Rediscovering Creativity.

[Visitor]

Recently retired. Worked for decades as a counsellor, and now revisiting my childhood interests in creativity. But having difficulty starting 'a blank canvas' so-to-speak.

Then, not long ago, the local maritime museum acquired an old console for operating a local lift-span bridge. One of the museum's volunteer workers new I had done electronics in the RAAF during the 1980's. I was asked to examine the console for the possibility to have it operate a model bridge. I did so, and ended up volunteering to create a working model for the museum.

My friends doubt that I can do the project alone. That I have overestimated my skills and abilities. Maybe so, but I never thought I could not do it. However, I soon discovered that there are no plans available of the bridge, or schematic drawings for the electrical wiring of the console. I had to start from scratch. I am still trying to work it all out. This project will be challenging and testing. I feel that this project will help me rediscover my childhood creativity.

This will largely be a photographic journal. The reason being is that the museum's workshop is too small for the project, so it will be created in my lounge room. Photo updates will be sent to the museum's curator so that they can observe my progress. In doing so I will also upload photos into this journal.

Examining the console interior. To better map the wiring of the control panel I stripped all loose wires which had exited through the console base plate.

Reverse engineering is required to understand how each switch, and other parts, functioned.
 

 

[Loreena]

@Visitor Great..

[Guest Annetta]

Nice!  I'm excited to see more of your work!  Keep us updated!  Peace!

[Visitor]

Thanks Loreena and Annetta.

Decided to use the computer to draw a layout of the control panel. This will make it easier for me to grasp what is involved to operating a lift-span bridge.

Both the Control and extend/normal switches were unclear to me.

The control panel on top of the console could not be removed because of the wiring harness. Mapping the panel wiring seemed too difficult to observe from underneath. My girlfriend, Julie, suggested to use a dental mirror which she recently bought from an op-shop. She always comes up with great ideas. However, using a torch and mirror proved difficult in tight areas. Then a woman volunteer from the museum suggested to use my mobile phone camera. Another great idea. Help comes from everywhere if open to receive it.

From these photographs and notes, a diagram of switch connections was made. Below shows one of them.

Even so I still did not know what all these connections were for. I needed information on how to operate the bridge, but soon found out that was not possible due to security reasons. However, the operator was willing to to be interviewed. So a list of questions were compiled. At the interview, I showed a photo of the control panel. Though the operator never saw that panel before (panic), he was able to tell me what the switchers were for (relief).

From this information I soon realized that the wiring was largely irrelevant for a working model bridge. So I decided to strip all the wiring and start from scratch. This means it was time to start designing the electronics, with whatever was available, at minimal cost to the local museum (non-profit org).

It has been a long time since I have done anything in electronics. My knowledge in electronics is antiquated in comparison to modern technology. So I decided to keep it simple, and see if I can use minimal electronics and focus on using relays. 

 

[Visitor]

Here is a photo of the lift-span bridge which the console came from. It was built in 1964 and the console was replaced in 1995, and again in 2014. The above console was the original one.

[Visitor]

Note: Several tasks have already been started and some are completed. Those completed will be presented in this journal and told as it happened. Later down the track I will be at the stage where I am at the moment. Then updates will be less compacted as they are now.

  The museum's small workshop is not stocked for creating electronic equipment, so parts and material has been ordered in. In the meantime the control panel's operational sequence needs to be figured out. Oh, by the way, a model boat will be included. It will traverse under the bridge after the bridge span is raised.

The museum wants the display to be an interactive one for its visitors. That is, the visitors can operate the model bridge. Immediately this presented another challenge for me. Know the operational sequence has to be childproof. That is, for instance, the bridge span cannot be allowed to be lowered onto the traversing boat... This project is getting more complicated by the day.

Many years ago I saw a movie, Holy Man staring Eddie Murphy. In the movie, when people asked him to do something he always says, 'if that is what you want' and then does it. This project is much like that for me... accept accept accept. If the museum wants it, so be it. Even though I never built a model before, I feel as if my faith in my truth is being tested. But I do not believe anything is impossible. If it appears impossible it only means I do not yet understand it.

