Jimmy Carter - 1/144

[HardRock]

That rotor is a screaming piece of ****! Hardly any pitch to it. (Rule of thumb for marine propeller/rotor: pitch=diameter and developed blade area, less the hub, is between 60-70% of the disc). And there is no useful stator in there, just a four point shroud support. That makes this propulsor a dumb-ass Kort nozzle.

Don't equate pretty with useful. That propulsor is useless!

I get plenty of thrust from my PJ as applied to the 1/144 Trumpeter SEAWOLF. It's a frig'n rocket!

Why don't I just send you a proper pump-jet assembly for your long suffering 1/144 USS Peanut?

Yeah, the longer moment arm turns this piglet into a full-blown pig in a turn. Double or treble the area of the lower rudder.





David

You know, I have always thought that you would have made a great diplomat. Subtley, persuasion, empathetic argument etc., etc. Its all there (just waiting to emerge)!

[DMTNT]

That rotor is a screaming piece of ****! Hardly any pitch to it. (Rule of thumb for marine propeller/rotor: pitch=diameter and developed blade area, less the hub, is between 60-70% of the disc). And there is no useful stator in there, just a four point shroud support. That makes this propulsor a dumb-ass Kort nozzle.

Don't equate pretty with useful. That propulsor is useless!

I get plenty of thrust from my PJ as applied to the 1/144 Trumpeter SEAWOLF. It's a frig'n rocket!

Why don't I just send you a proper pump-jet assembly for your long suffering 1/144 USS Peanut?

Yeah, the longer moment arm turns this piglet into a full-blown pig in a turn. Double or treble the area of the lower rudder.





David

That would be fantastic if you were able to. Can you send me a PM and we can get it worked out? I believe it says your inbox is full.

Thank you!

[He Who Shall Not Be Named]

Only teasing! More like damned impressive. How's that?

While we're at it, I have a question for the headmaster... Do you recall when you fabricated the impeller for the 1/144 Seawolf what the overall diameter was? I finally hooked up my setup and was beyond pleased to see it works, but I'm curious how my prop compares to one that's proven. Mine was designed by a fellow from Spain on Shapeways who intended it for RC use, but to my knowledge has never tested it. Attached are a few 3D photos. It measures 35mm and is cast in bronze. I've done some hunting for 35mm props / impellers, and while there are a couple out there, the options aren't great. I'm size limited due to the dimensions of the impeller shroud, which is also a 3D printed component. I could use the kit supplied impeller shroud and a slightly bigger prop, but it would require some redesign of how it attaches to the stern on my boat.

A few observations:
* Whatever poor handling characteristics the stock Trumpeter Seawolf exhibits are made even worse when you stretch her into Jimmy Carter.
* All testing thus far has been with an un-shrouded prop, for what that's worth. I intend to attach it with some RTV sealant so it can be removable if need be in the future.
* My prop, as is, with the stock 2" SD motor does power the boat forward. Not achingly slow, but it's not also not a rocket. I suspect if it were faster, the rudders and planes might exhibit a bit more control authority. I also realize it's nearly 4ft long, and those little rudders can only do so much at their scale size.

That rotor is a screaming piece of ****! Hardly any pitch to it. (Rule of thumb for marine propeller/rotor: pitch=diameter and developed blade area, less the hub, is between 60-70% of the disc). And there is no useful stator in there, just a four point shroud support. That makes this propulsor a dumb-ass Kort nozzle.

Don't equate pretty with useful. That propulsor is useless!

I get plenty of thrust from my PJ as applied to the 1/144 Trumpeter SEAWOLF. It's a frig'n rocket!

Why don't I just send you a proper pump-jet assembly for your long suffering 1/144 USS Peanut?

Yeah, the longer moment arm turns this piglet into a full-blown pig in a turn. Double or treble the area of the lower rudder.





David

[DMTNT]

adorable?......

Only teasing! More like damned impressive. How's that?

While we're at it, I have a question for the headmaster... Do you recall when you fabricated the impeller for the 1/144 Seawolf what the overall diameter was? I finally hooked up my setup and was beyond pleased to see it works, but I'm curious how my prop compares to one that's proven. Mine was designed by a fellow from Spain on Shapeways who intended it for RC use, but to my knowledge has never tested it. Attached are a few 3D photos. It measures 35mm and is cast in bronze. I've done some hunting for 35mm props / impellers, and while there are a couple out there, the options aren't great. I'm size limited due to the dimensions of the impeller shroud, which is also a 3D printed component. I could use the kit supplied impeller shroud and a slightly bigger prop, but it would require some redesign of how it attaches to the stern on my boat.

A few observations:
* Whatever poor handling characteristics the stock Trumpeter Seawolf exhibits are made even worse when you stretch her into Jimmy Carter.
* All testing thus far has been with an un-shrouded prop, for what that's worth. I intend to attach it with some RTV sealant so it can be removable if need be in the future.
* My prop, as is, with the stock 2" SD motor does power the boat forward. Not achingly slow, but it's not also not a rocket. I suspect if it were faster, the rudders and planes might exhibit a bit more control authority. I also realize it's nearly 4ft long, and those little rudders can only do so much at their scale size.

[He Who Shall Not Be Named]

Those are adorable!

lol

adorable?......

[DMTNT]

Those are adorable!

lol

[He Who Shall Not Be Named]

David

[He Who Shall Not Be Named]

David

[He Who Shall Not Be Named]

David

[He Who Shall Not Be Named]

[He Who Shall Not Be Named]

After I posted, I kept digging through the forum history and caught a post where you mentioned that the SD comes with a couple of extra seals. Keeping in the theme of things I pounded the desk with my fist and exclaimed, “You son of a b*tch!” with a wide smile - ala Jack Ryan.

On a slightly more serious note, thank you for your kind offer of a replacement end cap. I may still take you up on one some day, but I decided to be bold. Never underestimate the power (or blind luck) of a determined man and his 12v Milwaukee drill. I bored out the offending seal, tapped a new one into its place, and sealed up the end with a touch of RTV. I think the gods decided to be merciful, and I now once again have a functioning 4th servo in the WTC. I’ll leak check it tomorrow, but I’m encouraged.

Thank you for the help.


-Brady

LOL. Glad it worked out for you, sir. Keep us informed.

David

[He Who Shall Not Be Named]

Really impressive, David! But what is such a tiny model good for? Id certainly NEVER put that in a lake...

Absolutely, sir! Pool toys only.

David

[Peter W]

I watched a video a few years ago with the Zvezda 1/350 scale Oscar II darting around a swimming pool. I imagine only a pool or Gin clear, very still water will allow such a small sub. I bought 1 when they came out with the wondering of whether it was posssible as I did also with the 1/350 Dragon Typhoon. Possibly best described as a technical exercise ?

Peter

[JHapprich]

Really impressive, David! But what is such a tiny model good for? Id certainly NEVER put that in a lake...

[He Who Shall Not Be Named]

David