Bronco 1/35 Type XXIII kit

[warpatroller]

Thanks Jeff. ON THE WATER cylinders are bigger than I thought they were.. And they probably really will get you on the water with minimum hassle. The VooDoo part of OTW cylinders is the water pump control electronics, and how the venting of the ballast tank works without it leaking into the dry areas, at least for me.

Andy, regarding Ron's Twin Piston Tanks, what keeps water from leaking through the hole in the piston, where it rides on the threaded shaft? Is it simply that the shaft is greased, and the grease keeps it from leaking through? Or is it more VooDoo..

[Guest]

Grease would push out under pressure. The piston is sealed using a stuffing gland. Inside the gland you can use waxed rope, ptfe string has also been mentioned, basically something that conforms to the thread, is waterproof but remains slippery to some extent to limit friction. This gland requires a bit of maintenance, like most parts of a sub, but from what I've seen they give little trouble. This design of tank has been kicking around for decades now, and you still see them in use, so they're rugged.

The thread has to be releatively smooth to avoid it tearing up the stuffing gland material, and I believe that Ron uses ground studding, which is better quality than the rolled stuff, but more difficult to find, and of course more expensive.

I think twenty to thirty years ago, when batteries and radio tended to be bulkier, having non retracting threads was a big advantage. Nowadays if you're cute with your choice of equipment you have bags of space to play with, especially when you bear in mind that the volume required inside the tube is mainly dictated by the pressure you compress the air behind the pistons and how much the internal seals can withstand.

So a retracting thread isn't such a limitation, and it simplifies construction of the tank a bit.

There isn't anything ultra complicated in building a piston tank. You do need a lathe really, as making accurate round objects without one takes a lot of bench fitting skill. However you do need to pay close attention to tolerances, especially with regards to the seal to bore size, as that can make a big difference to how the tank performs.

[JWLaRue]

The OTW dive system uses a solenoid valve to prevent pump bleed through. The electronics package ensures that the valve is open whenever the pump is running.

-Jeff

[Guest]

The electronics board also has probes which monitor the water level when the tank is full and empty. This is to avoid flooding the module, as a hole is drilled in the endcap of the ballast tank above the level of the probes to allow air to compress into the dry areas.

Probes in the bottom of the tank tell the controller the tank is empty, as the pump used doesn't like running dry, plus you're just wasting power.

The probes are most likely fed using a small AC current, as DC current will plate up the metal probes in water.

I would expect the unit also has a failsafe at loss of signal to blow ballast.

[csteika2007]

A new Type XXIII conversion kit is available from MAXIMUS-Modellbau Germany.

https://www.maximus-modellbau.de.tl

Best Regards
Christian

[warpatroller]

A new Type XXIII conversion kit is available from MAXIMUS-Modellbau Germany.

https://www.maximus-modellbau.de.tl

Best Regards
Christian

That module is almost as long as the hull! No "Torpedo Los" from a boat running that system.

[JWLaRue]

If that center, clear section is the space for the ballast bag, then I would think that the dive module could be shortened as there isn't much above the waterline to lift in a Type XXIII.....

-Jeff

[warpatroller]

The Bronco seems to require more ballast capacity than the 32nd Parallel. I filled the two halves of my 32P stock ballast tank with water this weekend. The total capacity of that tank is between 7.5 to 8 ounces. In comparison, the sub-driver most people have been using in the Bronco, has a capacity of 13 or 14 ounces.. Merriman says the best ballast design incorpates the use of the smallest capacity tank possible for a given hull.

I was carefully examining how the gas ballast system works on my 32P. I'm now thinking I may just build it stock, as 32P intended. The whole "rip that pressure box out thing", is one reason why I've had this kit sit for so long without doing anything with it.

I read a write up/review where a German guy built one stock in 2003. Only modification he really did was substituting an ESC for the mechanical speed control. He used the stock gas balance system, tank and pressure box. That gas cylinder is huge compared to the old D&E WTC gas cylinders. The German guy said he got 25 dive cycles out of one fill up of the stock onboard cylinder. 32P stated the same, up to 25 cycles. One 500ml propel can, would give him 250 dive cycles, so he said. He also said the handling, and maneuverability, of the boat was excellent. He didn't lose it, it didn't sink on him either. I think there's a myth going around that if you use that stock 32P pressure box, your boat will end up in Davy Jones locker.. Your Doomed, like that old guy in Friday the 13th said to the camp counselors, "You're all doomed!"

