The Big Think

April 30, 2015

Blue Origin

Filed under: Space — jasony @ 8:27 am

Jeff Bezos’ Blue Origin tests sub-orbital spacecraft – CBS News: “Blue Origin, a rocket engine and spacecraft development company owned by Amazon founder Jeff Bezos, carried out an unmanned maiden test flight of its New Shepard sub-orbital launch vehicle Wednesday, the company revealed early Thursday.

A dramatic video posted on Blue Origin’s website showed the squat vertical-takeoff-and-landing New Shepard rocket being erected on a launch platform at the company’s west Texas development facility followed by a brief countdown — with Bezos looking on — then a smooth liftoff and a vertical climb to an altitude of 58 miles.”

The fastest possible mile

Filed under: Hobbies,Humor and Fun — jasony @ 6:10 am

The fastest possible mile | Gravity and Levity: “”

April 25, 2015

Techshop Day

Filed under: Maker — jasony @ 7:13 pm

Woke up at 5am and couldn’t sleep so I took the Baylor sign I’m making and went to TechShop. I spent the next nine hours laser cutting all sorts of things. Then I spent four hours working on the sign. Then I took a two hour class on grinding your own tooling (I’ll use the lathe tool I ground myself to work on R2). A little over fifteen hours at the shop and I’m done. Off to an early bed….

April 24, 2015

JAG 20 and Problems

Filed under: The R2 Project — jasony @ 9:39 pm

Well, I just can’t stop myself. Today at TechShop after a class I checked out the key to the FlowJet (I just love saying that so casually: “I checked out the key to the quarter million dollar FlowJet”) and pathed the JAG20 file in FlowCut. I figured I’d take the file back to the WJ to see how long the cut would take. I’ve done this before and know how it usually ends.

I loaded the file and did a virtual cut. 30 minutes for both pieces. There are 2 JAG20 parts that look like this:

JAG20.jpg

The part is the body-to-leg flange joint that connects the main frame to the leg assembly. It’s solid 6061 aluminum and 1 1/8″ thick. You can see it located here between the legs and the frame. It’s visible once Artoo is finished so it has to look right:

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I bought a slab of aluminum from Metals4U a few days ago in preparation of this part. This is probably the biggest, most nerve-wracking part I’ll do. Partially because it took me weeks to figure out how to design in Inventor (I finally got help from an expert at TechShop… he solved the problem in 5 minutes), and partly because it is, by far, the thickest part I’ll have to WaterJet in the entire project. The single hunk of aluminum measured 1 1/4″ thick, 11″ wide, and 16″ long. Cost me over $80! So no, I did not want to screw this up.

So I put the hunk of aluminum on the FlowJet table and zeroed out the Z axis to get the mixing tube right down on the metal. At this point you don’t want to smack the tube into any clamps or weights holding the stock down. If you do, you’ll break the tube and owe TechShop $250 for a replacement. Fortunately, I know the guy who teaches WJ (I am the guy who teaches W.J.) and we have procedures to avoid that.

So, the file was loaded, the stock was weighted down, and I even did a dry run without the pump running (the part that costs money). It was a 30 minute cut. Well, why not? I verified that the machine had been working well and went for it.

Part on table weighted down. File loaded. All ready to go!

IMG_0471.JPG

I hit ‘cut’ and watched with an eagle eye for the next 30 minutes as the water and abrasive jet slooooowly worked its way around the part. 4 holes, inside cut, outside cut, repeat.

The first part went off beautifully and I could tell that it cut through the material just fine once it was finished. The machine started in on the second part next. The 4 holes went fine (they’re first), but sometime during cutting out the center “shamrock” shape the pump started to lose power. Suddenly the cutting stream wasn’t making it all the way through all 1.25 inches of aluminum. You can tell this is happening because instead of the cutting stream passing through the material, the water starts spraying all. over. the. place. All over you. I got blasted with a muddy stream of grungy water (seriously, I looked like a motocross rider after a muddy ride). The normal procedure if this happens is to manually slow the cutting stream down. As I was already cutting at a pretty slow pace (which gives a better finish) I wasn’t too excited about slowing down further and making the cut even longer/more expensive. But it’s better than the cut being ruined.

So I slowed it down (which you can do mid-cut with a slider in the software) and managed to get the center cut done. On the last cut (the outside perimeter), the jet was still having issues. The solution was to slow it down even further. I think by the end I was cutting at somewhere less than 50% of the max speed and still unsure if it was making it all the way through.

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Here you can see the layers of garnet that get blasted onto the parts during the cutting process. It’s an incredibly messy machine to operate.

