Saturday, March 14, 2020

Stay Rational

I made a sticker of my blog motto in case anybody needs to advertise their commitment to social isolation. You can download it and print as needed. But if you sell this I will hunt you down and rip your arm hair out with duct tape.

Thursday, February 27, 2020

New Motor Who Dis?

My 12 year old impact driver seemed worn out so I replaced the motor. That fixed it. This is called cutting to the chase. Here's a link to the part I used. Motor Service Assembly 23-30-0090.

I did some more research into the physics of what exactly is happening in an aging motor. As far as I can tell the issue is that the windings in the motor have a failure of the insulation. They get crammed with carbon dust or other conductive crud which lowers the insulation resistance and pulls more current from the battery. This is why you aren't supposed to use compressed air to blow out a motor housing. All these extra amps are burned up as heat instead of turning into torque. This is basic Ohm's Law logic. Motors are supposed to have a really high insulation resistance. When it starts to fall off then the motor no longer does the same amount of work with the given voltage. None of the sources I found come right out and say this. But that's the manifestation of the issue for me in particular.

My research did reveal that the smell I associate with my grandmother's old Sunbeam mixer creaming butter and sugar for pound cake is actually ozone and vaporized graphite. When my impact driver started making that smell it made me hungry for pound cake, but in fact it should've told me the brushes were breaking down. I always thought worn brushes manifested as an on/off problem. Apparently this other failure mode is also common.

There's a film that forms on the commutator made of copper and carbon and water vapor. It requires the exact right amount of current and humidity to make this protective film that is constantly broken down and reformed. I expect my very humid climate and only using my tool occasionally made it prone to over-filming which lowered the resistance even more, burning off even more of my current as heat, running down my battery really fast without delivering enough torque to get the job done. And also making that smell that makes me think of butter and vanilla.

I have a lot of tools now that are brushless, substituting permanent magnets and microcontrollers for carbon contacts. I will miss the sense memory of my grandmother's kitchen, but I don't have a lot of patience for a tool that won't turn a screw hard enough to pull the work together.

I made a video to show what it's like change the motor in one of these tools. I could've edited it to make it look like I didn't screw it up, but I think that sends the wrong message. Everybody ends up with a part leftover. You have to accept that anything you take apart you're going to have to take it apart again at least once to put back something you missed. Shooting video of the whole thing really helps you figure out exactly where you screwed up.

Live Oak Tripod Knob

I've sort of forgotten about my blog. I think I'll use it more. I've been doing a lot of YouTube videos and putting way too much information in the description. I should go ahead and put it on my blog.

So here's one. I broke the knob on my good tripod. I made a new knob out of some live oak I harvested from the woods from a long dead snag that has weathered down the the hard hard heart.

I made this last week and used it for several days but today I pushed on it too hard and it slid back on the stem and the glue failed and it spins freely now. So now I'm going to make another, better one. I'll likely make another video and add it here.

This time instead of cutting a knob out of a big blank I found a piece of weathered wood an appropriate diameter. I sliced it and drilled a hole only partway through this time. I polished the sides with nylon brushes on the drill press. I had to drill another smaller hole through the top to let the air out when I epoxied the stem into the knob. I broke two knobs in the process. Glad I started two more after I broke the first one. I think this is going to be a satisfactory knob.

While I was making a big mess on the drill press I polished up several more blanks that I cut at the same time. If anybody wants to try some of this wood to make something I have some ready to sell. Just need to photograph it and weigh it to calculate shipping and I can list it on Etsy.

Sunday, October 13, 2019

Longleaf Pine Needles: A Closer Look

We've been having a drought. It didn't rain all of September. The pine trees in my yard have been throwing down needles. I got a special rake just to deal with it. After I used my new rake and got the ground all nice and clean more pine straw fell. I decided to pick it up more carefully and sell it for crafts. I made a sample basket just to use in my photo of the needles.

One problem with picking up pine straw one at a time by hand is chiggers. I have several chigger bites right now and I haven't been in the woods at all. All I've done is pick up pine straw from my lawn. I'd be mortified if somebody got a chigger bite from a package I sent them. So I boil the pine straw in a concoction containing glycerin. Then I leave it in there overnight to cool off. Then I rinse the needles well and dry them in the sun. Repeat.
Boil it up
Yesterday when I was picking up the day's batch of pine straw I found 2 odd ones. They had 4 needles instead of the usual three. Then today I found 2 more odd ones. They had 2 needles. I decided I needed to look at these up close. Here is what I learned.

