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  • Issues with 30 year old Grizzly...

    Was doing some routine maintenance on my lathe, it's a 12x24 belt drive machine. I've had it for close to 2 years now, but still haven't done a lot with it, mostly still trying to teach myself how to use it. Happened to run it for a short time, maybe 10 minutes, with no chuck on it. When I shut it down, I noticed the inboard (chuck) end of the spindle was really hot, I mean yank your hand away hot. The out board end was only warm. What kind of issue(s) should I be looking for here?

    Okay, some follow up info. Since I don't have anything pressing I'm working on at the moment, I decided to go ahead and tear into this thing. First thing I found is that once I removed the lock nut on the spindle, the remaining nut was no more than finger tight, and I'm pretty sure it didn't move when I pulled the lock nut. I'm also pretty sure this isn't enough pre-load, but won't know for sure until I'm ready to put it back together.

    Once I got the spindle shaft out and could inspect the bearings, I'm seeing signs of wear. Both the races and the rollers are scuffed, and I think it's caused by a combo of wrong preload and contaminated lubricant. The lubricant for the bearings is added to open ports in the head stock, no caps or seals of any sort, so who knows what could get in there. The inside of the headstock casting is a mess of gear grease and drive belt particles, I'm sure some of that has found it's way in over the years. I think I need to come up with some plugs for this. I also have a suspicion that the port to the inboard bearing was at least partially plugged. I'm finding gummy lube in lots of places, some of it looks like someone tried using grease instead of oil.

    I'd add in 30 years of use, but it just doesn't show that much wear anywhere else. None of the gears are showing much, if any, wear and everything seems tight. I don't have a precision straight edge to check wear on the ways, is there another way to check that? The spindle shaft surfaces where the oil seals ride show zero wear, which seems odd to me based on past experience with a long line of beater cars and trucks :-).

    So the bearings are tapered roller bearings, Chinese (of course) 30211 and 30212, and I'm going to replace them. I'm operating on the assumption that if I can see the wear, it's time to replace them. I've been doing some research on bearings, but I'm in information overload. Can someone recommend a source for better quality bearings for this thing? And maybe even a brand and part number? Are there any pitfalls to this plan I need to be aware of?

    Oh, and while I'm at it, I could use suggestions on proper oils. The Grizzly manual I have calls for "general purpose oil", not exactly what I'd call specific. The lathe is in a heated shop, the coldest temps it usually sees is low to mid-40's, most of the time it's at 60 or above, with occasional spikes up to around 100. And on the subject of lubes, I've been using chain saw bar oil for way lube, is that okay or should I break down and buy a 5 gal. bucket of the real thing? That much will last me a couple of life times, but I haven't found a source for smaller quantities. And what should I be using for the feed rod and lead screw? I pulled off the carriage while I was at it, and the gear and half nuts are really gummed up with old grease. Can't be good for the works, although everything looks to be in surprisingly good shape. Thanks for any suggestions, later.

    Dave

  • #2
    Applied Industrial is one supplier-

    http://www.applied.com/

    SKF,Koyo,FM,Nachi,Timken all are good mfgs,almost forgot FAG is a good brand too.

    http://www.skf.com/skf/productcatalo...did=1300000211

    http://www.skf.com/skf/productcatalo...did=1300000212

    There is also Motion Industries-

    http://www.motionindustries.com/moti...ductSearch.jsp
    Last edited by wierdscience; 01-01-2012, 04:50 PM.
    I just need one more tool,just one!

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    • #3
      Enco sells way oil in a gallon jug, but I've heard of others using chain saw bar oil.

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      • #4
        Try using kerosene to clean the old gunk off whenever you find it, then wipe it down with generic oil to keep it from rusting. (Kerosene itself will leave some residue that will prevent rust, but its best not to relie on it for long)

        Real way oil is the best thing, 5 gallons might sound like a lot, but realise you can get to use it just about anywhere! And basicly use it as a cleaning agent for your lathe once you get the gunk off by dampening a rag with way oil and wiping it down after every couple uses or after cast iron/wood/other messy proceedures/materials. Its really a great oil for hinges, spring bike shocks, sliding surfaces of all kinds, and anything you don't want oil to drip out of as way oil is SUPER thick. Also good for rotary tables and carriage gearboxes and anything else that runs really slow.

        Way oil is so thick, Its one step below grease.

        That said, don't use it on the spindle or other fast moving parts, use hydraulic oil for that.
        Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

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        • #5
          Lube,for the ways Bar oil is okay,but if you want the real deal Mcmaster carries it in Gallon cans,also Enco or others might do the same.

