furnace update

 

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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:

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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.

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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.

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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.

Projects update

well, it’s been a while that I posted anything that I did up myself due to being busy. Lately, Ive been just working on my cnc machine parts slowly, and working on a foundry and melting down aluminum cans and such, which the cans take forever to actually melt enough to cast anything useful. I need to get the stuff welded up on my foundry so I can really cast some larger stuff, or get enough melted to do so, but for now, just testing my homemade refractory mix, Im just using two coffee cans, a stainless steel pipe from an old broom handle that was broken, and a computer fan/blower. It seems to work pretty decently after the lid is put on. I just use this charcoal that we found in the trash, and it seems to really work good after it gets started.

I wanted to get some of the soda cans and old computer heatsinks, and whatever else aluminum I run across into something that I could fit into my little crucible, and I hate doing the generic, so I designed alternative looking ingots instead of the generic gold bar, angle iron, or cupcake ingots that everyone else uses. Instead, I designed these wooden/plastic blocks that I just cast in the greensand, so I can get practice with casting stuff, and these are the ones that I came up with:

 

 

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Giant metal Legos! They’re 3 1/2″ x 2 1/4″ x 1 1/4″ in size, and they stack pretty easily into a small space rather than old pipes and cans. After I get a few made, Ill work on casting the mounts and such for my cnc machine and other projects where strength and where there will be a bit of heat, and the plastic will melt or deform. For now tho, Ill probably just be making my ingots and saving them for a non rainy day :P

 

What happens if you eat silica packets

this is one of those dumb questions that I found out of being bored and raw curiousity, so here it is:

Question: What Happens If You Eat Silica Gel Beads?

Silica gel beads are found in those little packets accompanying shoes, clothing and some snacks. The packets contain round or granular bits of silica, which is called a gel but is really a solid. The containers typically carry dire “Do Not Eat” and “Keep Away from Children” warnings. So, what happens if you eat silica?

Answer: Usually, nothing happens if you eat silica gel. In fact, you eat it all the time. Silica is added to improve flow in powdered foods. It occurs naturally in water, where it may help confer resistance against developing senility. Silica is just another name for silicon dioxide, the main component of sand.

Yet, if silica is harmless to eat, why do the packets carry the warning? The answer is that some silica contains toxic additives. For example, silica gel beads may contain toxic and potentially carcinogenic cobalt(II) chloride, which is added as a moisture indicator. You can recognize silica containing cobalt chloride because it will be colored blue (dry) or pink (hydrated). Another common moisture indicator is methyl violet, which is orange (dry) or green (hydrated). Methyl violet is a mutagen and mitotic poison. While you can expect most silica you encounter will be non-toxic, ingestion of a colored product warrants a call to Poison Control.

 

Copied from here:

http://chemistry.about.com/od/medicalhealth/f/What-Happens-If-You-Eat-Silica-Gel-Beads.htm

Pololu microstepping settings

Pololu stepper microstepping settings taken from pololu’s site.

 

MS1 MS2 MS3 Microstep Resolution
Low Low Low Full step
High Low Low Half step
Low High Low Quarter step
High High Low Eighth step
High High High Sixteenth step
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