Disclaimer: Author is not responsible for loss of life, limb or property. Author is not responsible for anything. In fact, author is completely irresponsible. I mean, you should see some of the stuff he gets up to. It’s amazing he hasn’t burned the house down yet. Don’t listen to him. Seriously.

How-To: Kitchen Floor Vacuum Former

Originally posted on MAKE:

Inventor/designer Bob Knetzger has 30 years experience making award-winning toys and other fun creations. Over the years, he’s contributed 20 articles to the pages of MAKE, but the very first was his Kitchen Floor Vacuum Former from MAKE Volume 11, so simple it’s evergreen. Want to make custom plastic 3D parts without a fancy 3D printer? Using your oven to melt the plastic and a household vacuum cleaner to supply the suction, Bob’s homemade vacuum former is the way to go. All you have to build is a simple wooden frame and a hollow box.

Bob waxes nostalgic in his intro:

My favorite childhood toy was the Mattel Vac-U-Form. The pungent smell of melting plastic filled my bedroom as I spent many hours molding little cars, bugs, and signs. The way the flat plastic changed shape by invisible vacuum power was magical and fun to watch!

Today, I use…

View original 104 more words

New Blower Setup

If you’ve seen the last few posts, you’ve noticed that I’ve been trying to use a modified hair dryer to run my furnace, but I’m kinda afraid that it might not work. So I was working on trying to make something extremely overkill and then I wouldn’t need to worry about not having enough air ever again. I tore apart a few old vacuum cleaners and modified everything, so that the motor assembly was enclosed, and would work with a lower powered DC set-up or as high of voltage as I need to get the amount of airflow as I would need.

This is what Ive come up with so far:

Photo0777 Photo0780

It’s made with parts of the sweeper, which was various parts of two motors, one full motor assembly, a few connector pieces that attach the hose onto the sweeper itself. There’s also a cut down blank cd spool that seemed to fit the motor into perfectly around half way down the spool case plastic part.  I plan on adding two printed pieces whenever I get some more printer filament, then Ill either cast them out in aluminum so they last forever, or just figure out some way to bolt everything together. So far, I plugged it back into the wall outlet with the original cord, and it does really well to blow air out of it, but is seriously overkill, it needs to have a variable speed setup on it so it doesn’t keep running at max speed and try to overheat itself after prolonged use.

I know it’ll supply enough airflow because when it was plugged in, it blew the stuff all across the room and blew the stuff off of the walls that was 5-10 feet away from me.

I took the light off of it because I didn’t really have a need for it, and the wiring diagram for it is like this:


credits go to wikipedia for the picture.

As you can see, the wiring for the lightbuilb really isn’t needed for the model that I had, it was just connected between L~ and N, so removing it would not hurt anything at all.

I will probably use it if I can figure out how to control the speed on it, but everything I’ve looked at is kinda iffy on the setup, or cant handle the current from the motor. The motor is a 12A motor from an old bagless eureka vacuum cleaner, and from what I’ve found, dimmer switches cant handle that much current, and neither do triac based designs from what I’ve found. Only thing I can really think of is to use a variac, but I don’t have one and don’t like having a bunch of bulky stuff attached just for a small blower.

For now, Ill probably just tape the thing all together and use some window screen on the inlet part so that nothing gets sucked into it, (including myself :P) and paint it so it looks better.

furnace update


Photo0750 Photo0751 Photo0752 Photo0753 Photo0754 Photo0755 Photo0757 Photo0758 Photo0759 Photo0760 Photo0762 Photo0763 Photo0764 Photo0765 Photo0766 Photo0767 Photo0769 Photo0770 Photo0771 Photo0772 Photo0773 Photo0776

My new foundry furnace progress

Since my little furnace burned up and died, I decided to go back and start working on my original one that I planned on from the start, but never actually got past basic welding and such on the thing. I got a little free time and went back to working on it again, and this is what it looks like so far. Im also building an air compressor at the same time out of an old air conditioner compressor and an old freon tank or empty propane tank, but that’s later on down the road.

Here’s some pics:

Photo0747 Photo0748 Photo0745 Photo0743 Photo0742 Photo0741 Photo0740


The foundry is made from mainly all junk we had laying around, and what I could source locally. It is far from complete, but it has a good start on it. I used clay/playsand/concrete lining that I used in my original furnace, which worked well for over 30+ melts and many many hours of running at around 2000 degrees. Due to it’s large size, Im abandoning the use of charcoal and going for waste oil burner since people around here just keeps tossing it out faster than I’d even be able to use it.  So I’d have pretty much an unlimited source of fuel for the thing forever, and with thanksgiving coming up, lots of people will be doing turkeys and such, so tons of gallons of peanut oil and such for my projects.

The old furnace lining died due to being scraped out during loading coal/charcoal into the furnace, and the coal turning into the black glass that you usually run into. You dont run into that with the waste oil burner setups, and I coated the thing in grey chimney sweep cement, rated at 3000 degrees, so it should last for a long time. I still need to get the fittings, pressure regulators, some various compression fittings for the oil and air, then hook it all up and put it all together. Also still need to find some type of blower, but not having much luck in that area, may just use an old hair dryer.

