Today my daughter and I went to the Museum of flight to take some pictures and to do the space shuttle simulator experience. At the end of the shuttle program, the museum of flight put in a bid to get one of the 4 shuttles. They did not win – the 4 shuttles are on display in New York, Washington DC, Cape Canaveral, and Los Angeles. You can go look at them there.

The museum of flight, however, got something more unique. It got the space shuttle full fuselage trainer. From the outside, it’s a mostly shuttle-shaped object made of plywood and steel, minus the wings.

The cool part is that for the small fee – okay, the rather large fee – of $30, you can take a tour of the shuttle cockpit. We paid our money and were scheduled for the 10:45 tour. Tours are limited to 6 people per tour (more on why in a minute), and you may need to book ahead. There are a lengthy list of restrictions; you need to be able to move around and deal with climbing in tight areas, and you can’t be too tall (they say 6’4” max).

Pictures are explicitly allowed. I’m going to be talking about what’s in the pictures; some came from the tour, some came from the internets, but a lot was already in my head.

I’ve always been a space guy – I watched the Apollo landing when I was 5 and have scrapbooks from Gemini before that. I’ve seen lots of pictures inside the shuttle, but I’m pretty excited at seeing real hardware.

You enter by sitting down and sliding into the round hatch. It’s not particularly difficult, but there isn’t a ton of space. That puts you in the middeck. There were 7 of  us (5 guest, two guides), and there’s not a lot of spare room to move around. They do have the hatch to the docking adapter (for docking with ISS) open, and that takes up floor space, but my first impression is that it’s really, really tight. The mid-fuselage of the shuttle is about 17’ wide, but you need to fit the pressurized cabin + insulation + structure inside of that, and my guess is that the inside is maybe 15’ across, and that’s before they start putting stuff on the walls. A 737 is around 12’ inside, and it’s maybe a bit wider than that, but not much.  The front part of the middeck is given over to floor-to-ceiling storage boxes; they are about 18” deep, and that leaves you with perhaps 8’ from the cabinets to the airlock wall in back. So, something like 100 sq ft or so.

Here’s a picture. I’m standing pretty near the entrance hatch, the storage cabinets are obvious in the middle of the picture, and the curved wall in the back is the outer wall of the cabin. Human to scale; the overhead is something like 7’5” from the floor, and is festooned with velcro to hold cabling.

In a full flight (7 astronauts), three of the astronauts would get to look at these storage bins shaking all of the place during launch. There are no windows on the mid-deck.

Soon after I took this picture, we split up the group; the other 3 tourists went up to the flight deck, and we stayed down on the middeck, took pictures, and listened to our guide.

Here’s one facing the other way; the lockers that were on the left in the previous picture are now on the right. The switch panel is on the outer wall of the cabin, and the section to the left of that sticks out a fair bit.

A better picture in the same direction. The section labeled “Potable” is the water dispenser in the galley. That’s the whole galley; perhaps 18” by 36” in side. It has a little oven in it. To the left is yet another storage space.

Here’s a closeup of the panel. Galley stuff across the top, and then the rest is all about the airlock – heaters, lights, that sort of thing. There are additional airlock controls (for oxygen, mostly) in a panel at the top of the waste disposal cubicle.

Facing aft, looking through the docking adapter into the payload bay. Did not get to meet the alien visible in the center of the picture. To the right of this is the ladder up to the flight deck, and then the space toilet shoved in an alcove. There isn’t really room for a door, so there’s a privacy curtain to sort of block the view, but I’m sure there are few secrets between astronauts in the tight quarters.

Detail of the hatch cover, which is lying on the floor. It would present no problem in space, but it’s a bit inconvenient on the ground.

We had about 10 minutes in the middeck, at which point the other tourists came down and we climbed up to the flight deck. This is the whole reason for the warnings and restrictions about physical capability in the description; the ladder is tiny as is the hole you need to fit through. You climb partway up, sit on the edge and then lever yourself over and crawl to the side. Then you can stand up. Very carefully.

Even with a bit of a hunch, the only place I can stand up is directly under the two view windows; they look direction up and are around 16” square. I can turn around if I am careful. Soon there are 3 of us up there, and we get the spiel on the cockpit. They have the commander and pilot’s seat section blocked off, we can’t more fore any more than we are and without a wide angle lens, I can’t take any real pictures. It’s maybe 4’ by 3’; perhaps a bit more. It reminds me a bit of the Los Angeles class submarine we toured in 2000 or 2001, but it’s way tighter.

