What’s underneath?

People ask me what the Leitra velomobile I ride is like under the fairing. Here are two pictures of the frame that I took last time I was doing maintenance on the bike and had all the fairing pieces and seat removed.

Leitra frame front

Leitra Frame front

From the front, you can see the two piece, carbon fiber leaf springs for the front two wheels. The “Y” shaped bit at the very front is where the front fairing attaches and pivots for entry and exit. The seat snaps into the frame just ahead of the rear wheel. In the center of the back of the bike is the rear wheel which sits inside a wraparound fender that keeps water, snow and dirt out of the seating area.

Leitra frame rear 3/4

Leitra frame rear 3/4

From the rear, you can see the Bionx electric motor assist. It consists of the linear motor hub in the middle of the rear wheel and the battery mounted under the left arm rest. The cargo area of the fairing sits above the rear wheel on the rack-like extension. The “V” shaped parts in the middle of the rack and two small strips on either side of the rear wheel are carbon fiber leaf springs for the rear wheel.

The frame is hard to pickup and put on a work stand, so I usually just hang it from my work stand with a loop of rope as shown. This lets me turn the rear wheel and adjust the derailer and lube the chain.

Cars on Campus #7 – BMW i8

BMW i8

BMW i8

I’ve been keeping an eye out for this car since I saw it drive past me in Lafayette a few months ago and while I didn’t find it on campus, I’m glad I stopped and looked. It’s the first BMW i8 I’ve seen in person. I didn’t strike me as “sexy looking” as the McClaren, but it is easily as sophisticated and certainly “greener” given its hybrid IC/electric drive train and full carbon fiber chassis. I would say it looks more futuristic.

There’s a big open scoop in the hood and these weird tunnel-like features in the rear just as the rear window blends into the body. I’m not sure if they look good or just weird.

BMW i8 - rear 3/4

BMW i8 – rear 3/4

BMW i8 - front

BMW i8 – front

Summer 1978 #tbt

This is where I spent my summer in 1978. #tbt

OSR Tipi Exterior

OSR Tipi Exterior, Dwight McKay

This is the tipi I lived in as part of the staff at Onteora Scout Reservation in upstate New York. This was taken as they were finishing pitching the tipi. I was part of the Troop Leader Training group that ran at OSR before the start of camp, so I was not able to help with the tipi set up, but was able to go visit the tipi for a few minutes while TLT was running. Here’s the interior.

OSR Tipi Interior

OSR Tipi Interior, Dwight McKay

This was my first “dream job”. I taught native crafts, wore native clothing much of the time and loved every minute of it. I learned a lot that summer.

Cars on Campus #6

Welcome to exotic car territory. I saw this McLaren 12C (I think) behind Young Hall back in April. Love the color! Note that the roof line is just slightly taller than the door handles on the Camry in the next parking spot.

McLaren 12C side view

McLaren 12C side view

McLaren 12C 3/4 view

McLaren 12C 3/4 view

McLaren 12C engine

McLaren 12C engine

Quill Work

At last month’s Tecumseh Lodge meeting in Indy, Larry Kincer taught a class in quill work. I’ve wanted to give quill work a try, so I was glad to have the opportunity. Embroidery with porcupine quills is an old (17th century) method of native american clothing decoration. Dyed quills are wrapped or woven in patterns.

Quillwork, front side

Frontside of my quillwork practice piece.

We used pre-dyed quills Larry brought and worked on wrapping them in simple rows on strips cut from a plastic container. Thin strips of rawhide would be the preferred material once you get the hang of wrapping, but the plastic strips worked OK for practice. After clipping off the barb from the quill, the quill is softened either by soaking in water or holding it in your mouth. Next, the quill is flattened either by running it between your teeth or using the back of spoon or knife blade. The flattened quills are wrapped around the strip, once or twice depending on length. The end of each quill is bend over beginning of the next quill and the wrapping covers the ends so that they hold each other in place as you can see in the picture below.

Quillwork practice, back side

My practice quillwork piece, back side.

Handling the quills requires some care and a tolerance for occasionally being pricked by the sharp barbs. The barbs are shaped so that your own muscle motion pulls the barb deeper into your skin. Larry had a porcupine hide with him with the guard hair and quills still on. The hide is covered with quills! You can readily see why you would not want to go grabbing one of these animals bare handed!

iCloud Drive: Large Folder Problem and Solution

I’ve had a love/hate relationship with cloud-based file synchronization services over the years. None seem to offer the golden set of reliability, security, privacy and tight OS integration.

