Help troubleshooting Landis roll grinder

Hey guys, kinda been thrown at this old WWII era Landis 14x96" Landis roll grinder since the other guy in the shop quit a few months back. I am fearing the spindle bearings are slap worn out, but wanted to get some other opinions. On small work (under 4"), it is OK, but on larger work it is HIGHLY prone to chatter and you take nowhere NEAR the amount off that you put on the dial... like I ended up putting about .060 total on the dial in .005 increments today and took only about .015 off the diam. This workpiece was a solid steel rod 13"x60" and I was grinding hard chrome plating to size. End result was great, within .001, end to end, but the time it took was ridiculous because it just wouldn't cut.

As massive as this machine is, and given the size of the rock and the spindle motor, am I wrong to think this thing should never notice a .0025 depth of cut? Am I pushing it too hard? Should I be upping the rotational speed of the work and/or upping the traverse speed of the table to eliminate this chatter, or are the bearings just toast and I have to live with what I have? In other words, am I doing this wrong or does this sound like a problem with the machine?

Spindle bearings are plane.

Are you running continuous or auto in feed?

Does the rapid in /out work properly?

My first guess is that you have hydro feed prolems.

Manual feeding on the head, not familiar enough to let it autofeed yet and not really required for what I am doing. I'm trying to round egg shaped parts out of the chrome tanks, so I pretty much have to mic every pass to make sure I don't go through the chrome. Machine not equipped with rapid (sucks, but my right arm is gonna look like Popeye's in a few weeks of this).

I put an indicator on the rock and tried to wiggle the wheel by hand to see if there was wear in the bearing. Nothing, so it's not the spindle bearings, as far as I can tell. No telling what the grade or hardness of the wheel is on this machine. It is pretty worn down and likely not suitable for chrome work. Doubt the cheap assed company owner will buy a new proper wheel though. About to take on some really whacked rolls tomorrow morning. Will report back then.

With an OD grinder there can be many different variables.

Spindle Bearings-which on your machine are a bronze bearing with continuous lube I assume, there should be a lube pump for the spindle.

It could be your workhead bearing.

Bad live/dead centers.

Or, the other guy just learned over time all the tricks to make things work?

Abbott Machinery Rebuilders in Alton IL would be a place to maybe call and ask a couple questions.

The other guys are GCH but I just don't know how much info they will tell you over the phone.

I agree with Cash as Abbott specializes in Roll Grinder rebuilds and G&L Boring machines. They also have their own Roll Grinding shop. I would ask if there is a maintenance manual and read it, ask everyone in the shop if anyone had ever adjusted the spindle bearings. See if the pages where it is described is full of finger prints, that a sign someone has messed with them. You should be able to mount a mag base on the wheelhead and do a rough test on the spindle. With the machine shut off and locked out It's better with the wheel off put a .0005" indicator on the spindle and then use a 4 x 4 and pry the spindle up moderately and see if there is any slop It's best to check it when it is warm and with it warm I would think more then .001" is to much. You can also check end play. Usually the manuals will tell you how to check them.

When they have been running for a couple of hours can you feel the wheel head casting outside the bearings warm? That's an easy way to see if the bearings are running at the right temp. You may want to also check the belt tension and number 1 thing I always tell people who see chatter is to look at the diamond dresser. Many times the diamond is dull and it frosts the wheel and make it chatter. Also when you dress it, I would advance the diamond a minimum of .002" on the final fast dress. If the wheel was out of balance I would think you would see an issue on the small diameters.

One other thing comes to mind. On a recent Center-less rebuild they had chatter issues and we finally pulled wheel and cleaned out all the rust that was inside the wheel mount. I would have never figured that was the issue, but that did it.

Rich

The rapid and the fine feed both work off the manual infeed screw.

Should be the lever on the far right.

Throttle for the infeed is the small one inside the auto/ continious nob (on the right).

Micrometer stop for the fine feed is on the right near the back.

Rapid is a cylinder that moves the entire infeed screw fine turns the screw the amount set on the micrometer stop.

Again, no rapid on this machine. The other, inoperative machine has rapid, so I know how that works, but not this one.

I'll check the spindle bearings again with the prying technique, but just trying to wobble the spindle by hand didn't move the indicator at ALL. I figure if there was a bunch of slack, it would have moved. Nothing has been adjusted on it, from what I see. Previous guy was a hack at best from what I am figuring out. He spent hours tying to get taper out of the work by beating the table with a big rubber sledge with an indicator randomly placed on the table and taking cuts to see if it was straight. I put a pair of indicators on the table in the location of the work, used the table adjustment screw to eliminate the taper using the indicators, and had it running within .001 over 4ft in a matter of minutes.

