Wednesday, November 28, 2007

More Hinges

I only spent about an hour on the tricorder tonight. I was wrapped up in a couple of other things, including going to the gym. However, I made some good progress.

The putty had a full night to cure, which made it hard as a rock. I snapped it off the styrene jig I had built, and it looked very nice.

A little bit of clean up later, and it's ready for some hinges.

Not pictured, but I slapped some putty on the door recesses, and used my jig again to get those all sorted out.

I then very carefully lined up the two halves of the tricorder, and taped them together with a styrene shim in between. Then it was off to the drill press to drill out holes for the wires.

I first seated the center hinge, and tried to line it up as perfectly as possible with the split between the body and the door. Then I added in the negative wire hinge. Of course, I tested the wires for conductivity before gluing it in place, and it worked well. There's no flicker to the light at all when I move the hinge. This makes me extra glad that I ended up replacing the hinges.

That's it for tonight. I'll do the final hinge and drill out the screw holes next.

Tuesday, November 27, 2007

Again With The Hinges!

So here we go again. Round three of hinge-mania. I may make mistakes as I go along, but I always learn from them. I've learned a lot from these false starts with the hinges, and I'm hoping I can apply everything I've learned to this iteration. And hope that this one is the last.

I start with a fresh pack of hinges. Got these at Home Depot.

I start by sanding off the laquer coating from the back of the hinges. Remember, It's all about conductivity with these babies.

I didn't need to sand the back of the middle hinge for conductivities sake, but I did it just to make sure they were all the same thickness.

After sanding, I tested each of the hinges to make sure they could carry current. They all did, and they were very stable. No flickering of LEDs when I opened or closed the hinge. So far, so good.

And then it was time to try something different. One of the things that bugged me about the previous versions was the sloppy way that the wires were soldered onto the hinges. Not only did it leave a big glob of solder that would often make it difficult to line the hinges up properly, but I'm not sure it was the most secure method. So I'm going to drill a hole in each side of the hinge, thread the wire through it, and then solder it.

In order to make sure the hinges were going to take putty and paint, I sanded the laquer off the front face and hinges themselves.

I soldered in my red and blue wires, then filed down the corners and edges of each hinge to make them easier to fit into their respective recesses.

Of course, I tested each of the hinges to make sure they were STILL carrying current.

With the hinges all set, it was time to turn my attention back to the body. I wanted to re-do the bondo squish on all of the recesses, to make sure the hinges will all be sitting at the same depth. I thought this would be easiest if I built a new jig. This will allow me to do the bondo squish on all three recesses at the same time, with predictable and repeatable results.

Here's the main body, getting the squish treatment. Fingers crossed!

As I write this, the putty is curing. I'll leave it be for now, and post results when I have some.

Once Again, It Goes To Pot

Just when things seemed to be going well with the hinges, it all falls apart.

When I last posted, I was on my way to installing new hinges.

I got them all glued in place, then screwed in the screws. Sounds good so far, right??

Well, when I went to open the tricorder, I found that the lid did not line up properly. It opened kind of cock-eyed. That sucks, and I was having none of it. So I ripped out the hinges, and I'll start again later. Every project has its tough spot. I guess this is the one for this tricorder.

Monday, November 26, 2007

LHS Lay Down

With the RHS now edged and awaiting it's mate, it was time to lay down the LHS, or Left Hand Side of the gun. I photographed a few different steps of the process for this half, just to show more of the techniques I use.

Before laying in anything, I need to powder up the mold. My plan here is to do a combination of resin and 1630. When I did the other half of the rifle, I found that 1630 isn't always at its best when it comes to tiny nooks and crannies, because of its viscosity. My plan for this half is to lay down resin into the more complicated parts of the mold, let it cure, then lay down 1630 on top of it. The primary motivator here is the large detail piece in the center of the mold. This detail was cast separately on the other half. If I attempt to do this detail piece in 1630, I would expect pretty poor results.

Anyhow, here's the mold.