There are many displays in the museum, too many actually. There is a lot of talk about not having enough room for new acquisitions, and having no storage facilities either. So I presented a drawing for a compact display where the bridge towers and span was no wider than the console. The curator said he wanted the whole bridge. He showed me the space it ought to take up. It was a cubicle 1.2 x 2.4 m (4 x 8 feet). Now this job is getting bigger too.

To build this model to scale, I really needed to find out the size of the bridge. Since there were no plans, the use of photographs and two reference measurements were needed. So Julie and I took our bicycles for a leisurely ride to the bridge. Took some photographs and measured the width of the road and the length of the bridge-span. The rest of the bridge measurements can now be deduced from this.

Julie under the right hand girder giving indication of its height from ground.

Back at home, I quickly figured out the size of the bridge and the scale size needed for it to fit across the 2.4 m space. 1 to 72 (1/72) scale was chosen. I am hoping the display layout will look like this...

[Visitor]

The bridge motor is a little too big for placing in the bridge span hut. So it will be placed under the display table, together with the boat motor. Both the bridge and boat will be pulley-cable driven.

I do not particularly like working with moving parts because they are potential trouble. The more complex, the more likely to be trouble.

For a while I have been haunted by what a sculpture-author wrote about moving sculptures; that a sculpture should not move. The reason being that mechanical / electrical apparatuses will inevitably fail. If the apparatus cannot be replaced the sculpture remains static and losses its purpose. In the back of my mind I am trying to work out how to avoid that scenario with this model.

Interactivity is the main focus these days for museums. Its earlier attraction of seeing something new has been lost due to modern media coverage. Visitors come to a museum and see nothing really new. But if they are invited to interact with the display, then it becomes something new.

I am hoping this display will still be somewhat interactive even if the bridge and boat no longer move. At least they can get a feel for the control panel . Many of the kids that visit the museum often play for ages on the ship's telegraph, with its bells and clicking noises. Which drives some of the staff nuts.

The control panel switches are already loose and worn, I can easily imagine that they will not be working in a few years from now. So, if both display and console are now longer working, will the display lose its attraction and educational purpose? Perhaps, especially if the model was unattractive in the first place. So the plan is to make the best model possible with the minimal resources affordable.

To do this, I think I have to try and achieve two objectives.

1. First, is to make the model as service friendly as possible.
2. Secondly, to create a model display that can stand on its own without having to rely on it to be operational.

The service friendly objective would mean that accessibility to both bridge and boat motors, pulley systems and electronics need to be easy as possible. A manual needs to be put together with both operational and service sections.

The display objective could be achieved by creating a diorama. Also, with an aesthetic focus which may pull the 'model' from a artisan's to an artist's perspective. The artisan bit is already challenging enough. The artist bit is way up there, but as I said before, 'nothing is impossible'.

[Visitor]

Building the diorama tabletop.

Building the control box which will later be fitted to and under the tabletop.

[Guest Annetta]

Very cool!  I'm excited to see the final result!  

[Visitor]

@Annetta Me too. Thanks for following.

[Visitor]

Building the bridge. The first task is to put in the bridge footings and piers.

Could not find appropriate dowel thickness for the footings, so I had to cut them out and shape them. I used 3 mm bamboo skewers for aligning and doweling the footings and piers into position,

 

After gluing the footings I covered the edge between tabletop and footings with wood putty, so as to make it look as if the footings go into the water as opposed to being on it.

[Visitor]

Attaching the girders.

It is starting to look like a bridge. I am quite excited. The bridge model may actually turn out okay.

Edited May 13, 2017 by Visitor

[Visitor]

Gave the bridge substructure an undercoat before covering it with a road surface. I left areas untouched so I can glue the terrain in place.

The holes into the girder ends are for wires to act as contact points for power and signals to the bridge span.

Fender piers/pylons are placed between bridge and traversing vessels. The central piers in the outer sets have a hole through them for installing (red and green) navigational lights.

The outer pylons will be installed after the river gets painted.