I have figured out that the infeed dial reads diametrically, so now it makes sense that a .030" lump of chrome takes .060 on the dial to get rid of. I'll see what tomorrow holds.

Hi Mike, Maybe the machine bearings are the problem but I'd be checking you've got the right wheel for grinding chrome first. Workhead speed and feed rate are important also. I used to have a great little handbook that " Jones & Shipman " put out a few years back. It told you all you needed to know about cylindrical grinding. Unfortunately I lent it out and never got it back ! Regards Tyrone.

I would reduce infeed to 1 thou per reversal instead of 5 ,it could well be that what you are seeing is wheel wear ,this means that you are very quickly losing your dress which may be causing the chatter issues. Also slow down the work speed to reduce chatter ,speeding up will likely make it worse.

OK, took my Colvin and Stanley grinding book to work and read the cylindrical grinding section while the rolls were running today. I got two rolls done, but they gave me fits. I did reduce infeed to .001 DOC. Not sure it helped a lot, but sure didn't hurt.

Seems I have a multitude of problems condensing into a big mess. I am going to get the exact wheel specs tomorrow, if I can. Based on what was presented there, I have already figured out that the rotational speed is way too slow (on slowest belt groove), so I'm going to spin that up and see if it helps. I know I am almost at max capacity of the grinder (13.840" on a 14" grinder), so that large a diameter needs to be spinning fast, from what I read. I think the wheel is maybe one grade harder than ideal, but again, spinning faster will help that, and finally, I am grinding chrome, which is REAL hard, so I am reading that is also reason to run the rotational speed up. I think the slow rotation and fine cuts are just glazing the wheel, given the situations above.

I think the headstock bearings are shot on the workhead, too. Have never run one of these, but I don't think the workhead is supposed to sound like a cement mixer when you put a screwdriver to the side and put the handle of the screwdriver to your ear. I am getting coarse evenly spaced long unbroken waves in the work, which this book says relates directly to the workhead spindle. I may just have to deal with it to get a couple of more of these rolls done, but maybe then I can take that apart and see what's going on in there.

I am getting a lot of stuff figured out on the machine and realizing that nobody was really using it to its full potential for several years. The vernier dial was so nasty and dirty you couldn't read it. The feed ratchet has some serious rigging on it and the feed stop mechanism hasn't been used in probably decades. The ratchet and feed stop is so clogged up and frozen in place, I'll probably have to remove it to get it working. Going to get all that cleaned up and functioning right as I have time.

Lastly, looks like the table and pivot has not ever been properly cleaned and lubricated. You could turn the crank on one end .040 and the opposite end wouldn't move. After 30 or 40 shots of grease in the fittings, it started responding a little better, but I feel sure the sliding surface between them is covered in rust. Just need catch a free day and swivel the table far enough to get under the ends and give it a good cleaning.

Whoa-couple things-If you think your wheel is graded a bit hard you want to slow it down to reduce the SFPM and make it act softer. Not speed it up.

I think you will want to keep you workhead speed a bit slower as well.

yea-being at the max of the machine OD of what the machine can do will for sure make things tough. I know on our 24 x 144 landis if we do say anything over 12" it is a very long process.

The cement mixer workhead is for sure an issue.

One thing you may want to do-pull the workhead and tailstock and then pull the table. I bet there is 50 years of rust there. Clean them up and then re grease and your table should adjust for grinding parallel much easier.

What size is your grinding wheel?

Cannot find the exact grade on the wheel, but the owner says these are used wheels. Some guy he knew had a machine that used 36" rocks, but had to pull them at 30". Ours supposedly runs 30" down to 24", so we take these used ones and run the rest of the life out of them. He said they were s compromise kind of rock, not ideal for steel or chrome, but suitable on both to save having to buy and change wheels so often. From what I was seeing the chart, they call for a K or L for chrome and an L or M for steel, so I'm betting it's an M or L. This rock is about half worn, so that will help with the hardness, though. Not wanting to turn the rock faster, but the work. Everything I am getting from this book seems to indicate that is the primary problem I am dealing with... besides the condition of the machine....

Chrome guy didn't get the next set of rolls plated, so I tore into the machine today. Got the feed stop ring working and polished out the vernier so you can read it. Most importantly, got into the workhead. This thing was a mess.

The primary belt was too long. Motor was slid all the way to the rear and blocks between the adjuster screw and slide to allow it to tension in overtravel. One of the blocks turned out to be a piece of worn dressing stick, lol. Got that all loosened up and working right. Motor was loose on the slide. Got that tightened down. Getting a new proper length belt for that.