The wheels are from an old garbage tote that was supposed to have been crushed, but we stole the wheels from it since the tote was junk. The fuel tank is from a small fire extinguisher, (can you see the irony?) it is all done in 1/4 NPT brass fittings and copper tube except the fuel line, which is poly tubing. I went for poly tubing bc it’s what I had laying around from a kit that I got for the 3d printer stuff, but the tubing was the wrong sizes, but works perfect for this. Also with the poly tubing, its clear, so you can see if the fuel/oil is flowing through the stuff and into the furnace.

The atomizer setup in the thing is based off of the kwiky all fuel burner, so you can run diesel, kerrosine, engine oil, vegetable oil from resturants, old cooking oil like peanut oil and such, whatever you have laying around. The compressor will probably be used for that due to being a little cheaper to run than a commercial air conditioner, and alot quieter to be around.

The air compressor will be made from the AC freon compressor pump, empty propane tank, and various fittings, and will be very silent compared to normal air compressors. Most people used to use them for airbrushing setups, like the hobby airbrushing setups. It kinda sucks to be stuck near a very loud compressor for hours on end while airbrushing stuff, so they used to make these and it’s no louder than someone talking at loudest.

Here’s a video of the compressor unit all wired up and running:

Ill keep adding updates on things as I work on the stuff.

Makerfaire 2014 Part 3

Videos from Makerfaire 2014

Makerfaire 2014 Part 2

Pics from the Makerfaire 2014 taken on other cell phone

Makerfaire 2014 Part 1

My pics from makerfaire 2014 taken on my camera.

mini metal lathe project

When I was trying to make my 3d printer, I kept trying to drill the hotend bolts out, and kept running into trouble getting it drilled straight through. Since I couldnt find anyone with a metal lathe or a machine shop, I just kept wasting bolts and such trying to get one that was decently straight, so I decided that now that I can cast aluminum and such, that I would just make my own metal lathe from junk I had laying around.

So far, I only have the rails and headstock finished, but it’s a good start for doing it completely from scratch. It’s made from some cast aluminum, a bearing that was press fitted into what was some type of compressor for a car or something that we found in the trash and was determined to get it out, and some decently thick angle iron that I was given.

It’s around 1-1 1/2 feet long and should be good enough for just center drilling stuff like bolts, and cleaning up my casted projects. There’s a piece of paper in the second picture to show the actual size of the thing.

Here’s some pics that I took so far, which isnt that great because of the fact that I cant get my bluetooth adapter to work in newer linux versions, so just used the built in webcam and the program called cheese.




My coffee cans foundry

This is my little blast furnace, it’s just two coffee cans that are lined with a mixture of bentonite clay, sand, and a handful of sifted concrete. I usually just melt down aluminum in it, but Im pretty sure that stuff like copper or brass might be possible if I try to get it hot enough. I just use charcoal as you can probably see in the pics, and with the right design, it can get to temps hot enough to make heatsinks and other aluminum stuff to melt down quite easily, within 5-10 mins usually. Im not sure what mine runs at, but Im guessing it’s anywhere from 1200F-1500F.

It’s made with two coffee cans, one with the hole in the bottom of the can, and have around an inch thick lining on the outside of the refractory mix listed above, that is used as the lid, and the bottom is the same except the hole is in the bottom is in the bottom side of it, which a 1 inch stainless steel tube from an old broken broom handle or mop that I found, which in turn is attached to a fan blower that came out of an old computer, dell optiplex gx260 or something like that I think. The bottom part that holds the charcoal tends to get alot hotter than the top, and you have to wait for a few hours to let it cool down before you can even touch it to put it all away. The top part, it gets pretty hot also, but the refractory does a good job of keeping the heat inside of it, and not letting much escape so with my welding gloves on, I just pick the lid can up and set it on a nearby firebrick when Im ready to add more scrap aluminum, fuel, or ready to remove slag and pour.

The fans in those systems are really handy for this purpose, but when you attach 12v to them, they only go full blast for a second, then they run really slow. This is due to a temperature sensor inside of the fan assembly that causes it to run at the speed the computer needs to keep the cpu cool, and when it gets hot, it causes the air temp to rise, so the fan automatically compensates for that. That’s no good for this kind of work, so if you look above the sticker, there’s a little pannel that looks like electrical tape, and if you peel that off, you’ll find the thermistor, just take your soldering iron and solder the pins of the thermistor together, just using a solder blob to jumper across the pins. That will cause it to run full blast all of the time. Ive had many many hours of it running at that speed, and it never got above room temperature.

I just use a tin can and melt the stuff down in it, it seems to work for one or two melts usually, but just depends on the can really. I made my own casting sand (greensand) out of play sand that was really cheap at lowes, and ground up cat litter, and it seems to do pretty good, just make sure to run the sand through a sifter first before you try casting anything or you’ll find that it has some pretty large pebbles in the sand that you didnt see before and will make large pockets in your casting.




Here’s a video of it running, I love the flames shooting out of the top. :P


If you ever get into this stuff, make sure to test your aluminum scrap that your wanting to melt down first with just normal vinegar, some aluminum has magnesium in it and trying to melt something with magnesium in it tends to turn into a really bad day for you. It has an ignition temp at around 1200F, which is where aluminum melts, and burns at around 6000F, which will act like thermite and burn right through your crucible, and probably your furnace splashing molten red metal and glass all over the place at your feet.


Get every new post delivered to your Inbox.