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Re: Technical Talk

Posted: Fri Apr 13, 2018 12:21 pm
by Renegadenemo
Don't forget also that we haven't filled the sponsons with expanding foam, which saves about 36 kilos at the front end. Plus, we have the option to tweak the thrust line a little in our favour by adjusting the angle of the engine. Only a degree or two before the inlet trunk becomes the limiting factor but enough to make a difference. This of course would have been disastrous for record breaking but we can do it. And if all else fails l'm sure the army can rustle up a couple if sand bags. We'll get it working one way or another.

Re: Technical Talk

Posted: Fri Apr 13, 2018 11:50 pm
by Canopener Al
Cheers Mike and Bill, good answers indeed. Didn't realise the foam was not being added, some serious trimming options open then. Hope what is planned for the weekend shift is progressive. Alas tomorrow it for me is play on the paid stuff, then get my restortion progressed on Sunday.

Re: Technical Talk

Posted: Sat Apr 14, 2018 11:57 am
by Richie
I love auto correct :)

Rebuild / cockpit

Posted: Thu May 10, 2018 11:33 am
by Vernon
Hi bill / team
Just a quick one regarding a previous pic of the day cockpit view. How close to the original is the new seat & harness as it was mentioned it was more comfortable than the original? & was it really necessary to alter the position of the seat?
Thank you
Vernon

Re: A stupid question .. Or maybe not.

Posted: Thu May 10, 2018 9:26 pm
by sheppane
Canopener Al wrote: Fri Apr 13, 2018 1:03 am Just seen the lead weights appear on the last picture of the day. That picture has raise a question in my head that has been lurking for some time about the restoration of K7. Of course those lead weights had to be added because the money Donald had didn't include during the 66 modifications to actually do the maths accurately to rebalance the boat without trial and error. I would have doubted that the actual weight and moment of the craft was actually worked out until its first trials in late 66 that proved the trim was way out. Of course K7 is not the same trim as the 4th of July 1967, it has half the world supply of polysulphide sealant on it, plus lots of addition metal to repair the holes. I would doubt the trim is anything close to allowing sucessful planning to happen first attempt. While trial and error may only be the solution with funding and outside help, has anyone asked outside help in weight and balance and if anyone in the right field could stick weight and moment calculations into a suitable program to say.. "Stick X pounds there and the thing will rise? Of course if the budget says no, simple answer is go and play..
Bear in mind that one of the considerations in the 1966 refit was to move the centre of gravity forward to allow the boat a bigger safe operating envelope. This work was done by Ken Norris and John Stollery. They envisaged that the extra power of the Orpheus would be sufficiant to get K7 on to plane, providing the engine did not get overwhelmed by water entering the air intakes. That it did not work out as planned should not be seen as lack of thought in the modifications. A down on power Orpheus did not help in the initial trials of November 66. Please feel free to read the full story in the book that I wrote with Keith Mitchell.

Rebuild / tail fin

Posted: Mon May 21, 2018 11:38 am
by Vernon
Hi team
Just watched latest progress video.. excellent as alway & the work you have all achieved is incredible.
A quick question relating to the tail fin.. the rod that protrudes outwards.. what actually is it for?
Thank you
Vernon

Re: Technical Talk

Posted: Mon May 21, 2018 2:41 pm
by Richie
Vernon, it is the pitot tube and is connected to a speedometer within the cockpit.

Re: Technical Talk

Posted: Mon May 21, 2018 5:11 pm
by Engine 711
Richie wrote: Mon May 21, 2018 2:41 pm Vernon, it is the pitot tube and is connected to a speedometer within the cockpit.
Strictly, I believe its an Air Speed Indicator (or ASI) - https://en.wikipedia.org/wiki/Airspeed_indicator

Air Speed is determined from the difference between the static air pressure and the dynamic air pressure (the air pressure due to the boat moving forwards).

Pictures show K7's ASI above the steering 'wheel', at the top of the panel, slightly offset to port (or left...) - and clearly calibrated in MPH.

Re: Technical Talk

Posted: Tue May 22, 2018 1:12 pm
by Richie
but in answer to the question, the thing on the fin is still a pitot tube :D

Re: Technical Talk

Posted: Tue May 22, 2018 10:37 pm
by mtskull
Richie wrote: Tue May 22, 2018 1:12 pm but in answer to the question, the thing on the fin is still a pitot tube :D
Or to be precise, a pitot/static tube.