Here’s a picture I pulled from the net:

This is facing aft; the controls here are all related to payload; the control in the middle between the windows is for the arm. My head is stuck up under one of the windows.

Here’s pretty much what it would look like if you could take a nice picture of it:

The seats on the tour aren’t quite as nice and the console in the middle is covered with plexiglass to protect it, but this is pretty much it, though the trainer has the new “glass cockpit” displays instead of the original ones shown here. There are switches and circuit breakers *everywhere*. I start taking pictures of panels:

The intercom system control panel. I did not see an iPod dock connector.

Pretty sure this is about the controllers for the commander and pilot.

Gauges and controls for the auxiliary power units. The APUs use hydrazine (nasty stuff) to drive a turbine that turns a hydraulic pump, generating hydraulic pressure to move the flight surfaces (elevons and rudder). They are only powered during liftoff and landing. There are 3 separate APUs (redundancy),  hence the 3 sections. I really like the analog bargraph displays.

Downlink data multiplexer. Takes various data feeds and puts them together so that the data can be sent back to the ground.

This is all late-60s early 70s tech.

Flight computer with keyboards. Okay, so, that’s what we were told, but in fact this is really just the terminal for the flight computer system. There are, in fact, 4 computers scattered around the avionics bays that work redundantly and participate in an interesting voting scheme, plus a 5th computer with separately-developed software that can handle ascent and reentry only.  In the original versions, they could only hold one program at a time (in core memory), which made having the fifth computer (with the reentry code loaded) ready at all times a very good idea. They were later upgraded so that they could hold whatever the current phase was (ascent, on-obit, ISS (presumably)) plus the descent phase code.

The rest of the center console. Big and clunky. It has all a lot of useful controls; you can shut off the main engines or manually command the solid rocket boosters or external tanks to separate (if you have to do any of these you are probably already having a bad day); you can see how the radios work, or you can set up how the RCS controller works (used only in orbit).

Control panel on the commander side, mostly covering HVAC (I think NASA calls this “environmental”). On-orbit, the shuttle generates a lot of heat (people & electronics), and needs to cool down. It  radiated heat through large radiators on the inside of the payload bay doors; the controls on the right side that talk about “rad” or “freon” are concerned with controlling that. If the doors were closed, they boiled anhydrous ammonia (also nasty stuff); that’s what the NH3 boiler controls in the lower right deal with. There’s also a flash evaporator that seems to deal with boiling off water (H20) to get rid of heat. The shuttle generated power from hydrogen/oxygen fuel cells, so it always had extra water.

The left side of the same panel. This has water loop pumps and fan controls; fans are very important because there is no convection in zero gravity so you can easily get very localized hotspots. Also pretty important for people sleeping so they don’t accumulate a cloud of CO2 around their heads.

More water controls

Close up of one of the computer entry panels, this one on the starboard side behind the pilot’s seat (there is a commander and a pilot who can both fly the shuttle; there is no co-pilot because no astronaut wants to be labeled such ways).

My favorite panel; the video processing unit. Hey, they have wireless!

A few switches and a bunch of circuit breakers. Heater for the O2 tank, the smoke detectors, and the fire suppression system; they all have breakers here.

Copilot’s (I mean “pilot’s”) panel. Top left panel is a bit like the service panel in your house, but more complicated. Controls what power-supply circuits (“busses”) are energized, and there are a lot here. Just to the right of that is the CRYO panel; it’s all about the cryogenic (ie really really cold) liquid hydrogen and oxygen that are used to feed the fuel cells. Three sets of H2 and O2 tanks, heaters, and controls for the fuel cells themselves. I guess the guy on the right has all the power (ha ha). The panel below is about hydraulics, APUs, that sort of thing.

Those are all the panels I grabbed; I missed some commander-side ones. I didn’t get the aft payload ones because I was too close and they were covered by plexiglass. There are also all the overhead controls that I couldn’t get a good angle on, and there are a ton of switches there. Each pilot has controls over their audio feeds, and there are additional computer controls and a lot of controls for the OMS (orbital maneuvering system, used to change orbit and deorbit the orbiter) and RCS (reaction control system, used to rotate the shuttle and make small changes in position (such as docking with ISS)). Both systems use propellants; there is a fair bit of redundancy and this is where the controls all reside.

