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Archive for 2010

Good design! Low unsprung weight while retaining direct drive benefits.

Bad hub wheel motor design.
Bad hub wheel motor design.

I’m not going in to the details on particular attempts at hub motors, but even if executed perfectly they are bad.

Unsprung weight means terrible handling and reduced road-holding capabilities!

Done, end of story, move on.

Good news: There is an alternative.

In-board electric motors: You place the motors in the center of the vehicle and use standard short drive shafts to bring the power to each wheel. The downside? Space… you need to fit two motors (remember you no longer have a differential) as close the center of the vehicle as possible and either have the entire motor pivot or have short angled drive shafts from each one.
By placing the center of gravity of each motor almost completely off the wheel you mitigate the unsprung weight to almost nothing.

There are a couple other problems with wheel motors, you need a massive amount of current and a motor that is efficient over a wide range of RPM’s. Modern high powered IGBT’s and MOSFET’s are probably up to the task and when integrated in to intelligent power controllers, they can drive various forms of electric motors at high levels of efficiency and power.

The second problem ‘massive current’ is a bit harder. Battery chemistry is changing rapidly, but it is still difficult to find chemistries than can supply large current, long cycle life, reasonable price, weight, size, safety and the ability to be mass produced.

All said, drop the stock differential, the stock drive shaft, the motor, the transmission, exhaust, emissions equipment and all the other ICE components that become redundant and then you might have a chance of building something that has a reasonable power to weight ratio and efficiency level.

One last thing, as an alternative you could place the motor where the transmission is on a RWD vehicle, keeping the existing differential and drive shaft (a 100 year old design). This adds additional weight, but you no longer have the space restrictions and gain a bit of gearing which might lower your peak power needs.

This Detroit Electric design is ancient but a good compromise.


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10GBase-T / 10GigE Status Update

Friday, August 6th, 2010


So after my mild disappointment with Apple releasing an uninspired speed bump to the recent MacPro line (no case redesign (it could lose 20lbs), eSATA, 10GigE, FW1600, or even USB3.0), I started doing some research on 10GigE just to see the state of affairs.

Things I learned:

1. What I want is 10GBase-T the standard RJ45 cabling we all love.
2. Cat6 isn’t going to cut it, Cat6a or Cat7 are going to be the only ‘real’ options. I say it like that because under good conditions (short distances, low interference, not in big bundles of cables) Cat6 will work. But, for safety sake, I wouldn’t count on it.
3. Various fiber and copper cables are being used in the interim. CX4 and SFP+ are the common cables in use and are designed for shorter connections. But, they aren’t that interesting unless you’re building a small dedicated cluster and really what I want is something that interoperates in the rest of the GigE world.
4. There are 3 (that I could locate) actual 10GBASE-T switches, most are just gigabit switches with a couple 10GBASE-T uplinks OR are massive datacenter switches. The 3 I did find are too expensive ($11000-19000) for home use, but aren’t out of range for the right small business application.

Arista 7120T-4S
This 24 port swtich is really the best choice if you need ultra low latency (think network computing) and/or raw bandwidth (think editing RAW HD Video). It features 20 auto-negotiating 1/10GBASE-T ports and 4 SFP+ uplinks. Network World tests put the latency at a very stable 800ns! That’s 0.0008ms a.k.a. very, very fast. I would love a low cost 8 port version of something like this. A quick google product search shows you can pick one of these up for ~$13,500.

Dell PowerConnect 8024
Another possibility is the Dell 8024. It has the most configurable port setup (24x SFP+ (10Gb/1Gb) w/4 Combo Ports of 10GBASE-T (10Gb/1Gb/100Mb) or SFP+) and is the lowest cost of the bunch at ~$11,500 (google product search). If you need all 24 ports, or if that extra $2k is going to put you over budget or if you merely need the extra bandwidth 10GigE brings, this is probably your best choice.