          Headstock oil the last import gearhead I filled they recommended Mobil DTE LIGHT

          http://www.mcmaster.com/#
          I just need one more tool,just one!

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          • #6
            Originally posted by Black_Moons

            Way oil is so thick, Its one step below grease.
            .
            just depends what weight you get.

            for the headstock, hydraulic fluid is probably the best oil without additives that is readily available just about everywhere....iso 32 or 68, not sure which would be best, there are charts that'll let you compare to a SAE weight.
            .

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            • #7
              I have as yet to see the lathe for which the manufacturer recommends a single oil, but rather one for ways and another for the geartrain.

              My Clausing uses regular old non-detergent 30W for the internals and way oil for the externals per factory recommendations.
              "I am, and ever will be, a white-socks, pocket-protector, nerdy engineer -- born under the second law of thermodynamics, steeped in the steam tables, in love with free-body diagrams, transformed by Laplace, and propelled by compressible flow."

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              • #8
                Regarding checking the bed for wear, have an indicator on the cross slide and indicate the tailstock ways. As you move the carrage back and forth along the bed the amount the indicator moves is the amount the saddle ways are worn. Checked my South Bend that way and found .005" difference. Still turns parallel however so I'm ignoring it. Peter
                The difficult done right away. the impossible takes a little time.

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                • #9
                  I just sold an Enco 12x24 of about the same vintage. The ways were hardened and had no visible wear. I suspect yours also has hardened ways.
                  At any rate, here's how I check for wear on prismatic ways: Remove the carriage. Remove the upper half of the tailstock (optional), leaving only the base that slides on the TS ways. Mount your DTI on it so it will follow the front side of the vee-way nearest the apron. Zero it near the TS end and slide the base toward the headstock, noting the variance from zero. Check it high, low, front, back. If you see .001 variance, mark that point with a sharpie pen, single hash mark. .002" get 2 hash marks etc.

                  As for the spindle oil ports, those originally came with rubber stoppers in each hole. You can make up brass plugs with a knurled head and a slight taper that will work very well.

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                  • #10
                    Or you can use these. Oil hole covers.

                    http://www.use-enco.com/HTM/2011/img/949.png
                    Last edited by RetiredLE; 01-02-2012, 09:13 PM.

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                    • #11
                      Get accuracy grade ABEC-7 bearings if you possibly can. They will be expensive, but it's what would be specified, I think, for a spindle of the precision you are dealing with.
                      ----------
                      Try to make a living, not a killing. -- Utah Phillips
                      Don't believe everything you know. -- Bumper sticker
                      Everybody is ignorant, only on different subjects. -- Will Rogers
                      There are lots of people who mistake their imagination for their memory. - Josh Billings
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                      • #12
                        30 year old Griz? it may have had ABEC 3 or the roller equiv P grade at best... I'm betting the originals are not marked with a grade at all.

                        Buy the best you can afford...
                        Last edited by lakeside53; 01-03-2012, 12:26 AM.

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                        • #13
                          As I understand it, precision bearings are just selected out from the standard production. Bearings with run-out below the required level are marked to indicate where their high-spot is. If a spindle is also marked with it's high spot then the two high-spots can be assembled 180 degrees apart to minimise run-out.

                          Or you could take a bearing, mount the spindle in it and then machine the features requiring maximum concentricity. That will give you maximum accuracy.

                          Use ordinary good quality bearings and grind the internal/external tapers, faces etc. in situ.
                          Paul Compton
                          www.morini-mania.co.uk
                          http://www.youtube.com/user/EVguru

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                          • #14
                            "Precision bearings" often have different construction and assembly techniques. I can see selection for C2->C4 types (radial bearings - internal clearance), but not to find "precision bearings" among standard types.

                            Within the precision series, there will no doubt be a similar process.

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                            • #15
                              Your lathe may have had bearing damage from running with a lack of oil before you bought it or it may have developed while you ran it. I assume you did add oil before running. In either case, I would check the oil passageway for obstructions when you change the bearings. Investigate the details of the oiling system, just a simple passageway to the bearings or is there some kind of small oil reservoir? Perhaps other cleaning or repairs are needed.

                              And yes, if you can see or feel wear or damage on roller or ball bearings they definitely do need to be replaced. You can usually feel it before seeing it.
                              Paul A.
                              SE Texas

                              Make it fit.
                              You can't win and there is a penalty for trying!

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