All too quickly, our time was over, and we contorted our way back down to the now very spacious middeck, and exited in the approved NASA manner (grab the bar above the hatch and slide out feet-first). We went into the payload section of the trainer (not part of the tour).

This picture is looking forward, through the docking adapter at the storage bins in the middeck.

If you want to see my full-resolution pictures, you can see the gallery here.

I also highly recommend the National Geographic gigipan series.  See the space toilet (aka “Waste Collection System”) in all of its glorious detail (you can see the ceiling control panel if you zoom in).

Today I spent some time looking at the wiring state of the Outback. First, I pulled out the rear console, and took a look a the connector there (R43). It has 22 pins, but many of them are not populated. The ones that are populated are:

So… It looks like we have the illumination circuit and a decent ground (the ground for the seats and the accessory socket is shared), but we don’t have the +12V we need for the heater. A bit disappointing, but not unexpected.

I pull the fuse box cover off, and find that fuse 17 (the seat heater fuse) *is* present. I pull the lower console cover off – more than a little pain in the butt – and find out a few more things. First, the relay for the heated seats is not present. However, the location that it sits on the relay board is wired with 4 connections. So… my current theory is that if I have a fuse, I will be complete up to connector B97 (which is somewhere near the fuse box), but then I’ll have to tap into a wire there and run it the power from that.

I also still need to figure out how the dimming system works. Since 12V is supplied to the lights, I’m presuming that the dimmer supplies a voltage somewhat higher than ground, and that’s how the dimming works. Could be wrong, however.

When I was growing up, our pet of choice was the cat, and we had a string of them. We had friends with dogs, but never owned one ourselves.

My wife, however, came from a dog family, and when Samantha was nine, the “dog” topic was raised. I was ambivalent about having a dog, but was okay to go along with the other two members of the family. The search parameters were 1) a dog of intermediate size (ie not a tiny one), 2) a dog, rather than a puppy, 3) a mixed-breed, and 4) a breed that wasn’t too smart or too high-maintenance.

We hit on the first three and blew the third when we adopted an Australian Cattle Dog mix, and named him Sydney. Smart and attentive, but calm at the same time. He turned out to be a great dog.

A few months ago he began to have old male dog issues. Medication helped, and he regained a bit of his energy, but we knew that the condition was a progressive one. This week his symptoms worsened, so he went to the vet on Thursday for a visit that turned into an overnight stay. His condition had worsened, and there were limited options, none of them good.

Friday afternoon, we picked him up and brought him home, to spend his last few hours the way a herding dog should; with his owners, lazing and sleeping in the cool grass on a warm summer day.

And then we returned to the vet, to leave with only a harness and our memories.

He will be missed.

I recently spent some time in metal shop.

No, not like that. More like this:

I have for the last – well, let’s just settle on “many” – years been working in wood, and if I do say so myself – and I do because there’s nobody else around to say so – I’m pretty good at it. I can do carpentry well, finish carpentry okay, and I dabble in cabinetmaking, though I’m only okay at that.

And I’ve worked in concrete and tile a bit, but there’s one area that I haven’t done much in. Metal. I’m okay with a drill press, a hacksaw, and an angle grinder, and I can identify lathes, mills, and welders in a lineup, but I don’t know how to use them.

Okay, that’s not quite correct. I like to read and my mind soaks up a lot of useless facts, so I have a lot of theoretical understanding of machine tools and zero practical experience. I mostly regret my inability to weld.Welding is, after all, what separates humans from the other animals.

I decided to do something about my lack of metal experience, which led me to a bunch of web searching, and, finally, to the Metal Shop class at Makerhaus. The class meets for 5 Saturdays from 9:00 AM to 12:30 PM. It was pretty much exactly what I wanted, except that it’s in Fremont. Have you ever heard the joke about the man who stops by the side of the road and asks a farmer directions? The farmer thinks for a while, and finally says, “You can’t get there from here”. That’s what it’s like to get to Fremont from my house.

