Ornate Steel Mailbox - Design | Cut | Build™ - S3.E12

Discussion in 'DIY Projects' started by LECS - Tim S., Nov 28, 2018.

  1. LECS - Tim S.

    LECS - Tim S. New Member

    Jun 25, 2018
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    The season finale! For the last project of the year, Iggy and Aaron wanted to build a mailbox so everyone in the audience could “mail-in” their ideas for projects next year.


    Iggy started researching standard curbside mailboxes, and ... there’s quite a few rules to follow.

    Here were a few notable ones:
    • Dimensions needed to be at least 18.5” x 5” x 6”
    • No hardware can be sticking out on the inside
    • No more than 5 lb. of force needed to open the door
    Pretty specific, right? Knowing this, Iggy worked within the USPS requirements to create his design, which included a pull-down door held closed by magnets and a stainless steel shingled roof. Please be advised - this mailbox would be designated as a “limited service” mailbox because it does not include a flag. If you want to build this design at home and use it to receive AND send mail, you will need to design your own flag mechanism.

    *Please note, the image does not include the handle for the door.


    With the mailbox idea in place, Iggy draws the parts that will be cut out of 11 gauge mild steel in Torchmate CAD and nests them into one batch, allowing him to cut all of the pieces at once using the least amount of material.

    CAD Mailbox Parts.PNG

    Aaron and Iggy headed to the Torchmate 4800 to cut this batch with the following parameters:

    Table: Torchmate 4800
    Plasma Cutter: FlexCut 80
    Material: 11ga MS
    Amperage: 40 amps
    Cutting Speed: 90 ipm

    When you cut with plasma, there is usually a little dross left behind on the parts - even when your parameters are dialed-in. Aaron grabbed a grinder to start cleaning them up, and Iggy turned his attention to the shingles.

    As mentioned before, the design called for the shingles to be made from stainless steel. If you’re not cutting stainless steel regularly, it is easy to forget that cutting the material with compressed air creates a charred effect. The metal gets oxidized and becomes very difficult to clean. To avoid this, you need to cut with nitrogen.

    To hook up the nitrogen tank to the table, Iggy attached a high pressure regulator to the tank, added a MPT (Male Pipe Thread) fitting and a hose, unplugged the normal compressed air hose from the plasma cutter, and plugged in the nitrogen line. He then opened up the gas line to about 100-110 PSI.

    Nitrogen Gauge.PNG

    Don’t be fooled.

    There will likely be a difference in pressure between the tank and your plasma cutter, so if you don’t determine what your cutting PSI will be, you will be cutting with less pressure than the plasma cutter needs.

    To set your cutting PSI, head to the plasma cutter and turn the amperage knob all the way to the left. The torch will start purging gas. The gauge on the plasma cutter will then give you an accurate reading of your cutting PSI, and you can adjust your static PSI accordingly. Ultimately, the static pressure doesn’t need an exact figure, but your cutting pressure should be around 90 PSI.

    FlexCut front.PNG

    With the nitrogen all set, Iggy started cutting the shingles, but around the halfway point, he noticed the ‘Sample Voltage’ setting was turned off and the torch was cutting too high off the material. Someone had likely been cutting with different settings and hadn’t reset the table. Iggy switched ‘Sample Voltage’ back on, but the damage was done - there was far too much dross on most of the shingles. Too much time would have to be spent cleaning the parts, especially since stainless steel is such a hard metal. They decided to re-cut the file, this time using mild steel.



    Putting the issues with the shingles behind them, the guys turned to assembly. Iggy tacked up the walls of the mailbox while Aaron started TIG welding the shingles together. Iggy then bent the hinges for the door, tapped the holes for the bolts, and TIG welded on the Torchmate overlay.


    When Aaron was done with the shingles, they welded them onto the box and stitched the roof together.

    To bend the handle for the door, Iggy welded a piece of 3/8” All Thread Rod and a piece of 1” Bar Stock to the table and wrapped a piece of 14 gauge mild steel around them both. He then drilled a hole in the handle and plug welded it to the door.

    - - - - - -​

    Since this is the last episode of the season, we wanted to thank you all for watching “Design | Cut | Build” and interacting with us here on Fabrication Forum! Feel free to send us any project ideas you may have for next year! They will be printed out and put in our brand new Torchmate Garage mailbox!


    Tim, the video guy

    Attached Files:

    Last edited: Sep 3, 2019
    OcalaWill and Torchmate like this.
  2. stjefrey

    stjefrey Member

    Oct 12, 2018
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    Great Job Arron and Iggy! I'm going try doing one out of stainless and in my neck of the woods, we have a flag on the right to let the mailman know we have mail to go out. I'll post pics when completed.
    Torchmate likes this.

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