I worked for a electric motor/ apparatus repair facility during the 80's and 90's. We rebabbitted thousands of bearings. The babbitt bearing is the only bearing that doesn't have a life expectancy. If it is blued in correctly ( fitted properly ) and the oil is clean and maintained the bearing will last forever. It was common to have babbitt bearings that were 30,40,50 years in service and still good. Most people don't know that the bearings used in the older hydro- electric power plants were made from a hard wood. Like babbitt bearings these would last years. If fitted correctly the shaft should never touch the bearing, it rides on a .003 film of oil.
Like Keith, I have a horizontal milling machine with over arm arbor support. the bearing is just a bush. It's just the place where you want a 'tight' bearing for accuracy and reducing risk of chatter. I note K&T have an oil reservoir feeding the bush to keep it well-lubricated. My thought on this bearing is to make the outer bearing of a material that expands with heat and the inner bearing or shaft of a material that doesn't expand much. Then make the bearing an light interference fit - so when it's running, it'd be too tight and warm up - and that in turn would reduce the friction and reduce heat build up. You'd then have a self-regulating bearing - too loose and it'd cool and tighten, too warm it'd expand and loosen.
My Father told me about wooden bearings used in heavy machines where replacement and maintenance was a bear. I think I remember him telling me that they'd be soaked in wax or parafin and they'd run for a very long time.
Keep the oil clean and babbitt bearings last forever. Early tractors and cars had babbitt engine bearings. Many had shims that could be removed/adjusted as the engine wore.
A friend of mine showed me around a small hydroelectric power plant run by Central Vermont Public Service that had two relatively small turbines that ran on lignum vitae bearings on the lower end of an inclined shaft so that they ran in water which precluded the use of lubricant. I don’t exactly remember the service life of the bearing, but I do remember being surprised by their apparent durability, a good lesson in the function of plain bearings.
As a long time watcher I miss the older videos where you spent more time showing work - watching a skilled craftsman perform is definitely not boring, just FYI.
I love the fact that Keith,always says back in the day 'we'.like he was there,I believe he was spiritually,his heart beats here and there,that's his power.
All my life I've worked on 2 100yr old machines that had poured babbit bearings. Throughout the yrs I've always wondered how that process was done. Thx to modern tech of RU-vid and your channel, i now completely understand 😀 ❤️. Thx so much for your passion.
I've been sort of bouncing around watching this series in the wrong order, but it's been one of the most interesting and informative things I've ever seen, and I'm really enjoying it. But in regard to the pouring of the babbitt joints, every time you mention "damming material" I hear "damning material." And that really cracks me up. Just wanted to share.
I watched this a while back, but most of my RU-vid is on a TV so often forget to make comments later. This and the top half bearing pours are just super fascinating to me, even if they are pretty standard for your shop!
An old professional welder man always used his oxy-acetylene torch to blacken around where he was arc welding. Especially when it was an area that was visible. The weld splatter was very easy to remove because of the carbon layer. He always started the day with a new pair of Good Luck brand gloves with the hard cuffs on them. He would put them on the first thing in the morning, fire up his torch and use it to de-fuzz the gloves. Tony was a true artist-craftsman perfectionist and was the one that taught me that a true welder would not "stand by his work, he would stand under it."
Just as a historical note, Isaac Babbitt patented his bearing metal in 1839. For his invention, the U.S. Congress awarded him $20,000, which is equivalent of $640,000 in 2022 money.
Plain Bearings still play a huge role in machinery today, everywhere from lightweight consumer appliances to massive industrial machines - and engines, as you pointed out. Pour-in-place bearings like Babbitt are much much much more rare, but roller-type bearings have a LOT of limitations that preclude their use from so many different things. Today, plain bearings can be made from brass, bronze, cast iron, 'white metal' like in another comment -- but also plastics like nylon, Teflon (PTFE), and ceramics of all kinds. They're truly fascinating things, bearings are.
Many people don't understand that roller bearings (and especially ball bearings) concentrate the forces onto a relatively tiny contact point. They rely on "hard metal rolling on hard metal" as the friction surface. If you have a roller bearing that gets a whack (eg: hammering it into place), you can dent the bearing race or rollers, and the thing will destroy itself very quickly. Plain bearings work completely differently, in that an oil film is what supports the load. The bearings never touch the rotating part - they only exist to give the oil somewhere to sit against. This allows them to support much higher levels of shock and load than would be possible from roller or ball bearings. The best example is inside a motor vehicle engine. All of the bottom end uses plain babbitt-faced bearings, because they last much better than anything else. I am not sure about friction, as that is dependent on the type of oil used, and that's then a tradeoff with overall life.
Old technology still stands. Once working for a Swedish bearing manufacturer I remember the terms "static load" (still standing, not rotating) and "dynamik load" (load during rotation). Babbits bearings are surpricingly good to handle static load, load of combined static and load during low speed rotation.
As a mostly-woodworker and very a basic metal worker/machinist, I am loving the processes overall. But esp pragmatic/ practical things like using a sooty flame to soot-up the shaft before bearing pour.