Extreme Networks Summit X650-24t
While I’m a big fan of Extreme as the underdog of high performance network switching, unfortunately, as far as I can tell from the datasheet, the ports are 10GBase-T ONLY and aren’t backwards compatible with GigE or slower. This is a bit disappointing as they were a great company to work with back in the Static days when we used their products. On a positive note they performed the best on IGMP multicasting, so if IP multicasting is your thing, this is your switch! $18,709.86 on Amazon :)

Network world did a nice review (although its terrible to navigate) of the bunch and put the Arista on top. Here is the comparison chart for a general overview.

Further reading:
High Performance Made Simple: The 10 Gigabit Ethernet Cluster


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Safari
Safari

I mean that pretty much sums it up. I was really hoping 5.01 would fix it, but apparently, no such luck. Basically, if you have your keyboard repeat rate set to anything other than dog slow, Safari starts animating the scroll, then in the middle of starting to animate it sees the next keyboard input and interrupts the first scroll and just gets terrible. Using the mouse is super silky smooth, the arrow controls work albeit a little chunky, but, I suspect it’s merely because the repeat rate is slower.

I’m sure a method is getting reentered and somewhere an if statement is missing or broken… e.g.

if (animating == YES) DON'T INTERRUPT ANIMATION!;

In the video I first use the keyboard arrows, then the pageup/pagedown, then the mouse controls and finally some more keyboard.

Safari 5.0/5.01 Terrible Keyboard Scrolling Video Click HERE

Update: 9/8/10 5.02 did NOT fix the bug…so sad…
Update: 10/18/10 5.03 did NOT fix the bug…sadness continues…
Update: 4/14/10 5.05 DID fix the bug! Rejoicing ensues!!! Thank you Apple!


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DSL Reports Speedtest

DSL Reports Speedtest

So got my new 35/35 service running and apparently we’re getting close to the maximum upload. Verizon had called me on the upgrade date and told me that I would only get 29mbit upload because the ONT at the house wasn’t capable of more. He offered to send a tech out to replace it, so I said “sure”. The tech came out today and basically said he wasn’t aware of any speed difference on the other ONT’s. He called his boss and he said the guy I talked to was misinformed because the 611/612 ONT’s are all pretty much the same (just different port configuration and MOCA support) and won’t go any faster than my 610.

The second thing he said was they only guarantee 75% of the claimed speed (which is 26.25mbit) so there really isn’t much of an option at this point. I guess I’ll be satisfied for now, but I’m a bit miffed that they said they could fix it and now they can’t or won’t now.

I just wished the sales/service people who called you would actually not make promises they can’t keep. I think they continue to have a shortage of highly qualified guys.
I tried to do some searching for the AFC AccessMax SFH ONT 610X specifications, but I couldn’t find any useful data.

My old gallery of my FIOS Installation in case anyone is interested.

UPDATE 1/22/10:So my wife just reported that Verizon called back and DID claim it was an equipment problem and will be sending techs back on saturday to fix it (shaking head). Big company communication fun, I have no idea, I’ll update again Saturday.


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this is fios, this is big

This is FIOS. This is BIG.


The good news is the latest bundles as of 1/17/2010 while not great for everyone, are a good upgrade for me. Something changed last month and my bill was $10 up so it all coincides well for a change of plan. I’ll end up saving a few bucks a month while getting 35/35mbit service (up from 20/20) and a few extra FIOS TV channels. The bad news (and its not new news) is the Wi-fi hotspot joke they claim you get.

Verizon Wi-Fi is not available for PDAs, phones, desktop PCs or Macs.
In fact 64-bit Windows need not apply as well. It is ONLY available for 32-bit vista/xp. This is just ridiculous, wifi access is built on all open standards. It’s purely a marketing/business decision to alienate all of the PDAs, phones, Macs, etc…

It amazes me how Verizon can wave the Network Neutrality Flag and yet at the same time not offer any access to all to various devices. So, its network neutrality, as long as you’re the type of device we think deserves it.

The ugly? Well, the $1.99 mysterious fee is still an unknown factor and ETF’s have doubled on both FIOS and Wireless up to $350 and $360 respectively. FIOS prorates at $15/month and wireless is oddly $10/month which will leave a hefty chunk even at the end.

They continue to be my most hated/loved company. FIOS and FIOS TV are unparalleled, the wireless on the other hand? Well, lets just say I won’t be a quad-play subscriber any time soon.


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