Category Archives: Tinkering

Junk vibrobot

Junk vibrobot

There is a category of electric critters called vibrobots.  I hesitate to call them robots , but I guess they are autonomous moving things.  Anyhow, as usual, I have bits of junk laying around that tend to rear up and get in the way now and then.  I have an old motor I salvaged out of a vcr or something.  I also had wire insulation hangers from my crawlspace insulation project.  That’s about all you need to build a junk vibrobot.  I bent a paperclip in an L-shape and taped a screw to one end of it.  The screw attached off center of the motor shaft throws the balance of the motor off so it vibrates.  Since it is attached to rigid, skinny wire feet, the vibrations through those feet on a hard surface translate into motion…random motion!

Junk vibrobot

So, I zip-tied the end of the paperclip without the screw to the shaft of the motor.  I then bent the insulation hangers in an arc and zip-tied the 2 sets of legs around the motor.  I hooked a 9-volt battery to the motor contacts and away it went.   I tried putting little rubber feet on it but the bare wire on hardwood jittered the best.

Mo, our silly cat had to get in on the fun.  The kids had a blast running the v-bot around Mo.  They had it timed perfectly so he would jump in the air when it started spinning.  For a cheap toy, it was quite a bit of fun!  Just a word of warning though…if you do this on your dining room table, be sure the cat is not around.  Also, be sure your wife is not around as she will not be impressed with the cat on the table or with the little scratches the v-bot feet leave.  Of course, this is certainly not the first time I have scratched the dining room table…but that’s another story.


Click the image for a short video

Here are some other vibrobots that other people have made.  I have seen some that are solar powered, some that look just like bugs, and some that are made or worse junk than mine.

Itty bitty vibrobot
Bristlebot
Minty vibrobot

Solar Furnace – thermostat

Old wire thermostat

Earlier this week, I posted about my solar furnace project.  I can’t take all the credit for the idea of a solar furnace as they have been around for a long time.  Most of them seem to be passive – relying on natural motion from the warm air rising through the system.  This sort of air flow is not typically very strong (though it can be), so cannot open a louver or check valve.  Just leaving the hot air pipe open is an option though physics will bite back at night or when it is not sunny outside.  Just as hot air rises, cool air sinks so at night, warm air will syphon from the house backwards through the system.  Some folks drape a piece of plastic over the warm air output so that the warm flow blows the plastic open a little.   Cool air cannot flow back through the plastic, supposedly.

Thermostat for solar furnace

All that sounds nice, but I cannot be satisfied with simplicity when I can further complicate things with technology.  Being interested in saving a buck and doing the right thing energy-wise, I replaced our old thermostat with a digital programmable one a couple of years ago.  I noticed that the old thermostat had a mercury switch so I didn’t want to just throw it in the trash – instead I kept it in my stash of junk…and lucky I did.  This project is prime for my sort of junk.  I stripped the mercury switch and the bi-metallic temperature wire from the thermostat and connected it to an old computer fan.  I am building a box that will contain the thermostat and the computer fan.  The fan will pull warm air from the furnace across the thermostat.  While the air is warm, the mercury switch will turn on the fan which will blow open the dryer vent (that will prevent cold-air backflow) and send warm air into my room.

Thermostat for solar furnace

Initially, I had planned to power all of this with a solar panel.  My fan is a 12 volt, 0.62 amp fan (though I ran it just fine with a 9-volt battery).  To drive the fan directly from the solar panel (at 9 volts), I would need a 5.58 watt panel (watts = volts * amps).  I may be able to get away with a little less but the cost of a 4-6 watt solar cell would still cost somewhere around $50.  I have various 9 volt wall-wart transformers from old gadgets that I no longer need.

Louver for solar furnace

For now, I will just drive this system from wall power.  At 9 volts, when the fan is on, it will draw around 4-5 watts – about the same as a nightlight.  I can live with that.

My plan is to get all of this hooked up and running this weekend.  I will post again with the final project.  It is supposed to be cool this weekend so I guess the timing will be right!

