[Mikbul]

No chatter on work piece, bearing sKipping on bearing seats. The inside of my headstock was spotless and no paint on the bearings, the casting around the bearing had been taped off before
painting, no paint on spindle.

Attachment 222188Attachment 222190

[jherndon]

No chatter on work piece, bearing sKipping on bearing seats. The inside of my headstock was spotless and no paint on the bearings, the casting around the bearing had been taped off before
painting, no paint on spindle.

Attachment 222188Attachment 222190

Have you miked the bearing journals on the spindle and how easy did the bearing cones remove from the spindle? I'd be curious to know what you found. At this point I have not removed the spindle or bearings on the 8k. I decided early on to flush out the bearings with oil and see what happened. About a quart of oil was used, and the metal flakes comming out in the drain oil reduced to undetectable. The screeching noises I heard from the bearings have not reocurred since flushing. The heat produced during run-in of the bearings was more than I expected, and I contacted SB and was sent their bearing prelaod procedure. I did reduce the preload until the heat produced on the headstock is just warm to the touch after about 15 mins of running at 1000 rpm. I've had problem bearings before and most of the time the problem has traced to bearing preload. Roller cages on bearings can drag and cause noises until they seat properly hopefully before they wear out. I wish you good luck on the new spindle.

[Mikbul]

No I had to press the bearings off so the fit was good, In my case it was the grease and the prolonged running during break-in. After break-in I had no problems with heat and never touched the preload. Also the spindle nut was not too tight, I stuck an allen wrench in there and gave it a little tap and it came loose.

[jherndon]

Mikbul
Since I've not removed the spindle on the 8k, I was curious as to how you removed the bearing cups from the headstock? Some time back SB said to use a bearing cracker (grind and crack). I saw no way to get behind the cup to pull it on my 8k. Your headstock appears to be bored where access to the back of cup might allow a puller. Also what does the swarf guard/flinger ring look like it's made from? The photo in your post 202 shows it to be black. I hope you don't mind the questions.

[Mikbul]

The first one I ground and cracked but the second one I relieved the casting behind the race a little with a dremel cut off wheel sideways. You only need a 1/16" to 1/8" to get a drift on then there's enough room to get a very skinny chisel ( just as a wedge it works perfect) in at an angle and tap it both sides and then it's open enough to work the drift around. Second one took about 5 minutes. you don't need to bottom the chisel, just open up the crack a little so you can get a drift on it. In the photo below you can see the relief. The new races I pressed in (or pulled in).
I ended up making the relief in the first one anyway to get on it and crack it, the race is beveled on the edge so you just slip off it.
I thought the swarf guard or gasket as SB calls it I thought was anodized aluminum but I believe it's steel, feels too heavy to be aluminum. If find a magnet I can give you a better answer.
According to the all knowing fridge magnet both the bearing flange and swarf guard are steel.

Attachment 222418

[edn]

Hello everyone.

I bought my SB1001 (manufactured 2011) in September 2013. Right away I noticed the problem with bearings shown here

https://www.youtube.com/watch?v=wsja-va3WJ8 .

Grizzly sent me the replacement bearings which unlike the original are not marked "P5" (guess they are just normal class ...). The moment I put it on the spindle the new problem exposed itself - over machining of the spindle tube especially shoulders where bearings sit

https://www.youtube.com/watch?v=J7GDrvs68h0 .

Contacted Grizzly again and two months later still waiting for the replacement spindle.

While waiting I decided to run an experiment:
1. mount bearings on spindle using non-permanent retaining compound Loctite 641
2. grease bearings with "low-torque" synthetic grease - SuperLube heavy duty grease in my case
3. preload bearings and use lathe without any extra spindle lubrication
4. follow Timken run-in procedure for tapered bearings

The reasoning behind #3 comes from the Timken instructions on tapered roller bearings lubrication.

The use of “low-torque” greases (or synthetic greases) can be
considered for rib speeds over 13 m/s (2560 fpm), up to maximum
of 25 m/s (4920 fpm). Experience has shown that stabilized
temperatures, around 15° C to 20° C (27° F to 36° F) above ambient,
can be obtained at the maximum permissible speed.

The max rib speed on SB1001 with the stock motor is about 8m/s. So far I have 0.00025" runout on the spindle and bearings are not heating any more, unless I go to 2000 rpm for long periog of time.

I have pair of Timken ISO-Grade (P5) bearings waiting for a new spindle so I have nothing to loose with my little experiment.

