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Thursday, August 21, 2014

Random Verizon Rant

I hope someone out there finds this remotely useful. I never imagined how big of a pain it would be to switch from a post-paid account to a pre-paid account on verizon.

Let's say you have a postpaid account with multiple lines and the contract end date has come. Now let's say you want to get a new phone for one of those lines, but you want to get that phone on a prepaid account, but you also want to keep your phone number. That's what I wanted. I got on to shop for some prepaid smartphones and ended up buying two, one for each of the lines on my account, and 1 month of prepaid "allset" accounts with new numbers/sim cards to go with them...all under the guidance of a online verizon sales rep. She said that I would just call and they could activate the phones with my old number. Simple right? WRONG.

I was on the phone with verizon for no less than 4 hours being passed around like a hot potato. Almost no one knew how to handle this.

Tips and lessons learned to avoid this headache:
1. Do not buy more than one prepaid phones with prepaid accounts at the same time online. Make sure they are in separate orders. Shipping is free, so not a big deal.
2. Make sure your billing address is your shipping address. Their online ordering system can't handle separate billing and shipping addresses. Otherwise, you will have to call customer service for an hour to get them to re-enter the order with your billing zip code to get it to go through.
3. If you want to use your new prepaid accounts that you paid for, do NOT follow any online instructions on activating your new phones, i.e. do NOT switch the SIM cards. The only way to activate a prepaid phone with your old number is to call them.
4. Do NOT call late at night. They will go home and leave you on hold until the line dies.
5. Start with verizon wireless customer support and say "agent" in the menu. That will transfer you to a person. Explain to that person that you want to activate a new prepaid account and phone you purchased from with a number you currently have in a postpaid account.
6. WARNING: IF you ported a number from another carrier, do not let them deactivate your old line, or the number will revert back to the original carrier. There is another process they have to follow that involves higher-ups if your number was originally from another carrier.
7. Verizon stores (the legit ones) can't help you with this problem.
8. Ask lots of questions and be skeptical

The process is as follows: First to have customer service deactivate your old line and reserve the number. Then they have to toss you to the prepaid department. I think if you follow the above tips and have an original verizon number, the prepaid department can simply activate your new phone and prepaid account with your old number.

My experience: I did the opposite of those tips (at the suggestion of various verizon representatives who were all wrong). Thus, my experience was painful. Once I finally got to people who could help me...First they deactivated the line I wanted to switch. Then I was tossed to another department. They tried to activate my new phone but it wouldn't work. Then the line I was on hold on died around midnight. The I called again in the morning.  They tried activating the phones but found that the problem might be that I had purchased two prepaid phones on same order and the system got confused. Then they realized the old number was from another carrier and had to reactivate it in the original postpaid account to save it. Then they tried splitting the order so that the new phone could be activated. This took me to hour 4. Eventually they tossed the problem to "systems", which I'm guessing means tech guys. I got a few calls back, but after another 5 or so hours, it was finally resolved.

If the mistakes under lessons learned had been my doing, ok, I wouldn't be upset. But everything I did was under the guidance of verizon representatives!! At least all of the verizon reps were nice and friendly, and the higher-ups I talked to were helpful.

Monday, June 30, 2014

Over 2 years...

Wow time flies. It's been 2 years since my last post. Life... Graduate work is sucking most of my time currently. I need to start my thesis (in the field of cyrogenic fluid slosh dynamics) soon, which won't make doing side projects any easier.

Projects update:
-EHB and LITE are suspended until further notice. I'm currently in a small apartment with very little access to machine tools, which makes making things difficult. They will eventually be built and will be followed by some other similar projects I have in mind, probably a scooter.
-I'm working on my Level 3 certification rocket. It's going to be a half scale Phoenix missile.
-Also designing a huge rocket with some MIT Rocket Team cruft. More details on that closer to launch day (BALLS 2015)

I'll post a build log of my L3 rocket similar to my L2 rocket when it's complete.

Sunday, May 13, 2012

3 months....more ouch

Yeah...I haven't done anything on my boards. I got swept away by MIT's work load again. All my free time was spent leading the team that built this:

MIT DBF 2012 Competition Plane
It's our plane from the DBF competition this year. I am an aerospace engineer after all...gotta build some things that fly :P .

