After an awesome trip to Maker Faire San Mateo two weeks ago, Ellery and I decided our next project should be a vacuum forming table. While neither of us have any immediate plans for such a tool, we both thought that building one would be a fun project, and it would enable all of the members at Eugene Maker Space to create even more things. Once you have a tool available, you will often think of projects that would greatly utilize that tool.
We started out by planning out a table of our own design. We were aiming for a 3′ x 2′ table with built in heating element and vacuum. We planned it all out on the way back from Maker Faire. After we got back into town we did a bunch of research on vacuum tables and realized that the heating elements were actually more complex than we originally thought. I thought that having about 25ft of nichrome wire (drawing about 2.5amps) would be enough to heat the plastic to the proper temperature but then I saw that most vacuum tables use a LOT more power (20-30amps) I knew something must be wrong. I think the reason they normally use so much power is to heat the plastic quickly. I’m guessing the lower power oven we designed would have worked but it may have taken 15-30 minutes to sufficiently heat the plastic for forming, and who wants that?
After some more research, we found these plans for a really high quality vacuum forming machine. Many people have built this one and they all seem to get great results. A bonus of using this design is that the creator sells heater kits so you can be sure your heating element will work properly once you set it up. We started out by trying to reverse engineer the design from photos and drawings we found online. I think we could have built something really similar without the plans but really we were still stuck on the heater. We didn’t want to spend a few hundred dollars on a heater that didn’t work. In the end we bit the bullet and purchased the plans. Luckily, Doug (the creator of the machine) gave us a 50% discount since this will be a tool for the non-profit Eugene Maker Space. Unforunately the plans do not include much information on how to construct your own heater. It mostly just suggests using his kit heaters. Doug did a lot of research to figure out what heater would work best in the machine and it feels like he wants to keep that information to himself for now so he can sell more of the heater kits (understandably).
Last Tuesday night we brought the plans down to EMS and started building the base frame. We figured this would be a good place to start since it only really required some basic wood working and it would leave us with the base structure that the rest of the table would be attached too. We didn’t quite finish the base but we got pretty close.
We started out with eight 2″ x 4″ x 8′ boards and two 1/2″ pieces of plywood, each 2′ x 4′. That would be enough to build the entire bottom frame.
Ellery did some calculations to maximize the wood we could use from each board. We used those calculations to measur out all the cuts.
Then we got to work with the miter saw.
We got all of the boards cut to length at once to save time.
All boards cut to length
First we built the top frame. We ended up using the wrong side pieces for this. In this photo we used 30″ boards but we really needed to use 27″. The 30″s were all for the legs. We had to take this apart later to fix it.
Next we built the other two identical frames. One of them is for the bottom shelf and the other is for the middle shelf.
Ellery holding the completed middle and bottom frames
All the frames stacked up
That’s about as far as we got. We actually attached all four legs to the top frame, but it ended up being wobbly. After some inspection we realized that all four legs were not exactly the same size. We took those off so we could fix them but we ran out of time. We are hoping to have this wooden frame completed Friday night. We will probably also buy some casters to put on the bottom so we can roll the table around easily once it is complete. I have a feeling it will be pretty heavy.
When I first bought my 2008 Nissan Altima back in 2009 I used the auxiliary input jack on the stereo all the time. I noticed it was a bit finicky though. It seemed like you could push the stereo plug in most of the way but the final “click” into place was difficult. Eventually (about a year ago) something broke. The sound quality was suddenly terrible and I was only getting the left channel. If I wiggled the jack the right way it would start working again, but even that stopped working after a while. I figured the problem was probably a bad solder joint and wouldn’t be difficult to fix if it wasn’t built into my car. So I stopped using the auxiliary input jack. For a year. Last Monday night I finally decided it was time to fix this problem once and for all. I drove the car down to Eugene Maker Space and pulled into the shop.
Here is a photo of the stereo unit as a whole.
And this was the main problem.
Auxiliary input jack
Before taking anything apart, it’s important to disconnect the ground from the battery. This helps prevent any accidental short circuits.
