Bronco Type XXIII in 1/35th scale

[alad61]

David I know you made sure the prop shaft was true and you've probably considered what I am suggesting but could the actual propeller be off, in that it's thrust will push the nose down? I have read that these boats could crash dive at 9 seconds!! What about setting the forward planes a little positive. Between that and the adf then countering it may run more level, that's how I get my robbe seawolf to stay below.

[redboat219]

Maybe we need to call father Damian. You know, to exorcise the demons Very Angry.

[He Who Shall Not Be Named]

Romel is a pretty smart person!
Good move putting the vent towards the aft end, Genius! My Gato went in a steep dive once, awkward nose down angle, early in the trimming stage. It got trapped in an un-natural angle because of the air. Pretty sad to see it dangle like that. OK. just throwing ideas out there. Maybe something will stick.

I am sure I know the answer and that you verified this already, Are you positive you do not have the leveler set just the opposite of what it should be? In other wards if nose goes up the leveler is not trying to bring the aft down.

Romel, like you, is a complete pain-in-the-ass. But, you guys usually come up with some neat stuff ... only reason I put up with you bums.

Before I started calling you all sorts of mean names after reading your suggestion that I got the angle-keeper in there backwards I recalled that on at least two occasions I did just that! So, good call, Tom. But (this time, anyway) that is not the case with this boat: I've taken good care to validate that stern plane response to angular change is in the correct direction.

Check twice and cut once, as they say. Still looking for that magic answer. We know its out there, but currently out of reach.

I'm looking forward to reports from Big Dave and Manfred on how their Bronco Type-23's perform.
M

[He Who Shall Not Be Named]

http://forum.sub-driver.com/attachme...8&d=1364077418
This is the area I'm pertaining to. The area in front acts like a scoop funneling in air during surface runs. What if air trapped here causes the boat to pitch down. Even though there's a hole on top, water tension could be preventing air to vent.

That little 1/16" diameter hole in that picture was later enlarged to 1/8". So, no way air is getting trapped there. Good thinking though, Romel. We're all spit-balling right now, but eventually me or one of you bums will hit on the solution. Keep pitching, guys.

M

[redboat219]

http://forum.sub-driver.com/attachment.php?attachmentid=19378&d=1364077418

This is the area I'm pertaining to. The area in front acts like a scoop funneling in air during surface runs. What if air trapped here causes the boat to pitch down. Even though there's a hole on top, water tension could be preventing air to vent.

[trout]

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

Romel is a pretty smart person!
Good move putting the vent towards the aft end, Genius! My Gato went in a steep dive once, awkward nose down angle, early in the trimming stage. It got trapped in an un-natural angle because of the air. Pretty sad to see it dangle like that. OK. just throwing ideas out there. Maybe something will stick.

I am sure I know the answer and that you verified this already, Are you positive you do not have the leveler set just the opposite of what it should be? In other wards if nose goes up the leveler is not trying to bring the aft down.

[redboat219]

Could it be air is being trapped in the narrow stern. I know there's a small hole there for the rudder post collar but what about the tip?

[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

[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.

[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]

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.

[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

[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]

'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]

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