-2006, 11:11 AM
There seems no clear answer, so I find myself in a situation sometimes called “analysis paralysis” in my professional field.

I think a large part of the problem is that there are a lot of different objectives all mixed up. If your objective is to get the machine working again as quickly as possible you'll use one technique, if you're trying to return to factory specs there's another, etc.

Added to that there have been some changes in the field - 50 years ago there was no real way material you could add to build up a surface, so anything written before that became common will assume that you have to relocate drive systems, etc. 20 years ago there wasn't a castable way material, so anything... etc.

Then there's cost. If you have essentially free labor then one choice becomes the obvious one, if you're missing time another is best. If you have to make or buy gages it might add cost to one process or another and drive the choice (if you don't have a flat as long as your ways you're not going to have an easy time of things scraping the lathe bed).

I ended up going with a bed grind and using Moglice because it was something I felt comfortable doing. I used Multifil (like Turcite) on the cross slide as it was something I felt comfortable doing. Some replacement parts I made, others I bought, whatever made me comfortable.

Do what you understand and feel comfortable doing.

08-15-2006, 07:35 PM
Bad Dog,
If possible, get a copy of the article "Reconditioning a Lathe- Revisted" HSM Sep/Oct '04 thru Mar/Apr '05. It deals with the problems that you are encountering.

08-15-2006, 11:12 PM
something I felt comfortable doing. I used Multifil (like Turcite) on the cross slide as it was something I felt comfortable doing.

Rkepler (or Harry): where did you get your Multifil-426 tape? Is it only available direct from Garlock in those big 12 x 120" sheets? I was going to buy a sheet of Rulon-142 from McMaster, but it's very expensive.

Turcite-B, as best I can tell, is only for sale direct to machinery rebuilders.

Harry used MultiFil in his Monarch rebuild, but I Googled it and can't find it anywhere (for retail sale) -- all the hits are Garlock pages.

08-15-2006, 11:13 PM
If possible, get a copy of the article "Reconditioning a Lathe- Revisted" HSM Sep/Oct '04 thru Mar/Apr '05.

By the way Harry -- fantastic articles!

08-16-2006, 09:52 AM
Turcite-B, as best I can tell, is only for sale direct to machinery rebuilders.

These folks sell it: http://www.mtsandtg.com/products.htm

I've bought other stuff from them and always found them easy to work with. If you do use way material the epoxy you use is critical as well as the way prep, even how you spread the glue. These guys were the only suppliers of the notched spreader I could find.

08-16-2006, 07:11 PM
I got the Garlock Multifil 426 through Applied Industrial Technologies. I had to buy a full sheet of .030" thick material. Still got quite a bit left left over. If you need some, contact me off forum. I won't give it away, but the price will be reasonable.
I would imagine that other industrial suppliers handle it also. You just have to call around.

08-16-2006, 07:34 PM
Lazlo- Thanks for the compliment.

The people that Russ recommended are good to deal with. Russ told me about them when I was looking for a K&T part, they didn't have it, but they did put me in touch with a fellow that deals in K&T parts.