Next up, it's time to powder the mold. Why??? By putting baby powder or corn starch into a mold prior to pouring resin, you're doing yourself a huge favor. When you have a thin coat of powder in your mold, you'll be able to take advantage of a little thing known as "Capilary Action". Basically, the powder will physically draw the resin into hard to reach places, oddball corners, and tight spaces. If you ever get a resin piece with "blow outs" (the technical term for bubbles in the resin), this was probably caused by a person who didn't know to powder his molds. Folks, if you're pouring resin without powdering, you're just wasting your time. Or the time of whichever sucker is buying your resin parts. Rant over.

Just to be clear, lets walk through powdering a mold. The goal is to get a thin coating of powder over the entire mold, and in every corner. You do NOT want clumps of powder sitting in recesses. Clumps = bad.

I tend to put the powder on pretty liberally. You don't have to, but I want to make sure everything is covered.

I then use a brush to push the powder around, and make sure it's in all the recesses. Don't worry about clumps yet.

I don't have a photo, but the next thing to do is blow out the excess. I use a can of compressed air, but mainly because this mold is so huge. For a smaller mold, you can just turn it upside down and tap it a few times until there's no clumps.

And then you're ready to lay down some resin.

Recall that the first thing I'm going to do is pour in some resin, into the tough to get to places. I mixed up a little cup, and poured it into place.

I then used a chip brush to push the resin up against the walls, into the details that I want good exposure on. The purpose here is only to get a thin coating. I'm not going to wrestle with this stuff as it cures and try to force it to stay on the walls. Just a thin coat is all I need. I do this in all of the areas I want covered this way.

Because I have already walked through the process of laying down 1630 in an earlier post, I'll skip it for this one. I did things a little bit differently on this side, mainly because I realized I didn't need to be as tidy. Last time, I was really paying attention to getting crisp edges, not realizing that I'd end up sanding down all that flash with the cheese grater. That cost me time, which meant the 1630 had less work time.

Here's the left side all finished.

I forgot to post about a really cool thing I found at Home Depot. They now make these really neat tops for gallon paint cans. It adds a pour spout to any can. This is REALLY helpful, as it saves you all the time of cleaning up the lid after each pour. Without them, you also tend to get a bunch of stuff running down the side of the can after each pour, which gets really messy really quickly.

I gave it about an hour and a half to fully cure after my final lay down of fiber, and then demolded. Just like the last one, it came out beautifully. Only a TINY TINY bit of damage to the mold. I was a bit concerned about that circular detail piece, and what it might do to the mold upon exit. Recall that the free standing side detail mold died after just a couple of pulls. But no worries, it all turned out fine.

It took about another hour of work with the cheese grater and dremel to get all the flashing off and the edges up to snuff, but it turned out really nice.

There was only ONE tiny problem with the pull. One of the detail pieces, which is specifically poured in resin to avoid any problems, had a couple of blow outs in it.

Turns out, I didn't completely blow out all of the powder from the mold before pouring the resin in. There were clumps! This is what clumps look like when you don't get rid of them.

The good news is that it was a simple matter to just pour some resin into the mold to make some replacement parts.

Naturally, the piece came out great. Because I had some extra resin, I poured up copies of the other detail pieces, in case I ever need them, or something goes wrong with the mold.

Similarly, I poured up a duplicate of the center detail piece from THIS side, as I figure this will be the first thing to go on the mold when the time comes.

That's it for tonight. I spent WAY too much time on this tonight. I should be sleeping in prep for a busy day at work tomorrow, but the long weekend threw off my sleep schedule pretty thoroughly. Tomorrow, I'll take a look at mating up those two halves.

As always, thanks for reading.

RHS Clean Up

With the pull from the Right Hand Side (RHS) all out and cured, it's time to clean it up.

I started with my dremel (running at a low speed) and one of those big honkin fiberglass cutoff wheels. I ran around the edge and cut off as much of the flashing as I could. I'd say I left about 1/4" of space. I did not want to get too close to the body and risk nicking it.

After the flash was removed, I switched tools. I don't know what the name of this thing is, but it's basically a hand held cheese grater. It's great (get it??) for taking down resin pretty quickly, but you get a much smoother surface than if you used a dremel tool. Because you can cover areas using long strokes, you get flatness.