About DBF:
DBF (Design/Build/Fly) is an international RC aircraft competition sponsored by Raytheon, Cessna, and the AIAA. Every year in September, a new set of rules/missions are released, and 60-80 teams design, build, and fly a plane for those rules. The contest site location alternates between Tuscon, AZ and Wichita, KS. 1 plane is allowed, and the missions are usually very different, making it a complicated design/optimization problem. Also, weight is usually a HUGE scoring factor (in some years it's been the only one that really matters). Also, lithium batteries are not allowed...It's like Flintstones meet the Jetsons in that regard (NiMH battery tech meets top-of-the-line composite technology).
The missions this year were to fly as many laps as you can in 4 minutes, carry 3.75lbs of aluminum block for 3 laps, and carry 2L of water up to 100m as fast as possible and then dump it.

About MIT DBF:
We're a small team (~12) undergraduates, usually with one or two graduate advisers who help out here and there. No profs at MIT have the time to devote to helping the team out, so we're really undergraduate run.

About our plane:
Unfortunately, I can't tell you very much about our plane because DBF is SUPER competitive, and a lot of how/what MIT DBF does is secret. I can tell you what you see in the pictures though. This plane is the product of a semesters worth of design/analysis, and a semesters worth of building. (for a reference length: it's wing span is about 1.4m). It has composite reinforced (various amounts of carbon fiber/fiberglass/Kevlar...I won't reveal weights or locations) foam wing and tails. The airfoils are very precise thanks to the CNC foam cutters the Aero/Astro department has. The fuselage is made out of a honeycomb/fiberglass composite; we CNC milled our molds in house for this fuselage, and developed our own manufacturing processes. The propulsion system is: NiMH battery pack, Castle Creations ESCs with Axi Gold brushless motors, and APC propellers (different props for different missions).

More pics:

Filling with water.

The team.
How the competition went:
Not well. Fucking tornadoes. I'll start from the beginning though: The plane made it to Wichita via freight no problem. It was SUPER windy every single day there. First day, we successfully completed Mission 1 (the speed mission) in the morning with 6 laps, at the end of which, an ESC fried (it was a bad one...we weren't anywhere near the amp limit). Then we decided to call it a day and go do Mission 2 flight testing at a small RC airfield nearby. The next morning we successfully completed Mission 2 (aluminum block passenger mission) in 20+mph winds. We were sitting in the top 5 at that point (top 3 if you didn't count the heavy planes that had already finished all 3 missions, but were way too heavy to place in the final top 5). Then we were waiting around for our next turn (they cycle through everyone for flight attempts) to do Mission 3 when they closed the flight line due to some rain and high (30ish) winds. It's unfortunate...we designed our plane to be very fast, so it could have handled the wind. Oh well, we decided to go back to the hotel and wait for tomorrow, the last competition day. That night, 90 tornadoes ripped through Kansas, out of those, 10 hit Wichita, and 1 happened to go right through the competition site, wrecking everything. They had to cancel the competition; no reschedule, nothing. We were super bummed: 1000's of man-hours and 1000's of dollars went into that plane. But we went back to the small airfield and completed Mission 3 (2L water dump mission) in ~40s in 35mph+ winds. We did the math...if we had completed Mission 3 in anywhere close to that time at the competition, we would have won. It sucks...a lot. The judges decided to get rid of the 3rd cycle of flights in the competition (the one we did M2 on), so we ended up in like 12th (because we only had one mission score...), or something. The places are total bullshit this year; 1/2 the teams never even flew, and the ones who placed high would have placed much lower had half the competition not been canceled.
I'm just glad Tuscon doesn't have tornadoes.

I'd like to thank the MIT Edgerton Center, the MIT AIAA Chapter, the MIT GEL Program, Lincoln Laboratories, the Department of Aeronautics and Astronautics, Aurora Flight Sciences, and Lockheed Martin for their support this year, and hopefully in many years to come!

-Jed Storey
President, MIT DBF

Sunday, January 29, 2012

2 months...ouch

Needless to say (but I will say it anyways), I've been busy. Leading MIT's DBF team has taken up every bit of my spare time since november. Well, almost...

I got the hubcaps and spacers for LiteBoard's hub motors machined:

I did the spacers on the lathe, but the hubcaps I did entirely in the mill. I really like the mill method, rather than going from the lathe to the mill. It took a lot less time. I didn't check one of my drill bits though, and being a student shop, it was damaged, so the tip broke off in my part. I was lucky that it had gone most of the way through before breaking off, though, so I was able to get the tip out. I also decided to try loctite bearing compound this time, so I made the bearing holes slightly oversized.

Even though I haven't been building much, I've been gathering supplies: 2 hobbyking 80A car esc's, 2 more 6S 5000mAh packs (in addition to the 2 I have left over from ELB), all of the metal stock I'll need, 4 1.25"x4" colsons, a massive lipo charger and power supply, a $15 hobbyking 2.4GHz 2 channel radio, etc.

