Stingray Build

[alad61]

the ratemaster which I will attempt to make spin as well. I have an idea how to do that, perhaps a ring spur gear on a small pinion. but thats for later.

Would using partially spiraled vanes on the inside of the ratemaster get it to spin when its got water being pumped through??

I am so loving this thread!!!

[He Who Shall Not Be Named]

What kind of holding fixture or jig did you employ to hold the smaller tubes around the bigger one? Great stuff!

David

[RCnut]

Today I added the end bit on the Ratemaster and the front ring was added to as well. All I have to do now is make sure its 100% perfect and then wrap it in cotton wool, lol.

[RCnut]

What kind of holding fixture or jig did you employ to hold the smaller tubes around the bigger one? Great stuff!

David

I drew a circle to the inner and outer diameter and then drew lines across at equal intervals (with rulers and such) then took one of the tubes and marked the curve in each segment, this was then dremalled out and the complete ring template glued to the larger tube then the smaller tubes were glued into place and the gaps filled. Its by no means a perfect way of doing it but its turned out very symetrical and when spun round it does not wobble, which was my main concern.

[RCnut]

Would using partially spiraled vanes on the inside of the ratemaster get it to spin when its got water being pumped through??

I am so loving this thread!!!

If the jet outlet was as large as the inner diameter of the ratemaster it might work but its not so I doubt it, In any case I want to make the ratemaster work independently of the jet and possibly use it as it was intended, a contra rotating eddy damper.

[RCnut]

Couldnt resist, taped all the bits to see what it looked like. Not bad for three weeks work. But then if its a subject you really like it goes like that.:biggrin:

[He Who Shall Not Be Named]

OK! ... who do I have to kill to get a set of parts?

David

[RCnut]

Lol no one, We can do a barter type thing if you want, I'm wondering about the WTC, I think this model would suit one.

[He Who Shall Not Be Named]

I'm game. Let me know the maximum lengths your hull will take for a 2.5", 3", and 3.5" outside diameter cylinder.

As with most SF submarines, the STINGRAY had an impossibly high freeboard in surface trim -- but one we can get close if you keep the above waterline portions as light as possible, and we put the SubDriver down as low as possible.

Assuming you are close to what we see in the Phil Rae plans, I can use that as reference. What's the overall length of your STINGRAY? Knowing that I'll copy that drawing to that size, then skull out the SubDriver length-diameter-ballast tank size. I assume your glass lay-up wall thickness will average out to 3/32"? Will the cockpit be free-flooding or dry? Let me know what PJ you'll be using so I can work out motor and gear-train to match.

That grinding noise you hear in back-ground is likely Mike grinding his teeth.

David

[RCnut]

Ok I'll have a look in the morning and take some measurments and try to estimate the inner hull dimensions etc. BTW which Mike?

[Subculture]

Dave is referring to Mike Caswell, his guvnor!

My money will be on a 3" cylinder about 16-17" long.

Regarding getting the surfaced waterline. How about putting a valve in the top of the hull, and using a snort pump to blow air into the boats free flood cavity. That would give you an enormous amount of bouyancy to play with. A smaller tank could be used to trim for diving.

I don't think getting the ratemaster to spin will be easy.

[RCnut]

Right, I have taken som measurments (really rough ones) And by my reckoning a 3.5 inch tube would have to be 12-13 inches long to sit in there(And that would poke out of the top were the cabin sits) At 2.5 inches you could fit a 14 inch one. This is taking into consideration the Jet drive which has to go in there, And it will only go so far into the front between the missile tubes. Also the WTC would have to accomodate the shaft angle of said jet drive. Its got to be straight. Typical me again folks. I think WTC will have to wait till the things in Kit parts in front of me with a healthy supply of Pipes lol.

[Subculture]

If you're building it to submerge a water jet is pointless, you just want a shrouded prop. The ratemaster makes a very suitable shroud, if this has a two bladed prop with say three fixed stators in front (pre-swirl) that should counter the torque nicely. This will make things more compact.

A chap down in Portsmouth has a 36" converted kit. That has a hydroplane and rudder made from clear plastic all housed inside the ratemaster, works really well, and looks stock when you see it running in the water.

[RCnut]

Is it that one on you tube thats in the swimming pool?

[He Who Shall Not Be Named]

To expand on Andy's excellent suggestion: we de-water the hull using the propulsion pump-jet. This done by rigging the PJ with a special adapter section between its normal 'from sea' suction and rotor. Forming a Y selector valve. A slide-valve (between suction and rotor) girdles the inside of the pump-jet Y adapter. One leg of the adapter leads to a suction within the hull. The other leg is the 'from sea' PJ suction.

Slide-valve closed the pump-jet gets water exclusively from the 'from sea' intake on the bottom of the hull, like your SKY-DIVER. To dive, a vent valve (in the bridge floor) opens and water floods in through the pump-jet 'from sea' opening (rotor must be stopped), the hull floods and the boat assumes submerged trim; shut the slide-valve and you're on your way. To surface, the slide valve is open, the boat is broached to put the bridge into the air, the vent valve is opened and the PJ run, sucking water out of the hull, (you still have thrust, but reduced a bit) and the boat assumes surfaced trim at which point the slide-valve is shut and you're on your way.

A 14" long, 2.5" diameter SD is doable! After dry space contains the motor (which one?), ESC, control surface servos, receiver, V-tail mixer, ADF, and Lipo-Guard. Center space is the 'safety-tank' used only if the boat can't broach the bridge above the surface -- it'll use the SAS method. The forward dry space is for the battery and mission-switch.

How's all that sound, guy's?

David