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Spoke Hubs on the South Bend 9A

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  • Spoke Hubs on the South Bend 9A

    A while back I made some trike wheels.

    Photos best describe the method.
    This was the first wheel I had made.
    The methods for calculating the spoke lengths and pcd of the spoke holes did not work too well.
    So I made a mockup of the hub.
    https://app.box.com/s/h464ooyqrgi3eumx3nfxqhdov1p1w0px

    Here is the drill spindle that is held in the milling attachment. ( and in reply to Mike)
    The spindle has a ball bearing at the chuck end and an oilite at the rear.
    The ratio of the pulleys is about 3:1 and the motor spins at 8000 ~ 10000 rpm.
    The drilling is done at the rear of the lathe centre, with a 2.2mm drill.
    https://app.box.com/s/obyzljy3v8ivr8fvpozef8bdizipcjtr
    https://app.box.com/s/8nli28h6vc5nzzutcqtlxb22ej3qb3ot

    The motor is too small really, and I would recommend a motor rated at 200 watt or so.
    I converted the old dc brush motor from series wound to separately-excited-field.
    That increased the power and gave much better speed regulation.
    In taking the motor apart to reconnect the field, it is necessary to keep the armature in the brush end bearing.
    If the brushes pop out, it is a difficult job the get them back in. I used the pulley to retain the armature in the end bell.
    https://app.box.com/s/0jky4q1e79tdl96so1dblsdg3ahgx2jo

    The field curve of the motor.
    https://app.box.com/s/uh5oslzm6qm2wzh94p7v8u994kmhhi84
    Here is the circuit diagram.
    https://app.box.com/s/41p0t9jt7e4if490yder529bjjxik97y

    I have a vintage Hewlett Packard Dual 24 V supply mounted in ceiling over the lathe.


    The indexing of the spoke holes is by using the 64 tooth gear on the 63:64 compound gear used for metric threading.
    I made a "woodpecker", spring loaded as shown out of scrap cast iron with a beak brazed on.
    The 64 tooth gear means only 32 spoke hubs can be made.
    A 72 tooth gear would allow making hubs for the more common 36 spoke rims.
    https://app.box.com/s/ph3cxvdx4vrwiia3l3tnfdijmf32qn3y

    Here is the finished wheel.
    I used the simplest "1 cross" pattern, also all spokes are on the outside of the hub.
    I built the 2 smaller rear wheels in a similar way, and the wheels have been in use for 2 summers.
    https://app.box.com/s/mi94bxivahw6gtuv99knwxozc01c02gi
    Last edited by wombat2go; 07-08-2017, 10:54 AM.

  • #2
    Wombat2go,

    That is some really creative work on the indexing using what you have to get it done. The question I have, are you driving this wheel with the ring gear on the wheel? that in it's self seems like it requires a post to let us know what your building. If you have time share please it looks real cool.

    TX
    Mr fixit for the family
    Chris

    Comment


    • #3
      The spoked wheels are for a hand/foot crank trike for my son with special needs.
      I have been developing it for last 6 years as he grows up.
      The mitre gear is part of a "C" drive that transmits power down to front wheel which also has foot pedals.

      The last 2 additions ( the home built pedals and spoked wheels) are the most recent updates.
      I took fairly good photos of those additions so I was able to post them here.

      The photos of the rest of the project are a bit dated.
      When i get time I will assemble some photos and post details of the whole trike.

      Part of my purpose was to learn/develop the machining hobby by eliminating all store bought parts.

      I am nearly there ( except for the bearings, rims and spokes !)

      Thanks for the comments.

      Comment


      • #4
        I love it!

        What is the part taken from that allows angles and height adjustment?

        Comment


        • #5
          That is very cool, and the pedals too. Having lived through the 'cnc' era of custom mountain bike parts and having owned a bike shop, I am conflicted in regards to making one's own parts.. I appreciate the skill, etc but it became clear to me by degree that cold forged parts and precision ground cup/cone bearings are vastly superior to machined/unforged Al and cartridge bearings.

          So unless I need/want something that is not available, I buy it (Shimano usually) with a bit of guilt...

          Comment


          • #6
            Originally posted by mikem View Post
            I love it!

            What is the part taken from that allows angles and height adjustment?
            Thanks,
            That is the original Milling Attachment for the South Bend 9A

            Here is a photo of it in its intended use, which is quite limited, positionally
            https://app.box.com/s/8la5ijqc166eequ0lg6a393qjwd0myji

            Comment


            • #7
              Originally posted by softtail View Post
              That is very cool, and the pedals too. Having lived through the 'cnc' era of custom mountain bike parts and having owned a bike shop, I am conflicted in regards to making one's own parts.. I appreciate the skill, etc but it became clear to me by degree that cold forged parts and precision ground cup/cone bearings are vastly superior to machined/unforged Al and cartridge bearings.

              So unless I need/want something that is not available, I buy it (Shimano usually) with a bit of guilt...
              I agree, for professional bike work.
              I am in the area of prototyping.
              I run stress calcs on any critical the items I turn on the lathe, and the 4130 brazed weldments for the frame.

              Also, I have cut up 2 types of the under $50 pedals purchased from Niagara.
              The bearings in those are really sub standard. The misalignmeht and "lumps" can be felt rotationally
              In the pedals I made I used 696 RZ bearings. They are working very well. anecdotally , the friction feels lower than any of the cheap pedals I purchased.
              I was trying to think of a test jig to accurately measure pedal friction while under load, but I can't.

              Comment

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