Oberon submarine

[HHParticipant @hh]

Mr Needham,

                          You have deviated so far from the original plan that you must consider yourself completely on your own now.

Good luck, Hal

[ashley needhamParticipant @ashleyneedham69188]

Hal. Thanks for that. I know i have deviated somewhat. I was inspired by your original article as i stated in the beginning, and I am afraid all it takes is an idea and I`m off  !

I have no doubt that my sub will not perform in , er, quite the same manner as yours. But its fun trying. I had a very pleasant 2 hours at the pond on Sunday, even if I didnt actually achieve a lot.   Ashley

[ashley needhamParticipant @ashleyneedham69188]

this is what it looked at in the water, pictures taken by Sue North, a professional photographer who happened to be at the pond side and took a few snaps. Thanks Sue very much. The photos dont tell the whole story, as of course it didnt achieve a controlled dive (this time!!) but it sure tried hard.  Ashley

 

[Bob Abell 2Participant @bobabell2]

In my humble opinion, the model needs to be on the point of sinking and ballasted to be dead level on the water.

 

Have adjustable angle foreplanes and rearplanes………………..and Bob`s yer uncle!

 

Uncle Bob

 

PS……I think having rear planes set at the same angle as the foreplanes………..would descend the sub in a level manner?

 

It`s a doddle!

[60wattParticipant @60watt]

There is an annual submarine event tomorrow at Eaton Park,Norwich

 

If you turned up with Oberon they might let you off so long as you mention,every five minutes, that it was a rush job.

 

[ashley needhamParticipant @ashleyneedham69188]

Bob. I fiddled with the ballast a bit and the angle of the `planes when on the pond the last time.. I have swapped the fronts to the rear and made larger fronts now. I have ALSO cut some strips of lead bent so that i can place them on the rib to affect the trim very easily.

 

One would think that if the sub was balanced and the planes were set at the same angle it would sink on a level, eh? It didnt quite seem to work. HOWEVER. I have just thought that for that to be the case the planes should be the same size front and rear…hmmm..

 

I may take some tin snips along next time to cut the fronts down to be the same size as the rear in case another 2 hrs fiddling doesnt get it right. Thinking about that statement, I may actually do that before setting off. It also don`t help that there is a sticky out sonar dome on the front, and there is a bit of a bow shape just underneath causing who knows what hydrodynamic changes as it gozunda.

 

The other thing is, if it was in a swimming pool, it would possibly work reasonably well, but at the pond, one has wind,waves,ducks, weed and sticks to contend with (see the 4th picture, there is a twig hanging off the front). the white mast has to go as well. Black it is, or at least dark grey.

 

Enough paragraphs, bob??  Ash

 

60.. i have just realised the sub day is tomorrow and I am already out. But thanks for the mention anyway. Dash it all.

 

 

[Bob Abell 2Participant @bobabell2]

Ashley…………….I like the paragraphs!

 

I think the ballast is the key to success…………..is there too much air trapped inside?

 

Bob

[ashley needhamParticipant @ashleyneedham69188]

Bob.

 

There is no air trapped inside, as the top is flat underneath and below the waterline. The sail, sonar dome and rib are solid balsa though and thus fairly buoyant. I can only ballast until just the rib is showing, as any deeper and all there will be floating on top is the dome and sail! I have already filled in the holes I made to vent air, they are only needed on the initial dunking, and the large hand speeds things up in that department anyway.

 

It does go under with a bit of full throttle so i am moderately confident.

 

I was out on the pond 4 times with the Sunderland before it was performing correctly, and thats a floater (although the wings were trying hard to be hydrofoils for the first 2 times).

 

I have a feeling that if I had made a modern teardrop sub there would not be QUITE so much difficulty as the hull is devoid of extra lifting bodies. A hollow flooding sail may have been a good idea as well..Next one perhaps.

 

Ashley

[Andy HustlerParticipant @andyhustler32076]

Ash as memory serves me right the last sub to fly the jolly roger was HMS Conqcuer,sorry about the spelling,when she sunk the belgrano.

Heres a bit of history for you ash the term jolly roger comes from the french La Rouge Jollie a name given to a Welsh pirate Edward Teach who boarded french ships wearing a bright red coat and pieces of fuse wraped i his beard and lit apparently he was a big man and was normally drunk when he boarded the french ships hence the term JOLLY !!!

              I do belive an english royal naval officer sliced his head off

[Len OchiltreeParticipant @lenochiltree67043]

Hi Ashley,

Why not over ballast so that it definately goes down and turn the plane thingys to make it surface, “simple “.

 

Ricky Webb Designed a scratchbuilt sub made out of styrene, it was a ” Free Plan ” in a Mag a few years back.

 

Len.

[ashley needhamParticipant @ashleyneedham69188]

Len, I rather like that, you could have it siting on the bottom to suprise everyone by popping up now and then. However I forsee a drawback, or two…..

 

Ashley

[ashley needhamParticipant @ashleyneedham69188]

I plan to sail again tomorrow, Sunday. using my 7.2v NiMh battery 3700MaHr to bump up engine power and reciever voltage. Have the new diving planes on ; taking tinsnips to cut the front ones down to match the rear, if that appears to be  necessary . And waders…never know.  have cut bent and painted lead strips that sit unobtrusivley on the  rib to effect fine ballast changes. Have also cut a bit of balsa to wind the spare ariel wire lengthways as regards the hull rather than sideways to see if it helps reception ( hah, when underwater!!!)  .trimmed the wire down to match the slightly longer than my normal length wire ariel.

