Preventing machine rebuild and way scraping - scheduled maintenance

I was thinking we should share idea's on preventing downtime on your machine tools. We have many experienced machine builders, rebuilders, maintenance men. machinists with tips we can share to avoid the expense of rebuilding.

I see so many people who buy a used machine and automatically assume they have to rebuild the machine. Here, We are asked about how to repair this and that after the machine breaks. The majority of our work could be saved if the machine owner or machine owners maintenance men followed some simple rules or a scheduled maintenance.

I just saw this on the Home Page of Practical Machinist that can get us started.

6 “Healthy Heart Exercises” for Your Spindle | Oku

Another simple trick on Machine Lubrication on older machines is to install a pressure gage in the lube line so you can watch it. No pressure means? A broken line or pump issues. To much pressure means something is plugged.

On most older machines say for example a Bridgeport Mill, It has a lubrication manifold under the saddle left side that has Bijur Metering (jets) that get plugged up and limit the lube oil that goes to the ways. Depending on the hours on the machine they need to be replaced because they can get plugged. Lets share those types of things.

Another simple trick is to check the level and alignment at least once a year on production machine. If a machine is not aligned properly the ways wear faster then they should and they machine out of square / parallel.

I had a shop with a CNC VMC call me a few years ago, saying the machines ways needed scraping and it was not cutting square anymore. The first thing I did was ask them "when was the last time you checked the level / alignment?" They had a dumb look on their face and said "never". I put 2 precision levels on the table and started to check travel and one corner was low. I crawled under the machine and that leveling screw was loose.
Took me 1 hour and the machine was cutting straight.

Another time, a guy called me and said his lathe needed rebuilding because it was cutting a taper. Same thing the machine had not been aligned in years and the bed was twisted. Lets share those types of stories so when someone Googles an issue they will be brought to our forum. :-) Rich

Complacency and Apathy kill machines fast IMO.

Just simply cleaning your machines and then keeping them clean, inside and out, is a big help. I know a lot of guys hate doing it as it has "no direct bearing on the machines productivity" and stuff, but as I see it when you're getting in there on a regular basis, THAT's when you find the loose brackets, wearing parts, and chips where they shouldn't be and you can keep things from becoming problems or from getting worse.

With any industrial machine, I'd always recommend getting copies of any literature and becoming familiar with it. Find out what the maintenance schedule for the machine is for the original 8 hour a day work shift and adjust it accordingly to your needs. I've seen alot of machines where oil points were ignored because they "didn't use it THAT much" and consequently, the machine NEVER got lubed.

3 years or so ago, I got all of our machines manuals out and typed up a "general shop manual" that has a calendar with all the daily, monthly, yearly, etc. tasks for all the machines as well as modern lubrication equivalents and such. If something isn't seeing full use, sure we can omit a lube every now and then, but we're aware of it. When someone does a lube task at the end of the day, they date and initial it in the binder. Everytime a machine leaves or comes into the shop, the binder gets updated.

i have seen machines that used plastic oil lines that were cracked or leaking. sure they pumped the oiler but no oil was getting to some points.
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bridgeport table often the oil lines require sliding the table off to see the oil lines. just saying i have seen where plastic tubing can be a poor choice for many things especially if buried unseen in a machine

That was a big problem in the old days when they would install BiJur pumps in the bottom sumps in the carriage of a lathe. They would get gunked up and never work and you had to pull the saddle to reach the pump, so as M.B said it never got done. The machine builders would bury the BiBur manifolds under the table of Cinc. Mills. Under the saddle of a Monarch EE Lathe. Newer machines now mount them where maintenance men can get to them without tearing the machine apart. Nylon tubing is a maintenance mans friend, helps us make more $$ and loses machine owners $ in downtime when it breaks or get frayed wring something rubs against it.

Richard King said:

That was a big problem in the old days when they would install BiJur pumps in the bottom sumps in the carriage of a lathe. They would get gunked up and never work and you had to pull the saddle to reach the pump, so as M.B said it never got done. The machine builders would bury the BiBur manifolds under the table of Cinc. Mills. Under the saddle of a Monarch EE Lathe. Newer machines now mount them where maintenance men can get to them without tearing the machine apart. Nylon tubing is a maintenance mans friend, helps us make more $$ and loses machine owners $ in downtime when it breaks or get frayed wring something rubs against it.