After about an hour of grating away at the thing, this is what it looked like on the back side.

Dusted off, here's what it looked like on the front.

The edging is essentially done on this. When it comes time to mate up the two halves, I may end up doing a little more sanding just to make for a better fit. I doubt it will be as much work as I had to put it in to get it to this point.

Saturday, November 24, 2007

First Pull Out Of The Mold!

Today was a really productive evening! If you want to scroll down to the bottom of the page to see the final results, please do. It's quite stellar, in my opinion.

But let's start from the very beginning. A very good place to start.

My order of 1630 arrived the other day, but it wasn't until today that I had a chance to unpack it. It's a 10 pound kit. Each of these gallon containers is about 3/4 full. That's a lot of 1630!

Why 1630, some of you may ask?? Why not just use resin? Why not just pour it solid??? Couple reasons, though the main one will hit a nerve with you Seinfeld fans.

One word.


One of the most interesting properties of 1630 is that it has almost no shrinkage. I think the data sheet for it puts it at .02%. That's amazing, considering most resins range from about 2% to 5%. Resin shrinks less if you're pouring thin, small pieces, but more if it's thick and huge. (That's what she said). For examle, your average resin handgun is typically 1/4" to 1/2" shorter than the mold it came out of. That's a big deal. On a gun the size of this one, you might lose an inch or two. I don't wan that.

So while 1630 is more expensive, and a bit harder to work with, you benefit by having almost no shrinkage. It also tends to bond to itself VERY well. Most resins to a decent job of bonding to themselves, but not always. 1630 also sands really well. It's good stuff.

My first order of business for today was to repeat something I did the other day. I poured resin into the detail pieces on the rifle. Why? 1630 is great stuff, don't get me wrong. But it's not super strong on the detail pieces. When you mix up a batch, it's pretty thick. The resin I use is only SLIGHTLY thicker than water when it's pouring. 1630 is more like maple syrup when you mix it. What this means is that it's less likely to get into all the tiny nooks and crannies that you tend to find in those little greeblie detail pieces. So I poured in the resin.

The instructions and labels for the 1630 mention that you need to shake well before using. What they don't mention is that you need to mix the HELL out of it before using. I shook the cans around for a few minutes before cracking them open. I put a stirring stick inside, only to discover that about 50% of the can was a thick sludge!!! It looks like that creature from "Skin of Evil". You know, the one that killed Tasha Yar?


The same was true for the other half. I spent about ten minutes trying to mix it by hand, and then gave up. I needed a paint mixing bit for my drill! I hauled down to Home Depot and picked a couple up. They were only five bucks each. I got two because I didn't want to risk contamination of either half of the stuff. Who knows, a few ounces of part A might cause part B to cure overnight or something. Didn't want to risk that.

Even with the mixing bits, it took me about a half hour of mixing to get all the sludge mixed into the stuff. Ten bucks well spent.

Another little hint for you readers. Whenever you deal with resin, and ESPECIALLY when you deal with fiberglass, wear gloves. For under 10 bucks, you get 100. Not only will they keep your hands clean, but it will save you HOURS of picking resin out from under your fingernails, under your sking, and wherever else the stuff might get. They're just gold. Go get them.

With my gloves on, and my 1630 all mixed, I went to work on the mold. I used chip brushes (.59 cent throw away brushes) from Home Depot to apply the 1630 to the mold. It's brush on kind of stuff. I only mix up a little bit at a time. The stuff turns thick in about 5 minutes. That's how much time you've got to push it into every corner, and up on every wall. It's not thick enough to stay on the walls, but we'll get to that later.

I placed a couple of R2 batteries on the inside of the mold to help keep it in place. It looks like this top half of the mold was stored upside down for a number of years, and as a result has a bit of a sag to it. When turned right side up as it is now, that sag turns into a bulge. (insert off color joke here). The batteries keep the bulge down. My theory was that once a couple layers of 1630 cured, I could remove the batteries, and the hard resin would keep the bulge down while I covered up the rest of the mold.

After a number of applications, it was time to switch gears and start laying in some fiber. I guess if I wanted to get slick, I should have actually used fiber glass. It's probably stronger, and lighter. But the smell of it just kills me, and I wasn't sure if I had a big enough supply on hand for the entire job.

