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[Subculture]

Been working on a 1/24th scale Delphin hull. Dinky little thing at this scale, but large enough for mini R/C and lipos.

Hull master constructed from a bit of Hazelnut wood, turned up on the lathe, puttied and sanded to within an inch of its life. Parted off and set into a moulding cradle I constructed from 3/16" ply. Moulding in epoxy glass, a departure from polyester resin for me. Mould is four parts, and should hopefully be completed by tomorrow. Got the hatch, dome and propeller masters to build after that.

[Subculture]

All four parts moulded and trimmed. Have one very minor repair to do on one of the halves, then I will add some bolts to keep the parts together (clamps are just temporary) a light sand with 1200 grit, polish with Faraclea compound, then apply release agent, and mould the first hull. So far so good.

[Subculture]

First hull out of the tools. This is a very light lay-up- just one layer of 80 gram cloth, and one of 175 gram cloth, and no gelcoat. Laid up with equatorial separation then the pieces were cut fore and aft, and joined in the mould with 25mm glass tape. The hull parts weigh a gnat's wotsit over 21 grams. I am waiting for some o-rings to arrive, then I will machine a small aluminium bayonet ring to join the two halves together. This will stiffen up the area around the break point considerably, as it's very flexible at the moment.

[Subculture]

I'm sure this will be old news to many on here, but thought I'd make a few points about the radio gear I've assigned for the miniature Delphin. At the top of the picture we have two 5 gram servos, 9 gram servos are a bit cheaper, but would be too big for this model. Down from that we have a reversible brushless ESC from HK, nice little unit and cheap (about a fiver), rated at 10A, that's plenty, as the motor can only deliver 5A max. Next down we have a microgyros leveller, and below that a 4-channel Jeti receiver with pulse processing (cuts down on glitches). To the right of the RC is a 10 gram brushless outrunner. This is rated at about 40 watts, and just above that is a ten pence piece so you can get an idea of scale. Small stuff, but not the smallest equipment available by a long chalk. All this weighs about 40 grams, and a good chunk of that is in the wiring and plugs, so they are going to be trimmed back, and I plan to use copper clad 0.5mm epoxy glass sheet for the tech rack, and photoetch in the signal and power cables . This will tidy things up nicely too.

[essex2visuvesi]

are going to be trimmed back, and I plan to use copper clad 0.5mm epoxy glass sheet for the tech rack, and photoetch in the signal and power cables . This will tidy things up nicely too.

I thought of doing something similar with a mini build I have lined up, but your idea is certaily cooler!
I was going to use adhesive copper tape.  I have used it with great success on model railways for a DCC power bus and also for common earth returns on point motors and lighting.


By the way where did you find one of those receivers in 40Mhz?

[Subculture]

It's a dual 35/40 unit. They're sold as 35mhz units, but work fine with a 40mhz crystal plugged in. Happen to have that one already, if I was buying new, I would get a little 4-channel Corona synthesized unit from Hobbyking, as they're about the same size and weight, but of course no crystal required.

What are you planning on building?

[essex2visuvesi]

I thought the jeti was a bit smaller then the corona
Following the discussion t'other day regarding mini receivers I ordered the Corona 4CH synth from HK as I needed to order some other stuff for other projects (not all of them mine)


I won't taint your thread with my ramblings, so I will start my own shortly
Its a CC lee stingray with dynamic diving

[Subculture]

Plastic kits are a popular source of micro sub conversions. They do tend to be moulded thicker than is optimum- I guess no one considered nuts like us were going to try and make them work! The stingray should be easier than some having a very broad hull. Well worth looking at what Dave Merriman has done over at sub driver site with the little 1/230th skipjack conversion, specifically the method of using magnets to actuate the linkages avoiding the use of shaft seals or bellows.

[essex2visuvesi]

The main issue I had with planning the install was the servos.... even micro servos were too big.  While the hull is as you say very broad, it is also not very high.  The solution for this is micro linear servos.
I am going to start a new log later today as Seawolf from hell has to wait for a new gearbox or further inspiration

[Subculture]

The linear servos should be adequate for micro subs. They do have significantly lower torque than say a 3 or 5 gram rotary servo, but in all fairness, those have more than is required. I'd have thought the Stingray kit was deep enough to accommodate 3-5gram servos though, lay them flat if they're too deep standing upright.

Bear in mind the boat will have to be trimmed low in the water to work well as a dynamic diver.

[Davy1]

Good to see you building.
Thanks for posting.
David

[Subculture]

Okay, worked up the top structure. Fiddly little part to do, kept dropping the perisher until I fixed it to the master.

I've built this up on the original wooden hull master, and will pull a mould from it, and it will be made from epoxy composite like the hull. Dome is not pictured as I haven't vacformed it yet. Still a bit of fettling to do, but I'm 90% there on this piece now. The part has been made up from a piece of hazelnut (hazelnut tree in the garden, so plenty of free timber), G10 epoxy sheet and polyester filler to blend it all in.

[Subculture]

Haven't posted to this in a while.



Haven't had a huge amount of time for building lately, but have managed to machine a small 39mm I/D bayonet ring for the hull. This was turned from billet stock, and is machined to accept a small 1.5mm thick o-ring to minimise the room required for the seal and maximise access.



Easy job on a lathe pretty much hopeless if you haven't. Aluminium is chosen as it's easy to maintain tight tolerance, and also retains reasonable rigidity on a small thickness, which you just wouldn't achieve with plastic.

The ring is shown dry fitted to the hull, and will be bonded in with epoxy once a few other parts are installed. Weight of hull with bayonet ring is 28 grams (1 ounce), which was what I was aiming for. Now working on the contra rotating props.

[Subculture]

Moulded the tool for the bubble dome streamlining.

[unbuiltnautilus]

Fruity

[Subculture]

One of my five a day.

[unbuiltnautilus]

I hope you mean the Orange, cos I dont know where or how.............

[Subculture]

You behave yourself.

[Subculture]

Left the epoxy to fully cure through, and have plonked it in the test tank (bathroom sink) for a leak test, and it's tighter than a Scot on Burns night. Interestingly displacement came out at about 200 grams, about 11% more than calculated (based on the original vessels quoted 2.5 tonne displacement), so not too far out, and always handy when you have a bit more than expected.

[Subculture]

Streamlining canopy moulded. This is one layer of 80g cloth and two layers of 110g cloth. Thin and light but with epoxy resin, bullet proof. Cloth moved slightly from the mould right at the front. I'll fix that in the mix by dobbing on a bit of thickened epoxy and putting it back in the tool to set. I've pencilled in the cut marks.

[Subculture]

Canopy trimmed and test fitted. Next job is to make a master for the clear hemisphere/bubble dome, cut the tail feathers from G10 sheet, and make the props, then it's all go on the insides,

[Subculture]

Haven't updated this in a while. progress has been a bit slow over the past couple of months, but got around to making the dome master. This was turned up using a form tool on the lathe from a couple of bits of scrap wood, then spot putty to fill in a ny nicks and coarse grain, sanded smooth with 500 grit paper, but shouldn't be polished.



Intended to vacform this from some 0.5mm PET, but thought I'd try just pressing it through, which worked, sort of, but sadly had a little bit pinch up at the back of the dome. So I'll think I'll have to do it the proper way.


Close but no cigar!



Mocked up inside the trimmed canopy.