Bronco Type XXIII in 1/35th scale

[ffr2608]

What do I get if it works? I like cash and round polycarbonate tubes.........
I never drive from the rear. This is no forklift.

Lead it from the front and the rear planes keep it level.

Darrin

[He Who Shall Not Be Named]

So, is it the large sail causing the issue? As you increase the speed it creates a larger drag forcing the bow up? But others with Type XXIII have it working o.k. - mine does not go fast, but does dive and stay level with no adjustments. Once it gets out of dry docks (again) I will run it at a faster speed.
David, I am sorry you are going through this, but selfishly, I am learning from your experience and the great suggestions.
Peace,
Tom

Darrin's observation is the best thing I've heard yet -- I have an immense respect for this guys work and place great value on anything he says.

(That's the build-up ... now, if his suggestion does not work, I will vilify him horribly tonight when I report back on the results. No good deed goes unpunished here!).

M

[He Who Shall Not Be Named]

Hello David , I took the Apc out of my XXIII along time ago after fighting this problem . You have seen mine run at Carmel ,I set the rear planes on full up and front at half dive angle and she will run at level depth all day . I never move rear and only use front when on surface . Just a idea .


Jim H.

No ****!??.... So, I'm not crazy.

I will try that tonight, you nasty old model-builder, you!

Film at Eleven.


David

[trout]

So, is it the large sail causing the issue? As you increase the speed it creates a larger drag forcing the bow up? But others with Type XXIII have it working o.k. - mine does not go fast, but does dive and stay level with no adjustments. Once it gets out of dry docks (again) I will run it at a faster speed.
David, I am sorry you are going through this, but selfishly, I am learning from your experience and the great suggestions.
Peace,
Tom

[jim h]

Hello David , I took the Apc out of my XXIII along time ago after fighting this problem . You have seen mine run at Carmel ,I set the rear planes on full up and front at half dive angle and she will run at level depth all day . I never move rear and only use front when on surface . Just a idea .


Jim H.

[He Who Shall Not Be Named]

Sir,
Is it possible that the water ingested by the open shutter doors is being expelled out of the stern free flood holes on the bottom of the boat thus causing the stern to rise when at full speed?

Yes, that's what I was thinking too. But, after putting tape around the shutter door opening and finding no change, I can now discount that as the cause of the pitch-down problem. Good thinking though.

M

[redboat219]

Think David has already tried that.

Maybe time to try flow visualization around the bow using cotton thread. There's something there generating negative lift.

[goshawk823]

Easy enough for David to test. Slap some masking tape over the shutter door openings and try it again...sam

[trout]

That is an excellent thought in my mind.

[GNuge]

Sir,
Is it possible that the water ingested by the open shutter doors is being expelled out of the stern free flood holes on the bottom of the boat thus causing the stern to rise when at full speed?

[Warpatroller]

Wow, still having issues with the Bronco! It can't be the hull design (I would be shocked if that was the cause). It sounds now like it is going into an uncontrollable dive once it reaches a certain velocity, as opposed to your earlier reported porpoising action. Is this critical velocity, which causes the dive, considerably faster than a correct scale velocity for the model?

I have that infamous 32nd P 23 kit. Unfortunately mine is not assembled and I've therefore never had it in the water. I've just been told many times over by people who have had stick time with them in the water, how well that model is supposed to run. Simon included two large metal ballast weights to be installed on the bottom of the hull (on the exterior of the hull bottom).

I have got the torpedo door mechanism schematics scanned (finally got around to it). I have a lot on my plate right now and have had to put RC sub stuff on the back burner. I will get the scans posted in the not-too-distant future. Looks like the tube door stuff is premature at this time anyway. The auto crash dive condition needs to be rectified first.

If it were my boat, I would disconnect that pitch controller. Lock both stern and bow planes. Trim the boat so it's level when submerged. Then run the thing from zero to the desired max velocity and observe the hull's attitude. If it still nose dived, I would deflect the stern planes with their trailing edges facing upward, incrementing their pitch until the nose stops dipping down. If the deflection required to level the boat is extreme, then there is something seriously wrong somewhere that is disrupting the flow of water over the hull or a problem with fore-aft weight distribution. But what do I know? Nothing compared to David really. But I still try to help out.

Another stab in the dark might be to try a different propeller. A standard three-bladed prop maybe that you have laying around that's known to work well. Maybe there is something weird about that propeller's thrust after attempting to make it more scale like in appearance.

The additional fins forward of the planes (front & rear) were simply plane guards on the real boat. They were not stabilizers. My 32P plane guards are not perfectly straight.. Their surface area is relatively small, also, as David mentioned.

David, I never did receive any fittings kit from you in the mail. Hopefully you just haven't sent it out yet. Just keep it there at your shop until you get all this worked out with the Bronco. I am in no hurry to receive the fittings kit, so it is obviously not a priority in the least.

Steve

[He Who Shall Not Be Named]

Nope. The boat is getting the signal at all times. Checked that first. Something els, something weird, is going on I have not figured out yet.

M

[MFR1964]

David,

I think Tom has a point about loosing signal underwater, you can do a simple range test, get her submerged and leave her hanging neutral at the scope, then walk away with the transmittor, leave a observer or yourself behind to see what happens with your divingplanes.
Or program your divingplanes to stay neutral when having signal loss, the sternplanes won't be the problem because your adf will always profide a signal, i wonder what happens with your bowplanes.

Manfred.

[He Who Shall Not Be Named]

Since the leveller has been replaced (assuming with a known good one) and you have played with weights, what else is there? Wiring, electrical short? Surging power? Signal getting lost and fail safe kicking in? Front plans are not aligned with aft planes?

Beats me, pal. I've put it away to get to the production work again -- many unfilled PO's and parts I have to get out to long waiting customers.

M

[trout]

Since the leveller has been replaced (assuming with a known good one) and you have played with weights, what else is there? Wiring, electrical short? Surging power? Signal getting lost and fail safe kicking in? Front plans are not aligned with aft planes?