Spammers have been attacking this page so I have turned off comments.  If you would like to have a discussion, please post on one of the other solar furnace posts or send me an email message.  My contact info is in the “about/contact page”.  Sorry for the inconvenience.

 

A salty bunch

Microscope work

We gathered a jug of salt water from the ocean 2 years ago on a trip to Tybee Island near Savannah, GA.  I had in mind when I collected it to do an experiment to show the kids how to separate the salt from the water, how crystals formed, how to research stuff, etc.  I finally got around to it last weekend.  We did several experiments which have had mixed success.  First, we looked at various things under the microscope including epsom salts, table salt, and sugar.  In our first experiment, we suspended a string in a cup full of ocean water.  No crystals formed on their own so we are waiting on evaporation to expose the salt.  We also mixed epsom salts and water to form crystals.  This was sort of cool but not as dramatic as I had hoped.

Making salt crystals

Next, we supersaturated water with table salt.  Crystals have definitely formed on a suspended string.  Crystals have also formed on the side of the jar in which we are doing our experiment.  We put a bunch of salt in that jar so the effect is pretty dramatic.  This was closer to the effect for which I was hoping.

Both of these experiments were pretty slow to show much effect for kids though.  Being anxious for my kids to ohh and ahh at my scientific knowledge and ability, I found a recipe for making crystals from salt, liquid bluing, and ammonia.  making salt crystals

As a base, we tried to use a piece of cardboard rolled up in a tube.  My expectation was that the cardboard would wick up the water and make a little crystal tree.  For some reason, the cardboard did not wick any moisture.

Mrs Stewart's crystals

I guess it was too dense (or maybe I was?) so the crystal tree turned into more of a crystal shrub.  Still, the effect started within a day or so.

Anyhow, here are some additional methods to make crystals.  The kids were in to it for awhile and had a good time checking on the progress.  I’d recommend it for your own edification as well!
http://britton.disted.camosun.bc.ca/snow/boraxsnowflake.html

http://www.squidoo.com/groweasycrystals

making salt crystals

http://silken-didyouknow.blogspot.com/search?q=crystal

http://www.science-projects-resources.com/crystal-science-projects.html

 

Solar furnace

Passive solar furnace

Being a cheap-skate, I am incredibly excited about doing anything I can to put a little extra green in my pocket.  I have been looking online and thinking a lot about making a solar furnace to supplement our home heating.  We happen to have replaced 2 screen doors with full-length windows so I was presented with a couple of large pieces of tempered glass.

Insulation for passive solar furnace

You can look around online for solar furnace or passive solar heat and find tons of additional information, but basically, these things work by capturing heat and using the principle that hot air rises.  I snaked clothes dryer exhaust tube side-to-side through an insulated (with sheets of styrofoam insulation) wooden box.  I covered the insulation with roofing felt to make the inside of the box black (plus I knew roofing felt would live through high heat).  I painted the box and the dryer hose with flat black paint so it absorbs heat very well.

Air passage for passive solar furnace

Cool air from my family room floor is pulled in to the bottom of the system.  The sun heats it as it sits in the tube.  The heating causes it to move upward eventually running back into my family room at about waist-high level.

This version does not show a blower on it yet so air flow depends purely on the principle of hot air rising.  I am working on a version that uses a small fan powered by a solar panel to move the air.  I’ll post more on that later as I get the details worked out.

Passive solar furnace

Anyhow, for the results…I set this in the sun at about 4:30 one afternoon.  The input temp was stable at 62.8 degrees F.  I then measured the output temp.

Input air temp

I could not believe it but my digital thermometer maxed out when the temperature got over 160 deg F.  The last picture I took before it maxed out was at 157.3 deg F.  I have no idea what the temperature actually got to but I saw at least a 100 deg F temperature differential!

