Title milling

Moving along with the Porsche themed PCCB dual monitor stand I decided I would add on an extra bit-o-bling. I was able to get my hands on a Porsche alloy wheel center cap and wanted to incorporate it into the stand somehow. I thought I would use the cap as dual purpose and decided to mount the emblem onto the monitor side of the stand but also create some functionality to it. Since this stand is being used in a place of business I thought an integrated business card holder would do the trick.

I wanted to mount the cap to the card holder and design the holder with similar motorsport look, feel, and finish as the rest of the project. I went off to the metal shop and got my hands on a small section of 3.5” solid round 6061 aluminum. My plan was to mill out the back of the aluminum in order to fit a stack of business cards in it. The front would get cut on the lathe to allow for flush mounting of the center cap. The back will then get capped with a steel disc held on by a motorsport looking set of stainless steel Allen head 5mm bolts.

So as with my previous posts I am going to run the same format and use photo captions to help outline what I was trying to accomplish. I also thought that I would include some screen shots of my Sino DRO (digital read out) from my milling machine. The math functions are super cool and I grin from ear to ear when I get to use it. For those who are not familiar with DROs, and their functions, you may find it interesting. I love using that thing. Anyway…on with it!

Center cap and 6061

Here is a shot of my starting materials. A factory Porsche center cap and a chunk-o-6061

Center cap mod

The plastic tabs that secure the cap to the alloy wheel are going to need to be removed. A cut off wheel and some sanding made quick work of it.

Center cap bezel

I machined out the center of the 3.5″ aluminum of the lathe. It was cut just enough to allow a press fit of the center cap.

Perimeter milled

Next I moved onto the milling machine and started to hog out the backside to allow for a stack of business cards to fit. I machined the perimeter first using a .250″ end mill. I wanted to ensure the bottom corner radiuses were fairly tight so that the corners of the business cards would not be strained.

Business card pocket

With the perimeter cut I took the remaining material out with a .500″ 4 flute endmill.

Roughed out backing plate

It was time to move onto the backing plate. I plasma cut a circle out of some scrap steel and cleaned the edge up best as possible on the belt sander. I then drill a hole through the center (which will get filled later) and bolted the plate to the aluminum to allow for more precise clean up.

Backing plate clean up

Here I was able to mount up on the lathe and clean up the backing plate perfectly.


So the next 7 pictures are screen shots of the DRO on the milling machine. My plan is to drill 6 evenly spaced holes close to the perimeter of the steel backing plate. Using the DROs math function I am able to program the dimensions and then let the DRO do the thinking. The first step is to enter the PCD function. I am unsure what exactly PCD stands for however it is refered to as the Circular Arc Dividing Function (PCD Function)


Next I need to tell the DRO where the center of my circle is. I have already set my X and Y table to the center of my steel plate and zero’d the machine therefore my center co-ordinated are X=0 and Y=0


Next I need enter the diameter of the circle which the center of the holes will be drilled around. In my case a 2.90″ diameter circle will inset the Allen head bolts perfectly.


Next I need to state how many holes I am drilling. There are 2 ways of doing this. In my case I want to drill 6 even holes. So why do I enter 7? The reason is evident in the next 2 steps. I choose 7 because I am going to drill around 360 degrees which means my 7th hole will actually end up exactly where my first hole started. I could choose to enter 6 holes however then I will need to program to drill only 300 degrees. Follow me?


So this is where I dictate how many degrees I am dealing with as well as my starting point. My intent is to start at 0 degrees which, in CAD programs, is aways at the 3 o’clock position.


My finishing angle with be full circle and therefore is 360 degreees. When using 360 degrees I always need to add one extra hole therefore this is why I choose 7 holes. I could perform the same math function by choosing 6 holes but then my end angle would need to be entered in as 300 degrees.

NO 5

And here is what the machine spits out. This is a shot of the 5th hole co-ordinates. All I need to do is dial my X and Y table to 0 co-ordinates and the machine is set in proper position to drill my 5th hole. I can continually toggle among holes 1 through 7 as need be. That it! Takes about 30 seconds to program and the rest is giggle time.

Drilled and tapped

Here is the final shot of my 6 evenly spaced holes. I ran the DRO through the drilling sequence 3 times. First was to mark the holes with a centering bit, next was to drill, and the 3rd time ws to tap. Perfect results.

Card holder plate

Here is my “motorsport” look using stainless Allen head 5mm bolts.

Roughed out holder rear

I built a discreet littl perch to hold the assembly up at an angle. The perch will also allow for mounting of the holder onto the front of the monitor stand. The steel backing plate will get powder coated to match the monitor stand.

Roughed out holder front

And here is the roughed out final product. The aluminum still needs some touch up but overall it came out nice. Fairly clean lines, nothing “over the top”

  1. The Stu says:

    That looks phenomenal Gord!! No clue what the readout means hahaha but the product itself is awesome. So badass.

  2. Jason says:

    Awesome stuff. Your work is always so clean and simple, but leaves me thinking, “damn I never would’ve thought of doing it that way”. And your toys… I mean tools… 🙂

    FWIW, PCD stands for Pitch Circle Diameter

    • gordsgarage says:

      Thanks Jason, the card holder turned out clean and simplistic. It is always a challenge to know when to stop. Less is more. Thanks for clering up PCD for me, makes sense.


  3. RonPauly says:

    Looks great.

  4. Steve says:

    I sure enjoy following your projects, Thanks
    For me one of the biggest challenges is always clean cable routing. Have you considered any of this, especially since it’s on the customer facing side?
    Keep up the good work.

    • gordsgarage says:

      Thanks Steve, glad to hear you tune in.

      Cable management has been a consideration for me. I keep flipping between not doing anything and trying to come up with an unique approach. Part of the issue I have is that the monitors pivot 180 degrees which makes securing the cables not an option, they need to flex. I had considered just machining some aluminum rings to help guide the cables but then decided against it. I don’t know…should I address it? I would like the attention to detail. The desk only has one cable hole and it is stuck off in the corner. I would need to come up with something super clean that would be cool to look at but at the same to not advetise that I am managing cables. Maybe I need to go back and look at the desk where it will sit, perhaps a few moments in silence may bring rise to an idea. If you’ve got a plan don’t hold out, send it my way. I will give you full credit.


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