Bases + Electrical Connections

Tchail · Post by **Tchail** » Tue Jun 08, 2010 10:08 pm

Over the past many months I have been working on a lighted model of the Enterprise-D.

I'm happy to say that I am finally at the point where I am ready to start thinking about how to connect my model to the outside world.

I was wondering what method others have used.

Right now, I have leds and a flasher circuit running at 9V, as well as a lightsheet circuit at 4.5.

So I could use a standard RCA audio jack - a male end epoxied to an aluminum rod for the base and a female connection inside of the Enterprise-D.

Or I'm also considering using either connectors for USB, S-Video, or Ethernet.

Any ideas/suggestions/past experiences/bad experiences would be welcome.

(Especially considering how nose-heavy the D is...)

-Tchail

Sparky · Post by **Sparky** » Sun Jun 13, 2010 3:19 pm

the rca jack is probably your best bet, they mak heavy duty 1/4 phones, for electric gutiar hook ups if you need to support a heavy model.

One other option is if you want to set the model on a pillar style base, you can have brass etch pickups. on the ship and pin contacts on the base. The model lights up when set on the power pin contacts. be sure and use a diode in line to keep from reversing the connections by accident.

http://www.kc6sye.com/techmages_4_30_04.html

Kylwell · Post by **Kylwell** » Sun Jun 13, 2010 3:39 pm

You mean audio jack, not RCA jack don't you?

Sparky · Post by **Sparky** » Mon Jun 14, 2010 11:50 am

Yes that's right, I was thinking RCA brand or something...

en'til Zog · Post by **en'til Zog** » Mon Jun 14, 2010 2:27 pm

You might use a 1/4 inch STEREO audio jack & plug - That way you would have one "channel" for 4.5 V, the other for 9 V, and the common ground for, well, ground.

DLMatthys · Post by **DLMatthys** » Wed Jun 23, 2010 7:22 am

Thom,
Will the flasher circuits you are going to use work and look OK at 4.5 volts?
If it does bring them both to the same operating voltage to 4.5 DC
A problem solved quickly and simply?

brt · Post by **brt** » Wed Jun 23, 2010 8:34 am

if it's a 555 timer, I understand it will drop about 1.7 volts. 4.5 volts going in wouldn't be enough for some LEDs.

Tchail · Post by **Tchail** » Wed Jun 23, 2010 8:52 am

DLMatthys wrote:Thom,
Will the flasher circuits you are going to use work and look OK at 4.5 volts?
If it does bring them both to the same operating voltage to 4.5 DC
A problem solved quickly and simply?

The circuit "will" work at 4.5 volts, but it is significantly dimmer.

So much for trying to use a cheap circuit - it ended up biting me in the bum.

Next time, I'm going to use your Federation Flasher kit.

But I guess the whole point of this kit (for me) is really to learn something and produce a work of art.

-Tchail

DLMatthys · Post by **DLMatthys** » Wed Jun 23, 2010 1:45 pm

Can you change the resisters that go to the LED to a lower value?
That may brighten it up at 4.5 volt.

We might be at the same stage on our Galaxy Class builds. The task I am doinf now is to make a display base with some switches and push button controls. The only flashing lights I will operate is a LM3909 to make the strobes blink. I adjust the boards 4 strobe resisters to work with 120 ohm

Tchail · Post by **Tchail** » Wed Jun 23, 2010 2:02 pm

Hey Don,

I tried changing the values of the resistors, but doing that caused the circuit not to work at all.

So I've decided to use the DC/DC converter breakout from Sparkfun.

But I'm also changing the resistors on the Bussard collectors, so the nacelles will run entirely on the 4.5V circuit.

For a connector I've opted to go with an S-Video connector. It has 4-pins and I was able to purchase a 3-foot extension cable. The female side will go into the model, and the male side will be used on the base.

As for my progress, I'm currently in the midst of windowing.

Last week I did my first application of Enviro-Tex to the windows on the bottom half of the secondary hull.

I found that when mixing Enviro-Tex, there are lots and lots (and lots) of small bubbles in the resin.

Placing tape on the outside of the model and filling the windows in from the inside didn't seem to leave any tape residue on the clear windows, which is good.

However, I need to try your trick of putting a small hole in the tape to let the air bubbles out.

But I found out the hard way that what you "don't" want to do is to place a small square of celophane on the outside of the model, place tape over the celophane, and then fill the window from the inside.

That created small celophane shaped squares of Enviro-Tex on the outside of the model. Enviro-Tex is tough stuff - it didn't respond too well to sanding, so I ended up having to scrape a lot of it off. Not to mention having to clean out my grid lines.

Even though my kit is still "very" much a WIP, I'll try to post some pics soon.

-Tchail