The tri-sign adventure

So I started working at the Miami Children’s Museum again on the exhibits team and boy, did they have some puzzles waiting for me to solve when I got there!

One broken rotating billboard sign (I have no clue who made it, and this is a good thing, because I’d otherwise yell at them)
One SparkFun Redboard
One Pololu motor driver

One 24vdc power supply from Marlin P. Jones

One ginormous Leeson 1/4 horsepower right angle gearhead motor


(and that’s just where I lost count)

This is the guts of one of those three panel rotating signs, like you see on billboards. Note the dead variable freq drive controller at top.

This sign was designed with absolutely no consideration for maintenance once installed. It’s totally ridiculous. The triangular aluminum rods that the sign panels are snapped into lift out (I discovered this after fighting with setscrews on their bottoms for most of a day thinking that’s how they came out!) revealing… a ginormous nigh impossible to access Bodine AC 3 phase 208v motor being driven off a Delta VFD… Uggghhh!!! The VFD was toast, its programming was unknown, it all had to go!




The original pic based timing board.


Call in the Redboard! The Red board is a nice Arduino compatible sold by Sparkfun. Now a quick note as to why I love the RedBoard:
a) it’s cheaper than the original Arduino designs;

b) it uses a more stable FTDI serial adapter (to the best of my knowledge, genuine, thus unaffected by the infamous FTDIgate…)
c) lower cost;

d) all SMT construction with a completely flat back side you can simply Velcro inside a panel.

The only shortcomings I see with it are that the USB mini-B connector isn’t quite as common as say, a Micro USB, and that you cannot quickly swap the ATMega328 like you can on an Arduino Uno. However, I have only ever ONCE managed to blow out an ATMega328, and that required severe, hilarious amounts of abuse. I’m not too worried about blowing the board. That being said, if you’re new to electronics and want to play with the Arduino platform, it might not be a bad idea to pick up a Ruggeduino. They have REALLY GOOD protection on every possible input and output. You can also get the ATMega328’s used in the socket on the Arduino Uno for like $3 a pop on eBay preloaded with the bootloader, just in case. I have a few of them in my spare parts that I’ve never had to touch. Knock on wood?


The original hall effect sensor assembly, reused in the finished product.


New DC gear head motor. The old ac one was removed and ANGRILY launched into the recycle pile. In other news, the recycle pile made a fabulous noise when I shot putted the motor into it. KERWONK!!!


On a side note… SIDE note… When you get a right angle gearhead motor, there are some where the shaft comes out the left and some where the shaft comes out the right. On the original Bodine motor, it was swappable. On this Leeson motor it is also swappable. On a Dayton motor from Grainger, IT IS NOT!! Check the proper orientation before ordering, this led to an odd false start. Swapping the shaft is a procedure involving draining syrupy, sticky, STINKY gear oil…!!


I was only able to use one of the mounting bolts. None of the other bolt holes from the old motor lined up and access to the bracket to drill it would have been impossible without removing the entire sign from the wall. Even drilling through both layers of metal and just going right in would have been impossible due to another immovable exhibit component in front of it (argh!!)



Before it grew its wings.



The blue LED means success, in this case. The weird winged thing is an LM7805 I recovered off the old timing board and reused because I’m all eco-friendly like that.



Peeking at the top of the power supply.


And now… What’s left of my hands. The one on my thumb, when it happened I just slid my wide silver ring over it and kept going… Can’t be bothered to stop for mere blood loss! 😉


Daffy Duck bandage. I win.


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