So I just laid in the fiber with another coat of 1630. I'm using fiber that I picked up at Kragen Auto Parts. It's not the sheet stuff, it's the type that you can pull apart with your fingers. I like that stuff better. It seems to handle odd shapes with sharp corners better.

I start by pouring in some wet 1630, then I drop fibers on top of that. I usually try to have some order to my "drops", and try to get the fiber where I want it to be. Then I dab the brush into my cup full of resin, and dab at the fibers until they're nice and wet. You want to make sure the fibers are soaked all the way through.

The fibers add a ton of strength, but also keep the resin in hard to stay places. Like up on the walls of the rifle. Usually the resin just wants to slide down into the base, but with the fibers there, a bunch more of it stays.

Here's a close up of the tip of the gun, with some fibers sticking out to show you what I'm talking about.

After a few more applications, I was done. It took a bunch of time. I think it's very important to note again that I did this in a large number of small applications. If I tried to mix up a big batch of 1630 then get it all spread around, I would have failed. The stuff sets up too quickly, and you've got to work fast when you're trying to get it into all the corners.

And now I was at a juncture. With all the resin in the mold cured, I needed to decide what to do next. I had two choices. Demold the thing, or leave it in there. This decision is really related to how I plan on joining up the two halves of the mold. Do I want to do the join inside the mold, or once the two pieces are out.

Along the way during the work tonight, I decided that I was going to opt for the former. I was going to demold the gun in two halves, and join it outside. Why?? Because I'm not sure how the mold is going to hold up. For all I know, trying to pull the clamshell in half while there's ten pounds of resin inside could cause it to tear in half. I don't know how fragile this mold is that's been sitting on a shelf for ten years. I don't know how many pulls have come out of it, or how many more can. After what I saw happen to the mold for the detail piece, I was definately worried. So I figured it was time to demold.

And here she is!! It took me about five minutes of pinching and pulling to get this out of the mold, but at the end of the day, it came out pretty smoothly. To my surprise, there was ALMOST no damage to the mold. There was a tiny, half inch long, 1/64" high strip of rubber that ended up stuck to the gun, but that was it. VERY impressive. I was worried that one pull was all I was going to get.

Just for reference, I put the resin detail piece in place, to give the readers and idea of how it will all fit together. Looks pretty darn good.

I don't know how much I'm going to get done tomorrow, so I may wait until sunday to do the other side. now that I'm feeling comfortable with the materials and mold, I think that half will go faster.

Now that I'm done with this half, the mold can be returned to it's home, high inside my garage.

Time to seal up the 1630 too. I use a rubber mallet to pound the lids back into place. Not only does it get the lids securely on, but it doesn't crunch them up like a regular hammer might.

All told, it took me about 2 hours to get this half of the mold done. My knees are killing me!!!

Hinges Revisited

The whole episode with the hinges has gotten me a bit distressed, so this evening, I spent a lot of time working on my mangalore rifle buildup, which also has its own blog here. I made a lot of progress on it tonight, so if you haven't had a chance to check that page out, now would be a good time.

But let's talk about the tricorder!

Tonight my goal was to take another look at those blasted hinges, and see what I could do.

I started by removing the two outer hinges. These are the ones that have the wires soldered to them. This was actually pretty difficult, as the putty I am using is like solid rock. So I had to dremel away enough of the putty to expose the screws, then clean out the grooves in the screw head with an x-acto, THEN unscrew them using a tiny phillips head screw.

After that, I just had to scrape out the epoxy and excess putty. I was back at square one.

I figured out that the problem was that the hinges have a coating on them that makes them non-conductive. I needed to figure out where to go from there.

I dug up a few more hinges that I had lying around. Laying around? I dunno. But anyhow, I found some more hinges.

I lay (laid?) them flat on a piece of sand paper, and sanded away for a while, until it looked as if the surface had changed a bit. Got less clear. More foggy. Looked like I was down to bare metal. I rigged up my power supply, connected everything, and voila! (not to be confused with "viola", which is an instrument. Or "walla", which is a noise drama kids make when they're onstage simulating background/ambient crowd noise)

This was promising, and it looked like I was on the right track. It now appeared that as long as I sanded the coating off the back side of the hinges, they were able to conduct electricity. That was cool.