The weeks before I order the materials for class:

• A 2” aluminum rod 12” long
• A 2” x 24” piece of steel (3/16” thick IIRC)
• A 4” x 12” piece of sheet metal (also steel)

The first week finds me in a class with 6 other students, with various levels experience; some have never done anything shop-like, and others have taken classes before.

I should probably note that the previous picture is not, in fact, the Makerhaus metal shop, which is smaller and quite a bit cleaner. Here’s a quick tour, though it’s a bit more lived-in now. It contains the following tools (strangely, I couldn’t find the list on their website):

Main room:

• Drill press
• Horizontal bandsaw
• Lathe
• Magnetic brake for bending sheet metal, a pretty nice one.
• A manual shear for cutting sheet metal, also pretty nice.
• A big vertical mill.

Hot/Loud room:

• Belt/Disc sander (for smoothing and preparing metal)
• Air compressor (for the wood shop as well IIRC)
• Sandblasting chamber.
• Welders (2 MIG, 1 TIG)

Both rooms have appropriate benches and there is some auxiliary equipment (welding jacket and helmets, clamps, etc.). There are some community tools outside the shop in a rolling tool chest; they are the quality that you would expect from tools that are used by random people.

The first day is about introduction and safety, and our instructor Alex walks us through each of the machines, showing how to set them up and how to perform various operations. Oh, and telling us how we can hurt ourselves on each of them. His introduction is good, but I’d also like to have some guides to read before each class to remind myself on the basics, and perhaps links to some online videos. We ended the first day a bit early after going through all the tools.

The second day is getting started on the project. The project that Alex gave us is a candleholder with a welded steel frame and turned aluminum holders for the candles – which would let you use all the tools – but you can choose another project if you would like.

This is probably my biggest complaint about the class; it would have been very helpful to have an idea of the project scope ahead of time. If I had known that, I would already had something in mind and would have saved a couple of hours. I think it was harder on the other people in the class; I’m used to taking a concept and iterating on it a few times, so I got to something that would work quickly. It would really help to have the basic project and some options available online.

I choose to do a modification of Alex’s design. It’s going to have a frame welded together out of the steel, and I will turn and machine the aluminum into candle holders.

At this point, I don’t remember what I did on which day, but I’ll talk about each of the parts from start to finish. In reality, I jumped back and forth between them, but I think this will be a bit clearer.

Frame

I do a few drawings, and then mark the steel and cut it to length on the horizontal band saw. It’s an interesting machine; you lift the blade up, and then in comes down under gravity with the rate fine-tuned by a valve. I cut out the lengths that I need, and then take them into the hot room. I square up the cuts on the sander, and then bevel the ends so that there is room for the weld bead.

I do a test weld with some scraps. We’re using MIG welding; there is a spool of wire in the welder that feeds out when you hit a button on the welding torch, and that wire is energized. Assuming the workpiece is grounded, you touch the wire to the metal and it arcs, vaporizes, and melts the material that you are welding along with the wire. The “IG” part of “MIG” means “Inert Gas”; while the wire is feeding through the torch an inert gas (CO2, argon, some other gases, or a mixture (I told you that I had lots of theoretical knowledge…)) flows to the welding spot, pushing the oxygen away and facilitating a nice weld. You can control how much voltage is put into the gun, and the feed rate of the wire through controls on the welder. With a bit of adjustment, I get a decent – if a bit big – bead across the metal, but the weld I tried between two scraps looks really rough (who did that weld? Vandals?)

I move onto the welding the frame pieces. I get acceptable results (enough penetration for the weld to be solid), but the bead is pretty big and not very even. It’s really hard to see what’s going on; the welding helmet auto-darkens to keep from frying your eyes (a good thing), but all you can see is a green light where the arc is and a bit of a glow from the melted metal along the weld line. The second one is a bit better. I then move to the 90 degree joins where the candle holder will attach to the wall. My results here have the same problem as before, with a lot of extra metal at the join, but the penetration is okay. I realize afterwards that I had the wire feed a little high; a slower feed rate would have gotten me a good weld with a smaller bead. I think. I also think there may be a small welder in my future.

I decide to do the rest of the finishing for the frame at home, as I have the right tools and I think my drill bits are in better shape. I drill three holes to mount the candle holders, and then countersink them on the back (so I can use flush screws), and then two holes on the upright that will be used to mount to the wall.

