1943 South Bend 16" x 60" Lathe Resurrection - Page 16
Close
Login to Your Account
Page 16 of 16 FirstFirst ... 6141516
Results 301 to 311 of 311
  1. #301
    Join Date
    Sep 2014
    Country
    UNITED STATES
    State/Province
    Arizona
    Posts
    552
    Post Thanks / Like
    Likes (Given)
    385
    Likes (Received)
    142

    Default

    If anyone is interested, I thought I'd show a quick real world comparison of shrinkage between the pattern and the cast part.

    I was told ahead of time by the foundry to make the pattern larger than the desired finished part by "1/8" per foot." That math works out to 1/98th, so I scaled my Fusion360 CAD model up by 1% as the last step before sending it to John Saunders' CNC. The photos below show both the pattern and the part overlaying a 1:1 scale printout of both the scaled model and the as-designed model with no scaling.

    Overall, the shrinkage guidance was really good. There are some minor deviations between the as-designed outline and the finished part. This is mainly the result of my overzealous hand sanding to clean up the CNC tool marks. I'm positive that if John had a second chance at cutting the patterns and could modify his workholding strategy, there would be no hand sanding required at all.

    img_6330.jpg img_6332.jpg img_6333.jpg

    I should note that, if you're using a material other than gray cast iron, the shrinkage factor is likely to be different. Just check with your foundry and they'll tell you what they typically experience and adjust your pattern scale accordingly.

  2. #302
    Join Date
    Sep 2014
    Country
    UNITED STATES
    State/Province
    Arizona
    Posts
    552
    Post Thanks / Like
    Likes (Given)
    385
    Likes (Received)
    142

    Default

    Castings are, by nature, rough. For these parts to function as a sealed housing for all the switches and the tachometer, I needed to clean up the mating surfaces between the enclosure and the back cover.

    There's an old saying that goes, "When all you have is a hammer, everything looks like a nail." In this case, when all you have is a lathe, everything looks like a turning job. I knew the setup was a little sketchy, so I added a piece of all-thread through the spindle bore to keep the part from popping out of the old smooth jaw chuck.

    I'll be honest and say I was a little scared of it at first and tried to baby the cut. That was a horrible idea because cast iron doesn't like to be babied. Light cuts just chew tools up and you get nowhere. Once I figured this out, the job got a lot easier. The first one took over two hours messing around with feeds, speeds, and depth of cut. The second one took five minutes, and that's only because I didn't go quite deep enough on the first pass.

    img_6383.jpg img_6384.jpg img_6386.jpg

    And here's a short video compilation cutting the second piece. In hindsight I wish I had centered up the all-thread because it makes it harder to watch than it already is. Haha, enjoy a good laugh at my expense. The cover plates are up next for the same facing op, but I'll be using a faceplate for those. Should be a little easier.


  3. Likes Paolo_MD liked this post
  4. #303
    Join Date
    Jan 2013
    Country
    UNITED STATES
    State/Province
    Arizona
    Posts
    63
    Post Thanks / Like
    Likes (Given)
    32
    Likes (Received)
    51

    Default

    How many dollars to have those cast, if you don't mind me asking?

    -Tim

  5. #304
    Join Date
    Sep 2014
    Country
    UNITED STATES
    State/Province
    Arizona
    Posts
    552
    Post Thanks / Like
    Likes (Given)
    385
    Likes (Received)
    142

    Default

    Quote Originally Posted by Frenchy View Post
    How many dollars to have those cast, if you don't mind me asking?

    -Tim
    $210 including shipping. I think Cattail charges a basic mold setup fee that depends on complexity, then $1/lb for the material. My average cost for six parts was about $35 each not including the cost of the patterns.

    Full disclosure: If John had charged market rate for the CNC work, it might not have seemed like such a bargain.

  6. Likes Luisbueno liked this post
  7. #305
    Join Date
    Jan 2013
    Country
    UNITED STATES
    State/Province
    Arizona
    Posts
    63
    Post Thanks / Like
    Likes (Given)
    32
    Likes (Received)
    51

    Default

    Wow, that's very reasonable for just a few parts. Nice work on the whole lathe by the way.

