Resurgam Submarine

[Len Morris 2Participant @lenmorris2]

Hi Dave,

The early sailing with 'string and tape' was perhaps simply frustration at a long build and the need to get her in the water, warts and all! If you thought she was going to sink, believe me, so did I. Problem was that at that time if she had gone down, I had no means of bring her back up!

The other model of Resurgam you mention is David's F model. We met at Haydock and had a good discussion.

Len

[Amy jane SeptemberParticipant @amyjaneseptember49770]

Hi Len

Sorry, managed to miss this latest instalment from some reason

Really good to see her in the water under way. I fully get the desire to launch a boat before she's finished, some times you just need that little boost to refire the old enthusiasm!

She'll be fully functioning in due course, and we shall all celebrate with you!

[Len Morris 2Participant @lenmorris2]

Hi Amy,

Very perceptive! Forget about the vertical. Just needed to know about the horizontal. Even so, provided much fun for the family on the day.

January is a horrid month. Tax returns, VAT returns, car tax, MOT's etc. Just no time to do anything!

Feb will be different. Watch this space!

Len

[Amy jane SeptemberParticipant @amyjaneseptember49770]

….indeed I shall!

[Len Morris 2Participant @lenmorris2]

Hi Everybody,

Sorry to have been away so long. So far this year has been pell-mell. The blurb of January, new job in February and eldest daughter getting married in June! Not a lot of spare time but we progress- backwards!

Using the CO2 bicycle cylinders to blow the ballast proved uncontrollable at the end of the day. Early results were promising but the high back pressure created by the outlet restriction soon caused the valve spindle seal to fail. No criticism at all about the vales them selves, I was trying to use them outside their design parameters. I took them apart and tried several design modifications but to no avail. Each experiment would result in a £8.00 gas cylinder discharging in some 20 seconds up the spindle. Checked out the industrial offerings and found nothing really appropriate at a sensible cost. I am sure there is some mileage in approach but at the moment don't have the brass to throw at it (weddings!). Failed this time but next time I'll fail better!

Now to some brief sums. At her official water line, Resurgam's reserve buoyancy was simply the volume of her conning tower. Not a lot. For my model it amounts some 165ccs of water. Again not a lot. Experiments showed that a car windscreen washer pump would pump 195ccs into a closed coffee jar before the pressure beat it and the gear driven pump stalled. Enough to do the job but then the other option is pumping air to blow the tanks and the use of pumps from blood pressure monitors. Here,s a picture of my 'lab' set up.

If I'm going to go conventional then I'm not decided yet whether to pump water or air. Both demand a repeatable pressure change inside the hull.

Len

[Amy jane SeptemberParticipant @amyjaneseptember49770]

Hi there Len, good to see you back.

Congrats on the new job and your daughters wedding! Expensive business. ( I have two daughters, still little, but no doubt my turn will come…)

There are no failures, as long as you have learn't something!

It's amazing how much pressure those little wind screen washer pumps will give, we used one to pump the toilet cistern on the launch, would lift a good 7'. (didn't last all that long though…) I'm sure you'll come up with the solution though….

all the best

[Len Morris 2Participant @lenmorris2]

Hi Amy, thanks for that.. Here's a picture of the latest lab test. Decided to pump air and not water. The windscreen washer pump would do the job but marginally, and, when turned off, the ballast tank pressure simply beat it and the the water flowed backwards again.

The little air pump from a blood pressure monitor did the job very well with no flow back. Now need to get the bits installed!

Len

[ashley needhamParticipant @ashleyneedham69188]

Len. looking very good. Blood pressure air pump. Great

Ashley

Edited By ashley needham on 15/03/2015 07:55:33

Edited By ashley needham on 15/03/2015 07:56:10

[ashley needhamParticipant @ashleyneedham69188]

Len. Looking very good. Blood pressure air pump. Great.

