Stingray Build

[RCnut]

Bernie,

You know I can't resist doing an interior. You may know, but that XL-5 model I built for David Hersh (Starlog staffer) nearly forty-years ago featured not only a detailed JR. cockpit, but a fully decked out 'secondary control station' atop the main craft (I believe the model is now in the Greg Jein collection). I've gotta convert those slides to digital files one of these days.

I'll give the STINGRAY interior the same treatment I did for the 1/96 SEAVIEW. Like, below:

[ATTACH=CONFIG]14720[/ATTACH][ATTACH=CONFIG]14721[/ATTACH][ATTACH=CONFIG]14722[/ATTACH][ATTACH=CONFIG]14723[/ATTACH][ATTACH=CONFIG]14724[/ATTACH][ATTACH=CONFIG]14725[/ATTACH]


No problem making it free flooding.

David

NICE!!!! This is the stuff I have seen you do in the past, cant wait to see what you do with Stingray.

[He Who Shall Not Be Named]

Bernie,

You know I can't resist doing an interior. You may know, but that XL-5 model I built for David Hersh (Starlog staffer) nearly forty-years ago featured not only a detailed JR. cockpit, but a fully decked out 'secondary control station' atop the main craft (I believe the model is now in the Greg Jein collection). I've gotta convert those slides to digital files one of these days.

I'll give the STINGRAY interior the same treatment I did for the 1/96 SEAVIEW. Like, below:




No problem making it free flooding.

David

[RCnut]

Just a quicky, The Ratemaster as discribed is a Contra Rotating Anti Torque Eddy Dampner, OK that was a bit anoraky but It may just work as a trim function. As it stands its a side to side paddle. So, It could affect the forward direction one way or another depending on which way its spinning. Of course it may not do much at a low RPM but it will be interesting to find out. If it works lol.

[Captain Scifi]

Hi Guys,
The target speed for the rotor is about 65 - 75 rpm, interestingly, the rotor does not provide forward momentum at all and holds a steady rate of spin whatever Stingray's forward knot speed maybe, even if that is zero. I have been studying the cabin layout and should be able to produce a CAD drawing soon (walls and floor plan). This is for the static modeller really as I am not sure what would happen if left to free flood. I know David is the expert here so was hoping for a little guidance?

The Cabin vac forms are done and successfully test fitted one lamination of 1mm PetG with a 2 mm lamination of styrene directly over to produce the outer skin. Windows will be cut in the styrene layer and a perfect fit maintained. Mamas, you are a clever guy....

[RCnut]

Cheers Subculture, I would appreciate any help (Links etc) you can give.

[Subculture]

You can Du-B bearings. these are bornze backed bearings with PTFE. They can run dry but they're designed to run best in water, as it helps keep the bearing cool, no other lubrication required. Norbert Bruggen stocks them, you can also get them on fleabay.

I can give you a link for some exquisite little motors with planetary gearboxes, available on ebay, they do about 170RPM on 3 volts. Any good?

[RCnut]

The RM housing rings as supplied will need to be glued together with solvent weld. Three Blind nuts will need to be fixed to the back so the modular part, whatever its function can be inserted using three screws. I heated up the blind nuts and pulled them into place and reinforcing with Superglue. As you can see quite a neat little affair. Next the jet installation.

[RCnut]

So called 'sealed' bearings, in water, aren't!

The seal is a keeper of factory injected grease, it is not a water barrier -- the sealing element actually works against us. Here's how:

The bearing spends most of its life out of the water, enjoying an atmosphere that has a significant fraction of oxygen in it. Yes, yes, they say, stainless steel, but there's always a whiff of iron in there (intentional or not). Your bearing spends a very small fraction of its life in fresh water, just long enough for the water to get into the seal, soaking the balls/rollers and races. And when you pull the thing out of the water, the seal does a great job holding the water against all the metal parts, where the water starts working with its good buddy, Oxygen, to eat the bearing elements alive! Put unlike metals nearby and Mr. Ion joins the pig-pile!

Go with oil impregnated brass bushings. We're not launching the frig'n Space Shuttle here!

David

Thought so and will do.

[He Who Shall Not Be Named]

David

Something for you to answer, How good are sealed bearings for keeping out water? The spin gizmo has 3 sets of 2 bearings holding the mandrels. I was thinking of using brass bushings instead. The RM does not need a high RPM so I would have thought this would be an acceptable option......?

So called 'sealed' bearings, in water, aren't!