Needless to say, I was excited when Apple finally released iCloud drive with OS X Yosemite (10.10) and iOS 8.1. According to Apple’s documentation, data stored in iCloud drive is encrypted in transit and at rest. Apple has not explicitly said if they scan your files while on their servers, but Apple’s statements to date make me think that they do not. I would call Apple’s security good, their privacy “probably good” until proven otherwise and their OS integration excellent. While some folks have had issues with iCloud reliability, it’s worked well for me over the past year, so I’m willing to give it a try as shared file storage space.

So, with that background I decided to move off of Bit Torrent Sync (which is very good, but not well integrated into OS X or iOS) and onto iCloud Drive right after I installed Yosemite on my iMac and MacBook Pro. Yes, I know, I was asking for early adopter problems and unfortunately I was not disappointed.

My initial attempt was a simple move of files into iCloud Drive using the Finder. This worked fine for a few small (< 2GB) folders. However, when I moved over a large (42 GB) folder with some animation asset collections (> 10,000 files per folder). I ran into problems.

For reference, the iCloud drive folder is hidden. You can find it in your “Library” folder at “~/Library/Mobile\ Documents/com~apple~CloudDocs”. This directory is what is mapped to the “iCloud Drive” folder in the Finder.

After much digging around, here’s what appears to happen:

  1. Upon moving files into the iCloud Folder, meta-data for each file is recorded locally for purposes of tracking file changes.
  2. The local meta-data is bundled up, apparently on a per-folder basis and transmitted up to Apple’s servers in batches as files are written to the iCloud drive folder.
  3. When a large enough group of files changes all at once (or nearly so) as happens with a large finder copy, the bundled up meta-data groupings get very large.
  4. When more than 100 files are updated all at once, the resulting meta-data bundle exceeds the size of a single database commit on Apple’s servers and the sync process registers an error and stops working.

How did I find this out? There’s a ASL-based log of all of the iCloud Drive sync processing that can be found in the directory /var/log/com.apple.clouddocs.asl. You can view it either using the Console application or using the new “brctl” command, like so:

brctl log -w

The “log” verb specifies log file viewing and “-w” invokes a “tail -F” style of continuous playback of the current log file. The Console app can do the same thing by picking the directory listed above and the most recent log file in the directory.

The tell-tail error message is as follows:

documentContent/731CDF0F-DD1C-4D7B-A627-5EED6E245B9A:(com.apple.CloudDocs:__defaultOwner__) = <CKError 0x7f8d08d919a0: "Limit Exceeded" (27/2023); server message = "Database commit size exceeds limit">

It’s the last part of that error, the “server message” that’s important. The “documentContent” code is unique to my files. You will have a different one.

To work around this problem, I did the following:

  1. I tar’d up the animation asset folders I had lying about in my source folder. I did that and the total number of files in the overall folder dropped from over 100,000 to just over 12,000.
  2. I reset the iCloud Drive meta-data store, by killing off the “bird” daemon (killall bird), removing the meta-data store which is found in ~/Library/Application\ Support/CloudDocs/ (cd ~/Library/Application\ Support ; rm -rf CloudDocs), and immediately restarting the Mac.
  3. I then waited until the iCloud Drive sync process rebuilt the meta-data and finished syncing successfully as evidenced by activity stopping in the log file (see above) without any new errors appearing. This can take several hours.
  4. Finally, I copied over the remainder of the folder slowly, leveraging a simple infinite loop in bash and the bandwidth usage control in rsync, like this:
while true; do rsync -av --delete --max-delete=10 --bwlimit=4 --exclude-from=/tmp/exclude source-dir/ iCloud; sleep 5; done

The combination of the infinite shell loop, the delete limit and bandwidth limit on rsync causes the copy to move slowly enough to avoid a mass file change, even when deleting files. This takes several hours to finish, but works without error.

The contents of /tmp/exclude were picked to avoid duplicating Apple specific file meta-data and the meta-data directories used by Bit Torrent Sync which I had been using previously. The contents of /tmp/exclude are:

.DS*
.Sync*

If I were starting to move to iCloud from scratch, I would use the shell loop and rsync shown above right from the start to avoid problems.

I hope this helps some OS X Yosemite users escape this problem and avoid several days of detective work to find and work around this issue.

NOTE: As always, when moving important files to new drives, make sure you have multiple backup copies! It’s really easy to accidentally delete things and it’s absolutely required to have a backup to compare to once you believe things have worked! I am able to say this worked because I compared the results on two Macs to a known good backup and every file matched, byte for byte.