I had the good fortune of stumbling across this 5 part 4 hour long documentary on the making of the Boeing 777 the other day. A fascinating look into the job of making a long range wide bodied airplane, and interesting to note that Alan Mulally who they highlight is now the CEO of the Ford Motor Company. Part 1 is embedded below, with links for the other parts below that.
I spent the last 3 years getting a degree in aeronautical engineering at RPI. I have a full time job lined up doing airplane engineering too, so maybe someone will find this useful. Some generic RPI/engineering comments in here too.
This year for Christmas Santa brought an Atlas 618 for Christmas. Well, this one was actually sold as a Craftsman 101.07301, but they are the same thing. The picture is just the machine, but it came with all of the tooling and equipment it was originally sold with, as well as some additional tooling. Someone just had it sitting on a shelf when my dad (er…. Santa) picked it up.
It hasn’t been used in a while, but it is actually in pretty great shape considering. I’ve been degreasing the old oil that has turned into varnish and regreasing everything, in addition to removing the quarter inch of dust that has settled since it was last used. There are little pieces of brass and plastic shoved into various corners, so I imagine that was what the last guy who used it cut with it.
The back gears are pretty close to stuck, but I think that is mostly just due to the ancient lubricants that have turned to stick-i-cants. With a firm hand on the chuck, it will barely spin. So that is tomorrow’s project. Also, whoever mounted it’s current base put the motor in a place such that it interferes with opening the door that covers the back gears. I plan to move that motor back a little bit to get better clearance on the door, so I’ve got to go pick up a new belt tomorrow. Below is where the motor will be mounted after tomorrow, and also a great shot of the back gears.
Spent quite a while cleaning out the lead screw and the carriage. Nothing some WD-40 as a degreaser and a toothbrush couldn’t clean. Can’t wait to finish the cleaning/refurbishing phase to start cutting some metal!
It appears there is a great Yahoo! group for the Atlas 618, and there multiple sites for general purpose reading.
This is a mechanical calculator I built as a Christmas gift. It is based a CAM and follower where the path of the CAM is determined by the sine of an angle. I got the idea from the video below on the calculators the Navy used to determine trajectories before the invention of the digital computer.
Since I started late, I never quite got the pin working as well as I would’ve liked. Therefore it is a little loose, and makes the operation not quite as smooth as I would’ve liked. All the CNC work was done with the same machine I used in this post. Based on these principles I’ve got a bunch of other ideas though, so hopefully the mechanism will work better in the future.
This weekend I stumbled across a fantastic resource. Keeping airplanes flying is a tricky business. There is definitely more to learn than you could hope to derive on your own. Conveniently, people have been flying airplanes for 100 years and counting, so there are plenty of opportunities to learn from the trials and tribulations of others.
There are literally dozens of textbooks on the subject, but they are often filled with lots of math, and not a whole lot of real hands on examples. However, the Experimental Aircraft Association ran a series of articles by John Roncz in the early 90s that do a great job of explaining basic airplane design and pitch stability concepts. In fact, in earlier years EAA ran fascinating technical articles by the fistful. Today the magazine is written with a much steeper slant towards a pilot as opposed to an engineer or homebuilder, but the membership is still well well worth the $40/year cost.
You’ve probably never heard of John Roncz, but he is quite a prolific aerodynamicist. He has worked as an consultant on several Scaled Composite airplanes and is a friend of Burt Rutan’s. To find the articles log onto Oshkosh365 go to Sport Aviation back issues and search for articles by John Roncz.
If you aren’t interested in the technical stuff, here is a fascinating presentation he gave at Oshkosh last year talking about a multitude of Rutan airplanes and some of the aerodynamic challenges that had to be overcome. Really fascinating stuff.
Let’s face it, you’re probably a head-strong do-it-yourself well meaning person who might like to save some cash every now and then. You’re not intimidated by anything and you’re willing to tackle the most complex of tasks with the most primitive tool set. So, when you’re dog used your macbook as a trampoline inevitably resulting in a broken screen you thought…. “hey I can probably replace that”. That’s when your journey begins. You, sir or madam…. should read on.
I’m writing this article to give some much needed advice to those of you who are willing to (or maybe forced to) crack into a 13.3″ macbook for……. well any reason really. This is geared toward the laymen who may have some technical experience before but maybe could use a could of helpful hints in key areas. Maybe that iFixit guide only got you so far…. or perhaps that guy on youtube actually missed several screws that were holding the entire top case of the laptop on. That being said, the internet is one of your most powerful tools when breaking into one of these god-forsaken plastic puzzle-boxes. However, take everything you read with a grain of salt, often times people have a tendency to post information about their equipment which could easily be mistaken as the same model as yours. Most of the time members of forums have their hearts in the right place but sometimes they miss the mark by either not providing enough information or providing the right information about a different but similar model. TL;DR- Use Google and sanity check with your physical laptop to make sure people aren’t talking out their behinds!
Apple loves screws. So, be aware of this and start out prepared. I would recommend using a piece of duct tape folded over (sticky side out) or a magnetic tray to hold these minuscule little devils because trust me, you aren’t going to find these at your local hardware store. So, here is a handy list of what you should have close at hand:
From here on out, I’ll try to recommend a couple of guide (with some good pictures) for you to follow and I’ll include what they left out so you don’t make the mistakes I made. I am finding that many of these guides are very cookie-cutter and may list the steps with pictures but have very little detail for anyone to actually follow.
Start by removing the plastic bezel that surrounds the screen, I carefully used the larger flat head screwdriver to get this started and then used my fingers. Keep track of the small plastic fasteners that hold the bezel on, some will probably stay on the case while others will come off with the bezel. Don’t break the small tabs on them because you’ll need to bend them properly back if you ever want the bezel to fit flush again!
Use this guide for pictures and more information but don’t get too carried away just yet.
What they don’t tell you:
Now, once you’ve got the bezel off the next step is to remove the hinge cover. Unless you are some type of ninja master or are naturally gifted at making plastic deform and reform to your will, chances are VERY good that you will not be able to remove this piece without either severely marking up the laptop case, breaking the piece or damaging the wiring below. The safest and best way to remove this piece is to take the top case completely off and loosen the hinge screws to give yourself more room to play with. To be blunt, unless you really know what you are doing, I would NOT attempt this unless you want to replace a lot more than the screen.
So, take out the screws for the hinge cover put them in a good place and leave the screen where it is! Otherwise, it will be a constant annoyance as it falls out dangling by the pair of wires that are hidden underneath the hinge cover. It’s almost like Apple planned it this way. From here follow the top case removal steps.
It may seem obvious which screws to remove the top case (keyboard and trackpad piece) but…. it’s not. There are not only the obvious outside screws, but there are quite a few in the battery compartment as well. Some are actually under a metal bracket which has three screws of its own to remove. Then there are 4 more in the battery compartment toward the front side of the laptop. Now, when you actually remove the top case be careful, there is a small, fragile ribbon cable connecting the keyboard to the logic board if you pry on it the wrong way… it will not work anymore, I know this to be true because that is exactly what I did. Once you’ve got the correct screws free wiggle the board up carefully and be aware of this cable in the center of the board. The only way to remove it is to hover the board like an inch about the case and slip your hand in there, grab the tab where it connects into the board and carefully remove it. Yanking the board pulls it the wrong way and stresses the cable and it has a highly likely hood of ruining it. It may not even be obviously in two pieces but it just doesn’t work anymore. There are some little
If you do end up breaking this cable…. you can be a little tricky and get a replacement for free but more on that later. That’s really all there is to the top case removal.
Now that you’ve got the top case off you can remove the hinge cover safely without damaging pieces. Apple cleverly/devilishly hides some important wiring in and around the hinge area so be aware of this as you remove the cover. Start by loosening the screws on the bottom half of the hinge to give yourself some wiggle room to remove the cover be mindful that the screen can still exert some considerable torque on these screws while you’re messing about. Now use a flathead screw driver to pry from one side and work the cover out with your hands. If you feel like the cover is caught on something…. it probably is. Don’t force it. Look at the backside of the laptop and figure out what you’re caught on. I gingerly used a small screwdriver to move any wiring out of the way but probably something plastic would be best.
For the record, I did actually chafe a couple of wires while I tried to remove this hinge cover improperly. If this happens to you, they can be repaired using liquid electrical tape and a toothpick or a q-tip. I highly advise you take your time and do your best to avoid this all together.
Now you’ve got that bastard out. Right on.
Alright, this is the easy part. Take out the screen by removing the frame the holds it in there and all the screws that go with it. There are two flat cables that plug into the screen which are easily removed.
Now throw in your new screen if that’s what you’re into and checkout the notes on reassembly.
I’m not going to cop out and give you something like “assembly is the reverse of removal”…. “Q.E.D.”…. etc. There are some hints that I wish I had picked up on sooner to help you put this thing back together so it looks just like new. Cause there is nothing worse than a “fixed” laptop that looks like it’s being held together by hopes, dreams and bubble gum.
I’ll leave out the obvious and skip to the stuff that will help you most.
1. Screen Bezel- It doesn’t really matter when you put this back in but this is the best way to do it. Carefully remove each plastic snap that may have come off with the bezel with a small flathead screwdriver. Yes,These. Now, you see those little clip parts on the end? You need to gently use whatever means you have to bend those slightly back so they fit back in their hole in the screen frame. I used a small flathead and some patience. To reinsert them into the frame, put one end in first holding with a couple fingers and squeeze and push inwards to get the other clip into the frame. Do not try to force these clips in while leaving them on the bezel. You will almost certainly ruin them. Now the bezel will snap back on very easily.
2. Putting the hinge cover back on can be a bit of a struggle. Make sure to push all the wires that connect to the screen back before you push the cover back on. Also if you don’t get it right the first time, push it on halfway and poke stray wires back in with something small and plastic. Keep working it back on and then tighten the hinges back up.
3. BE CAREFUL WITH THE KEYBOARD WIRE. Plug it in BEFORE you put on the top case…. well more like as you are putting it on. You get the point.
Hopefully, you’ve found this guide helpful and possibly it saved you a bit of frustration. If not, well then you probably don’t fall into the very small group of people that this article was intended for. Best of luck!
This summer I’m living in Massachusetts and working as an intern at MITRE corp. While I’m down here there are few things I had been planning on doing. One of which involved going to an MIT Swapfest, must to my delight I made it to last month’s swapfest and it was really cool! I showed up a little later in the day (probably after a lot of good stuff had been picked) but still found a few cool things. All in all, I bought an el-cheapo current clamp meter, a couple of terminal blocks and 6 extra large schottky diodes. I got a decent deal on everything but it was definitely hard to not go too nuts, it is very easy to let your mind run away with your wallet at this type of event!
Also, while I’m down in MA I wanted to checkout this whole “hackerspace” thing. Luckily, I found Artisan’s Asylum a pretty well established place where lots of local artists, makers and tinkerers come to do…. well lots of stuff. Sidenote: they are doing so well in fact that they are moving in August to a much larger space!
Anyways, I wanted to do some easy projects at Artisan’s just to get the feel for the place so I figured that building a 3 phase rectifier for general purpose testing would be a good idea. Luckily, I planned it out a little bit and knew that one side of the diodes I had purchased at the swapfest fit right into the terminal block. After a little creative wiring I could have a pretty compact rectifier that would could handle nearly 40amps (continuous)…. not bad. So I poked a few holes in some scrap metal that was lying around Artisan’s and threw it all together. The 3 phases from the generator will be crimped onto the blue terminals and the opposing diode sides are positive and negative.
I had also ordered some 1/4″ thick 12″ diameter steel discs from Wagner, it’s the largest size they offer. You can’t find anything that large from Mcmaster or many other metal suppliers. Total for the two discs and shipping came out to around $50 which is pretty reasonable for that much metal (trust me, it’s heavy), that is unless you want to buy them pre-made from the pros here. At first glance, it may not seem worth it to buy them pre-cut but if you value your time (who does that!?) then it is definitely worth it to just buy them. For me, it was just the fact that I wanted to do it myself as a learning experience. Luckily, I didn’t have to do it all myself thanks to the help of Eric at Artisan’s (local machinist guru and all around cool guy) who helped me basically through the whole process. I’d never used a CNC mill before but by the end of it, I could hold my own. It may still take me a while to fumble around on the Accu-Rite interface but I’ll get there. For anyone who is looking to get familiar with machine shop tools (drill presses, lathes, mills, etc.) I HIGHLY recommend this series of videos that was put out by MIT in like 1995. They’re very well done and apply to both complete newbies and those who think they are familiar with shop tools.
The blank discs are pictured below.
We used an edge finder to determine the center of the disc, from there we could program the machine to position itself exactly where we wanted (within some tolerance of course). The discs both needed to fit a “4 on 4″ trailer hub which basically just means 4 studs on a 4 inch diameter circle. I actually purchased a really nice trailer hub from Northern Tool that is complete with a zerk fitting, coincidentally I think I bought the last one they had which is kind of unfortunate. The fitting will make it very nice if the bearings ever need to be greased on top of a tower (if you’ve ever done any work on anything in the air you’ll understand). However, I’ll definitely repack the bearings with something less dense for easier start up. Each disc also needed a 2.5″ center hole and one disc required 4 additional holes for jacking screws.
Tapping these 4 holes was probably one of the hardest parts of preparing the discs, tapping steel is not fun. I chose to go with a 1/2-20tpi threads so I could really finely adjust things, Otherpower and Hugh Piggot’s designs use 13 tpi typically I imagine mine will be a little harder to work with on a tower but hopefully a little more precise during assembly. Here is the first disc sitting atop the trailer hub, these studs will be pounded out and replaced with threaded rod.
The two rotors with holes in them, the one with 4 holes has an ever so slightly smaller center hole but I realized that it wasn’t a crucial dimension as it will be behind the bearing.
I’ve got to get some sort of OK to use the welders at Artisan’s, so the next step is to finalize the design of the supporting metalwork and get welding.
This past weekend I bought a HobbyKing Kinetic 800. Except for buddy boxed flights on an Apprentice 15e, the vast majority of my flights have been with at the Ultra Micro size. I’m really much more interested in much larger airplanes, so I’ve been interested in flying larger planes. The Kinetic fits the bill, with its 31.5″ span. Since it shipped from HK’s US warehouse in California and I’m in Washington for the summer, it arrived 2 days after ordering. Success! As promised, assembling it took all of about 15 minutes (but I don’t have the patience for stickers). I bought an 800 mAh 3S lipo and an 800 mAh 2S lipo, and used an AR6400 I had laying around since HK does not stock the DSM2 compatible receivers in the US.
Unfortunately, out of the box the mounting for the horizontal stabilator was not square to the plane. It was probably kilted 5-10 degrees. However, loading some weight on it for about 15 minutes took most of it out. It’s still a little out of square (1 or 2 degrees), but it trims out and doesn’t noticeably affect flight characteristics.
With that, it was time to fly. The maiden hand launch with the 2S was a little hairy, likely a product of an inexperienced launcher and an out of trim airplane. It required a little bit of rudder (mostly because the control linkage was a little long), and a whole lot of elevator. About 30 clicks of nose down subtrim, with the battery all the way forward. However, once it was trimmed there was plenty of pitch authority, even if there wasn’t a whole lot of nose down elevator left. The lateral authority was also great, the plane rolls with no issues.
I love flying it. Unfortunately, it was really hard to land. It seems to have great control authority until it slows down to 10 mph or so, at which point control authority diminishes very quickly, which usually results in digging a wind tip and watch the plane cartwheel. Fortunately, the foam this thing is made of is FANTASTIC. I cartwheeled with the 2S probably a dozen times, and there is no damage to speak of. To help counteract this, I got rid of the aileron splitter and moved to separate channels to enable the use of flaperons. This has helped quite a bit, the plane really does slow down better, and landings have become much easier. It still takes me most of a football field to come in though, and its very easy to come down too fast. It could really use some more drag to land.
Then, I switched to the 3S. With the 3S, this baby climbs! If it isn’t unlimited vertical, its right on the edge of it. It still glides great throttle off, and really didn’t require much of a change in trim to fly straight and level. Here, it really proved it’s durability too. Some of the earlier crashes with the 2S had loosened the clips that hold the 2 piece wing off, and during a turn at about 20 feet above the ground, the right wing popped off. This also caused the left wing to pop off, and it lawn darted in. However, there was no damage! Seriously impressed. (You can see the clip responsible in the image below. Basically the clip begins to separate from the foam, but if you check it rigorously it is a quick fix with some foam-safe CA)
Unfortunately, the extra weight really increases the stall speed, and makes landing it for me darn near impossible. After gliding nearly the length of a football field at low altitude, it finally met an obstruction. My depth perception is pretty terrible, and I realized it too late to move out of the way. It was also probably my fifth go around, so I was getting pretty anxious to get it on the ground as people were starting to move onto the athletic field, and I was still worried after the earlier lawn dart experience.
Overall, very pleased with the purchase! I plan to practice landing with the 2S until I’m extremely comfortable with that before moving back to the 3S… but I must admit the 3S is pretty off the wall fun. The 2s is still very pleasant though.
A few weeks back I purchased a Parkzone UM Night Vapor, to fly in the gym at our apartment complex when it was too windy outside to fly my Trojan. Unfortunately, the apartment complex has a nasty habit of closing the gym when it is supposed to be open, so I’ve been doing a lot of outside flying, which led to the below picture.
On a whole, I’ve been very impressed with the airplane. It took *a lot* of abuse to get it out of that tree (about 20 feet off the ground, and no ladder), and the only damage was a very slight tear in the elevator and wing and a wrecked tail skid. A touch of scotch tape and it was ready to fly again. I’m a little to lazy to craft a new one, but she flies and ground handles the same without one, and the slight reduction in weight probably makes it fly a little better.
The provided 70mAh battery gives a 5-10 minute flight time, but using one of my 150mAh batteries I’ve gotten a solid 20 minutes of flight, and a slight improvement in power. The higher capacity battery weighs about 2 grams more (which is a 10% weight gain for the AUW), but it must be offset from the ability to pull more power.
It handles well in the air, with the 70mAh battery you can loop and fly inverted for the first 2 or 3 minutes, with the 150mAh I could invert and loop through basically the entire flight. Supposedly by removing all of the nonessential weight you can get unlimited vertical, but I kind of like the safety factor of the extra material, and I think the landing gear adds to the look of the airplane. According to rcgroups you can switch out the stock motor with the motor for the UM J-3 cub, and get a significant improvement in performance. I think I’ll probably do this in the next few weeks. At any rate, it is an absolute blast to fly around, and I highly recommend it to anyone whose flown an r/c plane before. Even if you just had a little bit of sim time, you could probably handle it. Note the next video is with the 70mAh battery.
I got it stuck at the top of a 20 foot tree next to my driveway...
I’ve been spending my short summer break at home being extremely productive… not really. The great thing is that I’ve had plenty of time to fly, since the winds are calm, and my yard is reasonably sized. I’ve definitely noticed a big improvement in my flying ability. When I started a few days ago, every other moment was “AH! TREE!” or “AH! BUILDING!” I still hit the ground, or a tree (see above) occasionally. So, I recorded myself flying. It’s not that great (I had a hard time keeping the plane in the frame), but it gives some indication of my improvement. I also hit a tree (off camera) about three minutes and thirty seconds in.