Archive for February, 2011

You can call me Dr. FrankenCircuit

I kind of can’t believe this part actually worked.

You may remember I mentioned buying a monitor on eBay, and that I want to make integrate it into the old typewriter.

Here’s the eBay picture. I didn’t want take any before pictures, so this will have to do.

Boring, isn't it?

 

 

As it sat, it was 3 3/8″ thick and would have looked awful, so I decided to rip it all apart into it’s constituent elements.

I'm down to 3 circuit boards and the panel

Now, the monitor is about 5/8 inch thick, and it will look much much better when I get it attached to the typewriter.

I want it to end up looking something like this.

Something like that.

 

 

Now, I plan on making a new case for the monitor and mounting it on hinges.

Originally, of course, all of those circuits were stacked up on the back of the monitor.  I want to put those down further so the monitor remains as thing as possible — almost like paper.

There was one problem.

I’m pointing to the place where a wiring harness goes into the back of the model. it extended all of four inches down and was going to muck up my plan to put the circuits down at the back of the typewriter in a nice clean black case.

This left me with a tough choice. I could either reconfigure my vision for this project, or find some way to extend the wires.

I’m sorry I don’t have any process pictures here, but I ended up deciding to extend each of the wires.

So I found a circuit board with paired holes, soldered the lead just before the plastic input piece into the circuit board, then soldering an extension wire out. Then I had another board to input the extension wire and then solder the other end of the wiring harness in there.

Maybe a picture can explain this better…

I call it "Son of FrankenCircuit."

You can see the plastic input bracket or wiring harness  on both sides, and then the two thin plastic circuit boards in between.

Now, as I’m doing this, I’m thinking that I’m pretty much a moron. That having the circuit boards mounted lower on the project is not that big of a deal.

I knew that I bought a used monitor because I would invalidate the warranty as soon as I opened the box. But I’m still thinking that I wasted my money.

This isn’t amazing circuitry work. It’s just pain staking. I had to cut one wire at a time and then go through four solders, and then move on to the next wire. I was terrified that if I cut more than one wire at a time I would lose track  and mess everything up.

In all there were 28 wires and 112 solder joints.

Here’s a picture of half of those….

There are way too many man hours into this, and it's only half.

Here’s another point I find in every project I make. There’s always one little detail I”m not willing to compromise on. In this case, it was the placement of the monitor circuitry. I get maniacal about the bottom of door jambs when I’m installing hardwood floors and I get way overzealous when it comes to patching and sanding drywall joints. I just want everything to be the way I want it to be on these projects, and end up spending way  too many hours on superflous details.

But in this case, I was worried that I had also wasted my money on this monitor.

I finally make the last solder and let it cool, and then rush down stairs to plug everything in and see if it worked. I was careful not to break any solder joints this time.

To my shock, my disbelief, and my amazement at my own abilities, I got this…

It worked! I shit you not.

I guess this project has paid off somewhat. I made 112 solders and got it right on the first try.

I was so excited that this all worked, I was beyond giddy. You should seriously hear the voice message I left my girlfriend. I sound like a little girl who just got her pony.

So! The typewriter part is 99% finished. I still have to get some of those bastardly little feather contacts into just the right spot. And most of the time, when I fix one, the one next to it gets knocked out of line.

That means, with the monitors wires extended, I have to fabricate the new frame and find a way to attach it to the body of the typewriter. Then I’m going to have to connect all the wiring, make black wire looms for anything that’s gangly and sticking out, and make an enclosure so that all of the circuitry is concealed.

I’m finally starting to get to the point where I can see all of the different elements of my vision coming together, and I can’t wait.

 

Switches

I know this is long overdue. I’ve had a setback or two, and spent as much time tinkering and not accomplishing much as making major breakthroughs.

I think the difficulty with these kinds of projects is that you always get new ideas midway through the process and end up redoing things again and again, likely damaging old work in the process.

The first major problem I ran into was that the reed switches that came with the USBtypewriter kit kept breaking on me. Whoever made them decided that glass would be a great encasement for something with steel leads your supposed to bend.  I also needed more then the four I was given and had to come up with something

After breaking 3 of the 4 and having the magnets that are supposed to trigger the switch cause innumerable headaches, I came up with my own idea. Obsewve.

Now this is downright nifty

 

Now this one I’m pretty proud of… especially because those wires aren’t visible when I button everything up.

You can basically see that I took two feather contacts and wrapped one around a moving piece of the return levers innards and put another one on the back of the casing. Now, in order to hit the enter key, you have to actually hit the return lever on the typewriter.

Check out how this is supposed to work.

