So I realized that I have exactly *one* copy of the circuit I am using for the Gecko drivers. Normally I live out of my engineering notebooks but in this case they were unavailable when I put this circuit together. I am posting the circuit here as I want a backup and I am about to overhaul the electronics for my mill to add a bunch of additional safety features.
Circuit for gecko motors driving the big mill
It seems I spend more time on this project waiting for glue to dry than on anything else.
Here you can see the tool well before I add the holders for the different pliers and wire cutters.
Need to permanently add the pliers tool well
Despite a frustrating number of measurements and test fits I somehow still had the tools protruding higher than I would like. To drop all the tool heights by another 1/8 th of an inch I ended up cutting a hole through the support base and then gluing in side supports. Grrr.
And this is what going too heavy on the glue looks like
I guess I went heavy on the glue here. Once it dries I am scraping the excess and adding more support pieces – so this first round of gluing was fairly fast and dirty.
Testing out another problem for my book. This is really just my trying to re-word a centuries old classic. So let me know if the wording is acceptable here:
On his twentieth year working for a pearl merchant Isaac was offered a reward. He was presented with three vases. He was told that each vase contains an equal number of pearls however the vases contain different types of pearls. One vase is labeled as containing white pearls, one vase is labeled as containing black pearls, and the remaining vase is labeled as contain an equal mixture of black and white pearls. The vases are opaque and have long throats the drawer has no way of seeing what the vases contain or the color of the pearl they have chosen until the pearl is removed from the vase.
The merchant tells Isaac that each vase is labeled inaccurately. The merchant suggests that they take turns drawing pearls from the vases in an effort to correctly re-label them.
As a reward for faithful service he tells Isaac that if he can identify how to correctly label each vase first – he can keep any pearls he has drawn. However if the merchant can correctly re-label the jars first Isaac has to return any pearls he has drawn.
The merchant offers Isaac the chance to draw first, should he accept?
I think one of the weirdest parts of going to the dojo is that from the moment you step in the door you senses start winding up. When you first walk in the door it is just like walking in any room with some muffled noise coming from the next room. Then some time before getting both your shoes off you realize it is positively noisy.
The muted noise from the next room has become a bunch of distinct distinctive noises; a regular thump – thump – thump coming from someone working the heavy bag, the shuffle of sliding feet from practicing Kata, and the especially distinctive noises of people sparring. People moving, falling, dodging, and striking – they all make distinctive noises. From the moment you walk into your brain starts pulling the initial swirl of noise into its distinctive and components.
Meaningful training requires being able to put the rest of your life and the outside world aside while you train. It is difficult at first, but the longer you train the easier it is to put the rest of your life on a shelf while you train. Eventually when you walk into the dojo you just automatically start shifting gears and getting ready to train. Before you hit the mat training is all you are thinking about – at least on the good days.
Today it just hit me, this bizarre combination – just as my senses were revving up and the number of inputs my brain was starting to track was exploding – my overall clarity was increasing. I only had a moment where I could observe the whole process from the outside – but it hit me with almost physical force.
It is the kind of think that makes me sad that so few people train in any kind of martial arts. It is an amazing experience.
Front view
So the test fit is a big load off. Everything seems to fit exactly as expected. Not looking forward to making all the little dividers and boxes for the left side of the tool chest.
Contents of the box as things stand now only have 22 things. I decided to not pack so much into the toolbox. It contains fewer tools but I can carry it farther. Right now the box contains:
1. Folding wood ruler
2. Zippo lighter
3. Razor knife
4. Back saw - crosscut
5. 12oz hammer
6. Impact hammer
7. Small lineman’s dike
8. Wire cutters
9. Needle nose pliers
10. Locking pliers
11. Two 1 inch chisels
12. 1/4 inch chisel
13. 6 inch pry bar
14. Try square
15. Speed square
16. Adjustable square
17. Coping saw
18. Hack saw
19. Panel saw - rip
20. Panel saw - crosscut
21. Metal tape measurer
22. Wrecking bar
There are a whole pile of other tools I still need to make holders for – but that is what is in the box so far. Now that I have the tool wells glued up I can check clearance and make the mounts for the lid mounted level.