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the prototrak bridgeport mill i used one day i had knee so high the sliding metal cover to keep chips out caught on column dovetail and when i lowered knee i bent it. to replace it i had to take the table off and then i saw the cracked broken plastic oil line tubing. for years i faithfully pumped the oil pump in the morning never realizing oil was not going to all the points
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i agree its bad design to have the tubing covered or buried where it cannot all be seen

Replacing the way wipers would be a priority, don't let them get worn, hard or damaged.

A pressure gage on the way oil system is not 100% reliable indicator of it working properly. I worked on a machine that had a network of Trabon metering blocks feeding the individual ways. One block fed 3 other manifold blocks, X Y and Z. We cleaned the X and Y meter manifolds. The gage was damaged, so I replaced it. All looked well, when the pump cycled you could see the needle move in jerks as the meters allowed oil to transfer, the gage went up as high as 40 lbs at times. The gage was 100psi max. After a few weeks, I saw the gage damaged and stuck at 60 psi. I figured it was a bad gage and replaced it with another 100 psi gage - good one again, from McMaster. A couple more weeks, that one failed too. Replace it again, cycle the pump a LOT, watch the gage, all seems well. A couple months, another gage fails, put a 200 psi unit on. It fails again. Suddenly the machine starts to make noise moving in X, sounds like a rubber way cover squealing. Not the cover. Lots more diagnosing, the gage has failed again.

Short version - Hook up a grease gun converted to oil and use it to pump #2 through the way oil system one leg at a time. FINALLY we see the gage hit 200 psi. Turns out one of the meters in the 3 meter block was sticking intermittantly and starving the X axis, and pegging the pressure gage at the same time. Cleaned the block and meters and all is well now. Would never have found it if the X hadn't started to eat the Turcite loudly enough that we could hear it. I don't know how to trigger an indication of trouble like this happening unless you have a pressure gage with a tell-tale.

I was thinking of a BiJur one shot type oiling system like the majority of machines I see. I have been telling people lately about trying to slide a .001" feeler gage under the wipers. Also when you replace them put a wedge behind them so the wiper snow plows the dirt off to the side instead of just pushing it forward.

I think something I see alot at shops is when the oil is low in the tank, they simply add new oil to the old oil. A few times of doing this, and the oil inside jsut becomes that brown sludge that clogs oil lines. We recommend taking the tank off and cleaning it prior to filling it with all new oil. It seems to keep the lines in better shape by not keeping old nasty crap in the bottom of the tanks.

Seems normal to me, but most shops don't do this.

Jon
H&W Machine Repair

Years ago I had a company called me at 3 PM with an emergency breakdown. I took 2 employees there and tore the machine apart, working until 12 Midnight. It was a Pratt & Whitney Tape Mate which was a nice well built compact machine and popular 30 years ago.


As we pulled it apart we discovered the Turcite was ripped off, the hardened ways still looked good and worn less the .001", The reason it was screwed up is because the nylon Bijur lines were plugged with small slivers of aluminum chips. Yes plugged! As we traced back the plugged lines to the pump we discovered the pump was mounted inside the enclosure guards, the spring loaded 1" flip cover was open (spring was broken) and the oil reservoir was full with oil and aluminum chips. We opened the pump and the 3 screen / felt filter on the bottom of the one shot auto pump in the reservoir was not there. The lube system had a factory installed pressure gage and alarm on the control too. We opened the electrical panel and there was a jumper cable on the alarm. It was insane we figured that night.

The next day we didn't get back over there until 10 AM as I had to order new parts before driving over there. As we were working around 10:30 an old fart who reminds me of a pain in the ass forum member walks up to us and said " We open at 7 AM and expected you to be here at 7 AM!" I said "Sir" we worked until midnight and then had to drive home. I didn't get to bed until 2 AM! He said he didn't give a damn and we should have been there at 7 AM.... I looked at my men and said..."pack up the tools, we are leaving!!" as we did that the company owner rushed over to us and said where are you going? I was pissed and said some old SOB in a white shirt came over and gave us a bad time about getting here at 10 AM. I can laugh about it now, but I was super pissed then. The owner apologized and said it was his retired Dad and to forget about what he said. Then the machine operator walked up and asked when we would be finished? I asked him about the pump and he said. "That damn pump filter kept plugging up with chips so they took it off and then the dang alarm on the control was shutting them down, so the maintenance man jumped the alarm after management (old fart Dad) told him to as they had a BIG Job to get out" LOL