With many thanks to http://www.usbtypewriter.com

Having a magnet inside that enclosed space was a hassle. I’d say on in every ten hits, the magnet would find something else to stick to. Now I have solid physical switch contacts in there that aren’t going anywhere. When the two pieces of metal hit, it creates a complete circuit and a signal is sent to the sensors.

With that in place, I moved on to the shift.

Shifty~

Essentially, the piece attached to the lower contact raises up when the shift button is hit, and that comes up and hits the upper switch.

This one was a little bit different because you can’t just attach them to the computer. The metal of the chasis is used as a ground, and it would probably cause some form of heinous interference.

Let me take a moment to express me deep and ardent love for electrical tape. It’s like the best invention since Guinness. It sticks to anything, and can be restuck dozens of times. It’s the best field bandage known to man for a contractor, and it insulates electric current. So I took some electrical tape and super glued the feather leads to it and then taped them into place. I also used some epoxy on the one that’s hanging upside down.

Here’s another thing that I am totally geeked out about.

The USBtypewriter kit has a switch on the circuit board that allows you to assign a key a secondary function. In other words, reach around to the back of the typewriter where the circuit board goes, hold that button down, and hit 1 for F1. I’m going to have to use it for more common keys as well, but this will allow me to have a plethora of functionality I might have missed.

There’s just one problem.

The interface board is supposed to be on the back of the typewriter.

… Now.

I noticed my typewriter has a button on the front that doesn’t appear to do much. In fact, the back end of it isn’t hooked up to anything.

Random button. Just chillin'

My solution was to build a little bracket and epoxy a similar switch to the one given in the kit to the area behind that button. Basically, I hit the button on the front, and the buttons plunger hits the switch for the interface board.

 

Brillaint!

I’m getting achingly close to the point where I can put everything together, hopefully calibrate the machine once and for all, and just sit back and wait for the monitor to show up.

 

Two steps forward… well, you know the rest.

So, you may have noticed my last post was actually written on Underwood. It was geekily exhilarating, but short lived, and let me show you why.

Not going to cut it

I’ll quote Jack Zylkin, the inventor of the USB Typewriter here:

“Underneath every typewriter (at least, every typewriter I’ve seen) is at least one springloaded crossbar that runs underneath all the keys.  When a key is struck, it pushes on this crossbar, and this causes the carriage to advance, the ink roll to move, and so on.”

Well, my typewriter doesn’t work this way. There is a bar that goes across the bottom, but none of the keys actually hit that bar. They don’t come within an 1/8 inch. I tried to pile layers and layers of electrical tape on there, but it wasn’t going to get there.

So that’s when I got impatient, and had the idea to leave the feather contacts that populate Frankencircuit just kind of float under the keys.

And I was able to wrangle them into place and get them more or less stroking. But the problem I did not anticipate was that the bar I placed them on rotated just a tiny bit every time I hit the space bar, and the solders started to crack.

So, after a whirlwind 12 minutes of semi-functional typing, I had to scrap that plan.

So another trip to the hardware store later, I had myself some 3/16 steel rod and some heavy duty epoxy putty.

That should help!

You can see the second black rod I installed.  I had to figure out how to use two hands as four, but I got it stuck in there just where the keystroke ends.

So now, I was able to create the project as Zylkin intended, and here you have it.

Nice n' Neat

Much better

Now you can see that each feather contact is supported and has backing so that it will stay in place. Each contact can be wrapped and even glued into place. This will ensure that the piece should work for a good while.

But for those of you who thought I might be getting some sleep or doing anything fun… or for those of you who worry about the future of Frankencircuit, worry not!

Messy

It's still LIVES!

As I find in all handy projects, whether it’s sanding drywall or laying a hardwood floor, you will atone for your sins. Making the feather contacts without care and soldering them in a sloppy manner is going to cost me twice as much time on the flipside.

The good news is that I got most of that done.

The bad news is that I broke two of the reed switches that allow me to hook up things like the shift key, the repurposed number one, and just wait until you see where I hide the question mark and hyphen keys.

The problem is that the little bastards are very difficult to find without ordering them on the internet, and I DON”T WANT TO WAIT. So we’ll have to see what happens there.

Until then… I kind of think I might be done for a couple of days. I can’t really calibrate the machine any better than I did last time because I don’t have a 1, a question mark or or a shift until I get parts.

That being said, I picked up a cheap monitor on Ebay. I thought about buying a new one, but I’m going to void the warranty within 5 minutes of getting it out of the box to fabricate a new casing for it and put in on hinges. So, once that gets in, I’ll have my hands full with the more interesting design aspects of this project. As much fun as the technical end has been, I can’t wait to be working on the phase that doesn’t involve cauterizing-hot irons and burning most of my fingers.

But fear not! I’m sure I’ll find a way to injure myself.