So after two years I finally tested for my green belt. It probably didn’t hurt that somehow Sensai’s polite suggestion of “You should be at the test this saturday” had apparently become “Be at the test this saturday - or else”. Ok. I added the “or else” part but I think it was fairly implicit from his tone and the look. So, yeah, I made sure I was at the test. Apparently Mr Moran was walking arround taking pictures, and posted them online. Nice of him - but it was weird - he must have been invisible for most of the test becuase I hardly noticed he was there at all. Then again - I guess that is a requirement for a good photographer.
So first, Mr Koons is officially the worst dance partner ever!
On some of the throws he did work in a sweet joint lock on the elbow. I think it was an accident but I am going to certainly want to go back and look at that technique later when I have more control with my Karate.
Oh, and the obligatory belt picture.
Being a big fan of duct Jason has twelve brand new rolls out in the garage, but unfortunately none of them say how much tape is on a roll! To help Jason plan out a big duct tape project can you figure out how much tape is contained on each roll? You are able to measure that the tape is wrapped around a cardboard tube with an outer diameter of two inches, and that the tape wraps around the tube until it has an outer diameter of 3.5 inches. The tape measures out to be 0.01 inches thick. What length of tape is contained on each roll?
The wording needs a bit of work - specifically I want to add some reason why Jason wants to know how much tape is on each roll - but for now I am stumped. I originally wrote it with him wanting to make a suit out of duct tape for his high school reunion - but the absurdity eclipsed the problem. Eclipsing the problem is sort of an ongoing problem when I write this stuff up.
My main problem here, I think, is that it is a very simple problem if you have the tools to solve it - but I am not sure if it is too difficult if people have never worked with power series. I wrote up the solution as an introduction to them - and that is the goal of this problem: to get people thinking with power series.
As always my answer is on the book site I set up. The comments below are just for discussing the problem / people to post their answers.
Tristan and his friend Joe are playing a game of catch. They are fifty feet apart from each other and tossing the ball back and forth at approximately seventy-five feet per second. Two thirds of a second elapse between each of the throws of the ball and the corresponding catch. During that time the ball travels one hundred and sixty seven feet. How is this possible?
Ok, so my first attempt at a lateral thinking problem was a bit of a disaster. Konrad and Jason both were not happy with it and I am trying to figure out a way to re-work it so that the problem is not trying to figure out what the heck I am thinking!
Apparently since I want to publish I need to hold off on posting answers here for copy write reasons. So I will post the answers on a separate site and use comments here as a way to discuss the problems.
So I hate “lateral thinking” problems. Seriously. They usually seem to be more of an exercise in thinking about how other people think – normally an interesting if not enjoyable topic – but somehow sucked dry of the positives of the experience. Never thought much about why I feel that way but I will certainly give it more thought now that I need to write some for my puzzle / math book.
So at some stage I need a tutorial on how to approach these sorts of problems algorithmically – to that end I wrote up this example.
A problem I found online for “lateral thinking” was stated as:
Problem: “How can you throw a ball such that it always comes back to you?”
I am paraphrasing the problem but this restatement has the critical property of the original – at least one answer that is obvious from reading it. Answer: “Throw the ball straight up!”.
These problems always have a basis set of assumptions. For example that the person is in a gravity field or on Earth, that that they can’t throw the ball at escape velocity. I broke down some examples below that have easy graphical representations of the problem. The graphics should help with the book and relaying understanding.
Book notes: examples on breaking down lateral thinking
So I already noted this correction in the previous post - but this is what they find a repeated / missing element in a collection of values from 1…N-1 should have looked like.
Correction - find a repeated / missing element in set of values 1..(N-1)
Just writing this problem down is making me realize how much I have forgotten. Time to crack open the books. I mean I even forgot my notation for mapping into a set with conditions!
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