The next machining I'll do is probably coring out the colsons.

Left to do:

  • core out colsons
  • machine axle adapters and hubs
  • wind stators
  • order rotor plates
  • find/buy hall effect sensors
  • assemble motors
  • test motors/esc's
  • assemble massive lipo pack (6S4P)
  • laser cut grip tape design
  • assemble board
  • add lights
  • +more
Wow that's a long list :/ . I hope I have time this semester to work on it. I'll only be taking 3.5 classes to give me time for DBF and this, so we'll see how it goes.

Monday, November 14, 2011

Here we go!

I’ve been busy, but I’ve somehow found time to work on LiteBoard. Oh right…what is LiteBoard?

Now Presenting LiteBoard:
But first, some history: I want a light*, fast way to get around campus, which is the same premise and idea that evolved into ELB. Unfortunately, ELB turned out to be more of a prototype and a learning experience. Now I want a light*, fast, and polished product to get around campus. Sure, there are commercially (and cheaper) available options, such as a bicycle (can’t pick it up and take it to class…also not original and would get stolen), roller blades (no way…I’d kill myself on those), kick scooters (lammeee), electric scooters (lammeerrr), hub motor scooters (so not original)…but I wanted a longboard. So I came up with the EHB concept, and started acquiring parts for it. But once I did a weight build-up, I realized that EHB wouldn’t actually be much lighter than ELB, so I suspended work on it. I’ve been riding around on the mountainboard I bought for EHB for awhile now…I have to say, it is a great way to get around. It’s just slow: I can only maintain about 10mph.

LiteBoard is the V3 concept that I came up with after completing ELB. V2 is/was EHB, but even though it would address most of the problems ELB has, it didn’t address one very important one: weight. ELB weighs 40lbs. EHB is predicted to weigh 35lbs. Liteboard: 25 lbs.

Not enough time to do a rendering=screen shot.
Lite will be a 2WD hub motor powered electric longboard (actually a longboard this time, and not a mountainboard). Each motor will be ~1100W, producing ~3.9Nm of torque each. Lite’s estimated top speed will be ~25mph. The basis of Lite is this longboard:

Pending cool grip-tape design

Randal II 50deg 180mm trucks, ABEC11 97mm Flywheels, and a bamboo/maple deck I got off of ebay (it was incredibly cheap, yet very high quality. ebay=good source for longboard parts). The deck needed some modifications to use the massive 97mm Flywheels:

Initial cutout lines. 
1st try: didn't remove enough.
Second try: Now the wheels don't bite the deck when I turn.
I think it looks awesome...
Why did I need 97mm Flywheels? …

Detailed Motor design:

I couldn't get a good angle of the internals. The axle extension is not round, but keyed to fit with the hub that is pressed into the stator.
Since ELB ended up with about twice as much torque as I’d ever need, I decided to shoot for the same amount of torque/motor for LiteBoard, but cut the number of motors in half. I followed the same design process I used to design ELB's and EHB's motors: Start with simple calculations, move on to SolidWorks CAD drawings, import DXF's into FEMM, modify CAD, repeat...

FEMM pre-diameter shrinking.
The motor underwent one large design change as a result of FEMM. Turns out that pretty much the whole stator was saturated, so I wasting a ton of energy. I shrunk the magnets from 3mm to 2mm thick, and shrank the whole OD of the motor by 4 mm, and only took a .1Nm hit in the process.

Estimated Motor Specs:
# Phases
6S Lipo
Max current
Torque (FEMM)
No-load speed
Stator dia
Stator length
Rotor OD
Magnet thickness
Magnet grade
# Poles
Motor width
Motor OD

The high current, low voltage method was picked in order to use HobbyKing’s 80A car ESC, which is about 1/3 of the cost of an equivalent Kelly Controller, and about ¼ the size. It also has a sensored option that I plan on using. I will likely get some pretty serious I^2R losses, but I’ll try to keep wires as short as possible and pack the stator with multiple parallel strands of magnet wire (thinking 22Ga). 8 parallel 22ga stands has same resistance/m as one 13ga strand…idk, I’ll see how many strands I can fit.
The stators are Scorpion Power Systems 5535 18T stators. They come in their S5535 motor series, which are about $400 a piece…which is why I bought the stators directly from them again ($140 for both, free DHL express shipping). Yet again, they are very high quality:

I officially love these guys' work.
I decided to bite the bullet and go with BigBlueSaw for waterjetting my rotor plates. Turns out that 11*.125” =35mm to within a fraction of a mm…I got lucky there. 22 plates will run my $250…ouch! But I did the math, and if I spent the amount of time working that it would take me to machine the rotors, I would come out ahead if I just have them cut for me (and waterjetting them here is a no-go…it’s freakin’ expensive).