Now that has to be one of the dumbest things I had ever seen or heard. But the old fart dad was so interested in making parts and money he never though about the consequence of crap maintenance. When we invoiced the owner I thanked him and said keep up the swell maintenance and laughed....They became a great customer after that. Remember the old TV commercial about a Fram oil filter ? "You can pay me now or PAY me later" That is what I said to the owner back then...lol Amazing I can remember that like it happened yesterday. Rich

I've told this story before, but when we bought our second VMC (2006 Hardinge), we didn't realize it used grease for the ways until it was on the floor. We asked one of the techs installing it what to do (we had no experience with way grease) and he said to pump "white lithium grease" in as the control directs.

Fast forward a few years and we see that a couple of the distribution blocks have had the plastic tubes pop out of their push-to-connect fittings. We dig a little further and find that the grease has hardened in the lines and isn't getting to the ways.

So over the course of a couple days we pull all the covers off and one by one, replace the tubing and pull each truck to we can rinse them out and start fresh. We were lucky that the machine hadn't worn enough to effect it's accuracy but it was a good lesson that that expensive "Kluber Isoflex" grease is worth it. If we had read the manuals when we first got the machine, we could have avoided the mess.

It also boosted my prejudice against "grease" mills . Oil may be more work in the long run, but it's so much more forgiving IMO.

Hey Ya'll,
This is so obvious that it should be self evident, BUT ! If I've had this conversation once I've had it a hundred times.. USE the lubricant that the manufacturer recommends. IT's really just that simple but I've been in shops where any old thing that resembles oil is dumped in machines with no regard to what is going where.. Why is it so hard for some folks ( and management) to source the proper oil/grease ? IF the manufacture calls for a certain grade of way oil why not just buy it instead of dumping tractor hydraulic oil in the way oilers ? I've almost come to blows with some managers over this.. They come down and complain about finish or machine down time or some other thing.. You try to get them to understand about 'stick-slip' ( improper oil on the ways) or that 5wt hydraulic oil is not a substitute for dte heavy medium ISO 68..
As fur Mr. King's story about 'white shirt'.. Well I worked for a guy like that.. We called him 'cobby' as even a short observation/interaction with him would lead one to believe he had a corn cob shoved somewhere unpleasant.. He used to toad about the shop saying " parts are rusting up, work faster".. Fortunately he was just a vice president and more often than not had a pressing engagement on the golf course so he left us 'lower slobvians' in the shop alone to make him money most of the time but when he was on the floor watch out. Ya just knew something stupid was coming down.. ( I did have an outstanding foreman and the QC guy took me under his wing and I learned alot in that shop of what to be and what not to be ) Anyhow.. 'cobby' got a bunch of military hydraulic fluid from some where ( shop was next to an airport) and he had it stuffed in every machine.. Just couldn't get it through his skull that the 100 ton brake was squealing because it was meant to be greased instead being doused in surplus hydraulic oil.. That guy was a one man wrecking crew.. Ignorance and apathy and power make for lots of scrap..
Sorry for the rant but this has been an issue in every shop I have ever worked in..
Stay safe
Calvin B
PS on the original topic.. keep it clean ( you more often find potential problems during cleaning as some else has already stated) Clean up in the morning first thing.. don't clean at the end of the day when you tired.. You find more stuff when your head is clear and your not thinking about 'getting away' from work

Calvin these are the sorts of stories the young guys need to read and hear so they don't make the same mistakes. :-) When I have my classes I love having older retired experts come and observe so they can tell the "tricks of the trade". So much knowledge would be lost if we didn't have these forums to share.

Your story reminded me of the time I taught a class at Cloyes gear factory in Paris AR and while there the shop foreman came up to me and said "You have to help me save the machines in the plant" I looked at him ans said "what?" He went on to explain how they had hired a new purchasing agent who was clueless and had the foremen come into his office one day and this PA told him they were ordering to many brands and types of oil for the plant and he thought they could just buy 1 type to do everything. LOL So this guy said can you use way oil in spindles? And the foreman said no. Then he said can you use spindle oil on ways?

