Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Pleasure boats, Sports, Race, Power and Leisure Boats: => Topic started by: Retro modeller on March 02, 2018, 10:23:37 pm

Title: Touchwood bluebird
Post by: Retro modeller on March 02, 2018, 10:23:37 pm
all painted and finished now, this on a 3 cell going to a 4 cell next run


https://youtu.be/kfY9T8zH7p8 (https://youtu.be/kfY9T8zH7p8)
Title: Re: Touchwood bluebird
Post by: imsinking on March 03, 2018, 10:26:45 am
That sounds & looks great  :-)) ,  it sounds like an inrunner ? The balance looks good too  with a 3s 11.1v would a 4s add weight in the wrong place ?, it'll ramp up the rev's the extra 3.4v . . .
Bill
Title: Re: Touchwood bluebird
Post by: Retro modeller on March 03, 2018, 02:10:17 pm
I don’t think so I run two 2200 mah In parallel, it runs so straight and level I think two 4s batts would be no problem, but I think it’s about scale speed now, it looks very real as it is, motor is an In runner 2200kv, this was a long long build.
Title: Re: Touchwood bluebird
Post by: imsinking on March 03, 2018, 02:34:22 pm
Wow , just worked it out, your maxing at 24420 rpm on 11.1v. . .
And it will be 32560 rpm at 14.8v  %%
Parallel LIPO's is OK? how are you keeping track of cell discharge . . . I use a single 5000mah 11.1v with a cell discharge /alarm meter set at 3.4v per cell + the cut off on the ESC , I haven't blown meself up .. so far The 4s is heavier than the 3s pack & if your doubling up the weight increase will be tidy , don't be too quick coming back across the previous wake , that's what saw Donald Campbell off . . .
You've done a good job , no matter how long it took .
Bill  :-))

Title: Re: Touchwood bluebird
Post by: raflaunches on March 03, 2018, 04:13:47 pm
Looks brilliant  :-))
She looks every part of her bigger sister.



Bill- it’s now considered to be only a minor contribution to the crash, jet engine engineers believe that Bluebird suffered an engine surge which causes the gas turbine to blow the exhaust gases backwards through the engine out of the intakes. The reverse three point design of the Bluebird hydroplane means that for it to balance on the three points the engine has to be carefully taken up to full power and slowly back again otherwise it either won’t plane or as we see in the crash the momentum and lack of down force from the engine pushes the bows up and cartwheels the boat. As to what caused the surge is unknown but several theories are a fuel blockage starving the engine or a disruption in the fuel flow possibly from the wake and rather empty fuel tanks.
The reason why this is taken seriously now because the footage was studied and slowed down enough to see the Jet efflux on the water at point of lift off- there isn’t any! The spray you see is from the water brake as Campbell tries to stop Bluebird.