  1. The rough feeling edges are a badass row of spines angled toward the very sharp pointy tip.
  2. Three needle bundles are a neat triangular packing scenario. But four comes out as an overlapping pinwheel arrangement. The 2 needle one has cup shaped needles and a hole up the middle
  3. Longleaf pine needles are a helix and the number of needles = the number of turns
  4. The 4 needle pine straws are heavier per unit length than the 3 needle ones. Comparing individual needles I mean. It's not just that there's an extra one
Questions that remain unanswered:
  1. What happens that makes some pine straws have a different number of needles? Is it a recessive gene?
  2. What makes the gene expression happen? Chaos?
  3. Is it the same thing as three leaf clovers having 4 leaves sometimes?
  4. How come the number of turns in the helix equals the number of needles in the bundle? This is not a Fibonacci sequence. It's something else. Nothing I could find about helix math addresses this inside shape business.
  5. Why did I only find one paper with a cross section image of a pine needle? And it was from New Zealand. Come on!

Here are some images from my toy USB microscope
Sharp tip of a 3 needle pine straw, 10x

Spinose margin of a 3 needle pine straw, 60x

Cup shaped back side of a needle from a 2 needle pine straw, 10x

Trying-to-be-a-triangle back side of a 3 needle pine straw, 10x

Giant ridge on the back of a needle from a 4 needle pine straw, 10x

Here's some cross section images taken with my phone with a Moment Macro lens

Sections sliced with a razor blade in a drop of water

Sections through the fascicle, held together with thread and hot glue.

The helical design of the n=2 pine needles I looked at came out with decreasing pitch with the increase in number of needles.

2 needle straw, 9 1/2" long/2 turns = 4.75" pitch

3 needle straw, 10" long/3 turns = 3.33" pitch

4 needle straw, 12" long/4 turns = 3" pitch

I could examine n=15+ of 3 needles pine straws and see if pitch is consistent or if number of turns is consistent over various lengths. I'm guessing the number of turns is the same and pitch will vary with the length of the needle. But it was obvious just looking at them that the 4 needle straw is a higher pitch helix. A lot of needles I pick up seem to be more twisted though. I should see if I can tell what is different about them. I usually don't keep those as the flatter ones are nicer for coiling into a basket.

Finally I was curious about the mass per length. The 4 needle straws just feel chunkier.

12" of pine needle: 4" x 3 of a three needle straw  = 0.14 g 
vs 3" x 4 of a four needle straw = 0.16 g
(Sorry for using inches instead of cm. I measured off this cutting mat marked in inches. 12" = 30.48 cm)
3 needle straw = 0.0046 g/cm

4 needle straw = 0.0052 g/cm
This is rather meaningless with a scale only precise to 0.05 grams, but I just felt like the 4 needle straw was so much beefier I wanted to know if it was the individual needles or if it was an illusion because there was one extra.

I drew my observations so I could remember what I learned. If I find more of these aberrant pine straws I'll increase n.

**UPDATE 13 October 2019 **

I found more 2 and 4 needle pine straws today. My hypothesis about the number of needles = number of twists would appear to be false.

A days collection of 2 and 4 needle pine needles
I picked up a few hundred 3 needle pine straws and ignored thousands more. I mostly pick them up by color. I go for the brightest yellow ones because they're the freshest. UV darkens them after the chlorophyll goes away.

I have a new hypothesis about the twists. I saved 2 regular 3 needle pine straws to examine closely. One had almost no twist at all. It also had 3 distinctly different colors of needles so it was easy to verify it didn't twist. The underside of the needles seemed very symmetrical.

Needles with hardly any twist. Very symmetrical.

Trying to capture the height of the middle ridge 
I also saved a super twisty one. This one is so twisty the needles tangle up and require careful separation. 

I didn't take a photo like this of the other bundle because there was nothing to see. It was just straight.This one twists hard.