The rest of the work on the frame is grinding and finishing. I do a fair bit with a metal grinding wheel in my angle grinder, do some research on what to do next, and buy some sandpaper flap discs.

I use them to finish grinding off the welds – the 90 degree ones are especially fun – and then work to get an even finish. I stop at 80 grit, partly because I like the look, but mostly because I’m not sure I can get a better finish, and at this point the roughness looks intentional.

That pretty much completes the frame. Here are a couple of pictures. It took about 15 minutes of grinding on each of the 90 degree beads to make it look that way. I do like that, unlike wood, if your weld is good, you pretty much end up with a seamless look where the weld was.

Back and underside. The holes are countersunk to use flat-head screws. You can see the still-a-bit-ugly weld bead on the right side.

Here’s the top/back side. The weld was done from the underneath, which is why there is a visible join line. If I had been smarter, I would have welded across the top and then ground it down for a nicer look.

Close-up of one of the corners. I’ve cleverly drilled the mounting hole so the candle holder will mostly cover the ugly seam.

Candle holders

My design for the candle holders is three 2” sections of aluminum bar. This is a bit complicated because I need enough room to chuck the bar in the lathe, but it can’t be too long because the lathe isn’t great, so I settle on one 7” section (which I’ll machine two holders out of), and then one 5” section (which will give me the third holder). The lathe looks like this:

We’ll start with the lathe. It holds a cylindrical piece of stock (we call that a “rod” or “bar”) in a chuck and spins it. In the middle is the carriage, which is a very sophisticated and precise tool holder; it has wheels that you can turn to move the carriage left and right (x axis), front and back (the y axis), and a third bonus axis in the XY plane that can be adjusted to different angles. I start by “facing” the end of the stock; turning it to get it flat. This is done by carefully moving the tool until it starts to cut on the end, and then turning the wheel to push the cutting away from me (towards the center of the bar). Move a fraction to the left, and repeat. Keep doing this until you’re satisfied. How well it works depends on how much metal you are trying to take off, the angle of the cutting tool (which is just a pointed metal triangle in this case), and the speed at which you turn the crank (also known as the feed). After a couple minutes, that is done, and I move to cleaning up the outer part of the cylinder. You do this in a similar manner, except you advance the tool away from you until it starts cutting and then turn the X-axis crank to move the tool to the left. Advance the tool and repeat, until the cylinder is round and you are okay with how it looks. Your initial cuts are pretty quick, but you need to go slow on your final cuts as the tool is actually cutting a spiral, and if you advance it too fast it’s pretty obvious.

This is what it looks like when I’m done:

To make the holders look all fancy, I cut grooves into them. I lay them out and mark the aluminum with black sharpie, and then turn some shallow grooves about 1/4” wide at the end of each piece. I do this three times, and I’m done with the lathe. Here’s a blurry picture of the grooves (better pictures later):

I need to cut the sections that are turned so that I can keep machining them. I think it’s common to do this on the lathe with a parting tool, but we don’t know how to do that, so I cut two off with the horizontal band saw. This is very slow going, and they get so hot I can’t hold onto them, so it’s a trip to the dunk tank outside to cool them off.

I should probably clarify that I mean something like this:

not this:

I don’t want to hog the band saw because there are other students who need to cut up their metal, so end up doing some careful research at home, and cutting off the remaining one on my DeWalt chop saw. You *can* cut aluminum with a good high-tooth-count (80 or so) carbide blade if you keep the feed rate slow, and it only takes about 3 minutes to cut all the way through, which is faster than the band saw. Note that even with a  shop vac hooked up, you’re going to get aluminum all over your garage.

And it’s off to the vertical mill, which looks something like this:

There is a spinning cutter that is mounted vertically (like in a drill press). You clamp your work into a vise attached to the worktable. There are handles on the mill that allow you to move the table left and right (X axis), in and out (Y axis), and up and down (Z axis). You can also move the cutter itself up and down (Z axis). The Makerhaus mill is old, big, and weighs at least a ton; it has controls to do CNC (computer-controlled) machining that we won’t be using. It looks exactly like this:

I take my three turned pieces to the mill. My plan is to flatten off part of the circle on all three of the holders. I put in a couple of spacers to raise the stock to the proper height and clamp it in, putting the flat ends against the clamps. I will be using an end mill to do the machining. End mills look like drill bits except they are flat on the bottom and they are made to cut moving to the side.