Ground cable removed
I was able to find some information online about how to remove the stereo. It’s surprisingly simple for the newer Nissan Altimas. In almost a scary way. It made me realize just how easy it would be for someone to steal the stereo if they were so inclined.
The first step was to remove the plastic panel around the air vents. The ideal tool would be a plastic pry bar but I didn’t have one of those. I used a really old Visa gift card to start prying the plastic away, then I used a flat screwdriver for more strength. I used the plastic card to protect the plastic from the hard metal screwdriver. I didn’t want to scratch or dent the plastic panels if I could help it.
Prying the vent panel off
I had to pry apart both sides of the panel. At some point I heard some snapping sounds that were quite scary but it seems it is actually perfectly normal. Once I got past those snaps the panel just sort of slid out towards the back of the car. Then I was able to lift it up.
Once the panel was removed, I could see the two phillips screws that hold the stereo bracket in place on top.
Next I had to remove the bottom plastic panel to expose the bottom two screws. This is done much in the same way as the top panel, only I found it to be a bit easier.
Removing the bottom panel
Next I covered the shifter area in cloth (lab coat) to protect it from getting scratched when I pulled out the stereo.
Protective lab coat
Then it was time to remove the screws.
Removing the screws
Once all four screws were removed, I was able to pull out the stereo. It actually snapped in around the sides so it took a bit more effort than I anticipated to pull it out.
There were a total of four plugs connected to the unit. One is for the proprietary Nissan antenna connector, one is for the AC controls, and two go to the stereo itself.
The plugs were in there pretty good but after some wiggling and finger strength I got them all out.
Some of the plugs
Once I had the thing out of the car I had to figure out how to take it apart in order to get to the stereo jack. My first inspection led me to believe I had to remove four torx screws on either side of the unit. It seemed like these were holding the main stereo into the whole assembly and removing them would allow me to slide out the stereo piece to access the audio jack.
Side torx screws
I managed to remove the four left side screws, but I ended up stripping out one of the screws on the right side because the torx bit I had didn’t fit perfectly into the screw. Oops. At this point I thought I might have been screwed but further inspection showed that I might not actually have to remove those side screws after all. I decided to remove the top metal panel to get a look inside of the stereo.
Inside the stereo
Once I got a look inside I was able to see that the audio jack wasn’t actually physically connected to that large unit anyway. The jack is in the small square whole near the top center of the below photo.
Can't reach the audio jack
I inspected the unit further and decided that the front panel looked like it should be able to come off. I found two small phillips screws on either side holding it on, so I removed them.
Front panel screws
Then I realized that there were four more black torx screws holding the front panel to the main metal unit. I didn’t want to risk stripping them out and I couldn’t find the right size bit anywhere in the shop. Luckily we are only two minutes from Harbor Freight! I drove down there (with gaping dashboard) and managed to find some security bits that included the proper sized bit.
Harbor Freight saves the day!
So now it was time to remove the torx screws. There were two on the top.
Top front torx screw
And two on the bottom.
Bottom front torx screw
Once all the screws were removed, the plastic was still holding on snug. I looked around and saw that there were some small snaps holding it in place around the edges of the unit. The below photo shows some of the snaps after I pried up the plastic to get it off.
Front panel snaps
Once all the snaps were pried up, the unit just came apart into three pieces.
This allowed me to get direct access to the solder joints of the audio jack.
Audio jack solder joints
Surprisingly, they didn’t look too bad. This made me worry a bit because I was hoping to just fix a solder joint or two and be done with this project. I plugged in the stereo plug and used a continuity tester to see which solder joints corresponded to ground, left, and right channels.
I was able to find the ground and left channels, but not the right. This made sense because the right channel was the one having problems. For the hell of it, I decided to just reflow all of the solder joints and see if it would magically fix the problem. I tested continuity again and got the same result as last time. That indicated to me that the problem was actually inside of the audio jack and not just a solder joint. Time to take this thing apart even further!
First I removed the PCB from the front plastic bezel.
Audio jack with rubber pulled back
With plug inserted
Once I had the PCB separated from the bezel I was able to remove the audio jack. I used some desoldering braid to make quick work of the job.
