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Thread: Babbitt bearing work

  1. #1

    Babbitt bearing work

    Not sure if this is the correct section for this but I thought I would share, mods feel free to move this if needed. I worked on repouring the main bearing for my bandsaw today. I know this is not foundry work strictly speaking, however it still involves some molten alloy, and the bandsaw is used for all my patternmaking here in the shop so I'm hoping this counts.

    Here is the bearing assembly, I had already removed the old Babbitt, and cleaned the bearing shells. I spun down two collars on the metal lathe and threw one on each end of the shaft. As it sits in the photo, the shaft is indexed to roughly the center of the bearing shell.

    IMG_0225.jpg

    Next are a few photos of the process...
    The shaft is covered with a light layer of soot, so that it will release from the Babbitt after it is poured. The putty material is a high temperature damming compound to keep the liquid Babbitt from leaking out where it shouldn't. After the lower half of the bearing is poured the lower shell is cleaned up a bit with a file in preparation for the next pour.

    IMG_0230.jpgIMG_0232.jpgIMG_0233.jpgIMG_0236.jpg

    In order to keep the Babbitt in the upper shell from bonding to the lower shell, some high temp gasket material is installed in the lower bearing assembly, and the process of sooting the shaft, and damming the ends is repeated so that the upper shells can be poured...

    IMG_0237.jpgIMG_0240.jpgIMG_0243.jpgIMG_0244.jpg

    Once cooled the bearing shells are split and cleaned up a bit. I drilled and tapped the upper bearing shells for the eventual drip oiler installation. Last photo shows the newly poured bearing being test fit into the bandsaw with the oiler. Once everything checks out I will repaint the bearing shells, and press the lower band wheel and drive pulley onto the shaft. Final adjustments can be made to true up the lower wheel to the upper by adjusting the set screws in the main casting.

    IMG_0245.jpgIMG_0248.jpgIMG_0249.jpg

    As always comments or feedback are appreciated.
    Last edited by Junkyard; 08-06-2017 at 11:55 PM. Reason: spelling
    ...Dave...

  2. #2
    Moderator DavidF's Avatar
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    What grade Babbitt did you use??
    A calm sea does not make a skilled sailor...
    http://thehomefoundry.org

  3. #3
    Quote Originally Posted by DavidF View Post
    What grade Babbitt did you use??
    I used a lead based Babbitt for this application. The brand name is magnolia anti friction metal. The bandsaw in question is on the low end of the scale with regards to load and rpm's. For higher rpm and marine applications I have used tin and nickel based Babbitts in the past. I order the Babbitt from a company called magnolia metals. They have very good customer service, and reasonable pricing. I usually touch base with one of their staff if I am venturing into a new project. They sell many different types of Babbitt alloys and are happy to discuss which is the best for your application if you ask.
    ...Dave...

  4. #4
    Moderator DavidF's Avatar
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    I will touch base with them. There is a couple motors here at the plant (500 hp electric) that run babbit bearings and have to be repoured every couple years. Funny thing is they used to last alot longer than they do now. The shafts look good but i have not mic'ed them, so im wondering if they have been using the right babbitt metal. I did cross reference the oil and what we are using is a correct replacement.
    A calm sea does not make a skilled sailor...
    http://thehomefoundry.org

  5. #5
    Quote Originally Posted by DavidF View Post
    I did cross reference the oil and what we are using is a correct replacement.

    I get my oil from a company called lubrication specialties corporation.

    http://www.steamenginelube.com/

    The guy that runs this outfit is top notch. He has fantastic customer service and can make custom hard to find lubricants for specific applications. Additionally they have some fantastic oils for Babbitt applications pre formulated and ready to ship right off the shelf. If you are concerned about premature wear on your bearing applications give them a call. They have always been a good resource for me in the past.
    ...Dave...

  6. #6
    Very nice Dave! I have poured quite a few Aermotor windmill gear cases and made replaceable inserts for a different brands of windmill. My next windmill adventure has bearing shells much like your band saw. So you just gave me a couple tips. ;-)

    I did not realize Magnolia was still in business. I have used some vintage Magnolia babbitt. If I need to buy new I generally buy from RotoMetals.

    What are you using for damming compound? I have a several year old box of Babbit-Rite, but I can't stand the stuff ... never holds like it should.

  7. #7
    Quote Originally Posted by Mister ED View Post
    Very nice Dave! I have poured quite a few Aermotor windmill gear cases and made replaceable inserts for a different brands of windmill. My next windmill adventure has bearing shells much like your band saw. So you just gave me a couple tips. ;-)

    I did not realize Magnolia was still in business. I have used some vintage Magnolia babbitt. If I need to buy new I generally buy from RotoMetals.

    What are you using for damming compound? I have a several year old box of Babbit-Rite, but I can't stand the stuff ... never holds like it should.
    The windmill bearings sound really interesting. I confess I know nothing about windmills at all. Do you have any photos of some of your past projects? Magnolia is very much still in business and wonderful to deal with in my experience. For the damming compound I use a product sold by Roto Metals.

    https://www.rotometals.com/putty-hi-temp-casting/

    I have used the brand name Babbitt Rite in the past and I have had similar issues. This could of course just have been operator error on my part. That being said, I like roto metal's product better. It is very similar to any damming putty you may have had experience with in the past and it is a bit stickier. So long as you keep it well sealed it last quite a while, and it can be used multiple times just like most high temp puttys. By the way, do you hand scrap your own bearings after you pour them? What is your process. I usually use a bit of bluing to identify the high spots.
    ...Dave...

  8. #8
    I should also mention for anyone else following along, that although the "professional" damming compound is very nice to use, it is not necessary. In a pinch, or on a budget, you can use water putty (let it cure first) duct seal, or my personal favorite Play-doh. These options tend to smoke a bit, but can easily be used to achieve good results with a little practice. Worst case, if you are not happy with the finished bearing, melt it out and try it again.
    ...Dave...

  9. #9
    Dave -
    When pouring an Aermotor 602 (1915-1932ish) gear case, I install a core shaft (blackened with acetylene smoke) into the case. Once centered, the babbitt gets poured into holes in the case (3). There are three separate pours for the mainshaft, and the unit needs to be tilted differently for each pour. There are also oil return groves formed into each pour (using babbitt rite to create the void).
    The green areas are the babbitt bearings for the main shaft.
    aer602oiling.jpg
    Top part of this (borrowed) pic is one of the pour holes. Bottom is looking down the snout. If you look toward the top, you can just barely make out one of the oil return groves.
    aj40.jpg

    That is just the snout. If you want to see more detail, go to the link below about 1/3 down the page in the section titled "How I repoured my 602 gear case". This is not my page, but the process is the same.
    http://www.windmill-parts.com/id36.html

    Now for a 1903 Aermotor (1903-1905), they have replaceable babbitt inserts. For these I made a couple jigs that clamp together (no babbitt rite needed). Once poured, I machined the OD & ID to size and a little milling machine work to cut oil slots and mill the tabs on the inside end.
    file.php?id=14379&t=1.jpg
    Pic of the completed inserts installed and one on bench.
    file.php?id=14389&t=1.jpeg

  10. #10
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    This thread is fascinating. Thank you all for sharing.
    "Success is 99% determination"

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