The foreman said No again but said if the PA wanted to ruin the machines he could and walked out of the office. Then from then on the PA told them to use spindle oil for all lubrication. So what I did first was have the foreman get a lubrication chart for the brand new CNC mill they had just bought for $250,000.00 and went to visit the PA with the foreman. I showed him the factory spec called out for Vactra 2 way oil and the PA said we will use spindle oil for that too. I said he was voiding the new machine warranty by doing that and if the factory techs came into repair the machine and discovered that he would get fired by management . I then said next time you change the oil in your brand new Cadillac to use spindle oil. That got his attention and they went back to the old system.

If you have a machine with any wicking for oiling replace it at least every 20 years.

Hydraulic oil doesn't last forever! Well the oil itself MIGHT, but the O rings/seals/FILTERS!/etc DONT! All that stuff breaks down into your oil. I know its expensive and a pain in the rear to dispose of and what not....CHANGE IT! Exessive heat? Exessive noise? AT LEAST ONCE A DECADE! lol Some oil companies will even test your oil for you and probably tell you its bad LOL

ALOT of hydraulic repair lately for this guy...

Also, strainers and filters are NOT the same! Check em, clean em, replace em, whatever, just pay attention to them!

Valves, pumps, motors, cylinders, etc, they get expensive and increasingly difficult to find! As does the folks who rebuild them!

Richard, this is an excellent thread topic that should be required reading for anyone in the trade. Especially mgmt. In my 40 year experience of machine building would concur insufficient/incorrect lubrication is the root of cause of accelerated wear. Beyond that, I would suggest an air hose is nearly as destructive. I have prohibited air hoses in my shop replaced by a powerful shop vac. After use, machines are thoroughly cleaned with a chip brush, soft rag and lightly oiled same as a fine firearm. Insist users leave a machine clearer than when they found it.

In defense of purchasing dept substituting oils, lubrication contracts are very profitable to suppliers. The BS I have witnessed from oil salesmen is criminal. That because their product is the same ISO grade it's 100% compatible. I have made a good living replacing shaper guides where Citco Sliderite 68 was substituted for Vactra 2.

On gear shapers, especially older generation machines cutting oils are mandatory. Have had machines submitted for rebuild used short term with water soluble oil. Coolant will strip necessary way oils from spindle and slides. Wear becomes a factor of 100:1 acceleration. In most cases I scrap the machine. If learning of a rebuilt machine used with water soluble I instantly void the warranty and cease all communication.

Remain in awe how ignorant shops are on grease applications. Most all machines I'm familiar with have tagged specifications. "Extreme Pressure" designations don't mean Jack _hit. Rolling element bearings require a distinctly different grease than plain journal bearings, lead screws and slides. Learn the terminology and percentage of molybdenum in various product.

10 fingers said:

In defense of purchasing dept substituting oils, lubrication contracts are very profitable to suppliers. The BS I have witnessed from oil salesmen is criminal. That because their product is the same ISO grade it's 100% compatible. I have made a good living replacing shaper guides where Citco Sliderite 68 was substituted for Vactra 2.

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What is different between those 2 products? Is one just not as good as the other, or are they for different application?

10 fingers said:

I have made a good living replacing shaper guides where Citco Sliderite 68 was substituted for Vactra 2.

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Like Mud, I am interested in this topic. What about Vactra 2 versus Shell Tonna S2 MX 68 (which is what I have in one of my machines)?

calvin b said:

If I've had this conversation once I've had it a hundred times.. USE the lubricant that the manufacturer recommends.

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Whoa, forgot this one ... for a while there was a fad of using straight TrimSol as way oil. It actually worked okay, more or less, at least on hardened and ground ways, but after a while the waxes clogged up all the distribution thingies in the lube system. Run some kerosene through the system to clean everything out and back to real way oil we went ...

At least it kept the coolant from getting contaminated

Years ago everyone started to use a white grease called Lubriplate that plugged up everything if you didn't clean out the old grease first. The soaps or chemicals would not mix well with others. I see they still sell it, so hopefully they have changed it's formula. I remember taking off bearing covers and there were huge hard chucks of it and the bearings were hard to turn. I took a lubrication class years ago at Trico Mfg in Pewaulkee WI and the Lubrication Engineer taught us to start with one oil and stay with that oil. He also said many machines builders did not have any references to follow on how to lube ways and that's why there were so many different designs as far as oil grooves and orifices / inlets.

Another thing I have been teaching lately is when you replace way wipers put a small wedge or machine the mounting surface on a angle behind it so the wiper "snow plows" the chips and dirt off the way instead of just pushing it straight ahead.