An important point missed by most "experts" about the use of Babbitt is the bearing housings in the frame or body of the machine do not have to be machined to get alignment with other bearings or bearing surfaces. A good example would be the Little Giant power hammer where the top shaft has to be dead square to the hammer slideways. Babbitt is used extensively on my Barnes camel back drill press. When setting up shafts prior to pouring the bearing material the shafts can be adjusted using shims, collars, jacks etc.
I have worked on alot of old machinery over the years,and the void between the two journals were often filled with waste packing for oil retention, some with brass pickup rings as well. Neat project.
I recently pulled apart the plain bronze bearings in the motor of a $10 pedestal cooling fan that had seized. It had some cotton gauze packing inside the bearing cup, to act as a oil reservoir. That was a nice touch in such a cheap appliance, however they had omitted the most important thing... it was bone dry!
The huge shafts that drove that screws on the Navy destroyer I was stationed on had babbitt bearings. A machinist mate on watch checked the oil lube system every hour. When we went through overhaul they repoured several of them.
All our crushing mills where I work are run on babbit..big babbit bearings. Always greased. The bigger mills have a grease injection system. I've been here over 30 years in maintenance and always used grease on babbit and they used it a hundred years here before I arrived! We had boxes full of babbitrite and still have a big pallet of babbit pigs.
Keith, Modern slow speed diesel engines use babbitted bearings for both the crankshaft and the crossheads. These bearings are a tin based alloy. They are poured into shells and the shells are fitted into the engine and secured. If there are problems with the bearings they can beb"rolled" out for inspection. Depending on damage the shells can be replaced without having to completely disassemble the engine. For a point of reference the largest slow speed diesel engines are built up to about 100,000 bhp at around 60 to 100 rpm. Bores are up to 980 mm and strokes range to about 2.5 m. Modern engines utilize systems to monitor temperature, movement, vibrations and wear. These systems allow the ships to run for extended times between physical inspection. Plain bearings are used for propeller shafts, particularly in the stern tube. Rudder bearings are also plain bearings. Ship's plain bearing materials range from tin based materials to synthetic materials such as bonded phenolics and materials such as Thordon. Ship's shaft bearings may be lubricated with oil, grease or water. Bob
i helped replace ironwood bearings in a ships stern tube once.the trick was finding the row of blocs used to hold the others in. once you nocked the key blocs out the rest would basically fall out.i keep thinking these blocks could have been sold as novelty items but they were all dumpsterized
@@ronalddavis When I started working many of the older ships in the fleet had lignum vitatae bearings. We had a stock of staves stashed shoreside just in csse. I wish I had asked for a couple. I would be a rich man . Bob
your doing a fine job keeping these old machines going, I watch most of your videos I myself can't do the physical work anymore but really enjoy what you do and the detailed explanations you give thank you
Very cool. Reminds me of my days in the shipyards. Pouring bearings and fitting them was a frequent task. I don't often get reminders of those days. Thanks Keith!
I pulled out a air handling fan 6 foot diameter that had plain (babbit I presume) bearings that had been in use for 80 years. This fan ran 24 hours a day all year and had never given any trouble apart from changing drive belts as needed. There was no wear apparent. Replaced the bearing for ball bearings as they wanted to increase the speed of the fan. They ran hot!
Thanks Keith...I do not restore old machines, but in my line of work have to deal with re-babbit for bearings every once in a while. We send it out, but understanding the process sure helps a lot! Love your content and always look forward to your next video.
Hi I have worked 30+ years bonding babbitt bearings for the Dresser Rand company both flat and round bearing in a centrifuge.I also have done a lot the way you are doing it I think the bottom was poured all the way a cross and the top half and half I would put x groves for the oilers that seemed to work very well.You are doing a good job and oh yeah you can us your torches to melt in more babbitt in those puddles thank for sharing!👍
In English class I was the only one that understood what Sinclair Lewis was trying to communicate. " (1922), by Sinclair Lewis is a satirical novel about American culture and society that critiques the vacuity of middle class life and the social pressure toward conformity. The controversy provoked by Babbitt was influential in the decision to award the Nobel Prize in Literature to Lewis in 1930. "
Thanks very much for sharing. Very interesting to watch. When I worked on large industrial engines, 15" bore and 20" stroke, all the 13.5" main bearings were Babbitt bearings, or at least had a layer of Babbitt between the shell and the shaft.
Keith, for whatever it's worth, back in the 40's, there was a cartoon made around the theme of Abbott and Costello called a Tale of Two Kitties, where Costello yells, "Babbitt, hey Babbitt."
With the bearing locks (locating holes) running the entire length of the bottom casting, I was wondering if the intent was to pour the Babbitt as a continuous piece on the bottom. That would not preclude you from pouring the tops as two sections, which is obviously required. Would a solid bottom bearing help with distribution of lubricating oil? Thanks for sharing... Very interesting!
I think the gap acting as an oil reservoir is a better way. The thing to remember that on the end with the saw blade pulley is that I suspect the tension in the blade will lift the bottom shaft - so the bearing surface will be on the upper half of the bearing.
