Skipjack 1/72

[greenman407]

Today I scrubbed down the sail with 220 sandpaper, followed by 320. All holes and imperfections feathered out, I then washed it with soap and water. Air dried it and then a nice application of denatured alcohol. Finally I went over it with a tack rag. Then I sprayed her down with Krylon smoke grey. Pictures tomorrow. The lower hull will be Rustoleum Colonial red, a dark red that lightens up nicely when you hit it with flat clear. The upper hull will be gloss black, again tempered with clear flat. Cant forget about the orange buoy hatches. For those Im using "Ace Premium gloss orange, should be good.

[greenman407]

Thats interesting Alec. Ive never built the Moebius model. My Seaview is a bit larger and is supplied by Rick Teskey of Canada. Its as docile as a Kitten to operate. If youve noticed my build on it youll note that its almost ready to go back in the water with some new mods.

[alad61]

Thanks Alec, I didnt know that you were down under. I notice your Avatar is a Seaview. Do you have one?

No worries mate. The avatar is taken from my static build of the Moebius kit. It is fully lighted with LEDs including the flying sub and diving bell. It took a couple of months to assemble all together. The FS1 interior is a pe set from paragrafx and was featured in the 2009 Sci-Fi Fantasy modeller magazine. At that stage Paul hadn't released his pe set for the Seaview so all the limber holes were cut out over a two period and a length of curved card was inserted to keep the light leaks back and represent the pressure hull. I painted it is a little bluer than it should be only because I took some artistic licence to represent a chromatic reflection from being in the briney blue.


I did have another that was converted from the Moebius model with David's fitting kit and sd. However I reckon that boat was cursed by all the gods. The thing I found the most notable with it was that it was a boat that needed all your attention and more to drive especially as a first rc sub. Live and learn as they say.

[greenman407]

Thanks Alec, I didnt know that you were down under. I notice your Avatar is a Seaview. Do you have one?

[alad61]

Mark try some thinners (not a lot)in your fillers to keep your wet edge a little longer or just cut back on the hardner. But I will admit that I don't use the evercoat brand down under, but I'd assume cutting back the catalyst a bit should still work with the evercoat range. I also found with the stuff I use cutting back on the catalyst takes longer to harden but it gives me extra sanding an shaping time when I get heavy handed

[greenman407]

Now thats a good idea. Ill do that.................next time. My only excuse is that this stuff becomes unusable pretty quick, so Im trying to get it on. Ya Know. If I had more time id smooth it out more.

[He Who Shall Not Be Named]

Could you possibly get any sloppier with the putty and filler applications??

Looks like you applied it all with fire-crackers!!!!

Next time first mask off the areas you don't want the putty/filler, then apply the putty/filler with a spatulla with some frig'n care!

You people!!!!!!!

M

[greenman407]

Anybody recognize it? I hit the whole thing with 220 sand paper, ill go back over it with 320 before painting. Evercoat Easysand and some off brand red spot putty.

[greenman407]

Thanks Dave.

[He Who Shall Not Be Named]

Auxiliary and AC suction-discharges. Open 'em up, Mark.

M

[greenman407]

As for the painting of this fellow, Im just now started hitting the seams with filler and giving the whole thing a rub down with sandpaper. What are these round dimples in the hull? Should I drill them out or fill them in? Your comments please.

[greenman407]

You are right Dan. My X-tail uses two servos with an electronic mixer. Therefore, all four surfaces are the rudder and all four surfaces are also the stern planes. There functions blend together. When the Scamper turns the sail lays all the way over past 45 degrees over to a full 90 and beyond. The rudder now becomes a stern plane that set for dive. To stop this, first you would have to know that its actually going down as it doesnt always do that, so visibility is the key. At that point you could swing the rudder over hard to port which would actually be full rise on the stern planes, in this condition but just for a moment.
With the X-tail, you will still have the same problem. I love to see a submarine banking into a turn.

[He Who Shall Not Be Named]

Most X-tails don't have a ram for each control surface. Typically the control linkages are just like those of the cruciform arrangement, only rotated 45-degrees. The two pair of control surfaces, each pair worked by one ram, work collectively to produce pitch and yaw forces. The Newer X-tails do go for individual control of the planes, each control surface pushed by its own ram, affording rolling forces in addition to the yaw and pitch.

The American navy -- in no small part to the conservative engineering practices imposed by Rickover (and today that thinking as dead as the man himself) -- was keen to keep computers out of the engineering and ship-control loop. So, back in the day, the simplified X-tail actuation scheme was front and center for the ALBACORE when it came time to play with that arrangement.

For the record: I'm with Rickover's philosophy here; if the steering-diving system aboard the boat can't be operated remotely with two phone-talkers and a pair of Snipe's pushing servo-control valves back in the engineering spaces, I don't want the steering-diving system on my boat! If a knuckle-dragger can't operate a system by hand, on site, then its a system that can kill the boat!

I wouldn't crew on a post LA class boat to save my ass!

M

[roedj]

Very clever. I understand - must file that idea away for future use.

Thanks for the info.

Dan

Wait a minute - I don't understand. I've studied his Delfin instructions - muddled through the German - and what I see is he has independent control of the two horizontal stabilizers, i.e., one servo for each stabilizer and one servo for the rudder.

As I said before, I would think that a cruciform tailed boat, when laying on its side in a snap roll turn would, in effect, be an "X" tail boat. Wouldn't one want total independent cobtrol of all four control surfaces - one servo per surface?

I have absolutely no lnowledge of how the prototype "X" tail boats work but I would guess that they have total independent control of all four surfaces with a computer keeping track of desired course, depth, and roll and making the appropriate adjustments as needed.

Or am I wildly over thinking this?

Dan

[roedj]

Two levellers mounted at 30 degrees to the keel centreline. You need independent control of the vanes naturally, and mixing can be done in the TX or onboard. Norbert Bruggen does this on his Deepflight Aviator and Delphin models. If you have a look at page 12 of his downloadable build instructions for the Delphin you can see how the levellers are mounted.

http://modelluboot.de/Anleitungen/An...lphin_4_10.pdf

Very clever. I understand - must file that idea away for future use.

Thanks for the info.

Dan