My swamp cooler keeps my under garage 96… so far! My printers started having issues printing PLA at those temps, 92 and under no problem, but the cnc’s were/are fine.
Anyone watch CNC Kitchen’s plaster annealing vid?? Particularly the increased temp properties he got with PLA? Not of use to us is the increased layer adhesion though, I mean that is good but I make the parts not depend on layer adhesion to start with.
I want to try annealing prints at some point, but I worry about dimensional stability.
Have you seen this from Dan Gelbart? He builds metal 3D printers that use the annealing process and has defined the shrink ratio. Interesting stuff and probably too complex for plastic parts but worth a look.
One of these days I might put together that wax extruder I keep starting, then I can make an aluminum MPCNC using lost wax casting. (Just have to remember to scale up the pieces by ~3% to account for casting shrinkage.)
Lost PLA casting is a thing as well, sparse infill and go. It has been done here once or twice. The last one I remember was a Z bracket, Barry was that you?
His videos are easily a full course in machining. The rest of his videos are pretty dang good as well. Wish I would have had him as one of my professors.
I remember something in my structural engineering coursed about the modulus of elasticity.
It’s why we like to use steel in structures because it gives a few more minutes of use while it’s failing but wood works until it does not work at all. Best use of resources is to combine the tensile strengths of steel with the compressive strength of concrete. The concrete also acts as a fire resistant layer.
I think my breakthrough moment was super early on in physics I think. When they asked us to calculate the loads on bending/breaking a pencil. You start doing the math and realize the one skin is in compression, the opposite is in tension, and the “lead” in the center is under zero load. After that engineering became much more clear to me. When math started to get applied to that sort of stuff I enjoyed it more, Then came materials and you can kinda get lost in the details, or get decision paralysis.
After school, making real things budget clears up that decision paralysis real quick…cheapest viable solution. Steel and concrete almost always wins for large structures.
I felt the same way when we actually used math to calculate the most efficient storage scheme for wine bottles when building a friend’s wine cellar. 
One moment that really sticks in my mind was support of theory by experiment as when you have the weight you drop that electrically marks(by spark) a piece of NCR paper while falling, the marks being a known time span apart allowing you to calculate the acceleration due to gravity. It was like WOW!, this all really does make sense.
For sure seeing something proved really makes a point stick. We had a demo it was some sort of train, it shot a ping pong ball sized projectile straight up and caught it in the barrel again, at rest. Then he turned it on and let it run down the track seeing it shoot it up and catch it on the move was mind blowing. One of the questions on that final was Santa slipping off a roof on to a slopped hill next to the house. Where would he hit and how hard…Aced that one!
One of the things I always felt should be stressed more in many courses, theory in practice. I found it much easier to remember and understand demonstration than words/numbers on a page. And especially for young kids I think an interesting demonstration goes far in making them curious about the world they inhabit which to me is a good thing.
At the risk of linking to someone else’s store…
Wasn’t me, maybe Dui.
I remember the physics teacher trying to tell us that friction did not depend on surface area. We were all arguing against it. The equation for the friction force is just the normal force times the coefficient of friction.
He took his binder, said, this is being pulled down with a force of 2N, so the frictions force is 1N. He opened it and it had twice the surface area. This is still 2N and the friction is still 1N. That still didn’t quite click. Then he said that each side had 1N normal force and 0.5N friction force for a total of 1N.
So in my mind, it was the pressure (normal force per area) times the area. That felt like common sense to me. But the area cancels out and it ends up just being proportional to the normal force. It makes total sense that twice as much weight on the same box would result in twice the friction. It also made sense that twice as many boxes with the same pressure would have twice the friction. The hard thing to grasp was that splitting the contents of a box into two boxes would result in the same friction. But you can get there easily with the math.
There are still a bunch of weird examples where things are funny. Like wide tires on snow. Friction is a bit magic. But I think in those cases it is more about trying to make sure the whole tire isn’t on a very slick spot. Or changing the coefficient of friction by making the tires not as hard. Or in some machines, a wider area with the same pressure is possible, so you get much more force.
20 years later (and I’m not that old) and I can still remember who was in that class, the order of events, who made what arguments and examples. It was an awesome day.
I ended up majoring in physics in large part because I enjoyed that HS physics class so much. It really had a positive impact on my whole life.
I remember the words: Draw the free body diagram 
I was in high school when a friend of mine tried to convince me that the friction given by breaks disks doesn’t depend on the size of the brake pad. I was incredibly stubborn, and he didn’t know the math to show me. I didn’t see it until later, but I ain’t gonna forget just how hard it was to convince me.
I remember that same day in physics. That really turned the brain upside down, lots of discussion that day in our class as well.
Man, not a physics guy here, and there weren’t a ton of upper level math classes available to finish off my math degree for my last semester. I ended up in intro to chaos and nonlinear dynamics.
I had a pretty major panic attack when the professor assumed we (all 7 of us) could just whip those up. Once I got to the math, I was pretty OK and got an A for the class but man alive it was a lot of work to get there!
I don’t have a clue what you are talking about. I majored in Philosophy and English… -_-
I remember that too. It didn’t make sense in my head. I know it’s true, I did the experiments that prove it.
Try convincing road racers of that, like the guys that put ridiculously wide tires on their cars “to increase the size of the contact patch.”
It’s made worse by the fact that wide tires have a demonstratable effect on the ability of a car (With sufficient power) to accelerate without spinning the tires, and you absolutely cannot convince them that it’s not directly because of the surface area.