@@millomweb I think I could argue both ways. I see Pros and Cons for both approaches. I could probably put together a pretty good argument that the split bottom/Well solution has a chance of creating a lubrication issue if the unit is not level, whereas with a solid bottom, it has a better chance of full/shared lubrication. It just appeared that the designer intended for a solid bottom with the position of the holes. What are the odds this thing left the factory with a solid bottom bearing. Both options are viable. Cheers to you Sir!
@@jeffreylee7184 I might just disagree with that :) I can't really see one long bearing being detrimental to the thing - other than extra cost of Babbitt. Please explain why you think a full length bearing would be inferior, thanks.
Always a treat watching the process and being reminded how to do it properly. I can attest to babbit bearings lasting my 1950's drill think they have been re-done but poorly they even forgot to drill out lubcrication hole (didn't find out to too late and it now has wobble :( )...so whats the saying prep is everything and oxy/ace torch helps too but sadly can't have one at mine no safe place to store it
All aircraft piston engines today use Babbitt bearings for the crankshaft (on all bearing surfaces, to the crankcase and piston rods). Hard to beat this technology. When properly oiled, it's the best bearing surface you can get. Zero wear happens at normal RPM. Extremely rigid as well for heavy load applications. Note: Aircraft engines don't use poured babbitt bearings, but rather "shells" made of a stack of Aluminum or Steel, then Copper, then Babbitt on top. The shells are slightly oversized, so it 'crushes' together around the crankshaft once the case is tightened, making good contact. Just an easier way to rebuild/replace the babbitt bearings in the future, since hot pouring babbitt would be impractical.
The straw walker shakers on our 1982 Class combine had laminated/oil impregnated wooden block bearings on the cranks. Maintenance free and going strong at 22 years when it was sold. They revolved at high speed but relatively low load.
In metallurgical terms, the skim is also called dross, and is the result of the heating, which does purification of the metal. Gold and silver miners used to pour their ingots of their own metals, and borax was a common purifying agent that helped to make the metal more convenient to carry, and as valuable as reasonably possible. Modern borates used to purify gold include anhydrous borax, used as a flux.
One question - i watched your episode on making the shaft holders to get the shaft at the exact right height, but are you just eyeballing the horizontal alignment? Even a tiny angle there would be a fairly large movement with the diameter wheel it's holding. Fascinating work as always!
Great fun Keith and I learned a lot. Question, why didn’t you raise the casting to an easier working height? You’ve got the tools and work supports. As I’m now an old man I try to position my projects so I’m comfortable. Not too late you’ve got scraping left to do…. Cheers, Will
Ford Model T and Model A engines use babbitt bearings. There are fewer and fewer guys around that do that work. Would interesting if you toured an engine shop sometime that did that work and compared notes. I believe they actually line bore the block after the babbit is poured.
Most that rebuild Model A and T engines convert to "modern" conventional shell bearings. If you plan to use the vehicle it is the way to go. Purists hate it, but we who do it, don't care. We enjoy using our antiques!
The babit bearings are much like the bearings in your engine. In fact, they aren't bearings at all. Its the oil that provides the actual bearings. These operate due to hydrodynamic friction. They also require RPMs to be higher than lower in order for hydrodynamic friction to work properly. The wear on these babits generally come from start up. Much like car engines. Keeping the surfaces cleaned and flushed is the main issues with these. As soon as contaminates enter and get trapped or built up, the babits will wear out and cause damage to the shaft as well.
As an old school engineer..sadly I learnt the hard way ...more is better less is an issue always pour too much it is not an issue to remove excess but to add to a poured bearing is. It will be fine though they will never know. Cannot wait to see the first cut on this incredible machine.
Interesting. With a heavy wheel and shaft and a tensioned blade both halves of the bottom bearing seem critical. Or will the top half do most of the work? And for the top bearing? Looking forward to the next pour on the bottom bearing. And the top bearing.
When I worked on DC motors they always had Phosfer Bronze bearings some had groves cut for the oil and larger one had a slot cut in the top of the bearing with a larger ring of bearing material rotating in the oil and taking it onto the shaft.
The Cadillac V8’s used various tracked vehicles in WW2 had bronze main bearings. This was used to keep these engines running longer if they had battle damage. After the war you could purchase these engines brand new as surplus really cheap. They were popular to install in trucks, and some larger cars. The bottom ends on these engines lasted for many 100’s of 1000’s of miles in civilian use.
Hi Keith. Just wondered about the keys in the center bottom. If you poured a full bearing on the bottom and only side bearings on the top, would that help support the extra force that the bottom sees when supporting the weight of the shaft, wheel, etc. When fully assembled?
The stuff that accumulates on top of the molten metal is not only impurities, but also oxidized metal. The skin will keep forming while it is molten, so don't let it sit for too long.
I wonder if you could tap into the cavity of the top casting and add oil there. Since you didn't pour a central bearing, oil from that cavity should flow nicely to both bearings.
Is that center gap going to be filled with oil as a reservoir? It looked like, because of the lugs all along the shaft, that the entire area would be poured.
IF you put a small piece of bee's wax in the babbitt after its at pouring temp (820 degrees ) it will bring all the impurities to the top. But for what your pouring it's probably not necessary. The rpm of the bearings we rebabbitted would be as fast as 3600 rpm.