Once the machine shut off I checked the parts and discovered that the first part to be cut (the one on the left in the photo above) came out brilliantly. Great finish, cut all the way through. Unfortunately, when I lifted out the part on the upper right I discovered that there were sections of the middle that didn’t get cut all the way through. Fortunately, though, it did lift all the way out so at least it got free. Unfortunately, the finish on the outside was terrible as a result of the gradual pressure loss.

Here’s a pic of the “good” part. You can see the smooth edges with just a hint of the typical jet “lag” on the bottom of the outside curve:

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IMG_0475.JPG

For the “bad” part, you can see not only where the stream didn’t cut all the way through, but also where the water jet “lag” on the outside is much more pronounced, resulting in a much more ragged and bad looking surface:

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And here’s a side-by-side of the good part and the messed up one (zoom your screen or click for a closer image):

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So, while I’m really happy to get these parts behind me, I am somewhat disappointed in the results, considering that for about the same amount of money I could buy an aluminum part that’s shiny and perfect.

I’m still cogitating on how I’m going to fix this. The good news is that the final piece needs to be 1.125″ thick (1 1/8″). The rough piece in the pictures is 1.25″ thick. So I should be able to reduce the thickness of the piece and “face off” the thin little bridges of aluminum that keep the inside section attached. This will also have the effect of making the faces of the part nice and shiny. I think I can do this on the lathe at TechShop but I’ll have to ask the pros about the best way to go about this.

As far as the outside of the donut shape, I need to see if the part can be a smaller diameter than the 6.375 listed in the drawings. I think it can. If I can safely shave off a few thousands I think I can get rid of those marks on the outside and make the part shiny.

Sorry to be so wordy. This experience was a relief in that the part is somewhat workable but frustrating in that I just don’t feel like I can completely trust that machine. I need to improve my skills on the manual mill and lathe but that takes decades. The WaterJet, while expensive, can let a newbie machinist cut any part they can design in the computer. That’s huge.

The final major part for the frame is the pair of side panels where JAG20 mounts. They’re .5″ thick aluminum (thank goodness) but also contain a lot of little holes that’ll make the water jet turn on and off quite frequently. I may wait a few weeks until the pump is rebuilt to attempt those. They’re only 20 or so minutes each but I really don’t want to mess those up. At least not the small little precision holes.

April 23, 2015

Looking Back at the Launch of the Maker Movement

Filed under: Technology — jasony @ 10:11 pm

The First Maker Faire: “”

April 20, 2015

JAG 01!!

Filed under: The R2 Project — jasony @ 10:08 pm

Exciting news on the R2 front. JAG 01 is cut! JAG01 is the part number for the topmost ring in R2’s aluminum body. It’s by far the most complex part of the main body (along with the leg support panels).

JAG01.png

Each of those holes (accurate to within +/-.005) mean that the FlowJet has to cycle on/off each time. In my experience teaching the tool, there is most likely to be a problem during a start/stop cycle. Yikes!

I’ve been putting off JAG01 for a few months now since it’s such a tough part and I didn’t want anything to go wrong. I laser cut the file in thin plywood using my Inventor .dxf file and it seemed right, but there’s nothing like actually water jetting a part to show you your errors. The FlowJet has been down for a few weeks at TechShop and they finally got it working again. I happened to be there when they did and the employee said they needed a test file. Would I like to run JAG01 in some scrap (too-thin) aluminum? YOU BET!

So we took about 12 minutes to run the file in some 18ga aluminum and I took the part and laid it out against my plywood version. Perfect fit! So I know the file worked fine. Now all I had to do was clamp the 1/4″ slab of 6061-T6 aluminum onto the table, take a deep breath, and go for it. I did that tonight and kept an eagle eye on the tool as it cut (not that I could salvage the part if anything went wrong). Fortunately, it worked! 18 minutes later I had a beautiful part resting on the FlowJet water surface and I could breathe again.

Below is a picture of all the pieces I have milled up in the past 6 months when I started this crazy project. Each part is accurate to within a few thousands of an inch. JAG01 is in the upper right.

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And here’s the frame so far balanced precariously together.

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Year 1 is the frame and I’m more or less on track to have it done in 4-5 months. I have to do two copies of JAG04 (the shoulder mounting plate), and then two copies of JAG20 (the shoulder flange). For JAG04 I’ll use the WaterJet again in combination with the manual mill. Then I need to go back in to a bunch of the holes that were WaterJet and either tap them with threads, or countersink a chamfer on the edge so the screws sit flush. For JAG20 I’ll be learning a whole new tool: the Tormek CNC Mill. That’ll take a month or two. I could buy the part online for about what it’s going to cost me to make it, but this project is about testing my boundaries and learning to do new things. I will have to buy some parts for R2 (the skin and dome), but I’m trying to do as much as I possibly can myself, and use the most difficult material (aluminum as opposed to wood). If I hose JAG20 I’ll consider buying the part, but I want to try first.