End mills come with different numbers of cutters (“flutes”) and you use them for different purposes. In this case, I’m using a 4 flute 1/2” end mill. I put it in the mill, and then crank the vertical adjustment to put the cutter approximately where I need it to be.

Ready to start, I call Alex over for some advice on how big of a cut I should take, he shrugs, I choose something relatively light, and as the cutter touches the metal, the metal rotates up, jumps out of the clamp and lands on the floor a few feet away. Alex reaches up and turns off the mill, and I turn to him and say, “Well, that was exciting…”. Apparently, my idea of clamping pressure isn’t enough, but luckily the aluminum is soft (compared to harder metals such as steel), so the mill just took a few nibbles out of the end, and I’m planning on machining the ends anyway. I put it back in the clamp, and get to machining.

The basic process is:

1. Zero out the Z axis measurement.
2. Move the cutter down until it measures a reasonable amount (I really don’t know what’s reasonable, so I’m doing light cuts. I’m pretty sure they are lighter than they could be).
3. Using the wheels on the table, move it back and forth under the cutter until the cutter has covered the whole surface.
4. Repeat steps 1-3 until you get tired.

This is all done by hand, and is a fair bit of workout if you are moving fast. It takes me quite a while to remove all the metal to take off about a third of the cylinder. My last pass is very light, so that the cutter will leave a nice finish on the piece. I convert my plan from machining all thee holders to just one; the other ones just get two flats machined into them.

After I’ve done this on the holders, I need to machine the ends. Some are rough from being cut, and others have a lathe finish and I want them all to match. The operation is the same as I’ve been doing, but luckily I don’t have to take much metal off and this doesn’t take too long. I choose to machine in a spiffy spiral pattern, which leaves the holder looking like this:

Finally, I’m ready to machine out the holes for the candles, which will be 3/4” in diameter. This is going to be complicated; I’ll use a series of drill bits moving up gradually in size, but I’m going to need to use an end mill because a) there are no drill bits here bigger than 1/2” and b) I want a flat bottomed hole. I’m going to have to proceed through a series of bits:

1. 3/16” drill
2. 3/8” drill
3. 1/2” drill
4. 5/8” two-flute end mill
5. 3/4” four-flute end mill

To make sure I stay on the right spot, I won’t touch the X and Y controls. Each operation becomes the following:

1. Lower the table so that I can fit the bit in the mill.
2. Put the bit in the mill (this is a bit involved – you choose the collet that is the proper size for the bit, put it in the collet nut, install that in the mill, put the bit in, and then tighten it)
3. Raise the table so that I can drill deep enough.
4. Zero out the Z axis measuring device.
5. Start up the mill.
6. Set the speed on the mill (around 2000 RPM to start).
7. Drill the hole, stopping perhaps once to clean the shavings off the bit.
8. Stop when the hole is the proper depth (I aimed for 0.6”)
9. Turn off the mill
10. Clean off shavings from the bit
11. Lower the table so I can get the bit out.
12. Remove the bit, take the collet out. 

This repeats for the 5 different bits, and I do it once for each of the candle holders, so that’s 15 bit changes. Here’s an annoyingly blurry picture in the middle of the process:

I get a good workout cranking the Z axis up and down. About 90 minutes later, I’m finished, sweaty, and the holders look like this. You can see that there is a slight burr around the hold; I need to touch that up with a dremel.

Only one bit of work left; to drill some holes in the holders and cut threads into this. I bought some nice flathead brass screws and figured out which tap to use. A test hole in one of the leftover pieces of aluminum to make sure I had the right size drill and the correct tap, and then I started on the holders. The holes were quick to drill, but the tapping is slow; do a quarter turn, back off, another quarter turn, and repeat, until it gets harder to turn. Unthread the tap, clean off the chips, and repeat the process until you get deep enough.

All that is left is the final assembly, and we’re finished:

Full gallery is here.

As far as the class goes, 8/10, recommend.

