Seawolf Afloat
 

Well at last the boat's finished apart from the paint job. I've got the ballasting done so I'm raring to go now. The only problem I've had was getting a good seal where the tray goes in at the rear. The gasket provided just wouldn't hold the water out on its own - I reckon it's a bit hard and overstretched when it's in place. I've managed to stop the leak by first putting a thin rubber band on the circle followed by the proper gasket, then another thin rubber band. The rubber bands seem to tuck themselves under the edges of the proper gasket and with being very soft they seal things up a bit. Wonder if anyone else has had a problem getting a good seal. Well thanks anyway to all those who have helped me with my first sub over the last couple of months - maybe see you under the water somewhere......

Ian

RE: Seawolf Afloat
 

WE NEED PICS!!!:D

RE: Seawolf Afloat
 

Hi Sweetrevenge, Thanks for your interest - unfortunately I had a problem the following day - I tried the sub in the test tank and found that I still had an air leak - after a couple of tries with various combinations of rubber bands I eventually managed to strip the thread at the front of the tray. I went to our local hardware shop and bought some larger size bolts and wingnuts. I've replaced the thin threaded bolt now and started glueing things back together. I remember reading on one of the forums some time ago that someone with a Seawolf had done the same - it just means that I'll have to take the top nose cone off after a days sailing to get the battery out - but that's not too long a job. I've since been told by some folk on one of the other forums that they seal the rear gasket with Vaseline or similar to keep the thing watertight, so probably tomorrow I'll be trying the test tank again. In the meantime here's a piccy from yesterday.


Ian

RE: Seawolf Afloat
 

Can you provide a better res picture? Nice Work.

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Hi I had built and sailed Robbe Seawolf apprx 3 years ago All the probs you are encountering I encountered as well. be patient Well done on yours it looks great.

RE: Seawolf Afloat
 

Hi Periscope

I'm doing a robbe U47 and had trouble in the same way with the seal. I found that a silicone rubber preserving jar gasket that's the same size, seals it very well with little pressure on the fasteners. I also customised my tank fastening system with bolts-bracket and wing nuts! It seems to be a common practice. We're not alone.
Jason[&o]

RE: Seawolf Afloat
 

Thanks everyone for the comments - it's nice to hear that my problems are not just individual to me. Thanks for the tip about the jar seal Jason..... I have managed OK for now by putting a coat of Vaseline onto the sealing ring before tightening up - I've heard of other people converting the WTC front section tray to a larger thread and using a wingnut - maybe version three will have a stronger thread system - but I don't mind doing my own mods if they work out OK in the end. Here are a couple of pictures of the model painted - these have been taken with a proper camera, the early one on here was just done with a webcam - hope these come out on the web OK. Swt rvge.


regards to all.


Ian

RE: Seawolf Afloat
 

looks fantastic.

I just replaces my siezed up prop shaft with a new one.

Its strange, but I dont have any problems with my seal....not a drop of water in mine.

RE: Seawolf Afloat
 

Hi Sonnich -Glad you've got your prop shaft sorted out now. I bet it was a bit fiddly replacing it. (but that's part of the fun of modelling;)) Glad you're able to keep the water out with just your seal - I think it probably depends on how good the machining is when the WTC is cut at the Robbe factory - I reckon you have been very lucky 'cos quite a few people seem to have the seal problem (or maybe you have a better rubber seal than some)- anyway a smear of vaseline soon puts it right - so if you have to replace your seal at anytime and it doesn't fit as well there's your answer. Anyway, glad you're on the water again Sonnich, or under it.

Ian


PS. Come to think of it - it's probably your building skills in keeping all the construction dead straight and level that's kept the water out....[sm=drowning.gif] Cheers...Ian

RE: Seawolf Afloat
 

Ice on the ponds have melted, and I have finaly been out with the wolfe.
Im in the process of trimming, and testing how much ballast to install.


Where do you have the waterline on youts ?