    -Tim

  8. Likes thomasutley liked this post
  9. #306
    Join Date
    Sep 2014
    Country
    UNITED STATES
    State/Province
    Arizona
    Posts
    552
    Post Thanks / Like
    Likes (Given)
    385
    Likes (Received)
    142

    Default

    You never know who will see a post on social media these days. Coastal Enterprises, the company that makes the high density urethane material we used for the casting patterns, saw the casting pictures on Instagram. They reached out about doing a little company blog feature, link below. If you're reading this and thinking of a casting you'd like to make, they do offer free samples and tech support on how to cut and shape it.

    Lost and Foundry: Restoring a WWII Era 16" Lathe - Coastal Enterprises

  10. Likes SBLatheman liked this post
  11. #307
    Join Date
    Sep 2014
    Country
    UNITED STATES
    State/Province
    Arizona
    Posts
    552
    Post Thanks / Like
    Likes (Given)
    385
    Likes (Received)
    142

    Default

    Continuing the machining of the switch enclosure castings. I picked up a 13-1/4" faceplate off eBay and was very fortunate to find the screw hole pattern in my back cover plate lined up perfectly with slots in the faceplate. Although they will later be drilled and countersunk for 5/16-18 oval head screws, it worked out well to temporarily drill and tap the holes for 1/4-20 screws just long enough for facing.

    The facing did get a tiny bit chattery around the edges, but nothing a gasket won't seal up once the screws are tightened to the rest of the housing.

    img_6433.jpg img_6432.jpg img_6455.jpg img_6465.jpg

    Edit: This is a good time to point out an observation. It looks to me like 13-1/4" diameter is about the largest faceplate that will fit on a 16" South Bend headstock (while a 16/24 machine with the same spindle thread could take a bigger plate). The rim of the faceplate nestles into the space between the two "Sphinx feet" on the headstock casting. I realized this when screwing the faceplate onto the spindle for the first time with two fingers on my right hand between the back of the plate and the headstock. The pain started just as the faceplate threads bottomed out on the spindle. One more thing I'll never do again...

  12. #308
    Join Date
    Sep 2014
    Country
    UNITED STATES
    State/Province
    Arizona
    Posts
    552
    Post Thanks / Like
    Likes (Given)
    385
    Likes (Received)
    142

    Default

    Next up is putting a bore through the bottom of the enclosure casting where the conduit pipe with all the wiring passes through. I'm using 1-1/4" nominal size Schedule 40 steel pipe, so it's about 1.660" outside diameter, give or take a few thou for the out of round shape.

    This would have been a really easy job on a vertical or horizontal mill with a boring head. Having only a lathe, a faceplate, and a few odd right angle blocks around, it was a bit of a Rube Goldberg project. Definitely should have used better quality screws, but it's what I had on hand.

    It worked, but I'd probably swallow my pride to ask for a favor from a mill owner before doing it again.

    img_6473.jpg img_6474.jpg img_6475.jpg img_6485.jpg img_6489.jpg

  13. Likes DrHook liked this post
  14. #309
    Join Date
    Sep 2004
    Country
    UNITED STATES
    State/Province
    Alabama
    Posts
    494
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    60

    Default

    Sorry to hear about your fingers. Did you say something about that time?

    It looks like the parts fit up well together. You may not even need a gasket.

  15. #310
    Join Date
    Sep 2014
    Country
    UNITED STATES
    State/Province
    Arizona
    Posts
    552
    Post Thanks / Like
    Likes (Given)
    385
    Likes (Received)
    142

    Default

    [QUOTE=nt1953;3054491]Sorry to hear about your fingers. Did you say something about that time?
    QUOTE]

    Nothing I would want to repeat here. I get to explain my two blue fingernails a couple times a day in meetings as well.

  16. #311
    Join Date
    Oct 2017
    Country
    UNITED STATES
    State/Province
    California
    Posts
    1
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    0

    Cool Thanks!

    Quote Originally Posted by thomasutley View Post
    You never know who will see a post on social media these days. Coastal Enterprises, the company that makes the high density urethane material we used for the casting patterns, saw the casting pictures on Instagram. They reached out about doing a little company blog feature, link below. If you're reading this and thinking of a casting you'd like to make, they do offer free samples and tech support on how to cut and shape it.

    Lost and Foundry: Restoring a WWII Era 16" Lathe - Coastal Enterprises
    Thank you for the shout out. Anything we can do to answer questions about machining Precision Board HDU, we are happy to do! We have speeds and feeds info, router bit selection guide and more on our website (linked to above) or you can call our tech support. Thanks!


Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •