Friday, July 30, 2021

Robot School 2021 - Grand Finale

A fun two weeks.  Actually just six afternoons.  But very productive.  We were able to get the word out rather specifically to middle school students with an interest in robotics and as such had very high levels of enthusiasm and almost no distractions.  A lot got done.  I suspect we worked them a great deal harder than is customary in a summer school class.  A few vignettes:

One of our big emphases this summer has been 3D modeling.  Carefully planning a design is what separates Engineers from Blacksmiths.  ( I say this with considerable respect for the latter btw).  But in terms of reducing wasted time, efforts and materials it just makes sense to model things first to see if they will work.  I mentioned in passing that if anyone had something they wanted to bring something from home we'd try to "retro-engineer" it on the 3D printers.  I was thinking, oh, maybe a plastic drawer pull knob or something.

Not a 1930's vintage spiral gear that came out of a meat grinder that someone's family wanted to still use!  From grungy part....

To complicated modeling including all the weird little swirly gear angles.  One of our more advanced high school students is helping here, but I suspect they are teaching each other at about equal rates

On to the printer.  In a break from previous school policy they recently got a bank of very effective Prusa brand printers.  

After a 3.5 hour run on the printer here is the old and the new.  Just a bit of filing here and there and it is ready to install.  I'd be doing a poor job as Your Humble Correspondent if I did not mention that this 8th grader learned the modeling program one week ago.

The major project for Robot School was determined in the middle of session three.  I said, "Hey, let's modify our existing test base with vision tracking, a box pick up mechanism and an autonomous program to select the correct box based on a reflective target, go to it, and grab it."

End of session five:  "Here ya go.  Oh, and you didn't ask but we are adding a beam break sensor to stop the box from being launched into the electronics".

As it happens the demo bot worked rather well until we started making improvements.  It got a bit cranky for the open house presentation but sometimes machines will be that way.  Still, a lot got done in a short time by kids who are going to be doing a lot more in the years ahead.

A quick slide show of Robot School 2021:

Well that's a wrap.  I'm exhausted.  Time to put the robots to bed until school starts up again in the fall.  They get to live in a display case now, and I don't have to haul them in and out for work sessions!

Wednesday, July 28, 2021

Puppy Hank

Dog sitting for a while.  I'd forgotten how much work an enthusiastic pup can be.  Actually I doubt any of our previous dogs were this high energy.  To my recollection none ever woke me up in the morning by jumping up on the bed and licking my face.

Puppy Hank, July 2021.

To be clear, I don't need a dog.  On some level - weighing the obligations of pet ownership - I don't even want a dog.  But......just look at that face!

Monday, July 26, 2021

Forgotten Brewery Caves - Mason City Iowa.

Apologies in advance for a bit of confusion with the two brewery sites of Mason City Iowa.  I blame The Music Man.  More on that in a bit.

I've known about a site just north of Mason City for years but until recently never had reason to go there.  It is in the Lime Creek Nature Preserve.  It is not hard to find, just a gentle stroll down one of the walking paths.

Set into a hillside we find a classic brewery cave.  I did my best to get photos of the inside but the glaring sunshine coming in from the barred door and from an open vent above did make it hard going.  Here is the view straight in.  There is a blocked off door leading to another chamber that seems to be rubble filled.

And here's a detail of the wall to the right.  This shows the spot light effect coming down from the open vent.  It was 101 degrees in the shade that day.  Or would have been if there actually was any shade.  The chamber went about 40 feet to the left and had a similar wall.

I always like to give a bit of history in these posts, but for Mason City it is rather difficult going.  Breweries in Iowa led a precarious existence as state wide Prohibition laws kept popping up.  And in this town two breweries get a bit muddled up by local history sources.

This brewery was the Spring Brewery.  It was established in 1873 by Brahm and McDevitt.  A man named John Schafer from Wilmar Minnesota was also a partner circa 1876.  In 1879 Mason City passed a law outlawing beer sales, and the State of Iowa enacted general Prohibition just three years later.  The brewery seems to have gone under circa 1880.

This brewery is on the banks of the Winnebago River.  But this has not always been true.  The body of water was formerly called Lime Creek.  But enter from Stage Left a certain Meredith Wilson.  Wilson was a prolific song writer who based his 1957 Broadway play and subsequent 1962 film on his boyhood home of Mason City.  When "The Music Man" became a resounding success it was felt that River City actually needed, well, a River.  Lime Creek got renamed and promoted.   So any photos that claim to show the brewery on Lime Creek could be either the one shown above or another slightly earlier brewery in town proper (Mason City Brewery, Carolina Street and 4th St. NE).  With the landscape so altered at both places it is challenging to figure things out, but I think this is the ruins of the Spring Brewery  when some of the walls still stood.

As I mentioned this is in the Lime Creek Nature Preserve.  No entry fee.  They have done nice work in preserving the site including spending $12,000 to stabilize the roof of the brewery cave.  The cornerstone of the brewery with the 1873 date on it is on display in the Nature Center.

Friday, July 23, 2021

Robot School 2021 - Second Report

The current crop of students has talent.  That's good, but also makes our job harder.  After three afternoon sessions they are about where we figured they would be at the five day mark.  So, we make the challenges harder.  A quick report from each of the three sub teams.


We will have near total turnover on the software side of 5826, so this is key.  They were started out with little robots, these guys have very similar programming parameters to the big stuff.  You can tell this is not a Builder, we don't go in for open toed footwear as there are plenty of aluminum shards flying around!

It's a little hard to "show" what they are doing, but in addition to the standard programming curriculum they are working on our big project for robot school  By the end of next week we hope to have a robot that can detect colors, drive to the correct color box (as designated by audience) grab the box and bring it to a designated unloading zone.  All autonomously of course.


Two video projects underway.  One is a promo video for business leaders who are worried about where they will find future employees with skills and work ethic.  The second video is more specific.  It will record our past headaches with belt drive systems and our current efforts to improve.  It's for a engineering firm that makes conveyor belts.  They'll show it to their engineers and no doubt quite a few suggestions, and maybe some sample materials, will be forth coming.  Everything jammed up again...


3D modeling software work has been outstanding.  Actual useful parts are being designed and kids who learned the program in the last 72 hours.  We also had some of them do the classic exercise of retro engineering a Lego.  This is harder than it looks.  I did this one when I took a class at Tech school  Mine did not turn out this well, and it took me way longer.  "Click"!

We currently have two robots active.  The previous competition machine and another for use as a test bed.  That's the one we will be modifying to grab boxes.  Here it is.  And the boxes, too.

We are also building a third robot.  This will feature some very exotic drive units called swerve drive.  It allows movement in all directions.  We have gotten progressivly better at custom frame building using aluminum tubing.  One key is shown here.  Wrap a tie down strap around it to hold it super snug before riveting it together.  

For practice we have also had them make some aluminum tube picture frames.  These will be for our new display area and will feature pics of previous year's robots and teams.

Quite a bit more is also going on.  We are gaining abilities with sprockets and chain drive.  They've had to trouble shoot and repair the old robot, which is showing its age these days.  We've had teaching sessions on material science and on fastener methods.  And a daily snack challenge.  As in 2019 the rules are: solve the challenge or the instructors get all the snacks.  A recent challenge was to tell us the weight of a cylinder 1.5 inches wide and 4 inches long, if it were made of different materials.  Lead, brass, aluminum, granite, bamboo.  They got them all, mostly by modeling the shape in software and swapping out various materials.  The modeling program then tells you the weight, center of gravity and all sorts of other information.

I'll try to post once more after our final session in a week.  It's an open house and we hope to have our videos premier and to have the build and software teams come together to make our box collecting robot work.  

Wednesday, July 21, 2021

Robot School, Summer of 2021

Back in the summer of 2019, before the world went off the rails with Covid, we ran an impromptu summer program called Robot Tuesdays.  It was just a chance for the current members of the High School FIRST robotics team to work alongside a batch of Middle School kids that we regarded as "prospects".  It felt odd at the time, some of the kids had just finished sixth grade and it did have a bit of a daycare center feel to it.  But not for long.  These were some smart cookies and we actually offered five kids a chance to join the Big Club while still in 8th grade.  Sure there were a few maturity issues, but generally the younger kids tolerated the squirrely high schoolers.  The alumni of Robot School version 1.0 look to be the backbone of the team going forward.

Because...Covid.  We, and everyone else,  lost a year of competition and most of a year of meeting at all.  This put us on track to lose a good chunk of the team to graduations and moving out of the District.  And the natural handing off of skills and responsibilities got disrupted.  Time for a rebuild season; but we've decided to Go Big.  Instead of retrenching and running a smaller team we are gearing up for an increase in team size and expanded activities.  

And that means it's time for a scaled up version of Robot Tuesdays.  Welcome to Robot School 2.0.

We have several priorities.  One is having all build team members learn at least basic 3D modeling skills.  I hold up a complicated part and ask how long it would take to make it by cutting, grinding and drilling.  Fine.  Now make 7 more.  Or, design it once and laser cut a batch of them.  Here students are on day one of learning Fusion 360.

In approximately an hour they were designing things like this:

And soon thereafter the files go onto the 3D printer....

Another priority is robot driving skills.  Everyone is encouraged to try their hand.  Among other things it helps incorporate the various disciplines of build, software and design.

Plenty more happening that I did not document.  Software is days ahead of expectations.  And our first custom built aluminum frame has been designed, cut and will be assembled shortly.  It should show off our new "swerve drive" project nicely.

Stay tuned.

Monday, July 19, 2021

On Being a Grand Parent

You do that which must be done.  Even unfamiliar things.  Tea parties.  Nurturing dolls.   It's hard work.  And you catch your (much needed) naps when you can.

Friday, July 16, 2021

Tree Shaped Tombstones - Mondovi Wisconsin

Now how did I miss these?  Mondovi has a cemetery on the edge of town and there were a couple of nice Tree Shaped Tombstones there.  But when I was trying to find Mirror Lake for Day Seven of Strange Fishing I spotted another cemetery.  This seems to be the older one.  As the other was called Sacred Heart and this one is Oak Park, I assume the usual religious divide.

And it has some interesting examples.

A nice one.

I will never stop admiring how this "tombstone moss" interacts with the stone to make things more beautiful.

Some odd symbolism going on here.  These "split trunk" models are always a married couple.  But this variant, where one is reaching out to the other, seems to be trying to say something.  An estrangement that was regretted after death?  

Construction details also interest me.  Here is an original base.  Some kind of rough reddish sandstone.  I suspect the concrete bases that are more commonly seen might also be originals...although some are clearly replacements.  These monuments have a relatively high center of gravity and do seem prone to leaning.

Never seen the like of this one.  There's always something new out there.

Wednesday, July 14, 2021

Lynn's Custom Meats

I don't usually plug commercial enterprises but today I'll make an exception.  Lynn's Custom Meats  is where we bring our venison to be processed.  And it's just an interesting place to visit.  Of course, it smells heavenly.  And.....30 plus varieties of bratwurst!  It's the kind of place I'd bring my UK friends should they ever venture into these more rustic portions of their former colony.

There's always something interesting visually too.

T-shirt for sale.  I think that's Lynn herself with MEAT GAL on her apron.

Help wanted.  Given the old saw about politics and sausage making I think its appropriate that the information given is minimal.

In the outdoor eating area.  I think this is just coincidence.  Must be, everything I encountered at Lynn's was not only edible but tasty.

Monday, July 12, 2021

A Useful new toy

We are looking ahead to robotics next fall, and in fact to doing another summer program for middle school "prospects" in July.  With the move into the school we have gained much, but also lost a few things.  In particular our access to the metals shop will be limited.  So I've been planning ways to do a significant build with just a few portable tools.

One thing that is crucial is cutting precisely.  Mostly aluminum, with weight limits this is the main building material.  And after some consideration I've decided that a miter saw will suffice.  These are more commonly used for woodworking but with a non ferrous metal cutting blade they are very appropriate for our needs.  I imagine we'll have access to one at the school, but just in case (and to acquire competence myself) I got one for my shop/team use.  And here it is:

Metabo sounds like a generic mutt brand but is actually the new name for Hitachi, a reasonably good manufacturer.  This model can cut miter and bevel, and has decent metal clamping ability.  You do have to mount it securely, here it is bolted down to an old cabinet door and affixed to a portable work bench.

I gear my work to what a total newbie middle/high school student might be able to manage safely.  And the Metabo/Hitachi C10FCH2 satisfied.