Audio jack removed
After inspecting the jack, I saw some snaps on either side that looked like they would allow me to get inside of the actual jack. This was a good sign because if I couldn’t get inside then I was going to have to replace this jack with a duplicate, which I didn’t have.
In the below photograph you can see the metal contacts around the outside of the jack.
Stereo cable plugged in
I tested continuity again on all of the plug’s pins and still the right channel was not working. I had to figure out which one of the pins went to the right channel and remove it. I just used some pliers to slide out the metal piece.
That tiny piece of metal ended up being the cause of the problem. I think it somehow got bent out of shape and wasn’t making contact properly. I tried a few things to help the problem. First I sanded the edge to get rid of some of the corrosion but that didn’t work. Then I put a small blob of solder on top of the edge to raise it up higher in hopes that it would press against the plug better. That only made it more difficult to push the plug in and resulted in the metal piece bending further. Then I noticed that the inside of the jack looked like it was a bit curved. Like if I pushed in the metal shim it would bend up toward the plug due to the curved design. I removed the solder and tried straightening out the metal shim so it would go further into the jack. This seemed to work. It took a lot of trial and error to find the exact way the shim had to be bent. If it wasn’t bent enough then the stereo plug barely snapped into place and could fall out easily. If it was bent too much then the stereo plug was really difficult to push in and sometimes would even bend the shim back out of the way again. I finally got it into a place that I thought would work for me. A continuity test proved it.
I soldered the jack back onto the PCB and did another continuity test just to be sure it would work. It worked. I put the stereo unit back together and re-inserted it into my car. I hooked up the battery ground cable again and turned on the stereo… It turned on! The buttons all seemed to be working! Now the moment of truth. I plugged my cell phone into the auxiliary input jack and started playing some music. The quality was superb. I got both left and right channels and it sounded so much better than it did before I was blown away. I forgot how good the cell phone audio was supposed to sound coming through the stereo. I screwed the stereo back into the dash and replaced the vent and bottom panels.
Back together again!
A job well done! The stereo got the last laugh though. Removing the power caused it to forget what time it was and also forget all of my saved radio stations. Easy enough to fix. It’s hard to believe all of that work had to be done because of one tiny piece of metal. I’m hoping it won’t get bent again. If it does, I’m going to have to try and just replace that audio jack. I’m keeping my fingers crossed though.
My work held a Mardi Gras themed party a couple weeks ago. I originally purchased a mask for the event, but when the event was postponed for a month I decided that it would be way cooler if I could have a mask custom fitted to my face. The easiest way to get a mask like that would be to make one! I did some research on the web and I found that it really shouldn’t be super hard to make a simple mask. I was able to put this thing together in two days time (barely).
The first step was to make the base mask. I wanted it to fit my face perfectly, so naturally it had to be molded to my face. My Internet research showed that the simplest way to get this result was to cover my face in petroleum jelly and then layer plaster strips on my face until they dried. The jelly prevents the strips from sticking to my face or any of the hairs. I obtained the plaster strips from our local Michael’s store.
Plaster and Petroleum Jelly
First, I covered my face in the petroleum jelly. I paid special attention to places like my eyebrows and hairline where there was more hair that could possibly get dried into the mask.
Next I had to start layering the strips onto my face. I tried to make sure they cris-crossed often to improve the strength of the mask. I had some help from Shannon with this part. That is until we kept making each other laugh. Laughing is a good way to wrinkle the mask so I had to boot her out of the room until it dried. We didn’t get too many photos of this process since it was so messy.
Start with a cross
Covering up more
Once I had all the layers on and it had dried enough, it was time to try and remove the mask. This involved me wiggling my face all around in weird ways to get the mask to detach. It seemed to stick to my forehead the most, but it came off with relative ease.
I let the mask dry overnight. The next day, I used some paper towels to try and wipe off most of the petroleum jelly from the inside of the mask. The mask was actually pretty strong with just the plaster. After I removed the jelly I cut the mask down a bit to pretty it up and get rid of any parts I just didn’t want.
Dried mask from the side
Next I decided to try and build up some features onto the mask to make it more interesting. I used black craft foam to build up some cheek bones and eyebrows. I cut out some shapes from paper as a template and then cut them out of the foam. I glued the first layer of foam to the mask using super glue. Then I glued the rest of the layers together to build up the features.