Took off the secondary reduction cover and instantly one of the belts fell out, broken. Then more pieces fell out, washer and nut that holds the drive pulley on the shaft were loose in the cover and the drive pulley was just floating on the key. The remaining four belts were almost broken through, so getting a new set of those. With no cover and no load on the spindle pulley, it was easy to spin by hand. The horrific condition of the bearings became very clear at this point, so time to remove the pulley.

The bearing retainer that goes around the spindle nose was broken. The dog drive ring on the spindle pulley was broken. Somebody crashed this machine HARD. Big deep wheel gouge in both pieces. The ring wasn't terribly bad, so I just brazed the crack and slicked it up. The bearing retainer was totalled. It came off with a 1/4 section piece broken out between two bolt holes, but it was also cracked almost completely through at the other two bolt holes. I am making a new one.

The spindle pulley bearings are junk. The cracked retainer and drive ring let water through the labyrinth seal, so the bearings got rust in them and ran that way for decades. From the way the pipe plug for lubricating the bearings came out, it hasn't been removed since the 60s. That may not be the only problem, but it was certainly a major part of what was wrong.

I just found out that there is supposed to be a brake on the workhead. No idea when that was removed or where it is now. I just hope I don't get a power flash that drops the disconnect on the workhead while the work is in contact with the wheel. Both these grinders are missing the brake.

So, that's it until at least Tuesday. Once I get these problems sorted out and give it a test run, I'll report back.

Oh yeah, one other question... is it standard practice to leave the workhead at the extreme left end of the table and move the tailstock only, even on short parts, or should the workhead be slid closer to the center when not running full length parts? Can the workhead even be moved like this, for that matter?

I went to service a customer and they had a surface grinder they had bought at auction because it look like new and a good price. I asked and they said too bad the spindle is shot and that will cost as much as we paid for the machine. I looked it over and the spindle rolled very nice by hand. Fired it up and shut it down quick because it was bouncing like all get out.
I pulled the wheel off and fired it again with no wheel and it ran like a champ. Went home just a half mile and got a new wheel.The machine ran like new. Not saying that is your problem but wheels can get water/oil logged and act very funny.
But good on small and bad on larger work??? I will have to think about that.

"so we take these used ones" so you have tried more than one wheel so not a bad wheel.

Tyrone said see what wheel... That is right on.

Just read your post #12 Wow.. hope they didn't run it dry for a few years.

Mike, never mention PM to your employer. Nice to tap 100 years of wisdom without letting the boss in on it LOL.

Indeed, JL! What happens on PM STAYS on PM!

Other simple way of looking at it, small diameters ok, large bad, gotta be non wheel related, ie like you have found its gotta be the work head - speeds and feeds. Have never ran a cylindrical but most of the ones i have ever been around were treated lathe like and only the tail-stock was moved. Exception being grinding tapers, were its some times easier to get to bits by moving both towards the middle.

Speeding up the work or slowing the grinding wheel will both have the effect of making it seam a bit softer.

One other thing we just found out on our grinder, which was fully rebuilt to CNC a couple years ago.

We were getting chatter.

Replaced the drive belts for the spindle with a brand new matched set-

Problem solved.

Mike C. said:

Oh yeah, one other question... is it standard practice to leave the workhead at the extreme left end of the table and move the tailstock only, even on short parts, or should the workhead be slid closer to the center when not running full length parts? Can the workhead even be moved like this, for that matter?

Click to expand...

We have standard practice that monthly we move the position of the workhead monthly. We normally are not grinding full length parts. A bulk of our parts are very short. But since the rebuild price was the about the same for our old 72" machine vs a 144" machine we went for the longer machine. Then of course we have done 156" long parts with half the workhead and half the tailstock hanging off the table!!

We want to keep even wear along the entire surface of the ways.

But-I think this is a very good question-and one I have asked my operators but never got a solid answer. if it were me running shorter parts I would think to put the workhead dead center of the table. then I would leave the adjustment on the left end "floating" and then make adjustments all with the right end. Since the middle is pinned it is not going anywhere.

adama said:

Other simple way of looking at it, small diameters ok, large bad, gotta be non wheel related, ie like you have found its gotta be the work head - speeds and feeds. Have never ran a cylindrical but most of the ones i have ever been around were treated lathe like and only the tail-stock was moved. Exception being grinding tapers, were its some times easier to get to bits by moving both towards the middle.

Speeding up the work or slowing the grinding wheel will both have the effect of making it seam a bit softer.

Click to expand...

It can be still wheel related in that the bigger the work dia the more contact so the wheel should ideally be softer ,as said already ,slowing down the wheel and or speeding up the work will make the wheel act softer ,but may make the chatter problem worse.

The proper way is to have the center of the work in the center of the table and move both headstock and tailstock of course this takes a bit longer but does make it easier to grind parallel.