It is important to carefully measure and scribe your part before you cut.  At that point you just line it up with this handy laser!

I was able to reliably cut within the degree of precision needed, and will do a bit better still using actual layout paint versus magic marker.  The saw can cut angles from -50 to +50 degrees, although I expect we'll mostly be using 0 and 45.  The laser marker looks a bit off here, but I think it might be refracting off the part a bit.  My measurements of parts cut look true but if we end up using this for the team I'll study up on fine adjustments.

This was an inexpensive buy at Menards.  Easy to set up.  Nice safety features.  It is scary enough that students will treat it with respect; and to be sure, nobody gets to use it without a formal training and check off process.  We'll also have each part inspected both after marking and again after cutting.

Gripes?  Just a few.  The instructions that came with it were lousy, sending me to the internet for a video that answered all.  And my gracious it creates a lot of little aluminum chips.  The catcher bag is useless and it requires diligent sweeping up.  Even with that I'm finding little silver bits tracked around the house.  It is not a tool you can set up just anywhere.

But this, or something similar, should be a workhorse in the robotics season(s) ahead.

Friday, July 9, 2021

An unlikely target of theft.

I have not been in the Minneapolis/St. Paul area since the beginning of the pandemic.  And now that things have improved in that regard I'm in no hurry to go back.  It's not the city I remember.  Rioters burned Uncle Hugo's Science Fiction Bookstore to the ground.  Axman surplus was looted.  Just a few weeks ago a man was shot to death in his car a hundred yards from my old house on 26th Avenue North.

But I did go to a ball game near downtown St. Paul, an area that has had less trouble.  Still, I'm not sure what to make of this:

I suspect this cement bus bench has been chained up to keep it from being used in barricades the next time things get stupid in the Big City.  Rioters alas seem more ambitious and organized these days.  I imagine they'll remember to bring bolt cutters.

Wednesday, July 7, 2021

A Playground for the Ages

In a secluded valley that is none too easy to get to even if you have been entrusted with the location, something quite unusual is being built.  It's a playground for grownups.  Some of it is above ground but most of the decade long project has been dedicated to excavating the sandstone cliff face.  A three dimensional maze.  A small tavern.  And assorted work spaces and projects in progress that sometimes just lead you to whimsical niches and shrines.  Its creators say people will be able to come here and enjoy it for a thousand years.   

Welcome to Sandland.

The people behind this project are unapologetic eccentrics.  Many of them come from the world of "urban explorers".  These are adventurous souls who seek out the tunnels, caves, sewers and other hidden places that form an underground network below the feet of oblivious city dwellers.  As this activity is not - to put it mildly - approved of by The Authorities, these people have "explorer names".  At Sandland these are used interchangeably with their (presumed) real names.

Here at Detritus of Empire I occasionally speak of my "underworld contacts".  One of these fellows is involved with Sandland so when I reached out regards a visit I had someone to vouch for me.  It lead a fascinating afternoon.

Here you see upper and lower entrances.  There is a cable car system to bring out excavated sand and dump it in a huge pile.

Into the labyrinth!  My guide gave me no directions in this three dimensional puzzle.  He said that it's the decisions we make are really the important part.  As my sense of spatial geometry is rather good I found a quick way through.  My guide seemed vaguely disappointed.

The maze is a system of low passageways,  you wear knee pads as there will be places where crawling is necessary.  That gets you right up close to the geology.  This is Jordan Sandstone.  Easy to mine and quite solid once it has been exposed to air for a while.  It also has beautiful striations of iron oxide and I think a bit of copper.  I thought it resembled a rich dessert.

In the other working areas of Sandland the tunnels are tall enough to walk in and wide enough for sand carts.  Wiring conduit, air vents and minor jokes are distributed liberally.

Another major feature is the "donut room".  This ring structure has seven passages coming off of it.  Why seven?  Because it is a number that people are not expecting.  Here a convoy of sand carts await their turn to be dumped.

The side passages go to various places, or sometimes go nowhere.  You might find a little shrine with colorful mineral samples.  You might find a remarkably challenging geocache.  Or you might find a Gabe Bar.  By the way, when this phrase is spoken through a respirator mask it sounds like something else.  But no, it was just excavated by a guy named Gabe.  Here I am tending bar, respirator snugly on as sand cutting was going on around the corner.