Today i had the waterline almost flush with the deck. But my sub wants to dive when running fast on the surface. I have to almost hold "full up" for it not to dive.
I have removed some ballest, and see what happenes now....maybe it wont even go under ;)


Testing in a cardboard box......no luxury of having a bath tub here :)

RE: Seawolf Afloat
 

Hi Sonnich - Your boat's looking good. My hull is just about on the waterline and mine too wants to dive if I go at full speed but I stop it diving by using full surface rear plane. I think this is pretty normal 'cos the subs is designed to dive as the speed picks up. Usually I just cruise on the surface at half speed and just flip the rear plane now and then to stop it diving. I did some trials today and found that if I sailed the boat straight and level then increased the speed to nearly full, the boat started to dive gradually and very realistically but the stern tried to lift slightly out of the water so I just flip the rear plane to the surface position which makes the stern initially duck under the water then I just keep the sub fairly level under water with the rear plane - but I have reset the front dive planes so that when the sub goes under the mast only tilts back to make the front planes level to stop it dashing to the surface too soon. The only problem I had was when I picked up a fair bit of weed on the prop, the prop slowed down a fraction and stopped me being able to push the stern under to dive - so I have added another two musket balls to the rear compartment to dip the stern down a bit. If the stern then runs too low on the surface I'll keep it up by using the rear planes - but until I can get back to the pond again I'm not sure what will happen. I think that unlike a surface craft the sub needs 'driving' all the time and the controls need adjusting all the time it's in the water - I reckon it's a bit like helicopter flying - there's no relaxing because adjustments have to be constantly made. I'm really enjoying my sub, especially as I get better with practice. Hope you get as much fun out of yours - I'm sure you will. I don't think I shall bother turning it into a static diver - I might later on build a nice looking world War two type of sub with railings and deck guns etc - but the ones I know about seem to be a bit expensive but I'll keep looking around. By the way I've had my bath taken out at home and replaced with a large shower compartment - so i'm in the same boat as you now Sonnich - I'll have to find some other way of doing my ballasting at home..... Good luck with your trials mate.


Ian

RE: Seawolf Afloat
 

Thanks

it is quite fun to sail around with ;)
The pond im sailing in is so murky, that I can hardle see it as soon as the conning tower has gone under. Luckily, the long antenna can be uses as both a atitude and depth meter ;)
I can trim mine so it glides along at the same depth and just let go of the controls.
2 times, i struck something on the bottom, and got stuck for a minute or so.....the nose just dug in, and the prop was sticking out of the water! Got a little worried ;)

Are you using the stock 6V battery ?

I had been sailing abot 15 minutes, and my ESC bagan to cut the motor because of low voltage. But when recharging, it had only used half of the battery.


I have now installed 2 3300niMh 6 cel packs in parallel, so I have 7,2V 6600mah........should last longer :-)

Not a single drop of water in it.
I have also slid some fuel tubing over the instalation bolt, to keep water from seeping in the front.

RE: Seawolf Afloat
 

Hi Sonnich - Well it sounds as if your pond is similar to mine - a bit murky, I lose sight of the sub as soon as it goes under water and I also use the aerial and mast to sight with. When the sun shines again it's possible to see into our pond to a depth of around a metre - that's as deep as the pond is. You seem to have got yours trimmed very well if you can stay level under water with hands off - I'm hoping mine improves with the extra stern weight. I never did get around to buying the stock battery - I made a wire cradle from a coathanger and I just use a 'Titan' Sealed lead-Acid battery of 6v 4Ah. My ESC is a Hitec EZX-R - I think they were designed for cars - the ESC will not switch on unless the throttle stick on th TX is in neutral as a safetly feature. I practiced in the pond yesterday for around an hour with no apparent loss of power - apart from, as I said in my last post, a collection of weed around the prop which slowed things down a bit. At one point I did an accidental nose dive and ploughed through a thick weed patch on the bottom - when the sub came up it had weed tangled on the front planes and it was draped over the nose cone and also the prop was heavily tangled - but at least the sub came up thank goodness - saved me paddling. I think you're very lucky getting a fully watertight seal - but at least a smear of Vaseline grease on the gasket keeps my water out. If you remember I stripped the thread on my front fastening bolt and I replaced it with a bigger sized one and use a wing nut to tighten up with - it just means undoing the top fron nose cone to do this, but I only have to do it once when getting the boat ready and once when I come home and want the battery out. I thought about going to the pond again today but the temperature outside is only 6 and there's a really cold wind blowing so I'll wait for a better day. I just wonder how you have set your front dive planes - mine are just tilted slightly forward then only go level when the mast tilts back - If my stern is a bit low I might try angling the front planes a bit lower on my next test.