The seal is a keeper of factory injected grease, it is not a water barrier -- the sealing element actually works against us. Here's how:

The bearing spends most of its life out of the water, enjoying an atmosphere that has a significant fraction of oxygen in it. Yes, yes, they say, stainless steel, but there's always a whiff of iron in there (intentional or not). Your bearing spends a very small fraction of its life in fresh water, just long enough for the water to get into the seal, soaking the balls/rollers and races. And when you pull the thing out of the water, the seal does a great job holding the water against all the metal parts, where the water starts working with its good buddy, Oxygen, to eat the bearing elements alive! Put unlike metals nearby and Mr. Ion joins the pig-pile!

Go with oil impregnated brass bushings. We're not launching the frig'n Space Shuttle here!

David

[RCnut]

David

Something for you to answer, How good are sealed bearings for keeping out water? The spin gizmo has 3 sets of 2 bearings holding the mandrels. I was thinking of using brass bushings instead. The RM does not need a high RPM so I would have thought this would be an acceptable option......?

[He Who Shall Not Be Named]

Flattery will get you everywhere, Mamas!

Yeah, we yank the pot out of a 'standard' sized servo, put a heat sink on it's 'amplifier', wire it in parallel with the main motor ESC and we're in business if I can raft the servo above the main motor. If that turns too quick/not enough torque we simply use one of those old, nasty Astro-Flight motor-planetary gear units (the stacked gears permit a zillion-to-one ratio if we need it) and a little MTronik's ESC to drive it. We'll make this beast work!

Get me that kit, I'll size the largest SD diameter that will fit and perform my magic tricks.

I'm stoked! Break out the Bongo-Drums!

David

[RCnut]

Hi Guys!

Back from the seaside and ready to start fettling, lol. David, I have been thinking along the same lines for the ratemaster motor and to that end got hold of a Graupner item but the ratio is still to high. It needs a very low rpm and high torque to spin the Rt at a reasonable RPM. I did consider a High power disabled servo but its configuration would make fitting awkward. I think you need to have the Stingray asap to be able to solve these and many other questions Oh wizard of all things Submarine type stuff.

[Captain Scifi]

Bernie,

I'll be going with the PJ Mamas recommends -- the only modification in that department will be a customized gimbaled nozzle as the commercial one is only able to swing in the yaw axis -- we need one that will throw water about the pitch and yaw axis.

Hi David, that's sensible, he is an expert fettler when it comes to making it go/stop/left/right/up/down and backwards.

I will indeed develop a specialized WTC/SubDriver for this particular model. No ballast tank and it will be outfitted with the ESC and motor recommended by Mamas. Once I get mine going I send one to Mamas in compensation for the STINGRAY kit, then, with the design frozen I'll produce them commercially.

Ok, I'll wait to see what develops and jump in when the hard work is done.... :biggrin:

Back to the pump-jet: I will be making an 'add-on' device that taps into the suction side of the PJ -- this to de-water the models hull using the PJ as the 'pump'. More on that here and in Cabal Reports as work gets underway.

Oh ... a thought for Mamas:


I'm thinking a separate, well geared, smaller motor to work the RateMaster. It has its own ESC which is controlled in parallel with the input to the PJ's ESC. So, two motor outputs from the SD's motor-bulkhead: one from the brushless kick-ass motor to the PJ, and a second output driving your three-wheel RateMaster rotating gizmo. Whacha think, oh Wizard of all things Anderson?

David

[He Who Shall Not Be Named]

A Stingray capable one please, as I can't find your listing for them I can't answer this specifically. I am trusting you will make a WTC or a modified version thereof and a custom thruster unit to match. It's this "best fit" recommendation I am really after as a place to start.

Bernie,

I'll be going with the PJ Mamas recommends -- the only modification in that department will be a customized gimbaled nozzle as the commercial one is only able to swing in the yaw axis -- we need one that will throw water about the pitch and yaw axis.

I will indeed develop a specialized WTC/SubDriver for this particular model. No ballast tank and it will be outfitted with the ESC and motor recommended by Mamas. Once I get mine going I send one to Mamas in compensation for the STINGRAY kit, then, with the design frozen I'll produce them commercially.

Back to the pump-jet: I will be making an 'add-on' device that taps into the suction side of the PJ -- this to de-water the models hull using the PJ as the 'pump'. More on that here and in Cabal Reports as work gets underway.

Oh ... a thought for Mamas:


I'm thinking a separate, well geared, smaller motor to work the RateMaster. It has its own ESC which is controlled in parallel with the input to the PJ's ESC. So, two motor outputs from the SD's motor-bulkhead: one from the brushless kick-ass motor to the PJ, and a second output driving your three-wheel RateMaster rotating gizmo. Whacha think, oh Wizard of all things Anderson?

David

[Captain Scifi]

A Stingray capable one please, as I can't find your listing for them I can't answer this specifically. I am trusting you will make a WTC or a modified version thereof and a custom thruster unit to match. It's this "best fit" recommendation I am really after as a place to start.