A Skipjack in Ireland

[The Boattrainman]

David,

It was great to have the banter with you, if you and the missus are ever in this part of the world drop me a message, I'd like to have a beer or two with you............!

Rob

[He Who Shall Not Be Named]

David,

It was great to have the banter with you, if you and the missus are ever in this part of the world drop me a message, I'd like to have a beer or two with you............!

Rob

Thank you sir. And if you're over on this side of the dirt-ball, come on over and we'll stuff you with good Filipino chow.

David

[The Boattrainman]

An update on the Skipjack in operation, here is the shakedown cruise at my local boat pond, which is a bit murky this time of year.




Sits well in the water.




And diving to one meter.........going......




...........going.................




....................gone.................




..........and hovering just off the bottom!




The only mods I made was I installed three decent servos (Savox Digital Micros), and this stopped all glitching and twitching, but the sub required more trim tests in the bath.

Everything is working as it should and so far the WTC is dry as a bone, I'll be heading to deeper water in a few weeks.

The Boattrainman

[He Who Shall Not Be Named]

Congratulations, sir!

David

[trout]

Beautiful, well done!

[The Boattrainman]

Thanks guys.

Putting some of the stuff I learned into the U-Boat 557 build, especially around the WTC which will have to be a semi-custom unit.

I noticed given I had a stretch of open water that even with the 6.1 reduction gear box on the motor, this little sub really moves, had to dial down the values at the Transmitter to calm it down, quite hard to control at speed.

Also, trying to access the 'dive' button (flooding the Piston Tank, which I have set up as proportional channel 5, a rotary switch on top of the Transmitter- top right in photo below) while holding the sub steady with left hand throttle and right hand rudder / dive planes, was tricky especially at even scale speed. I'm thinking of swopping the rudder to the left stick with the throttle, leaving my right hand a bit more free to tweak the 'dive' button.

Good fun all the same!

Rob

[The Boattrainman]

Update on the Skipjack, it's been six months since I've had a chance to take it on the water, due to our poor winter and concentrating on my U577.

So I treated the sub to a spring clean up including......



......replacing the tiny o-rings at the end of the prop shafts......




.......... the threads in the plastic housing that takes the 2mm bolt that holds the two halves of the hull together were gone due to constant in/out, so I put in a 2mm brass rivet nut instead, plus I tidied up small nicks in the paint work.

Off to my 2m deep canal!

Here is the sub with, launch straps and equipment case ready to go.



And diving and manouvering well.




I had changed the receiver settings as per David's recommendations (Pitch controller on the rear planes only), but there was something still way off.

Then it hit me, major noob mistake! I had the Pitch controller the wrong way round, instead of lifting the bow when it nosed downwards, it was pitching it down further.

To fix it, I had to move the Pitch controller........



.......luckily it works either mounted flat or on it's side, screwed to the side of the motor housing, it used to be under the pushrod on the left.

That sorted out the smooth diving and surfacing.




One final adjustment was I moved the throttle and rudder to the left stick, and the dive planes on the tower and the piston tank to the right stick.......



.......and the rear dive planes via the Pitch controller to channel 6, the round knob on the top right, as it's not sprung I can set the rear dive planes to perfectly level and never touch it again. I'm sure this set up breaks some time worn code, but I just couldn't get used to the dive functions split between left and right stick.










So some final thoughts.

I had to dial the throttle function way down, this sucker really moves, and faster under water then on the surface for a given setting. Using the End Point Adjustment (EPA) on the Trans, they are now set to 50% for forward and 45% for reverse.

The piston tank is very busy, it really sets the depth and the Pitch controller keeps it level, the planes on the conning tower are only used for fine adjustment.

There is a 'sweet' spot, where the subs scopes are just below the water, any more ballast and it heads for the bottom, but once achieved, and the speed is kept under control, the tower planes come in to play.

The single piston tank causes no problems, the sub dives clean and level, even at a stand still, blowing the full tank when at 2m depth sends sub screaming to the surface nose first, exciting but scary.

It doesn't matter a jot where the extended receiver wire is positioned outside the WTC, I have it laid loosely along the side of the WTC and I got 2m of depth and 120m of distance (any more and I couldn't see the sub even on the surface). I had a hole in the base of the conning tower to push the wire up high, but it is not needed.

I got 50 minutes of run time from the 5000mah Lipo, no idea how long it will last, a shower of rain ended the session.

The endless sessions in the test tank (bath), messing about with ballast bars to get the sub perfectly level just under the surface have paid off.

The Boattrainman

[trout]

Outstanding Captain!