I do not see how oiling of the bearings can help as when bearings spin the oil will be pushed out due to pumping effect of a tapered roller bearing so unless it is circulating oil or jet, or mist it does not make any sense. It messes everything inside and outside the late and this is about. it.

The third problem I have with this lathe is that taper of the D1-3 plate on the chuck never touches the taper on the spindle which causes runout of 0.005 - 0.020". I expect it to be related to the poorly made spindle and not taken any actions till I get the replacement spindle.

Ed

[Mikbul]

On page sixty two of Timkens lubrication of tapered roller bearings states: "Oil is a better lubricant for high speeds or high temperatures" among the ways to lube with oil is the oil bath and that's what we have here, Timkin says:
"The housing is designed to provide a sump through which the rolling elements of the bearing will pass. Generally the oil should be no higher than the center point of the lowest rolling element.
"If speed is high lower oil levels should be used to prevent churning. Gages or controlled elevation drains are used to achieve and maintain the proper oil level."

As I'm waiting for my spindle that's what I'm working on. Now I ran my lathe for almost four months and oiled the bearings each day but I have a way to measure the exact amount of oil that goes in. I purposely over oiled the chuck side bearing one day to see if the excess would drain and it did, out the swarf cover and not into the headstock. When I took my spindle out I had no excess oil in the headstock at all, BUT if the pulley side bearing is over oiled the only drain is into the headstock. I see no reason a drain at the proper level can't be drilled into the pulley side bearing cover. Like I said I'm working on that and will post once I come up with a solution that doesn't void my warranty.

You definitely have a loose spindle. My bearings I had to press off the spindle, as they should, but not a really tight fit or you wouldn't be able to adjust the preload, which is a precise process, the bearing would move in jerks and not smoothly.
BTW I would appreciate your serial # and where it shipped from. The list is just curiosity and not just problem machines, but machines with non issues as well and how did they come to terms with the spindle oiling.

[Mikbul]

Turns out that's exactly where the drain is on the chuck side, half way up the lowest roller.

Attachment 223298Attachment 223296

[jherndon]

The observations made with the window on back of headstock (post 200) showed that oil is sprayed from both bearings to inside of headstock. I have 2 cups to collect drainage oil from the headstock, one under chuck side bearing and one under back of headstock. An oil drain channel was added to back of headstock and collects oil from inside headstock. Most of the drainage oil is collected by the back cup from the spray oil. The max. rotational velocities these bearings operate at would allow grease or oil lubrication. Seems oil is more suitable because it is better at removing heat and small particle matter from the bearings than grease. The amount of spray oil observed surely would question the need for more drain holes on either end of headstock. If both headstock bearings are oiled and the spindle left off, drain oil is observed from both sides of the chuck side bearing and mostly from the inside headstock side of the rear bearing. My only concern is to maintain adequate bearing lubrication, and I'm considering installing an oil drip lubrication system for both bearings.

[edn]

Page 56 of "Timken Super Precision Bearings for Machine tool applications" says:

The use of “low-torque” greases (or synthetic greases) can be
considered for rib speeds over 13 m/s (2560 fpm), up to maximum
of 25 m/s (4920 fpm). Experience has shown that stabilized
temperatures, around 15° C to 20° C (27° F to 36° F) above ambient,
can be obtained at the maximum permissible speed.

....

When using synthetic greases, the limiting factor is the "lubrication
for life” concept (without re-greasing). Depending on load and
speed conditions, the grease life will typically be limited to 5000
to 8000 hours.

As I mentioned earlier, when new spindle arrives I will put headstock apart and document it's condition if anyone is interested.

Ed

[Mikbul]

If both headstock bearings are oiled and the spindle left off, drain oil is observed from both sides of the chuck side bearing and mostly from the inside headstock side of the rear bearing. My only concern is to maintain adequate bearing lubrication, and I'm considering installing an oil drip lubrication system for both bearings.

Because there is no drain hole on the outside of the rear bearing the drain hole would be preferred to me rather than into the headstock, it may be possible to put the drain holes slightly lower so too much oil can't puddle at the bottom and be pushed out. It would be ideal to oil it until it runs out a little on both sides for a normal run session unless you run it hard and fast that would be adequate. As the manual states extra can be added in that case.

[Mikbul]

Page 56 of "Timken Super Precision Bearings for Machine tool applications" says:

The use of “low-torque” greases (or synthetic greases) can be
considered for rib speeds over 13 m/s (2560 fpm), up to maximum
of 25 m/s (4920 fpm). Experience has shown that stabilized
temperatures, around 15° C to 20° C (27° F to 36° F) above ambient,
can be obtained at the maximum permissible speed.