Output air temp

Maxed out my thermometer
I have some more info to post on this but it will have to wait until later this week…

This sucks

Vacuum sealing a jar

I talked a little about drying beans the other day but I didn’t tell you what we do with the beans once they are dried.  Actually, we dehydrate and dry all sorts of things actually and this applies to everything we do.  As I have said before, I get hair-brained ideas fairly regularly.  I wanted to be able to vacuum seal stuff in jars but I couldn’t see spending the money to get one of the fancy vacuum sealers.  Foodsaver makes attachments for their powered products to evacuate the air from mason jars so I decided to give that a try with a modification of how the air gets removed.  I needed something that sucks!

Vacuum sealing a jar with a brake bleeder

I can’t take sole credit for these ideas but I can’t remember where I saw a similar discussion on the idea.  Anyhow, a brake bleeder sucks just fine and, in fact, even has a vacuum guage on it to tell how much it sucks.  My first plan was to integrate the brake bleeder with the mason jar sealer.  Although I wouldn’t want to hand pump a brake bleeder all day long, I can pull a vacuum of 20 inches of Hg in about 30 seconds.  The mason jar sealer works perfectly for that.

Vacuum sealing a jar with an hvac pump

Moving on to bigger and better, Harbor Freight (a cheap tool supplier) has a vacuum pump for evacuating hvac systems.  You simply hook it up to your air compressor and it will draw around 28 inches of Hg.  I couldn’t make it work as well with the jar sealer for some reason though I didn’t try too hard either.  You can (as I did) fashion some sort of a cup-like end for a piece of hose.  You could use a stout film canister or a small piece of tupperware or somehting similar.

Vacuum sealing a jar with an hvac pump

Punch a hole in the lid of the jar and put a piece of duct sealing tape (the shiny silver stuff, not regular duct tape) on the lid leaving the hole exposed.  Hold the cup over the hole and tape and start the vacuum.  When you are finished, slide the cup off across the tape sealing the hole.  The vacuum will further hold the tape in place providing a great seal.

Vacuum sealing a jar with an hvac pump

With a little effort, you could probably use the hvac pump with the jar sealer too so it is worth a try.  My “cup” solution works for things like large pickle jars or other containers that aren’t mason jar sized.

Vacuum sealing a jar with an hvac pump

A traditional vacuum cleaner will not pull sufficient vacuum for this to work by the way.  You’ll need something designed to draw (from what I have read) somewhere around 15-25 inches of Hg to be sufficient.  Also, this is not a replacement for canning stuff that should be canned.  We only store dehydrated stuff this way.  Anyhow, it’s a pretty cool option for storing garden stuff and it can be pretty cheap depending on the junk you have laying around your workshop.

My first time…

Knifty knitter loom

They say you never forget your first time…knitting.  This weekend will forever be in my memory.  This special time of my life was beyond my expectation.  Why do people have such a hard time talking to the kids about…knitting?

So I was inspired by the folks at Children in the Corn to try this form of loom knitting.  I have never been one to have enough patience to sit down and do stuff like this so their mention of knocking out a hat in an evening was appealing.  I have never heard of Knifty Knitter looms so I wandered out to our local junk retailer and bought the cheapest one they had.  There are a variety of looms for making all sorts of things but I wanted to ease into this.  My wife accuses me of too often jumping into things with both feet so I decided to honor her and only spend $4 on this newest hobby (if it becomes that).  So, the cheapest loom that the junk retailer had was the flower loom.  The package assured me that I could make all sorts of things besides flowers so I figured I was set for life.  Never mind the pink loom or the purple hook.  I was about to be a knitter.

Knifty knitter loom knitting

What I didn’t know was that the only pattern that came with the loom was for flowers.  A quick internet search turned up the only other pattern for that loom – the friendze scarf.  Cool…I have a daughter…she’ll dig a friendze scarf knitted by her Dad on a pink loom.  This isn’t wierd at all.  Sure enough, Abigail loved the first scarf I knitted.  She danced around as I worked on the first one.  She sang and laughted and giggled and hung around while I worked.  She even said she loved me for knitting her a scarf.  She took it to school to show her friends and teacher.  I really like knitting now…that’s the easiest $4 I ever spent!