Craft foam cheek bones
Craft foam eyebrows
Once I had the features built up, I had to cover the mask up in Wonderflex. Wonderflex is this awesome material I found online. It’s a stiff plastic sheet that becomes soft and sticky when heated. You can use a heat gun to make the plastic malleable, and then apply it to a surface and use your fingers to mold it to shape. The plastic is self-adhesive so it sticks to the object you are molding too. I decided to use this stuff to smooth out the mask and get rid of that rough plaster texture. I figured the plastic would also smooth out the cheek bones and eyebrows.
I first cut a piece of Wonderflex that I thought would be big enough for the entire mask.
Mask and Wonderflex
The Wonderflex has a smooth side and a rough side. I wanted to put the smooth side on the outside so the mask would have a smoother texture.
Close up of the Wonderflex
I didn’t get a lot of photos of this process because I was finishing the mask on the day of the event so I was in a rush. You can get a basic idea of what I did with the few photos that I did take. I ended up having to cut my one sheet of Wonderflex down into smaller pieces. I was hoping to use just one piece to prevent any seams from showing on the mask but the mask had so many features it proved difficult.
It seemed like the best approach was to just get the Wonderflex to stick to the mask and get a basic shape around all of the features. It helped to wrap the Wonderflex around the edges of the mask to help it stick down. Once I had an entire piece of Wonderflex stuck down it was easier to reheat areas and smooth it all out with my fingers. This stuff is so great in that you can reheat it as many times as you want. I also found that if you heated it and pressed it enough, you could basically squish two pieces of Wonderflex into each other and almost completely remove any seams.
Getting close to done
Trying to just cover the mask
Wonderflex wrapped around the eye holes
Just needs a bit more smoothing
The next step was to paint the mask. The cosplay website that sold the Wonderflex recommended using acrylic paint. I bought some red and black paints from Michael’s so I would match Shannon’s outfit and got to work. I didn’t get any photos of this process because time was starting to run really short and my hands got pretty messy with the paint.
After the paint was applied, I had to add feathers. What proper Mardi Gras mask doesn’t have feathers? I added a couple of black and red feathers for flair using super glue. The super glue didn’t work out too well because once it fully dried, it left some white residue on the front of the mask. I’m thinking I can probably just paint over that if I ever want to use this mask again though.
Painted with feathers glued on
Glue residue after it fully dried
Next I super glued some felt to the inside of the mask. The idea was that it would cover up the plaster and hopefully provide a softer surface against my skin. This didn’t work as well as I had hoped. The felt I put in the forehead area stuck pretty well, but the felt in the cheeks didn’t stick enough and I ended up having to remove that felt because I ran out of time before the party.
The final step was to add some sort of strap to hold the mask to my face. I used my Leatherman knife to poke some holes in the sides of the mask to attach some lace. I found some suede black lace at Michael’s that I thought would give a fancier touch to the mask. I just poked the lace through with a small screwdriver and tied it to the holes. Voila! Mask complete!
Lace tied from the back
Lace view from the front
Once thing I wish I had noticed before I started this project was that the super glue says on the packaging not to use it for fabrics. Apparently the glue eats through the fabric and doesn’t work as you would hope. I learned this the hard way by using the glue to hold the felt in place. When I got to the party I assumed the glue had completely dried since it had been about 45 minutes to an hour but I was WRONG. I wore the mask for about 45 minutes or so and then took it off. What I saw after that was a bit disconcerting.
Those white spots on my forehead are from the super glue. It hadn’t dried to the felt but it dried really fast once it made contact with my skin! Luckily, the mask didn’t actually glue itself to my face. The glue just seeped through the felt and dried to my skin. I ended up leaving the party early to go remove the glue from my face to ensure I didn’t break out in some kind of rash. I had to rub acetone onto my face (probably not the best idea) in order to dissolve the glue. I removed most of it with the acetone and now a few days later there is barely anything left of it. My skin seems fine so far, but consider this a lesson learned the hard way. Don’t use super glue on fabrics, especially if those fabrics are going to be pressed against your skin!