Ashley

Edited By ashley needham on 15/03/2015 07:53:27

[Len Morris 2Participant @lenmorris2]

Hi Ashley,

Thanks for that. Just so you know, the air pump was extracted from a wrist mounted blood pressure device bought of ebay for a tenner. The pump is so small that your initial reaction would be 'this is not going to do the job'. It pumps for England and easily managed a 6 inch depression in the test tank in just less than 50 seconds. More importantly there was no backflow over a period of some 24 hours. Game on again!

Len

[Len Morris 2Participant @lenmorris2]

Hi Everybody,

Sorry not to have posted anything for over a year but some major issues arose akin to having to move the house sideways 6 feet! That and all the other usual domestics put hobbies on hold for a while. Can now see some clear blue water and Resurgam is on charge as I write. The outstanding task is to sort the ballast tank system.

Just as an aside, finally managed to get to Laboe mid June to see U995. Outstanding! Here's a pic of me standing by the waggley bits at the stern. Regards, Len

[Len Morris 2Participant @lenmorris2]

Hi Everybody,

I now need to make 2 pinch valves. I couldn't find any ready made for models and the commercial ones available from industry seem very expensive and only go down to 12v operation.Having pondered the matter I'm going to try the following unless anybody has any better ideas. Here's a small jig clamp:-

It measures about 25 mm in any direction. You can see how the lever action is turned into a plunger action to squash a piece of tubing. This is how I envisage the final set up:-

The nice thing is that not much movement is required on the levers to get the 6 mm throw required so it is well within the range of the servo movement. The jig clamp linkage multiplies the servo effort by a small amount, but the really neat thing is that the linkage goes over centre a the end of its throw taking the holding load off the servo.

That's plan A at the moment. No doubt I'll plan Z shortly

Regards, Len

[Len Morris 2Participant @lenmorris2]

Hi Everybody,

Well, we are finally of to the races. After much messing about over the summer with propane cylinders pinch valves etc, I finally saw the light! To begin with a least I'm going to use a snorkel tube (12 inches of 4mm brass). This allows me to blow the tanks, pump the tanks up, know where the boat is in the water, and know how deep she is. All without the use of any pressure cylinders and always with enough air to bring her back up.

The module is built and tested (using the blood pressure monitor pump and the Vauxhall manifold air valve). It works a treat on my test rig of plastic bottles in bowls of water.

Job now is to get everything into the hull. Photos to follow as I'm battling windows10 at the moment!

Regards, Len

[Len Morris 2Participant @lenmorris2]

Hi Everybody,

Here are some pics. Firstly the dive module:-

Servo to throw the two micro switches. One for the air pump (surface hopefully!) and one for the air release valve (dive).

The system works on the bench as the following show of my plastic 'bottle sub' :-

That was the up, and this is the down:-

Now just get it in the hull. Hope to do so by the 10 December and have a trail sail at 10 pm. That's when Resurgam sailed in 1879.

Regards, Len

[Len Morris 2Participant @lenmorris2]

Hi Everybody,

Just an update. The plastic bottle sub worked perfectly during an evenings work but would loose air overnight and sink. The leak back through the dive system could have been lived with in practise but it just annoyed me! Eventually it was traced to back-flow through the air pump. I found a one way valve in the aquatic part of the local pet shop. It worked but the plastic it was made out of was so brittle it just didn't survive the 'Rickover test' ( my hamfistedness)! Decided to make one and her it is:-

It's the sawn off end of a hypodermic needle. The plunger is chucked away and the sealing washer hole punched in the centre for a tight fit in the silicone tubing that is pushed through the hole. This bit of tubing was then blocked at its end by pushing into it a small ball bearing. The tube was then split once with a surgical blade between the seal and the ball stopping short of each. When all was assembled it worked a treat without any sealant at all and the plastic sub floated for England. Having said that, the whole job was sealed with 'fish-tank' silicone just for a warm feeling. Here's the full dive unit squeezed into the hull:-

Having stripped her down to this level I decided it was time to consolidate the 'temporary' lead ballast weights and get them lower in the hull. Although not particularly clear you can see a lead weight stuck to the top of the battery at the bottom of the last picture. Here's a recast consolidated weight to suit the lower hull shape:-

And here's how it fits in the hull.:-

There's a weight either side and they both move with the battery.