 

Taking the small boy with the Seahawk and one other, to be decided. Actually i have decided but its a secret.

 

Ashley

[ashley needhamParticipant @ashleyneedham69188]

Paqtial success. The main problem is the motor cuts out once diving, and thats because the ESc is playing up I think these Viper units cut out at the slightest excuse, as the rudder is still twiddleable at the bottom of the stream and so the recveiver is still receiving ok.

 

I need A.N Other ESC, any ideas and a PM to me for two plse, 20A ones will do fine.

 

WHEN i put the sub in the recently dredged stream and trotted along holding the transmitter  over the top, it worked fairly well, and dived more or less level and continued (possibly ACTUALLY on the bottom, not sure) on underwater ok.

 

It still looked good and was again watertight. The speed is adequate barring the dreadful stuttering.  ho hum

 

Ashley

[sammykParticipant @sammyk]

hi ashley try powering up your reciever from a dedicated battery ,i had the same problem with a viper controller.since i fitted a 6 volt supply for the reciever the fault has gone allso make sure no water is in contaft with your aerial.regards sammyk

[60wattParticipant @60watt]

Um,try with the aerial inside the watertight box?

Edited By 60watt on 16/08/2009 19:45:35

[ashley needhamParticipant @ashleyneedham69188]

I think a bit longer ariel, and laying out the rest of the receiver wire lengthways (using the whole length of the sealed bit) may do the trick. After all, all those other subs work, dont they ???   Ashley

[ashley needhamParticipant @ashleyneedham69188]

Who`s the daddy !! who`s sub goes up and down (and up again!)  with a bit of throttle. Oh yes.

 

The control under water seems to have been sorted, I think due toi the different ESC, and after much trimming with weights big and small it dives very nicely

 

in fact it dives at about 1/3 throttle so I need to do some work so it will only dive at 2/3 or more, otherwise you cant go anywhere unless its scraping on the bottom.

 

2hrs on the pond, no leaks and battery still lasting. Result.

 

Ashley

 

Next project paleeeeze !

[Bob Abell 2Participant @bobabell2]

Congrats….Ashley!………A few pictures would be nice.

 

Nice paragraphing too!

 

Bob

[SubwarrierParticipant @subwarrier]

I have just found out how to create a photo album so here are the photos that I took today of the Oberon sailing, as I said before very well done – I am impressed.

Steve J (Association of Model Submariners)

Oberon diving

 

Oberon surfacing

Oberon submerged and very stable at periscope depth.

Regards

S

 

[ashley needhamParticipant @ashleyneedham69188]

Cheers Steve, Great pics and an independent witness !

 

The man has an Ohio nuke. We thought it was a torpedo he was wheeling across the car park when he arrived. I think the pond rose an inch when it was lowered it in the water .

 

Ashley (jealous)

[Chris PearceParticipant @chrispearce30862]

Hello Ash,

 

Good to see you and the rest of the mob at the pond, your sub looks great, reminds me the time on HMS Otter…. mmm. I was very impressed had a big smile . So now you have plans boats and subs on the water. well done me old ship mate, look forward to a bigger one.

 

see you soon

 

CP

[ashley needhamParticipant @ashleyneedham69188]

Out again today..and had to REMOVE ballast to get the trim the same as last week??   shows you what difference water temp/density makes.

 

It was sitting very slightly lower than last week and disappeared under the water with embarrassing ease at barely 1/4 throttle.

 

Must try next week with the 7.2v battery for a bit more oomph and the front planes turned up very slightly so it only dive at 1/2 throttle or a bit more.

 

Steve the submariner (minus boat today) said a friend of his has a “K” class sub, surface runner only….now theres an idea!  loads of interest on the top deck what with the swan bow as was  fitted later, and how many subs do you see with a funnel!!

 

he also ran a method of variable ballast past me, viz…you have a double acting windscreen washer motor operated to suck/blow off microswitches switched by max “trim” on full rudder….ie suck on full left/trim, blow on full right/trim. A small bag is connected to one nozzle and the other connected to a periscope tube. Taking in air or was it water?? allows you to trim remotely for surface running or to a level low enough for diving (its not intended to provide a proper static dive system. Clever eh??  perhaps on the next one i build….  a K for instance????

 

Ashley

[ashley needhamParticipant @ashleyneedham69188]

I knew i had it wrong, its called a vented tank!! the tank is vented via the periscope (or whatever) tube, and water is sucked in or out. The venting lets you do this, otherwise it would be sealed and call for stiff construction due to the greater pressures…

 

Ashley

[Bob Abell 2Participant @bobabell2]

This is the write up for Ashley's Oberon submarine for Andy

I had to use all my Sherlock Holmes skills to find it!

Bob

[ashley needhamParticipant @ashleyneedham69188]

Yes it is. The plan was in MMi and NOT MB, so will this be available in myhobbystore or not?

I would have made it a bit bigger in retrospect, to be a bit more impressive in the water, 4 feet would be good, and made the top hollow somehow, or out of pine, not balsa.. The lack of any surface detail is of no import. Ballasted for diving, the top of the top rib is barely breaks the surface.

Ashley

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