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.

2014-07-11-202749

2014-07-11-202825

2014-07-11-203020

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.

Photo0457

Photo0453

Photo0459

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:

 

 

Photo0450 Photo0451

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

Projects update

Well, I havnt really posted anything in a while due to being busy and such, so here’s an update.

The reprap prusa is finished, and runs really great, it actually runs better than my little printer alot of the time and gives better prints, but also pulls more power due to the heated bed. For now, I just have it unplugged and am using the old printer to print out parts for my cnc machine that Im making.

Im also making an aluminum forge which will be essential in making the cnc machine due to wanting metal mounting parts for high strength and reliability. Also due to the low payout for aluminum atm with recycling, it’ll be alot better to make my own parts that I need custom, and alot cheaper since I have alot of old computers, which the heatsinks, harddrive bottoms, platters, and a bunch of other stuff in them are all made with solid aluminum.

The cnc design that Im making is of my own design of printed parts, which Ill cast to aluminum, and 2×4 boards that I have on hand. after I get everything built, Ill try to upload it to thingiverse as usual. The design should be around 15x15x6 cutting area, and I kinda wanted it to cut stuff like thin wood, or acrylic (plexiglass) if I can. after the z axis is built, Ill try to find some way to make it into a quick release setup, and have it interchangable with a bluray laser assembly, which will be good for engraving pictures and cutting light wood or plastic also. (that’s the plan anyways, who knows if it’ll really work :P) The electronics are a custom board running polulu drivers attached to nema17 motors for x/y/z axis, and will contain an onboard gcode parser called grbl.

Im not really sure what Ill do with the cnc machine tbh, maybe use it as a cnc carver/engraver, I think that’s what they’re called, where you put a piece of wood on the bed and it cuts 3d pics out of it and such.

My old laptop also died, so made a new one out of junk and such from the trash like the last one, I redid mint linux mate and finally abandoned ubuntu due to it being slower and none of the stuff I was trying to get working would run without having to fight with it.

beta:3950 thermistor table for marlin

here’s the thermistor table for the thermistors with a beta of 3950, 100k ohm type. These can usually be found for really cheap on ebay and such, but finding the table for marlin firmware is a bit difficult so here it is, just replace type 8 with this code in thermistortables.h.

#if (THERMISTORHEATER_0 == 8) || (THERMISTORHEATER_1 == 8) || (THERMISTORHEATER_2 == 8) || (THERMISTORBED == 8) // QU-BD silicone bed QWG-104F-3950 thermistor
const short temptable_8[][2] PROGMEM = {
         {1*OVERSAMPLENR,        938},
         {31*OVERSAMPLENR,       314},
         {41*OVERSAMPLENR,       290},
         {51*OVERSAMPLENR,       272},
         {61*OVERSAMPLENR,       258},
         {71*OVERSAMPLENR,       247},
         {81*OVERSAMPLENR,       237},
         {91*OVERSAMPLENR,       229},
         {101*OVERSAMPLENR,      221},
         {111*OVERSAMPLENR,      215},
         {121*OVERSAMPLENR,      209},
         {131*OVERSAMPLENR,      204},
         {141*OVERSAMPLENR,      199},
         {151*OVERSAMPLENR,      195},
         {161*OVERSAMPLENR,      190},
         {171*OVERSAMPLENR,      187},
         {181*OVERSAMPLENR,      183},
         {191*OVERSAMPLENR,      179},
         {201*OVERSAMPLENR,      176},
         {221*OVERSAMPLENR,      170},
         {241*OVERSAMPLENR,      165},
         {261*OVERSAMPLENR,      160},
         {281*OVERSAMPLENR,      155},
         {301*OVERSAMPLENR,      150},
         {331*OVERSAMPLENR,      144},
         {361*OVERSAMPLENR,      139},
         {391*OVERSAMPLENR,      133},
         {421*OVERSAMPLENR,      128},
         {451*OVERSAMPLENR,      123},
         {491*OVERSAMPLENR,      117},
         {531*OVERSAMPLENR,      111},
         {571*OVERSAMPLENR,      105},
         {611*OVERSAMPLENR,      100},
         {641*OVERSAMPLENR,      95},
         {681*OVERSAMPLENR,      90},
         {711*OVERSAMPLENR,      85},
         {751*OVERSAMPLENR,      79},
         {791*OVERSAMPLENR,      72},
         {811*OVERSAMPLENR,      69},
         {831*OVERSAMPLENR,      65},
         {871*OVERSAMPLENR,      57},
         {881*OVERSAMPLENR,      55},
         {901*OVERSAMPLENR,      51},
         {921*OVERSAMPLENR,      45},
         {941*OVERSAMPLENR,      39},
         {971*OVERSAMPLENR,      28},
         {981*OVERSAMPLENR,      23},
         {991*OVERSAMPLENR,      17},
         {1001*OVERSAMPLENR,     9},
         {1021*OVERSAMPLENR,     -27}
};

#endif 
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