RE: Seawolf Afloat
 

hehe...chicken ;)

It was 6 degress here today, and blowing 10 m/s
But I had to try it out again today. Well, removing the balast is rubish. It is much harder to make it dive, and the prop cavitates easier when going under.
I have the front planes level. I tried to varie the angle in several positions, but level is best. least drag, and its easier to trim for level sailing under water.

Im going to add more lead today again.

The poor thing struck the bottom several times, lifting out the prop from the water ;)
Here are some pics:

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A few more.

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Last:

RE: Seawolf Afloat
 

Thanks for the pictures Sonnich - Your pond seems to be bigger than ours - looks nice too.
If you have your front planes level do you just dive with the rear planes? I've put some pictures on so you can see how mine sits in the water - providing that I've got a good speed (no weed fast) I manage a dive OK - but if the boat isn't going too fast the rear dive plane makes the boat cavitate - perhaps I need a bit more weight.

RE: Seawolf Afloat
 

yes, it wil dive fine with the forward planes at neutral, and oly using the rear planes.

ill try again tomorrow with more ballast. I dont think the cavitation can be avoided entirly though.

RE: Seawolf Afloat
 

Well.....it went great.......then realy bad ;)

The extra weight in the sub is perfect now. It dives very very well now, and hardly cavitates anymore.


But....the pond I am sailing in is a deathtrap;)

I submerged, for a few seconds completely, and expected it to come up a few meters further down the pond. But then it surfaced at a 90 degree angle than the course i had set out the first place. bummer i thought, and i headed in to the shore towards me.....but the i realized that i had no rudder control. Only throttle. A few minutes later, i managed to get it back.

It must have hit a large rock on the bottom. The nose has fractured, and the lower aft fin had been completly sheered off, only hold on my the servo pushrod.
Its all easily repairable, but annoying anyway :)

Yesterday, i also striped out the aluminium hull retainer threads......that was a bummer too. But I managed to make a new one using 4 nuts,a hex bolt, brass tube, and a an alu insert all glued together with stabilit. Works great.

RE: Seawolf Afloat
 

That is some damage you have there. Dang dude...


-Cobalt saber

RE: Seawolf Afloat
 

Gosh - every submariners nightmare - sorry to hear about that Sonnich. As you say it's all repairable but it's really annoying. Our pond was freshly dug out for the club to use, so as far as we know there's nothing in it unless some clown pushes a shopping trolley into it - even then I think it would be noticable - the ponds not very deep. The front connection threads are a bit flimsy aren't they - thats a good idea of yours, I'll try to get a piece of brass tubing to fit inside the sleeve on mine and then fix a nut onto the end to save me undoing the nose cone each time.

If this weather stays reasonable my plan is to go to the pond tomorrow and do some more dive tests - I've got plenty of musket balls to weight it down - then I'll probably try having the front planes level like yours. Some cavitation is OK as long as the sub eventually goes down but the last time mine lost power due to the weed around the prop the sub just sat there with the nose under the water and the stern end just blowing bubbles as I went around the pond. Anyway some extra weight will hopefully fix it. Hope you get yours repaired soon - I think the Seawolf is great fun - easy to build and easy to operate.

RE: Seawolf Afloat
 

As good as new!

I must say, that the Pattex Stabilit Express glue is great for gluing plastic.
I have never used it before, because I thought it was a little expensive.
But it is worth every penny. Fast drying, extremly strong, and easy to sand. Could not get any better.

RE: Seawolf Afloat
 

Well done Mate - glad to see you got it sorted. - by the way, ....how did you know I like Budweiser :D - Nice Heli too.

Ian

RE: Seawolf Afloat
 

Hi Sonnich - if you're still reading this thread you might be able to help me. I think I need a bit more weight to get a better dive without having to flip the rear dive plane into the surface position to force the stern under water. I think you said that you had your decks nearly underwater - do you have a picture of your sub just sat in the water so that I can get an idea how low I should have mine? I'm also going to try having the front planes set at level like you,
but I'm still waiting for our pond to be cleared of weed - it was so bad today that surface craft couldn't cope with it. Thanks mate.

Ian

RE: Seawolf Afloat
 

Hi Ian.

Sorry, no pics of the new setup.
I just accidently bought this second hand minesweeper, which is out of prodiction that I have been looking for for a few years. :D
I have too amny projects! :)

But the waterline is exactly at the deck leve on the seawolf l. Even a few millimetes make a big difference aparently.
it rises noticably slower in water, when you push it down with your hand.