Len

[Len Morris 2Participant @lenmorris2]

Hi Everybody,

Just for the record, Resurgam set sail 137 years ago today.

Len

[Paul TParticipant @pault84577]

Len

Congratulations on devising a superb dive unit.

Paul

[Len Morris 2Participant @lenmorris2]

Thanks for that Paul, very kind. However, ever the optimist, I prefer to think of it as a 'surfacing unit'. Never had a problem making them sink!

Len

[Len Morris 2Participant @lenmorris2]

Hi everybody,

Just for the record here's a pic of the consolidated ballast weights in their brass frame:-

And here's how they fit around the battery:-

Simple enough but some simple jobs seem to take a disproportional amount of time. The battery is not actually 'square' so getting a snug fit was a challenge. Also, had to make it twice as the fist design worked perfectly on the bench but the lower battery terminal prevented assembly in the hull! Now sorted and on we go.

Len

[Len Morris 2Participant @lenmorris2]

Hi Everybody,

Here's a couple of pictures of mi dive unit in its final form. Although it could be crammed in the hull it wasn't an easy fit so it was modified to get rid of the big silicone tubing loops and make the aluminium frame fit snugly. :-

And here it is finally installed in the hull and plumbed into the ballast tanks :-

Job now is to tidy the wiring and put her all back together again. Shouldn't be that bad as when I took her apart I wrote myself a 'Haynes manual'. It's amazing how with a long project you (well certainly me) forget how things were done!

On the subject of switching things by R/C, I'm using a standard servo to activate two micro switches from a 7th channel on the TX which is simply a switch (full left, neutral and full right). Belt and braces and works a treat, but, does any body know of a 'black box' solution that simply plugs into the RX and switches 'A on' or 'B on' according to the TX switch? It would save a servo, 2 micro switches, a lot of room and a lot of mechanical messing!

Len.

[Len Morris 2Participant @lenmorris2]

Well, were getting very close now. All the kit's installed and she's buttoned up. Here's a pic:-

The snorkel tube/aerial mast is the bit poking up at the back of the conning tower. The white plastic tube is a temporary fitting to show me the water level in the ballast tanks. Plan now is to get her into the test tank and set all the ballast. Have made a load of lead weights with magnets attached to stick to the hull. The challenge will be getting the dead ballast weight and the ballast tank level adjusted so that minimum air will be needed to take her up and down. Then, I hope to do away with the snorkel tube and let the hull deal with the pressure / volume changes. Adjusted right, the air requirement should be very small as Resurgams freeboard is very small.

Seasons Greetings to all,

Len

[Dave MilbournParticipant @davemilbourn48782]

Belt and braces and works a treat, but, does any body know of a 'black box' solution that simply plugs into the RX and switches 'A on' or 'B on' according to the TX switch? It would save a servo, 2 micro switches, a lot of room and a lot of mechanical messing!

This will do the job, Len. **LINK**

Each relay is operated by one side of the Tx stick and you can program either relay to be latching or toggle by simply moving a small DIL switch on the circuit board. Unit is about 2" x 1.5" x 1" in its case.

Dave M

[Len Morris 2Participant @lenmorris2]

Hi Dave,

Thanks for that. I knew YOU would know! Followed the link, printed out the PDF data sheet – just the job! I've ordered one to keep in my back pocket. I don't intend changing mi boat at the moment as it's some 4 hours of spannering to strip her out but, when the wheel falls off (and it will!) it'll be there in reserve. Excellent guidance. Again, many thanks.

Len

[Dave MilbournParticipant @davemilbourn48782]

Len

You're more than welcome, m'duck……………..that's a lot of what this forum is for.

Dave M

[Len Morris 2Participant @lenmorris2]

Hi Everybody,

Things are are now getting a bit scary. Here she is in the hydrodynamic test facility of darkest Lancashire (mi old fish tank)!

Amazingly she seems to be sat on a relatively even keel and will only need a few trim weights to get her plumb bum.

However, she's well out of the water (about two inches). Job now is to balance the dead weight against the ballast tanks.

Merry Christmas to you all.

Len

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