There is a sort of underground tram way with winch for dragging out the sand.  Far in the distance is the Normal, Outside World.

Well, maybe the Normal World starts a bit farther off.  Above ground Sandland also has a rifle range, a trebuchet, an elaborate tree house and a decommissioned monorail train which contains a shrine to a retired Professional Wrestler.  Because, why not.

Will Sandland indeed be entertaining and puzzling people in a thousand years?  I don't see why not.  I've visited places underneath Rome, Orvieto and other towns that are in perfect shape after  longer spans of time.  The geology is stable, the engineering effort considerable, and this remote site seems quite unlikely to be developed any time soon.

A few parting notes.

Sandland is an undertaking that will not make sense to goal oriented people, which includes most of American culture.  They would ask "why?".  That of course is an irrelevant query.  Creative minds have already decided that it will be done.  All that is left to ask is when and how.

With my interest in such matters it has been proposed that batches of home brew beer be parked in Sandland to age.  This of course is an exact, if highly extravagant, analog of how it was done in the 19th century.  There are some logistical challenges but I've already decided that this will be done.  The rest is just figuring out the when and how.

I mentioned that Sandlanders tend to go by their "Underground names".  To get into the spirit of things I did say they could use my alter ego "Badger Trowelsworthy".  Now it is not easy to read expressions in dimly lit caverns where people have half their faces covered by respirators.  But I got the distinct impression that they'd heard that name before.  Curious and a bit disquieting.  If this turns out to be a genuine lead it would be the first hint of the old scoundrel since 2018. 

Perhaps we are not done with him yet. 


Monday, July 5, 2021

Extended 4th of July Weekend, 2021

The 4th is on Sunday this year.  That pretty much turns a three day weekend into a four or five day affair.  I'm OK with that, we got short changed last year and b'sides, I'm retired and have lots of time.  So....

July 1st. I went fishing with one of my sons.  Two new additions to the life list!  Channel Catfish and this beauty which is variously called Sheepshead, Freshwater Drum and Croaker.  The latter name is because when you grip them they make an odd noise.  More like guttural purring.  Definite candidate for a Strange Fish Geocach.

July 2nd.  Headed up to lake.  Traffic not too bad, you see such scare stories regards holiday travel.  All ambitions fade up here.  Just sitting around and enjoying.  Dog lacked ambitions to start with.

July 3rd.  I guess this was Free Enterprise Day.  The little town near our cabin is obviously a lot busier in the summer than at other times of year.  On this sunny holiday Saturday there were little sales going on all over.  Bake Sale, Book Sale, two competing Farmer's Markets, Thrift Sales.  Everyone seemed to be in on the act.  I went to the Lutheran Church bake sale.  When I was checking out they asked if I wanted a little flag.  Sure I did.  One stop shopping where you could find God, the Flag and Apple Pie.  Although to be accurate I got a plate of cookies.  Lutherans are good at cookies.

July 4th.  Parades.  One if by Land....

Small town Independence Day celebration.  Warm sun.  A fine turnout.  It began with an invocation by the local VFW Commander who was filling in for the ailing Chaplain.  A prayer for our country and the wish that we all work together in divisive times.  Then the Pledge of Allegiance and a first rate rendition of the Star Spangled Banner.  Sweet, sincere, done by someone who put the idea ahead of any personal affectations.  The VFW color guard led the parade.

I like the flag in the young lady's hair.  You saw many such flourishes.  

In addition to patriotism I saw a bit of American Ingenuity on display.  Here a building supply store has found a more efficient way to dispense sugary treats to the younger set.  Gutter segments that direct it right to the curb!

The message on the truck refers to the fact that they were giving away Double Bubble bubble gum.  Eh, no thanks.

And....two if by sea.

Our little lake has an annual 4th of July boat parade.  We sit on the dock and cheer them on.  It's once or twice around the lake then everyone back to water skiing or barbequing or whatever.

Everyone seemed to be enjoying themselves.  Young folk, old folks....


The Leisure Navy sails away.  Fireworks after dark, much to the displeasure of the canines.  

Another warm and lazy day forecast for tomorrow.  Company on the way.