Scott’s Project Smörgåsbord 1

Some nights when I head to Interlock, rather than having one single project, or a part of a larger project to work on, I have a bunch of little things I want to get done.  They have the tools and materials I often need to do this.  This past Tuesday was one such night.  I had four things I wanted to work on, and I got all four done!

1: I like to put handles on things.  My favorite handles are from Lowes or Home Depot, and are called “wire drawer pulls” as seen in the image above.  They’re relatively inexpensive at about $2, and are simple to install.  Generally they would be put on drawers in a modern kitchen or a clinical-type setting, but I like to put them on everything.  If something is portable, it should have a handle.  I just drilled two small holes in the plastic parts bin seen above, shoved the screws in from behind with some washers, and done!  I’ve used these handles for portable drive carriers, and other now-more-portable things.


2: My son, Jasper sometimes breaks his toys.  I usually am the one who fixes them.  Above are two wood bolts from his workbench.  The threaded screws came out of the bolt heads.  I just scraped out the glue from the holes, and cleaned up both sides with a rasp and some other things that probably weren’t designed for such things.  I added some wood glue, threw them in these clamps, and returned the screws to Jasper in the morning.


3: I had tried to fix my DLP projector a few weeks back.  There was something in the light path making half of the image dim such that if you shook the projector, it would clear up a little. I tore it down, and right between the spinny color wheel and the mirrors in front of the DLP chip is this little mirror tube collimator. The glue holding the four front-surface mirrors to the rectangular metal box had failed, and the mirrors became loose.  A couple weeks back, I had tried gluing it back together with epoxy, and it seemed to work, but a new, harsher shadow was in the projected image.  I needed to get some dental tools, mainly the little mirror tool, to see what was going on.  Sure enough, this little guy was aligned incorrectly.  A bunch of futzing with it later, and it is now fully functional!

4: I have been building little breakout boards for my stepper motor controller-turned-arduino boards.  I decided that for the animatronic bird project, I wanted to have a way to input joystick data.  I made a small adapter to go from PC Gameport Joystick to the widget.  I followed this project here for the correct circuit — basically just some pullups on the digital button inputs, and some pulldowns for the analog axis inputs.  I only wired up the first X/Y pair as the widgets only have two analog inputs available.  It was relatively simple to build.  I had built the main breakout board the night before at home, and i made the orange-wire to Gameport connector cable at Interlock.  With help from Nick, providing the old joystick, before I left i had written an auto-scaling display of the current joystick state.  More about this to come in future posts.

All in all, it was a densely packed evening, with four mini-projects completed.  Huzzah!

from on December 18th, 2012Comments0 Comments

Building a Vacuum Forming Rig: Part 1

One of the tools I will need for my Animatronic Avian project is a vacuum forming tool.  To be honest, I’ve wanted one since I read an article on the web about how to make your own Stormtrooper costume in the late 1990s.  It now seemed like a good time to make one, as I’d like to use it for producing the bird parts, and it seems pretty straightforward, so within a week, I was at Interlock, crafting up a vacuum plate.

The basic design I’m going with for the vacuum plate/box is a small box, with a shopvac connector on the bottom, pegboard as the top, screwed together, and metal foil taped to seal air gaps.  This is sort of a mixture of a few different designs I’ve found on the net.  The material will go on its own frame, heated by a heat gun, then pushed down onto the vacuum frame, with the shop vac turned on.  The softened material will get sucked in tight against the mold, forming it into that shape.

The basic frame is 12″ square.  I cut the pegboard to 12″x12″, and I cut a scrap of wood to 12″x14″ for the base.  I made this one larger so I could clamp it to a desk to keep it stable.

For the frame of the base, I ripped some 2×4 pieces into 2×2 ish stock.  To make this easier to assemble, I made four of these, cut to 10 1/2″ long, and arranged them so that they butt up against the others, as seen in the picture above.  They went together fairly cleanly, but there were some air gaps, but this isn’t important as the foil tape will seal it up later.  I specifically wasn’t concerned about tolerances on this as I knew the tape would cover it anyway.  The stock is held together using metal brackets, also seen in the above picture.

The base plate got a 2 1/2″ diameter hole in it to accept the shop vac hose.  I would have used a hole cutter to do this, but I didn’t have one.  Instead, I drilled a pilot hole and used a scroll saw to cut out the hole.

The frame is then screwed to the base plate (pre-drilling all holes, of course) and to the pegboard using drywall screws, AKA the “duct tape of screws”.

Next comes the foil tape to seal it up. Finally some door weather stripping to act as a good seal with the material frame.

The material frame was made with some 1×2 stock or whatever this was, from the scrap pile.  It was simply drilled and screwed together with more… drywall screws!

The material is taped to the frame (for now… in the future, I’ll build a better, less cumbersome way to secure the material.)

Then I heated it with a heat gun.

When it was time, the shop vac went on, and I lowered the framed material down onto the plate.

So… How did it work?

Not great.  It was ridiculously difficult to get the material heated consistently and hot enough.  The heat gun would burn a hole through the material if left in one place, but the material cooled off too quickly if you moved away from it for too long.  I need to build a heater rig to prepare the material.

I attempted to re-heat the material with hopes of getting it hot enough to pull in, while the vacuum was on.  It helped a little, but was quite tricky to work with.  I then removed the foamcore miniature arcade machine, and continued, thinking its height might be an issue.

I overheated some of it, melting through the plastic sheet.  Oops.  But you can clearly see the Duplo blocks, and the stupid Jar-Jar in the plastic.  Unfortunately, Jar-Jar made it unscathed.

One thing I wasn’t expecting was the odor of the plastic, especially this green plastic seen above. MAN, does it smell horrible.  When you see people mentioning “work in a well ventilated area” they aren’t kidding. The plastic continued to have a foul odor for a few hours after it cooled down. I had to drive home from Interlock with my windows down.

It shows promise, but it’s not quite there yet.  I wouldn’t call it a success, but I wouldn’t call it a failure either.

from on December 7th, 2012Comments0 Comments

Electronic Timer Repair

Our kitchen timer has been acting up recently, and with Thanksgiving quickly approaching, I needed to do something about it.  The push button for the start/stop function has been getting harder and harder to use.  In the past, I’ve cracked it open and cleaned out the pad underneath the rubberized button membrane, but this time, doing this didn’t work. I also  wanted a more permanent fix.

I decided to replace the membrane switch for that function with one of these tactile buttons.  I just had to make sure that the solder pads would line up.  I worked out an orientation in which the solder pads would match the pushbutton pads, as you can see in the next image.

The only issue is that rather than the rubber membrane sitting flush with the board, it now had to accommodate the shape and size of the switch along with the button which extended out quite far.  I used a pair of diagonal cutters to nip away at the rubber from behind to recess the switch into the button itself, Ben Heck style.

You can see this in the top right of the gray membrane.  The two contact pads have been removed, and instead there is the hole, into which the switch recesses.  The hole was made fairly crudely, but it works!

It’s been accidentally abused over the years, and as a result, the screws on the bottom no longer hold it together as the plastic has broken enough.  The strip of electrical tape around the base does well to hold it together while still looking super stylish! NOTE: It’s not actually very stylish, but rather, functional and should last for many years more to come.  No reason to throw it out, when an hour or so of work will get it fully functional again!

This post was originally posted on Scott’s blog here.

from on November 30th, 2012Comments0 Comments