Bronco Type XXIII in 1/35th scale

[trout]

Take video......please. Oh and if I am not being too pushy some photos also.

[redboat219]

Hello David,

Is it possible that the bronco models lack of negative angle on the stern fins is causing the pitch problem? My old 32 parallel type 23 has negative angle moulded into the thin airfoil shaped fins in front of the stabilizer and this boat is stable at all speeds. Then again it is not fast! Most photos indicate this negative angle and the Fritz kohl plans also show it. Food for thought. Good luck.
Sincerely,

george

How many degrees negative incidence are we talking here?

[He Who Shall Not Be Named]

Just got back from the Nauticus show. Put the Bronco 1/35 Type-23 in the water with the latest change -- an effort to correct the 'dive-of-doom' this model has exhibited since I first put it in the water over a month ago.

No improvement! Not one bit of difference! Damit! .... dive the boat, advance the throttle and I may have it for a few moments, but eventually the damned thing assumes a pronounced down angle and it just keeps going -- only recovery option is to go all back, emergency.

Damn!

I'm at a loss as to what to do.

M

[redboat219]

Definitely need to get hold of a working 32nd Parallel XXIII and see how she's set up.

[redboat219]

Maybe you need this, http://link.springer.com/chapter/10....-642-10690-3_8

[He Who Shall Not Be Named]

Maybe you need this, http://link.springer.com/chapter/10....-642-10690-3_8

Can you find a copy of that in English, Romel?

M

[redboat219]

Not sure if this is the same thing,https://www.google.com.ph/url?sa=t&s...50768961,d.aGc

[Buellman1]

How about an Eagle Tree Guardian which has multiple gyro stabilization? You could have gyro stabilization on all surfaces if you like. I have one on hand that I plan on putting in my gato and using the adf in my nautilus. Which means I'm assuming it'll work.

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXCUCV&P=ML

[He Who Shall Not Be Named]

'Gyro' stabilization (a misnomer, no gyro is involved, they now use velocity detectors, i.e. accelerometer) is not the means of determining displacement angle between the vertical gravity line and the vehicles longitudinal axis -- and that's what has to be measured if the devise is to detect and send corrections signals to get the vehicle on a zero bubble-angle.

And there's only one vehicle axis we need artificial stabilization: the pitch axis. And that's done with a device that can sense the vertical gravity line and work out the displacement angle between it and the vehicles longitudinal axis, and work out the proper corrective signal to the stern plane servo to get the boat back on a even keel. The ADF2 and other 'angle-keeper' devices are designed to do so and do the job well. If they are in working order.

I'm going to (once I find the time) build up a new SD for this beast, outfit it with new devices, and see if I can get this Damned Type-23 to work properly ... finally!

I do appreciate your input here, Buellman. Keep it coming. Obviously, I'm missing something here! In this matter, The Great David Merriman ain't so frig'n great!

M

[Buellman1]

The guardian does have gravity leveling in 2D mode David. I was originally planning on putting it in the gato first but it was on back order too long for me to wait. It finally came in and one of these days I will get around to trying it out to be sure. If its all legal, I'll try to post the instructions and maybe hook it up to some servos with a video. I think it can be set up like having an adf on both sets of planes with user override.

[He Who Shall Not Be Named]

The guardian does have gravity leveling in 2D mode David. I was originally planning on putting it in the gato first but it was on back order too long for me to wait. It finally came in and one of these days I will get around to trying it out to be sure. If its all legal, I'll try to post the instructions and maybe hook it up to some servos with a video. I think it can be set up like having an adf on both sets of planes with user override.

Thanks for the information, Buellman. I stand corrected.

Fair enough. Give it a go. At this point I'm snatching at straws in this matter.

David

[trout]

Maybe your sub is too balanced? What I mean is, when you dive the air in the ballast tank goes to one end (aft) and the sub rotates longitudinally because that shift causes the delicate balance to go imperfect too quickly. Maybe baffles would slow the movement of water in the ballast tank?
This would explain the porpoising as the water is sloshing around back and forth.

[redboat219]

Correct me if I'm wrong but I think the SD's ballast tank is designed to be completely filled with water when vented.

[trout]

As long as the sub maintains normal horizontal attitude, however if the sub tilts, the air will get trapped at the higher end because it can not escape out the vent.

[He Who Shall Not Be Named]

As long as the sub maintains normal horizontal attitude, however if the sub tilts, the air will get trapped at the higher end because it can not escape out the vent.

Romel's right. And Tom's observation is valide. However, the vent on the ballast tank is at the extreme after end of the ballast tank. It's placed there to insure complete flooding of the tank as the boat takes the 'normal' down-angle as it transitions from surfaced to submerged trim.

I'm confident that there is no free-water in the tank once fully transitioned to submerged trim. But, you've given me something else to give a second-look too.

M