The downside is that not all hinges are created equal. The danger with almost any tricorder build up is that the hinges are not always making contact between their two halves. As you open and close the door on the tricorder, the hinges sometimes lose contact, and therefore lose conductivity. So the power cuts off, and the lights go off. The main bummer is that it usually causes a flicker in the lights. It would be different if they just shut down. But it's an annoying flicker instead.

I went through the three or four extra hinges I had on hand, and discovered that each of them behaved differently. Only one of the hinges maintained power flow through the entire range of motion. All of the others cut out somewhere along the arc. No big deal, as I'll just have to pick up some more hinges later, until I find one that works properly. I tried using pliers to squeeze a hinge tighter, but that didn't work.

I took my old hinges, melted off the wiring. I tried sanding them down and testing them too, but they suffered from the connectivity problems described above. Off to Watto's Junkyard, I suppose.

Since I had one working hinge on my hands, I soldered it up, and installed it following the same proceedure I outlined previously in this blog.

JUST to make sure I didn't make the same mistake twice, I rigged up power and tested it to make sure all was right in the world. And it was. And it was good.

Tomorrow, I'll need to find some more hinges, and continue with this madness. I was really hoping to have this tricorder ready for painting by the end of the weekend, but this hinge business was a two day setback. Not sure if I'll make that deadline, but I'll keep working.

Friday, November 23, 2007

Reference Photo

A couple of folks have asked me to post reference photos, so they can get a better idea of what this bad boy is going to look like when it's finished.

Here's a good photo that I found online that was taken at the Star Trek Experience in Las Vegas.

The original props were made by HMS Creative Productions, who happen to have a website at


I know how you kids all love those disaster movies that have been so popular for the last few years. Perhaps this post will spike readership, as it's something of a disaster itself.

This is a good lesson in planning. Plan ahead. And test as you go. I don't know why I didn't think of this earlier, but I guess I'm glad I thought of it when I did.

I decided I should test the hinges to make sure that current will pass through them properly. After all, I need to get power to the lower half to light up a few blinkies. So I rigged up my power supply, attached an LED to it and... nothing.

I scratched my head for a while, played around with the wires, tried to isolate the problem... nothing.

I took a break, and came back at the problem later. After some thinking and testing, I realized that there is a coating of some kind on the hinges that is retarding transmission. I cannot believe I didn't think to test for this when I first soldered the wires in place.

The only solution I could come up with for this problem is to take out the hinges, use some solvent to strip off the retarding/retarded coating, and put them back in. Bummer is, I've already done a lot of work to get the hinges in place, and I'll have to undo that. Could even damage the tricorder along the way.

The thought occurred to me to just plow ahead, and make this tricorder a non working one. I do have another kit which I could start up later, and make that one working. That way, any lessons I learned on this build up (and I've already learned a lot) could be employed in the new build.

I actually committed myself to doing a static build up, but changed my mind over night. I've sunk too much work into this one to back out now. And besides, I'd rather have on working tricorder, than a static one now, and MAYBE a working one later.

So next up, I'll be pulling out the hinges. Ugh.

Hinge Clean Up

In the final product, the hinge bases will be invisible. They're underneath the body of the tricorder. So it was time to putty up the hinges. Once again, I deployed the Bondo Squish technique outlined earlier. I could have simply globbed putty in there, and then filed it smooth. However, I find having a smooth surface to begin with not only a time saver, but it also usually ends up looking much better. And smoother.

In order to minimize the amount of putty that was bound to get gummed up in the hinges, I masked them off with blue painters tape.

Then I got to the 'squishin. I gobbed in putty, then used the same piece of styrene I had used to align the hinges to squish the stuff into place.

It turned out VERY nicely. Just a litle bit of sanding, and a tiny bit more putty, and this side will be done.

In retrospect, I probably should have sanded off the primer from the bottom surfaces, to give the putty something better to grip to. Not a big deal, but I'll remember for the next side.