Electronics

July After Action Report

Mo at Alta-Mons

On July 16th, USS Missouri set out to engage all opponents upon the Alta Mons Sea. A Reconnaissance Report indicated a substantial minefield (moss) that would restrict Missouri's operational area. While no hostiles were encountered, the day did not proceed without incident.

Missouri was testing out her new more redundant propulsion system, which worked with mixed results: Her starboard engines ran without problem or failure the entire day - marking her first meet that she did not require some form of recovery. Unfortunately, the port motor kept blowing fuses (and still is even on the bench a week later - there is some weird ground short which even took out my multimeter fuse this evening, putting debugging on hold until morning).

Which Cells Fit Where

IMG_7018.JPGDrew has been trying to sell me on the idea of LiFePO4 cells for a while... has have Stephen and Keri... and it looks like they are about the only thing that is going to fit. Tonight I cut some dowels to the size LiFePO4 18650 cells to see what fit where. As I posted earlier I thought the 18650 cells would be the best fit. However, when I started trying to fit cells in the ship it was hard to get an eight cell (4s2p) pack to fit anywhere. No matter how I laid out the pack the cells were just barely interfering with rotation or touching the CO2 bottle.

Choosing Batteries

3102.jpgHoly <bleep>ing <bleep> is space tight in Nassau... I knew batteries were going to be tough but this is nuts... Last meet's discovery that Nassau basically needs to run at 12 VDC to get to speed was a major blow. It basically knocked out any possibility of using sealed lead acid batteries (SLAs).

Tweaks and Upgrades

So, I had a horridly busy week, and was exhausted come the weekend. However, I DID get some time to work on Mo, including replacing the old toggle-switch throttle with a new waterproof ESC (and figured out how to use it)... I still need to put a proper fuse-bank in on it, but that shouldn't take me long this week. I also got A turret re-mounted to the rotation bracket, so everything looks to be shaping up into good form for the target practice this weekend. Now, if only I can survive this week of awesomeness...

Inexpensive Waterproof Video Camera

0900688a80d2cd91_EKN037092_Mini_Video_Camera_grey_style_645x370.jpgI just wanted to let you know that Staples has a $70 off coupon for the Kodak Mini Video Camera. The coupon expires 3/26 and is good in store only. However, the coupon makes the camera around $30. It only takes 640x480 video but the price is definitely right. The camera is very small, very light and waterproof. You might want to consider picking one up (in store only).

 

Slow Progress

Last night I received a pair of 12v 6.2Ah and 12v 10Ah SLAs from my friend Cody and both sets seem to be good to go but the 10Ah batteries are a bit big for NC.  The 6.2Ah batteries are the same size as those that are normally marked as 7Ah so they should be an almost direct replacement.  The 10Ah ones are essentially the same dimensions as the 7Ah ones but about an inch wider.  It would have been nice to run on a single 10Ah battery so I could have a spare if needed but I have not figured out how to fit one.  Since receiving the batteries, they were all topped off and m

Hobby Lobby JETI Radio Compliance Problems

I don't know if any of you were planning to by a Hobby Lobby radio... However, you might want to stay clear of them.

From the American Radio Relay League website:

Water Will Find A Way

waterproof-fail-01.JPGFor many years I have discouraged people from trying to use watertight boxes or assembles. Most people in this club have taken that advise and I think would report it was good advise. Byron was one of the few people who did not. I thought I found, and dismantled, all of his watertight compartments in BC Lion but I missed one. Under the center turret there was a darlington-transistor/power-relay water-sensing circuit. Apparently the power relay got wet at some point before I bought the boat and was never died out. Even before I disassembled it you could clearly see that there is a lot of corrosion inside the water-tight box.

Wiring supplies

Today I recieved my order from http://www.cheapbatterypacks.com and I have to say that I'm quite happy.  Reasonable prices, great quality items and very fast shipping.  They are located in Oregon and I ordered on Friday of last week and recieved my order today (Monday).  I purchased some seemingly impossible to find banana plugs (4mm bullet type connectors) to use for charging leads, some balance taps, JST power leads and a bunch of large heatshrink.  The JST leads have very nice and long (~10") leads on them which is a welcome change from those sold elsewhere that

Power plants

I have been fiddling with the new Mabuchi motors that I received and so far they look large and promising.  At 7.4v they appear to have similar torque to my geared down Maxons but also appear to be even slower and more precise.  I am disappointed to see that they only have 2 M3 mounting holes as opposed to what seems to be a standard 4 holes.  I am looking forward to making a temporary motor mount and exploring how they perform.   Last night I confirmed that everything