I’m pretty good with wood. I’ve done a lot of carpentry – decks, sheds, finishing off rooms, a fair bit of finish carpentry (stairs, railings, wainscotting), and a bit of cabinetmaking.

Metal, however, is not my first choice, and when I do choose it, I’m a bit of a hack. I’ve decided to remedy that, and I’ve signed up for “Intro to Metal Shop” at Makerhaus, a hackerspace in the Fremont area of Seattle. The class started today. There are 7 students in all, 5 guys and two women.

Today was an introduction to the types of metal and how they can hurt you (be cautious machining zinc-coated steel), and how to use all of the tools in the workshop and all of the ways we can get hurt by them. The tools we covered:

• Horizontal band saw (used for rough cutting)
• Drill press (drilling holes)
• Shears (used for cutting metal)
• Brake (used for bending metal)
• Lathe (used for machining round pieces of metal
• Vertical mill (used for general machining)
• Metal sander
• Mig welder (used for, duh, welding)

The machine shop is pretty nice; there are two rooms, one for the clean tools, and then a second closed-off one for the loud and dirty tools. I tool a quick look through a window at the wood shop, and it looks nice as well. It is unfortunately inconvenient to my house, but as there aren’t any spaces like this on the eastside.

I had my eye on a Printrbot Simple, but luckily waited just long enough for the new metal version to come out.

They say that the build was of moderate difficulty. I’m an experienced maker in a lot of ways, and it was mostly easy but I wasted a fair bit of time figuring a few things out.

 Thoughts on the build:

1. The instruction manual is done solely in pictures. This works okay in most if you are used to looking at pictures and figuring them out, but if you don’t, it can be hard.
2. It would have been nice to have a page that detailed all the screws and small hardware from a size perspective. I spent a lot of time differentiating between the different lengths and sizes of screws.
3. In step 5, the wires had too much solder in places, so I had to bend them tight towards each other to get the nut off.
4. In step 7, it’s fairly clear how to put the belt on, but there’s no data around how tight it should be.
5. In step 13, the hole for the proximity detector was slightly too small; I had to screw it in. This would make tuning it later harder.
6. In step 14, it’s not clear how tight the tension should be.
7. In step 16, the z-axis block was slightly too wide, so the screws didn’t line up with the holes in the stepper frame. I machined a little of the plastic away with a dremel and it worked fine.
8. In step 19, it would be good to understand the tension level.
9. In step 22, it would be great to have a list of all the wires that need to be bundled here.
10. Step 24, there’s no way all of those wires will fit through the grommet. I got two of the 5 connectors through, and could get no more. I ended up cutting the grommet.
11. Step 26, it would be great to know how long each wire bundle should be to permit full travel.
12. Step 27, it’s really hard to see how the stepper cables should be connected, and it would be nice to have a description of which motors are X/Y/Z/E.

Then it’s onto the setup. This was quite a bit more frustrating than the build was.

I got the teensy driver (windows) and repertier-host installed easily. Then, it got difficult. 

Thoughts on the setup:

1. My power supply died the second time I plugged it in. Luckily, I had an exact replacement on hand.
2. It would be really nice to have a quicker way to set up the values for Repertier and Slic3r. This takes a while and it’s easy to mess up.
3. The print size is specified as 200mm and the center as 100mm, when the correct values are 150mm and 75mm.
4. Repertier won’t talk to the system until you hit OK in the manual controls part.
5. The setup guide says just to use the manual controls to check if the steppers work. This is a decent step, but it will not detect whether the steppers and switches are wired correctly. I had one stepper backwards and the Y limit switch not connected, but it took me hours to figure this out. I suggest the following sequence instead:
1. Use the manual X/Y/Z controls to verify that the steppers move, and that they move in the right direction. For example, if you press the “Z+” button, the extruder assembly should move up, and “Z-“ should move it down. This allows you to verify that the Z stepper is hooked up correctly. This should be done for each axis.
2. Use the home command in each axis to verify that the switches are set up correctly. In the manual control section, do the following:
1. Type “G28 X” and hit “run” (or execute, or whatever it says). The print bed should smoothly move all the way to the right, and then move back until it is centered. If there is any clunking sound, the X limit switch is not connected or not working. If the bed moves to the left, the X stepper connector is backwards.
2. Type “G28 Y”, and hit “run”. The extruder assembly should smoothly move all of the way back, and then move forward until it is centered on the print bed. If there is any clunking sound, the Y limit switch is not connected or not working.  If the bed moves all the way to the front instead of to the back, the Y stepper connector is backwards.
3. Type “G28 Z”, and hit “run”. The extruder should smoothly move down until it is close to the bed.
6. Better directions to set up the Z offset would really help.
7. I watched the video on setting up the auto-leveling bed. I understood the concept, but there really needs to be a guide for it.