 

[Visitor]

While building the bridge I was figuring out what DC power supply will be needed for the diorama. Twenty-four volts will be used for the control panel lamps and all other lighting, 12 volts for relays and motors, and 5 volts for servos and logic circuits. I have designed and built many power supply units in my past. So this one was not too much of a problem.

Printed circuit board layout and prepared for etching.

Testing the voltage outputs.

It felt good to turn the power on and not hear any load BANG or smoke from the circuit board. Or no blown fuses. Now that apprehension is over with. When it comes to electricity, it pays to check and double check again the circuitry before adding power to it.

 

[Visitor]

The diorama will have some sound effects with it. There is the alarmed bell to warn others that the bridge is about to be operated. Also the fog horn and engine sounds of the boat.

I cannibalized some electrical gear, for parts which I might be able to use for this project. A nice pair of speakers came from an old analogue TV set. However I needed to make a bracket for it so the speaker's diaphragm would be free to vibrate when mounted to the console. 

[Visitor]

Holes were cut into console to accommodate connectors, power socket, and speakers.

The museum president said if only the visitors would know what is in the console, seeing all the wiring etc. So big mouth here said 'why not show them via a perspex front panel'!. As quick as I said it the console became an extra display to the diorama. So now the console will be a diorama of sorts, about electrical wiring and electronics.

So now the console interior needed to cleaned and painted. I am hoping a dark bluish grey background colour will contrast the coloured wiring and circuit boards. The paint shop had exactly what I envisioned, and ironically it was called Boathouse.

To add extra lighting and drama I decided to add a indicators for the voltage outputs. The green LEDs indicate that power is okay. However, if the voltage line fuse blew, the green LED would turn off and a red LED will turn of, to indicate a blown fuse.

The terminal boards were cleaned, replaced, and with new numbers attached. The Power Supply Unit was now installed.

The console diorama is starting to look promising.

 

[Visitor]

Back to the bridge. The bridge span will have electronics stored in the operations hut. Power to and from it will need to be ultilized while it is docked onto the bridge structure. So underneath the span plate will require electrical contacts, wiring and two sets of navigational lights (red and green). The wires will need to be entrenched. I have already attached the road surface and footpath (Masonite). Also drilled holes for railing posts and bridge frame doweling, which will be installed later.

 

[Visitor]

Sometimes I feel the apprehension in me, more so than normal, as I adventure into unknown territory. Inlaying these wires is one of those times. Also, finding suitable contact metal for terminal ends. Now that I am thinking about it, the whole project is full of unknowns. Each step, event when worked out on paper, has its own unforeseen challenges.

Before completing the span substructure I want to see exactly where the wiring needs to be routed up along the span framework. So I built the basic frame structure before doing anymore on the substructure.

While building the frame a thought came to mind as to how to anchor the lift cables to the span framework. Fishing swivels would help to untwist any rotatory tension on the cable. By cutting them in half I would be able to sweat solder the swivel onto a filed (flat) head of a small bolt. It worked out as I envisioned.

The framework got extra struts put in; and span is put in place to see how it will look.

[Visitor]

The wiring in the span substructure got installed and routed partly up the framework. It took a while to find the appropriate springy metal for the contacts. 

Then I filled the trench work with wood putty. When dried it was sanded and painted with acrylic undercoat.

 

[Visitor]

Now for a more ______ phase. I am not sure what the right word is that contains both apprehension + curiosity.

The top portion of the bridge span is quite busy in terms of the parts that will occupy it. The whole creative process is both worked out on paper beforehand, yet a lot of it is still ad-lib.

On top of the span is an operations hut, balconies, gangways, railings, longitudinal and lateral bumper rollers (to keep span in alignment), and a light switch for operating the traffic lights for passing vessels.

I used 3mm MDF board for gangways and hut. Matchsticks for railing posts. Below, you can see that the cable anchoring points have been installed.

Next to the anchoring points are longitudinal bumper rollers. These were adapted from microswitch actuating arms. The black U-shape device is an optocoupler (light switch).

As the span is coming together, so too is my confidence in creating a model.