I had a great 8 hour training day on the reservoir on Wednesday using the new gear box shaft and coupler, then another 4 hours on Thursday. No problems at all. I checked the grub screws at the end of the day and they were still tight and locked down. So far, I have amassed about 300 km on the 5/16″ prop shaft, and new smaller gear box. Rick W. thinks it would be prudent to buy a back-up gear box from Mitrpak, and start with the new unit on record attempt day. So, that is what I have done. The new box is with Manny now for shaft lengthening.
My dipping rudder also worked, but didn’t provide as much turning momentum as I had expected. Here are the turning test results:
I was looking over an old blog post prior to the record attempt in 2008, and discovered some very useful speed data. http://adventuresofgreg.com/blog/2008/07/02/thunderstorms/
Specifically, this is pretty interesting:
|1. Every 5 kph of wind equates to .1 kph decrease in speed
2. Big rudder is .6 kph slower than small rudder. Small rudder is .1 kph slower than no rudder
4. Paint vs packing tape was worth a speed increase of .1 kph
5. Elliminating the prop strut is worth an additional .1 kph in speed.
6. Counter clockwise loops at Elbow Valley lake are worth an additional .2 to .3 kph average speed due to current.
7. remove the seals and backing off the lock-nuts on the gear box are worth an additional .1 kph average speed.
8. The narrowed 1/4″ spring steel shaft compared to the 3/8″ stainless shaft is worth .1 kph speed increase
I had forgotten than my small butter knife rudder is .6 kph FASTER than the rudder that I am now using (and had planned on using for this record attempt, and had used for the last record attempt). But now that I can use the dipping rudder to turn, I might be able to put the butter knife back which should add another .6 kph – this would be huge.
Here is how the speed averages are working out with the new boat:
OLD BOAT (2008 tests) = 150 watts, very calm water, small rudder, heavy boat, no prop strut, thin prop shaft= 11.4 kph
NEW BOAT = 150 watts, very calm water, big rudder, heavy boat (full water bag, paddle, food, SRM cranks), prop strut, thick prop shaft = 11.2 kph
NEW BOAT RACE CONFIGURATION THEORETICAL = 150 watts, very calm water, small rudder, light boat (1 water bottle, carbon cranks), prop strut, thick prop shaft = 11.6 to 12 kph ??
I’ve been talking to Skip about lake and weather conditions, and found some wind data for Whitefish Lake. It would appear that the end of September is a good time to find south winds which offers us a sheltered areas on the north end of WF lake. I made this wind map and plotted 2 possible courses of 3 km in length.
Skip thinks we can see BOTH turn around buoys from his living room window, so I think we can station BOTH official observers in Skips house with telescopes focused on the turn buoys. Carter and I could make a radio call as we near each buoy alerting an official to watch through a scope.
The First possible date has changed again to Saturday, September 28, 2013. If the weather looks decent on Saturday (forecast < 5 mph winds from the SOUTH to south west), then the race will happen on Saturday morning at 8:00 am. WE NEED VOLUNTEERS to act as official observers and to help out with web news broadcasting. If you think you can give us a day out of that week, please let me know, and also tell me what dates you would be available for.