Video blog of 1st sail on Canyon Ferry
After looking at the GPS, I am really not to worried about the crafts performance, and will be bringing you data on this shortly. The real problem is the ice surface.
Have a look at this video, which hopefully explains it a little better.
The problem with going fast is that you need to be able to support and transfer very large forces into the ice, and to do this the machine needs to be strong, and relatively stiff. When you need to absorb bumps over a range of speeds, this presents huge problems for a structure carrying high loads and a sophisticated suspension system is required. However, active controls are not allowed and there are also issues with the size and frequency of the bumps. The skate weighs over 50 kg and it needs to move at at a speed of up to 50 Hz over maybe 2-3 inches. To save confusing everybody, I won’t go on , but this challenge is nothing short of impossible. Imagine driving your car with steel wheels and no tyres over concrete speed bumps at irregular intervals at 120 mph.
Walking over the surface at slow speeds, you really don’t get a proper picture for the size and frequency of the ice bumps and I had been way too optimistic of what the natural flex of the main beam would accommodate. The end result is that the craft suffered a couple of failures during the first sail, that I was unaware of at the time.
Firstly the main sail bearing for the top section failed. This was a huge surprise and has performed perfectly for thousands of miles on land. It is a big industrial, self aligning machine bearing, that is rated for over 300 kg of axial load. The sail only weighs 25 kg, so well within design range. Secondly, the counter weight on the top section had bent very slightly down, meaning I could not extract it from the composite sleeve in the wing. This tube supports a lead weight in the end and was designed for dynamic forces of 10G (ten times gravity) to cope with any accelerations. However, it yielded.
Both these failures point to vertical accelerations of over 10G at the top of the mast, which is completely unacceptable. It felt rough from the cockpit, but not that rough!
Adding to the problems the lake had some more snow over the last day or two, which have exaggerated the drifts, extending the time that it will be out of action.
For now we have packed the craft up and will be repairing the two problems (easy fixes), but I am uncertain when we will be able to run again.
The bottom line is that to go really fast, the surface needs to be flat and this only happens at the start of the season, after first freeze and before any snow, or at the end of the season in March, when the surface melts, before the ice breaks up. My gut feeling is that the only opportunity is going to be after first freeze in December, but we will see. If the ice does get better this season, we will be back, but if not, then I guess I will be sitting by the lake in December while it is still water, waiting for the freeze.
If it was easy, everyone would do it, right?
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- Failed bearing
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- Closer inspection
Hi Richard, Too bad about the bearing, I’m sure you have already thought about a cable or rod through the center axis to hold the wing sections together, applying some adjustable tension on the bearing to prevent it from being pounded everytime the sections separate and come back together, but not too much tension as to restrict rotation. Just my two-cents worth.—Steve
Comment by Steve Stephens — January 28, 2009 @ 4:59 pm
Sorry to see and hear about the problems you are having. It was good to watch the video blog and I now have a better understanding of the condition of the rough ice especially from inside the cockpit. I hope conditions will improve and I will keep watching with fingers crossed for you and your team.
Good luck
Gordon
Comment by Gordon — January 28, 2009 @ 5:05 pm
Nothing great gets accomplished without first overcoming difficulties. Keep the faith. This has been a spectacularly bad year for iceboating on the North American continent so far.
As you know your choice of venues for this adventure is probably the best possible one. So just a matter of patience and preparation.
Thanks for the site and the efforts.
DN US4911
Comment by Dave Zoll — January 29, 2009 @ 2:32 pm
The challenge of reducing the unsprung weight, to improve suspension… what if you go away from traditional heavy all steel runners and go more with a design like hockey skates. Perhaps a carbon fiber “moulding” with only a small Steel blade portion attached, not the entire runner being made from steel…
Too bad about the rough ice… hope for a big melt then freeze.
Comment by Nathan — January 29, 2009 @ 10:17 pm
Sorry to hear about the failure… Could it be related to the propensity of metals becoming brittle at sub-zero temps?? Maybe a tension rod/ cable for downforce and a small heater below the tube prior to the run???
Comment by Larry — January 30, 2009 @ 6:13 pm
Thanks Nathan,
There certainly is some merit in looking at other suspension systems, but the combination of the required movement range, load range and frequency is no mean feat. I will try and talk to some experts on this, to see if there is a solution that we could implement. There are other problems with composite blades including durability, stiffness, straightness and of course, expense. Smooth ice certainly is the preferred option, and only a matter of time, hopefully!
Comment by Richard — January 31, 2009 @ 2:35 pm
Hi I think i know the problem with the hd cameras not working if you have not rectified this then drop me an e-mail
robj
PS. I am a cameraman
Comment by rob judge — February 10, 2009 @ 9:56 pm
hi Richard,
good luck to you and your team over the next few weeks.await to heart of a new record.
Comment by kevin williams — March 17, 2009 @ 9:29 pm
I put my link to our “toy” from 2005
http://www.surf.ee/news?uid=223&full=1
Comment by tom — March 31, 2009 @ 10:32 am
That is a machine and a half. out of curiosity how much did it cost to make this – if you don’t mind me asking?
Comment by Gavin @ UK Ferries — May 14, 2009 @ 3:25 pm