Once all the parts are done, drilled, tapped, countersunk, and fit together correctly, I’ll sandblast everything to remove milling scratches, then sandblast again using baking soda. Then it’s off to the anodizing step to give the frame a beautiful coat of anodized metal. Then I’ll laser etch a pattern into the frame.

There’s a long, long way to go.

April 18, 2015

Milling

Filed under: The R2 Project — jasony @ 7:10 am

More R2! Now that the show is over I’ve been busy teaching at TechShop and building a project for Baylor’s StuPro (a really cool CNC’ed progress board for the Sing groups). So I’ve been spending a lot of time at TechShop. The other day I got a few hours free while up there and decided to jump back on the mill to keep my meager milling skills sharp.

When you cut something on the Water Jet, you have to leave tiny tabs of metal connecting the part to the larger piece of stock. This is so parts don’t shift around while cutting or, worse, break free and sink in the tank. After the cut is done you have to break these tabs and remove the part. However, little sharp bits of these tabs are left behind on the part that must be dealt with. If you design the part right, the leftover tabs aren’t too big (maybe the size of a rice grain or slightly larger) and you can work them away with a file. But since I hadn’t been on the mill for a while I decided to take some time and remove them with that tool. Overkill? Sure, but logging time on the mill was worth it.

So I took 3 hours or so and sent about 10 parts– some large structural pieces, some support pieces– through the mill and removed the sharp little tabs. You can tell where my mill marks are because what is milled is freshly shiny and smooth aluminum (as opposed to the oxidized and rough cut from the Water Jet). But since these frame parts are going to be inside the frame and invisible I’m not too concerned. I’ll see if there’s anything I can do to clean things up later but my guess is that it won’t be an issue, and my plan to anodize the frame in the future will cover up a lot of issues anyway.

Next up: water jetting the main top “A” ring. It’s one of the biggest and most complex parts of the frame. I’ve been putting off doing this part because the water jet has been down and because it’s a rather long and expensive cut in a big (expensive) piece of aluminum. Fingers crossed.

Eating Out or Substance

Filed under: Politics — jasony @ 7:00 am

Shriveled grapes, shriveled liberty:

“Takings-clause jurisprudence is quite recondite. The government, however, says two contradictory things. It says the Hornes ‘acquired’ raisins and hence must either surrender a large portion of them — in some years, 47 percent — or pay huge fines. But it also says the Hornes do not have sufficient ownership of the raisins to raise constitutional objections.

The government says the Hornes voluntarily entered their raisins into the stream of commerce, so they must comply with the RAC’s raisin reserve requirement. But the Supreme Court has hitherto rejected the idea that a person must give a portion of his property to the government in order to purchase the government’s permission to engage in a lawful business transaction, such as selling a commodity. The government says its required contributions to the raisin reserve merely regulates raisin sales. The Hornes say it is not a mere regulation but an expropriation.

The government says it owes the Hornes nothing in exchange for the raisins they supposedly owe it, because they somehow benefit from the government’s manipulation of the raisin market. The Hornes say it would be unconstitutional for the government to come on their land to confiscate their raisins or the proceeds from their raisin sales, so it is unconstitutional to fine them for not complying with an unconstitutional requirement.”

Outdated laws should be deleted. Those who slavishly adhere to them in the interest of maintaining their bureaucratic organizations should be forced to look for another line of work. Eating out our substance indeed.

“District 12 shall continue to produce their quota of raisins”

April 16, 2015

But Can You Fit it On A Shark?

Filed under: Technology — jasony @ 12:08 pm

Instapundit: “General Atomics Introduces a Weapons-Grade Self-Contained Laser Cannon That Can Be Mounted On the Roof Of Your Car. ‘What we were able to find out about this thing is that it’s a laser weapon with output energies (that’s output, not total power in the system) ranging from 75 kilowatts all the way up to 300 kilowatts. To put that in perspective, about a year ago we wrote about how Lockheed was using a portable fiber laser to shoot down rockets at a range of 1.5 kilometers using just 10 kilowatts of power. Suffice it to say, 300 kilowatts is rather a lot.’”

April 9, 2015

Serious Lego Art

Filed under: Hobbies — jasony @ 10:57 am

Flickr: migalart’s Photostream: “”

h/t Scott for the link.

April 7, 2015

Gravity Power

Filed under: Technology — jasony @ 1:33 pm

Utility scale electricity storage and generation from a train and a box of rocks. What a great idea. Engineers are pretty clever.

ARES-Technology from Advanced-RES on Vimeo.

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