This pine straw is so twisty it was hard for me to get the needles all flat for a photo

I had to do them one at a time. See how the center rib is offset? I bet that's why it twists like crazy. You can count the rows of stomata. There are more on the left side than on the right.
I wonder if I had a good method for sealing these in their original shape and taking a cross section and a good microscope could I identify some structural component inside that would reveal the symmetry or lack of it in each bundle? I'm not sure it matters. Just basic knowledge I guess. Would be nice to know what is normal in case climate change makes something wacky happen. 

Meanwhile I'll keep stockpiling these wrong-number pine straws as I find them in case I get enough to actually constitute a statistically valid assessment. I should note I am not finding these all under the same tree. I found the two 2 needles straws on my actual front steps. The 4 needle straws I found today were in the shade on the North side of the shed. The other 2 needle straws came from over by the well. The 4 needle straws I found the day before were West of the shed and right by the steps to the lab.

Monday, September 30, 2019

It's an architectural problem

I watched the weekly diary video of SG Collins this morning and it was so concise I decided to dust off the old blog and post the links and transcribe it so I can refer back to it later.

For the sake of future me I'm also embedding the current event reference Collins is talking about. This is Greta.

And this is Collins. Rem acu tetigisti, Collins.

I've transcribed what Collins says (this is based on my limited training as an online transcriptionist where I was taught that it is ok to edit out extraneous conjunctions and mannerisms of spoken word irrelevant to the message.)

Greta I love, but based on some of the things that she says I think that she thinks that the people she’s talking to can do something. That they have the power to make change. A lot of people think that the politicians can fix it, or that world leaders can fix it. But I think that the problem that they’re trying to fix is kind of not something that any person can change because it’s institutionalized greed where there’s this sort of extra-corporeal creature that causes you to must-make-as-much-money-as-possible and to never do the right thing.
So I think she might think that people the people she’s talking to can make a difference. Maybe because I been around those people for all my life, or no, I’m sorry, I mean they’ve been around as long as I have, that it makes me think that she’s talking to the wrong people or she’s thinking of it the wrong way. 
If I could talk to Greta I would tell her that really the problem is an architectural one. The world is designed wrong. It’s designed accorded to nineteenth and twentieth century property principles. And I wish we could change that. Just change the way the world is designed so we wouldn’t be forced to do the things that people had to do because they were trying to sell cars and oil to us. But that’s just me. 
But millions of people are out in the street saying we want to change things. That can’t be bad. That has to be good. So I think it’s pretty splendid that we’ve got these young angry teenaged girls to tell us what for. Whether or not she’s that naive or if it’s me that’s naive? I don’t know.  — SG Collins 30 Sept 2019 

It was 7 years ago that I came up with the idea of doing a Small Year. My social isolation has allowed me to fend off that extra-corporeal creature as I've made only-as-much-money-as-necessary instead of as-much-as-possible. The farther I get from the more-money world the harder is is to make that necessary money. I can't make myself create things to suit other people's taste. I know that people are used to an overabundance of durable goods that cost less than than groceries. Mass produced imports are a boon to the must-make-as-much-money-as-possible world. I understand that a hand made item is inherently inefficient. I know there is little value in it as an item, but I still price things based on the idea that my time is worth something. Usually under $5/hr because I'm mostly selling prototypes, I'm not qualified for master level pricing. The value is in the making, which only the maker gets to enjoy. "People don't want to pay you for something if they think you enjoyed it" — Hank Green.

I price items just above what I think anybody will pay for them, yet still putting a much lower value on my time than I would get at a desk job. as a message to makers that what they are doing is worth something the rest of the world understands, dollars. I think of my Etsy shop as a place where people can go to steal my ideas as much as to buy something I made. Unlike sites that scrape my blogs or YouTubers who steal my videos, I don't mind if somebody looks at something I made and it sparks them to copy it for themself. (They just better not try to sell it.) I link to instructional videos for things I made right in the Etsy listings for people who want to make one themselves, if I was able to document it succinctly. And if somebody watches the video and think it looks too hard for them maybe they buy the thing from me and they can explain to admirers what was involved in making it, even if they didn't do it. I think that's important. But that's just me.

Maybe you'd like to buy something from my Etsy shop? Private URL registration is really expensive. I need the money.