Let's build a 5f2a Princeton!

Discussion in 'Shock Brother's DIY Amps' started by corliss1, Aug 28, 2020.

  1. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    In one of the many recent threads about Princetons I posted a picture of one of my recent builds, a point-to-point 5f2a built as a head in a small Hammond enclosure. One of my regular customers tried it out while picking up another repair and asked me to build another, so I figured I'd post some pictures of that process.

    Since I'm apparently doing multiple of these builds, let's make a routing template for the power transformer.


    IMG_5179.JPG



    Close enough. It'll get sanded and straightened out a bit more.



    IMG_5180.JPG


    Press the transformer down into the wood to mark the screw holes:


    IMG_5181.JPG


    Seems to fit well:


    IMG_5183.JPG


    Mark a center line on the chassis:


    IMG_5184.JPG


    "Let's start at the very beginning..."


    IMG_5185.JPG


    See how long a resistor reaches and mark that point:


    IMG_5186.JPG


    Drill a slightly awkward hole:


    IMG_5187.JPG


    Use a punch to make it much less awkward. Super fun that the tube socket mounting hole ended up being right in the middle of that "o":


    IMG_5188.JPG


    Scene from the inside:


    IMG_5189.JPG
     
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  2. WalthamMoosical

    WalthamMoosical Tele-Holic Ad Free Member

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    Great, let's! I'll just sit here and watch!
     
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  3. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    Let's make some baby starter holes for the fuse holder, switch, and pilot light:


    IMG_5190.JPG


    Those holes grow up so fast!


    IMG_5191.JPG


    Let's countersink that template so we have a way to attach it:


    IMG_5192.JPG


    Router bit with guide:


    IMG_5193.JPG


    And there we go:


    IMG_5194.JPG


    Routing aluminum always makes the coolest little pieces:


    IMG_5195.JPG


    Looks good - the rough edges are the protective layer of film on the chassis. It'll get deburred later on anyway:


    IMG_5196.JPG


    Fits:


    IMG_5198.JPG


    Laying out the Volume and Tone controls - gotta make sure there's enough room for the Fender knobs, which is what the customer requested:


    IMG_5199.JPG

    Holes for pots:


    IMG_5200.JPG
     
  4. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    So I have a bunch of these speaker output plates I designed for my other (usually full-sized) amp builds, but this chassis is a bit thinner. I want to use it since it'll give it a more pro look on the rear panel:

    IMG_5201.JPG


    I cut some 1x2 in half and routed a channel in it:

    IMG_5202.JPG


    Used the second piece to hold everything together. More drilling and countersinking:

    IMG_5203.JPG


    Routed off the edges. Once again, the roughness is just the protective film. It should be about 1/8" or so shorter than the chassis now:


    IMG_5204.JPG
     
  5. goonie

    goonie Friend of Leo's

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    Subscribed!
     
  6. Paul-T

    Paul-T Tele-Meister

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    Looking good!

    I've only just realised how easy it is to route aluminium. What router bit do you use?
     
  7. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    Anything. Literally any decent bit you use on wood is fine.
     
  8. WalthamMoosical

    WalthamMoosical Tele-Holic Ad Free Member

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    What about that plastic thingy that hides the sharp inside edges of the hole in the aluminum? Is that off the shelf, or did you fashion it, or re-purpose something?

    This is going to be an interesting and instructive show.
     
  9. screefer

    screefer Tele-Holic

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    subbed!
    I've been thinking about attempting this since you posted it back on Jul. 10.
    Very instructive.
     
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  10. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    Help me out here - which photo are you seeing this?
     
  11. WalthamMoosical

    WalthamMoosical Tele-Holic Ad Free Member

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    In post #3 underneath where you wrote "Fits"

    But looking at it again, I guess that's just part of the transformer body (itself being held in by four bolts). I thought it was a deliberately-installed softer edge that wouldn't fray wires going through the rectangular opening (such as for a grommet for a power cord).
     
  12. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    Yup - nothing else in that photo except the PT and chassis.
     
  13. Liam77

    Liam77 TDPRI Member

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    Nice. I'm impressed how you use teh wooden template to route the chassis for the transformer. I never thought about using a router for metal work.
     
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  14. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    @Liam77 - as long as it's aluminum. If you try and do that with steel, it's going to end badly.
     
  15. King Fan

    King Fan Poster Extraordinaire

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    Niiiiice.

    Did you say where you got the chassis? Your shop, or?? Looks great. What gauge alu?

    Plus I really like that DPST switch, and the way you're custom-locating stuff to fit PTP. I'm gonna enjoy this.
     
  16. screefer

    screefer Tele-Holic

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    Regarding your DPST switch, are those threaded lugs? Do I assume you will solder to those lugs? Would threaded lugs require more/quicker heat?
    Will you be switching both hot and common AC in?
     
  17. andrewRneumann

    andrewRneumann Tele-Holic

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    You have got to wear eye protection though. My experience cutting aluminum with anything is that it goes everywhere, including in your face.
     
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  18. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    Chassis is this guy, with a matching cover plate: https://www.amplifiedparts.com/products/chassis-box-hammond-aluminum-10-x-6-x-2

    I don't know if that's the *exact* switch I'm gonna use, they all have the same bushing diameter though.

    ^^^This
     
  19. Timmay

    Timmay Tele-Meister

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    Subscribed. I've been thinking of attempting a 5f1 this coming winter.
     
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  20. D'tar

    D'tar Friend of Leo's

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    While we're on the subject...

    Aluminum dust is potentially explosive. Just saying.

    That said,

    I've worked a lot with aluminum and never blew anything up.
     
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