I learned a few things along the way…superglue every other peg into the loom if you never plan to make flowers.  The pegs are designed to pull out for flowers but are a real pain for scarves.

Work around the loom clockwise but wrap the thread around individual pegs counter clockwise. If you don’t, you’ll gnaw off your own arm and beat yourself senseless with it…trust me on this one lefty.

Single color yarn is more difficult to work with than variegated.  Both are cool though.

Friendze scarf

Get more looms.  My daughter liked the first two scarves but I think she is ready for something cooler and bigger now.  These things are so simple to use that I will likely buy more and make more stuff.  I need to wear a winter hat in the cold as I have no hair to protect my noggin.  I tend to go through knit hats like I change underwear…at least once a month.  Being able to knit my own in an hour or so sounds pretty good to me.

If you buy a pink loom, don’t let your son catch you using it.  My boy doesn’t know why he teases me but he knows it’s funny.  That’s all I will say about that.

Special times…I will never forget my first time…knitting.  Now that I have done it, I can’t get enough.  I want to knit all the time – in the car, watching tv, outside in the woods, while other people watch.  I am a knit-o-maniac!

Making Apple Cider – part 2

Yesterday I posted about how we found some apples and mashed them in preparation for pressing out the cider.  I’ll let the pictures do the talking mostly.  I’ll include some lessons learned at the end.
Smashing apples for cider

Adding smashed apples to the pressing basket
Pressing apple cider

Fresh apple cider

Fresh apple cider

First pour of apple cider

We quickly learned that adding one apple at a time into the crusher is much better than dumping in 10 at a time.  We didn’t empty the bucket for every apple but we made sure one was crushed before adding another.  We also learned that you get a lot more cider if you crush the apples a lot.  We ran several batches of apples through the press with a “poor crush” and got much less cider than when we really crushed the apples.  We only got 2 gallons of cider so we ended up spending $6/gallon which is not cheap, though it is still of value to me since it is fresh and educational.  Anyhow, we’re getting another bag of apples and will crush all of them completely.  I expect at least twice as much cider.  I’ll make a good crusher for next year so this won’t be a problem then.  Some folks completely pulverize apples in a new, only-for-apple-cider dispose-all (like in your kitchen sink).  I didn’t want to spend the money but they do get a great yield per pound of apples.  I’ll likely make some sort of hand cranked grinder.

Apple cider taste test

We learned that yellow jackets and honeybees can smell apples from thousands of miles away and that they can fly at supersonic speeds to get to them.  Cover stuff up whenever possible.

Get a piece of metal to put between the bottle jack and the top of the wooden presing frame.  I thought of it before hand and am glad I did.  The bottle jack would destroy the wood otherwise.  Also, have several blocks of wood around that will fit into the basket.  The bottle jack probably will not fully press all the cider out at its fullest extension without adding blocks at some point to lengthen its extension.

Listen for stress on the wood when you are pressing.  The jack puts the whole system under a lot of pressure and you could tear things up pretty good if you don’t pay attention.  Wood will tell you when it has had enough.  Listen to it!

Apple cider taste test

If the cider pours over the top of the wooden plunger, release the pressure and let it go back down.  Press it again and you’ll get more cider out.  Also, cut a drain hole in your catch pan or empty it often so the cider doesn’t re-absorb into the pomace when you release pressure on the bottle jack.

When you are done pressing, keep pressure on the pomace a bit longer.  Cider will drain for a short while after you stop pressing.

I drilled holes in a single row around the lower side and the very bottom of the stainless steel pot.  I am not sure if more holes would be better or just make for a weaker pot.  I will not likely add more holes.

Run the cider through a coarse strainer.  It just looks better to me without chunks of apples floating in it.