....

When using synthetic greases, the limiting factor is the "lubrication
for life” concept (without re-greasing). Depending on load and
speed conditions, the grease life will typically be limited to 5000
to 8000 hours.

As I mentioned earlier, when new spindle arrives I will put headstock apart and document it's condition if anyone is interested.

Ed

I'm not going to argue over oil or grease, one factor to consider is shop and spindle temperature, you would have to monitor that very closely with grease if you have a cold shop that you warm up. I brought my spindle in last night and it took two hours to warm to room temp, and that's out of the headstock. When I warmed the shop in the past I waited until things warmed up then ran the lathe at 45rpm's for twenty minutes to get the oil and bearings warm. When I get a new spindle installed I'm going to check spindle temp, I might even run a heat gun on low for a bit trough the center of the spindle then wait until it stabilizes before proceeding. This frigid weather I've closed the shop down until the temps come up to keep the bill down.

[edn]

I am not trying to argue, just pointing out that there are other options for people who run this lathe at home which do not affect performance or lifetime and help keep workplace clean.

[Mikbul]

Other options are fine if your lathe is out of warranty. I work on Generac generators everyday and the warranty solutions come from tech support and then are implemented. I agree this is an unusual case but the manual specs oil and getting the proper amount in is the key to not slinging it all over. Since I started these threads I've given an answer to that although I haven't given the amounts I use per side and still won't until I get it back together and do some testing. I'd rather see someone over oil and make a mess at this point instead of waiting for parts. In the manual "a squirt or two a day" I think is too open to improper oiling depending on what oil can, how much per squirt etc. I have used a dosage syringe which gives me the exact amount in ML and a clear brake line bleeder hose. Little did I know I had grease in there. I also pulled the grease fittings and drilled out the ball and spring and turned plugs for the oilers, no more fighting with the spring pressure.
Dosage syringes are available at any pharmacy. The only problem with them is the plunger swells up and you toss it. I've decided to toss the plunger and just use the syringe as a graduated funnel with hose. That's actually not a dosage syringe in the photo but one I had a script for but the dosage type are to administer medicine to kids and have no needle connection so no script is needed.

Attachment 223472

[Mikbul]

This is how I'll use them in the future, Fill it to the as yet to be determined ML and let it drain in slowly as the bearing warms up, one on each side.

[Mikbul]

I measured the bearing seats and came up with 1.7706" on both. I can't get an accurate measurement of the bearing ID, I don't have an inside mic or a bore gage big enough. I believe .0005" per inch for an interference fit is what I remember.
By bearing # it's 45mm

[jherndon]

Calculations indicate inner ring rib angular velocity is less than 1700 fpm when spindle is running at 2300 rpm. If memory serves me "standard grease" would work OK at these velocities, testing may indicate adjustment of preload to control heat to acceptable levels is needed. An arguement could be made that the headstock as designed & produced by SB had grease lubrication for the bearings included from the start and some where along the way grease was changed to oil. Considering that the headstock has no way to drain oil, shield wiring and switch from oil spray, the bearings come packed with grease along with "grease fittings" for oilers. This train of thought leads me to think a heat issue may have caused SB to change to oil considering the bearing preload. Oil churning in the bearing produces heat build-up in the oil and therefore drain holes need to located as to drain away oil and maintain a minimum level to adequately lubricate the bearing. The bearings, while the spindle is rotating, both spray oil and drain oil away, it seems an oil starved condition could result without additional oil being added at some rate to maintain an adequate film. Greased bearings on the otherhand don't remove heat and small particles as well as oil. Seems to me a person could use grease or oil to lubricate the bearings although machine warranty may be an issue.

[Mikbul]

Funny, had someone else speculate that they changed from oil to grease when I found grease in my bearings. I respectfully suggest starting a new thread on 8K problems, that's not why I started this thread, it was to help new owners with any definitive information I could give them. At this point the spindle issue is still an ongoing problem and not solved.

[jherndon]

Recently went to Grizzly/South Bend website looking to purchase some parts for the SB1001 lathe and found on their list of parts many showed "This part is no longer available". Does anyone know what's going on with the SB1001 lathe? Could it have been discontunied and as parts run out thats the end of it. The lathe is listed in the new catalog, at a sale price of $1965.

[jherndon]

edn's post 210 - edn, I'd be interested In what you find when you go about replacing your spindle. You explained you have new Timkens (ISO class p5). I'd be interested to know the part number. Thanks.