Overall thoughts:

I’ve done a few prints with the printer, and it has performed quite well. Overall, I’m quite pleased.

About a week ago, I had a problem. My wife and I were getting ready to leave on a week-long ski trip to Colorado, and I had a cough. Not one of those light coughs, the kind of cough that becomes that is more of a career than a distraction, the one where you cough for 15 minutes straight.

It was, not surprisingly, making it hard for me to sleep. One night, while sitting up on the couch in the basement, waiting for it to stop, I decided to do a little bit of research. Just like anybody would do, I pulled out my laptop, fired up Chrome, and did a search for methods of cough treatment.

Okay, that’s not true; first I searched for cough and came up with an impressive list of deadly diseases that I had a minute chance of having. Then I did a search for cough treatments, and, after a bit of digging, ran across the following paper.

Diagnosis and Management of Cough
Executive Summary
ACCP Evidence-Based Clinical Practice Guidelines

The ACCP is, of course, the American College of Chest Physicians. Amazingly, the paper is free (most journal articles are not), so I pulled it up and started reading. It’s heavy going if you are a medical amateur, but basically, they did a huge study of the available evidence relating to cough and came up with expert recommendations. After a bit of reading, I came to the section on the common cold (section 11 if you want the details). It has two interesting findings:

1. Patients with acute cough (as well and PND and throat clearing) associated with the common cold can be treated with a first-generation A/D preparation (brompheniramine and sustained-release pseudoephedrine). Naproxen can also be administered to help decrease cough in this setting. Level of evidence, fair; benefit, substantial; grade of recommendation, A
2. In patients with the common cold, newer generation antihistamines are ineffective for reducing cough and should not be used. Level of evidence, fair; benefit, none; grade of recommendation, D

Pseudoephedrine was most commonly available as Sudafed, which was great stuff until it started getting used for meth production and got moved behind the counter (at least in Washington; in some states it’s by prescription only). Naproxen is available over the counter as Aleve. Note that dextromethorphan, the most common cough-suppressant in OTC cough medicines, is not recommended in this situation (it does show up elsewhere, as does codeine).

So, on the way to the airport, we hit a pharmacy, and I picked up some 12-hour Sudafed and Aleve, and, when we got to our first night, took both.

It made a huge difference; I had no big cough attacks that night. I did note, however, that the aleve made me feel spacey and I didn’t sleep well, so I dropped that in later nights.

Note that Sudafed makes an OTC series called “Sudafed PE”, where the PE stands for “Phenylephrine”, not “Pseudoephedrine”. You want the real stuff.

It’s the question that nobody asks.

They find out that you are a ski instructor, and they ask you where you teach, how long you’ve been teaching, but you can can see it in their eyes, that one question that they want to ask…

They’ve heard the stories – surely they must be exaggerated, but just as surely, there must be something behind them – and they want to know more, but they don’t ask. Maybe they think that you would consider it too personal to talk about. Maybe they think that a secret agreement prohibits sharing the detail with them. Maybe – and this would be the worst – maybe they are afraid that you would tell them that none of the stories are true, and that would shatter the picture they had built up in their mind.

The time has come to share the details – or, to be more precise – to do what is in my power to provide some confirmation of the rumors. I regret that, under PSIA policy, I cannot discuss certain matter, but I can provide an answer to one question:

As a ski instructor, do you get to teach a lot of cute single babes?

The answer is yes. I can confirm that, as a ski instructor, you do get to work with a lot of single babes. I can also confirm that the majority of them think you are great, and that the phrase, “babes dripping off of him”, is, at least sometimes, true.  And they are cute, some of them heart-meltingly so. It should come as no surprise if I were to tell you that working with them is one of the best part of the jobs.

Unfortunately – or perhaps fortunately, given my relationship status – the vast majority of them are 6 years old.