Apple cider taste test

We read that apples sometimes (often?) carry E. coli and that homemade cider should be drunk at one’s own risk or else be pasteurized.  I have read several things but apparently heating it to 160 deg for 1 minute is enough to kill all sorts of stuff.  I also know that heating cider too much ruins the pectin and sort of erases the “cider” taste/texture.  We haven’t gotten sick yet but will likely pasteurize and can most of the cider.  Officially, I’d recommend you do too.  If you choose not to, at the very least, refrigerate it so it doesn’t ferment too quickly (good for 5-10 days).  Of course, you can ferment cider and make adult beverages too.  I’ll leave that for you to research.

Apple cider taste test

All-in-all, this was a good time and I’d recommend building one of these if you have access to apples.  The kids had a good time and the cider is hard to beat!  Holler at me if you want a parts list or more specific/detailed pictures.  I am happy to help!

 

Making Apple Cider – part 1

Deer apples for cider

Last week I posted about making a cider press.  We put it to the test this weekend.  We took a lot of pics and learned a lot of lessons so I decided to spread it into two posts.  In preparation for making cider,

Smashing apples for cider

I soaked the wooden plunger in mineral oil to seal the wood.  Mineral oil is food safe, and if wiped off after soaking, will not perform its usual purpose (look it up if you are unsure what it’s usually used for).  The plunger was made from 3-2x4s sandwiched between two pieces of plywood and it held together very nicely.

Smashing apples for cider

Anyhow, I was going to use our apples but the deer got a hold of many of them and I plan to make more jelly with those that remain.

Smashed apples for cider

We happened to swing by the farmer’s market on Saturday and a man there had “deer apples”.  I asked him about them and he said they were apples from his usual bins that were either too small or slightly bruised.  We got to talking and he mentioned that when he used to make cider, he used the very same sort of apples.  I looked at them some and they were perfectly good apples so I decided to buy a bag – 53 pounds for $12.  To buy them as “regular apples”, I would have spent $89.57.  The added bonus is that they were a mix of varieties which makes the best cider (as compared to a single type of apple).

Bag of apples for cider

The kids and I dumped a bunch of apples into a food-safe plastic bucket and mashed them with a new sledge hammer.  The mash smelled awesome which caught the attention of the yellow jackets also.  They weren’t a problem but I was surprised at how quickly they found our spot.

Well, that’s about all there is to prepare for making apple cider. I’ll post more tomorrow about the actual pressing and taste testing!

Homemade Apple Cider Press

Cider press

Sometimes I get hair-brained ideas to build something that just seems cool.  My Mom says my Grandpa was the same way.  We prefer to build something rather than buy it if possible because we know we can do it just a little better (my own pride added there, for a bit of good measure).  I had a friend when I lived in PA that had an apple orchard and a cider press.  I remember a time or two going to her place and gathering apples and pressing cider.  Like most things home-grown, freshly pressed cider is better than store bought any day.

Cider press

So, my hair-brained idea this month was to build a cider press.  I had some scraps left over from the shed and a bottle jack from another hair-brained idea so I built this press from the left-overs.  My only real expense was a stainless steel stock pot (from Big Lots – $10) and a roaster pan to catch the cider ($5 at BL).  By the way, to drill holes in stainless steel, make sure you have a good, hard, sharp drill bit.

Cider press

Anyhow, the idea is that the round wooden block(made by edge gluing 3-2x4s and then gluing 2 pieces of half inch plywood to the sides, then coated with mineral oil to seal it) will sit upon smashed apples and will be pressed down into the stainless pot with the bottle jack.  The cider will drain out through the holes in the pot and into the roaster pan.  I have seen some fancy apple smashers, but for this project, it was much faster and more macho to use a new sledge hammer.  I washed the new hammer and coated it in polyurethane.

Cider press

To smash apples, we’ll simply drop it on a bucket full of apples until they are pulverized.     While the press could crush whole apples, to make proper cider, the apples must be smashed prior to pressing.  Someday I may make a normal apple smasher but this will do for now.  I coated the frame of the press in polyurethane to protect it from the elements and to make for easier cleanup.

Cider press

We haven’t tried it yet as the poly is drying (poly is food-safe once properly cured by the way), but I expect we’ll have cider this weekend.  I’ll post again to let you know how it goes!