Fabrication 101

Discussion in 'The Garage' started by xcflyn, Feb 4, 2013.

  1. xcflyn

    xcflyn Long timer

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    Good idea. It almost looks like he could just go about 1/8" thicker in material. Those bolts are not sticking out the bottom by a thread even. Maybe mill the dia of the hole and use a good bottom tap? May save the machining of the inside if he can just be a little thicker in material ? Guessing the material is already .250+"
    #21
  2. troidus

    troidus Long timer

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    I don't know what the specs are for threaded fasteners in plate aluminum, but for rivets in sheet aluminum, Boeing specifies that edge margin is 2.5x the fastener diameter. That's why I picked that number. I would guess that he needs at least the diameter of the fastener of undisturbed metal between the bottom of the hole and the bottom of the screw boss.
    #22
  3. sailah

    sailah Lampin' it

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    Remade the part using 3/8" plate. Bored the center hole on the lathe. transfer punched the holes, drilled 5mm holes close to the bottom using drill stop on the press. Tapped using a M6 but I need a bottoming tap to get all the way down. Have one on order.

    The one I made came out nicer than the waterjet part. I spent hours laying those out in CAD, took 30 seconds with a transfer punch and the holes are more accurate.

    You can see the stock donut gasket so I used some longer button head M6 bolts I had. I also clocked the fuel pump so that it will fit in the corner of the square tubing.

    [​IMG]

    [​IMG]
    #23
  4. troidus

    troidus Long timer

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    Would there be any benefit in radiusing the pump bore so the donut sits down lower and has a larger contact area and you can use shorter screws? Might reduce squeezeout.
    #24
  5. sailah

    sailah Lampin' it

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    probably but I was trying to get the part made. I thought about grinding a radius on a turning tool then got lazy:D
    #25
  6. Laconic

    Laconic Anodyne

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    You shouldn't need to do a radius, just a groove for the o-ring to sit in. Pretty sure the o-ring needs "containment" to work properly.

    Or does it compress into a groove in the pump? I can't see it too well.
    #26
  7. sailah

    sailah Lampin' it

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    I believe you are correct the groove is in the fuel pump flange on the tank. I'll chuck it up and redo it.
    #27
  8. Laconic

    Laconic Anodyne

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    If you have a Machinery's Handbook, there's a good discussion of how o-rings are supposed to work.

    Gland/groove depth should be 80% of o-ring cross section and 50% wider. You probably knew that, but I like reading the handbook. :D
    #28
  9. xcflyn

    xcflyn Long timer

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    That is correct, I always thought that seemed way big until I understood that with a o-ring seal the mating parts still "mate" and the O-ring is just compressing into the groove. I know on break down repairs there were times that we would use a 60/40 rule - as long as it was 60 -40 it would work "good enough" in low pressure situations to get the machine running. In those situations we would also short cut and use the tool on the shelf that was close. We seemed to get lucky 99% of the time, but we also were in the process of making a correct part while the quick fix was being used.
    BTW- next to thumbing through the McMaster Carr catalog, I too like to read the machinery's handbook. Guess some people are weird that way :D
    #29
  10. Laconic

    Laconic Anodyne

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    +1, but it can get costly. :deal We buy tons of stuff from them here at work.
    #30
  11. sailah

    sailah Lampin' it

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    I obviously did NOT know that:lol3 so thanks!! I'll measure the o ring and have at it.

    +1 on McMaster. I order from those guys all the time. The website is way better than Grainger so I usually order from them. Plus they are next day delivery being in Cleveland and shipping is always very reasonable.
    #31
  12. sailah

    sailah Lampin' it

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    Didn't want to get any closer to the threads. O ring fits in there perfect and I did make it 80% depth of O ring

    [​IMG]

    [​IMG]

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    [​IMG]
    #32
  13. Laconic

    Laconic Anodyne

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    Sweet! That will never leak.
    #33
  14. sailah

    sailah Lampin' it

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    Have you seen my welding?:D

    Thanks for the tip
    #34
  15. xcflyn

    xcflyn Long timer

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    new project- one for me. This will be hard to believe but my water jet has no jet on timer. The solenoid is a 24V so I decided to mount a timer on the unit and first task is to make a mount, simple : well nothing I do is simple and it seems when ever I take time to do something for myself I hurry and shortcut. This time will be no different.
    Down to business -
    Start on my piece of scratch paper and then set up to cut-
    [​IMG]
    fast forward to check fit
    [​IMG]
    little bit of brake work
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    Well the last two hits are going to require a heavy off set (gooseneck) punch to reach in and give clearance for those ears :ear - not those ears - the ones on the ends
    Of course I dont have a punch that is that narrow with that much offset - so a new project is started - make a punch
    starts with this -
    [​IMG]
    A few heavy hits and a tool is born - almost - needs more work to fit the holder but it looks like it steps over far enough.
    [​IMG]
    I think it will do the job, I will finish up on it tomorrow or on the weekend.
    [​IMG]
    #35
  16. xcflyn

    xcflyn Long timer

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    Then the tool needed a holder
    [​IMG]
    [​IMG]
    Now it can bend
    [​IMG]
    weld the edges
    [​IMG]
    And you have this- just needs a back piece made
    [​IMG]

    I had hoped there would be more contributions to this thread. I am interested in what others are making:deal
    #36
  17. MikeinEugene

    MikeinEugene Long timer

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    While I'd like to see others posting up their projects too, please don't abandon what you're posting now. I'm really enjoying it :clap
    #37
  18. kirkster70

    kirkster70 moto junkie

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    You guys are doing some excellent work! Thanks for posting up your pics! :clap I've been learning a lot by just following along.
    #38
  19. Benesesso

    Benesesso Long timer

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    Viton?
    #39
  20. sailah

    sailah Lampin' it

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    It's the stock one from the ninja, no idea sorry
    #40