Batteries: While I thought about trying A123 cylindrical cells for this one (specifically a 7S7P pack made of their 26650 cells), it turns out that it won’t fit under my deck. So I went with lipo again. Specifically, I’m going to buy 2 more 6S 5000mAh 25C packs from HobbyKing, and using the leftover packs from ELB, I’m going to make my own, slim 6S4P pack (22.2V, 20Ah).

Control: At first I’ll use a $15 hobbyking 2Ch. 2.4GHz system. But I’m planning on doing something like this eventually.

Tires: So my last post suggested a Colson 4”x7/8” rubber wheel was my best bet. But that was before I shrunk the OD of the motor from 74mm to 70mm, which puts it out of the range of the 7/8” one. So I’m going to use two 4”x1.25” ones.

From left to right: 4x7/8 turned out, 4x7/8, 4x1.25, 4x1.5,4x2

Note the huge void.

After digging a bit deeper: MORE huge voids.
 Next I tried the 1.5" wide one:

Only 1" wide of plastic inside (after turning out visible part of hub).  Guess I'll be using the 1.25" wheels (more plastic for press fit).
I was able to cut the rubber on these.
Again: another void...

Here's a table of 4" Colson rubber wheel data for your reference.

Safety: I’ll have the same setup as I did on ELB. A contactor sitting in the main battery line that is actuated by a magnetic reed-switch from a magnet strapped to my shoe. This will act as a fail-proof way to make sure that if I’m not on the board (anymore…), it doesn’t keep going. I’m also planning on wearing a helmet with it.
The ultimate goal is have a very sleek, finished product that achieves all of my criteria (safe, light, reliable, fast, etc…)
Anyways, that’s the plan so far. I should be able to get a lot of it done over IAP…we’ll see.

Oh, and to leave you with a cliffhanger: it’s called “Lite” for more than one reason ;) . 

Thursday, October 27, 2011

Wheel Study

I'll explain why I'm studying wheels in my next post. But for now: I studied some wheels.

More precisely, I bought a whole bunch of small rubber-treaded wheels from McMaster so I could measure them (McMaster doesn't have CAD of their wheels, which is annoying). I needed to be able to core out ~73-75mm of the hub.
I bought these: 2337T35 , 2337T42 , 2337T37 , 2829T68, 2829T56 , 2439T42 , 2243T22

All 4in wheels of varying widths and materials. I got them in and measured their hubs and 5 had hubs that were large enough, and only 3 of those were reasonably priced or would work for me (2337T42,2337T35,2829T68). Interestingly, the wider the wheel got, the smaller the diameter of the idea why. I like the super soft tire (2243T22), but it was really rounded, and I'm planning on putting multiple tires on *ahem* something.

2 of the 3 wheels are mcmaster's "Rubber Wheel" series. They are black phenolic? hubs with black rubber tread. The other one is "Performance Rubber-Tread"...actually Colson Casters! Nylon or polypropylene? hub with grey tread.

The phenolic ones are easy to machine...not nice, but easy. Phenolic is probably the WORST smelling material I've ever tried to cut...mix of shit and rotting vegetation. In fact, I gave up after a few passes. Even though the wheels are a lot cheaper, it isn't worth dieing for...

So I tried the Colson. MUCH nicer. Super easy to cut, and NO smell. Found my wheel!

Saturday, October 1, 2011

More EHB stuff

While I really didn't have the time today, I decided to do a little work on EHB.

I finished designing the battery box:

I used SolidWorks' sheet metal tools to design it. It's contoured to fit my deck. I plan on waterjetting it out of 1/16" 6061 aluminum. The battery packs are 4s1p 5000mAh Zippys.

I also did a pretty detailed mass calculation. It comes out to about 35lbs...which is annoying because I was shooting for < 30lbs. The motors are ~13lbs, and the batteries and battery box are ~5lbs. Unfortunately, the four kelly controllers weigh in at ~7lbs. Add in the deck and the trucks, and I get ~32lbs. Grrr...

So at this point, I have 2 options: Keep the current heavy configuration, or give in and make it 2WD (soo not as cool...). 2WD will save me about 9lbs, which brings the total down to ~26lbs.

I guess another option would be to suspend work on EHB and start LiteBoard. Though that would mean my $500+ investment in EHB parts would just be sitting around until LiteBoard is done...

We'll see what happens. Heck knows, at the rate things are going (I'm swamped), neither may get done by the time I graduate.