I had to laugh when the German guy called the liquid gas ballast system, "new" and "unusual" to Europeans, an "American thing". Yet he also noted it being closest to way the real U-Boat ballast systems work.. All the stock pushrod seals in the 32P are O-ring seals.. Maybe I could make my own Myth Busters video on the Simon Smith vacform pressure hull / ballast system design. Build it stock, run in my local lake, dive in open 15+ feet deep water, and see if it comes back up.. And repeat 25 times

Then build the Bronco, all high tech, with piston tanks, built with a Sherline Lathe and Tarantula 3d Printer. Run it in the same lake, and see if it sinks, or performs any better.. lol 1983 versus 2016 tech wars! A tale of two U-boats, worlds apart, in technology and construction.. One cutting edge, over engineered and over complicated. The other, hopelessly obsolete, a relic of the way things were done when 10 year old kids were digging coal and you wiped your bum with pages from the Sears catalog..

[salmon]

You are spot on about older technology works. I read the old SC Reports and those subs from 10+ years ago ran very well. Certainly not as compact electronics that we have today, but still dove and returned to surface in a controllable manner. I am blessed to have on of my heroes subs. Mike Dory's Albacore sub. WOW it has some very old technology in it, but Mike told me of how well it runs. When he gave it to me, he told me he left it neglected after a salt water run and now it does need rebuilding. One of the decisions I had to make is keep the old setup or start from scratch. In this case I am going to start from scratch. Anyways, please build a simple sub design and a technological wonders sub. It will be fun to see which you will like when it is all done.
Peace,
Tom

[bob_eissler]

There isn't much of the hull that needs to be above the water on a type 23 but it does have a problem. The conning tower is huge relative to the size of the hull. It may not weigh much but even a slight wind will weather cock the boat over unless it has lots of lead in the keel. Which means you need to make sure there is plenty of room for foam at the water line, outside of the wtc to balance it out nicely. I learned this one from experience after starting out with a 3" wtc with lots of wasted space in the 32nd parallel hull. Also a long wtc with weight distributed out at the ends really hurts turning performance.

[warpatroller]

You are spot on about older technology works. I read the old SC Reports and those subs from 10+ years ago ran very well. Certainly not as compact electronics that we have today, but still dove and returned to surface in a controllable manner. I am blessed to have on of my heroes subs. Mike Dory's Albacore sub. WOW it has some very old technology in it, but Mike told me of how well it runs. When he gave it to me, he told me he left it neglected after a salt water run and now it does need rebuilding. One of the decisions I had to make is keep the old setup or start from scratch. In this case I am going to start from scratch. Anyways, please build a simple sub design and a technological wonders sub. It will be fun to see which you will like when it is all done.
Peace,
Tom

Hi Tom. How did you end up with several of Mike Dory's old boats? I remember him telling me about his 32P XXIII. He said it had a Small World Models 3.25" WTC in it. He acknowledged it was on the big side, diameter wise, for that hull. Kind of a tight squeeze.. He also said an issue with the stock 32P pressure box, was flexing of the lid, which can break the long oval o-ring seal that sits underneath it. He didn't mention at what depths that could be a problem. I don't think it would be an issue running at periscope depth, if it is torqued down properly.. Could the rest of the box come apart, while undersea? I don't think so! Not with that Versilok holding it together. It is LOCKED together for eternity with that stuff! Now with the early production kits, where the buyer had to bond the box together himself, I'm sure more than a few of those came apart under the waves..

Many of these 32P boats are partially built, damaged/neglected or well used. If they are an unbuilt kit, they are usually missing parts. Mine is 100% complete.. Nothing is missing, nothing is damaged.. So, I think it would be cool to put it together as designed by Simon. I was tempted a few times in the past to start attacking the pressure box with a dremel tool, but then I stared at it and thought... No... I can't butcher this factory original boat.. Plus there is no way that box will come out cleanly, with that incredibly permanent Versilok adhesive holding it to the hull. It would be almost like trying to remove the Face Hugger from Kane's face without tearing his face off (remember that movie?), to completely remove it. I can't see how it would look pretty afterwards.. That is my new name for the 32P 23 Pressure Box, "The Hull Hugger'! Except it has its Death Grip from the inside, instead of the outside..

Who ended up with Dory's 32P XXI? I'm guessing the wheels were turned by Pittman 6V motors, with belt drive gear reduction, run off 12 volt sealed lead acid batteries in that one..

By the way, someone just became a paid Subcommittee member again..

[Guest]

Mechanically, little has changed in model submarines over the decades, and won't do so in the future. There are only so many ways of creating watertight enclosures and varying displacement, and they've all been done at some point or other.

Years ago, builders were somewhat restricted by the bulk and performance of the electronics and batteries available. Flat lid style enclosures offered a lot of space whilst keeping surface displacement to a minimum, assuming the lid was at or below the surfaced waterline. However they are nowhere near as good as a cylinder when it comes to resisting water pressure.

Despite the restrictions in equipment years ago, some builders really pushed the envelope and produced some advanced models that can stand up well against the best of todays creations. However the cost to the builder was often much higher, and generally it required some specialist knowledge to get things working well.

Also bear in mind that the majority of people in a hobby are imitators rather than innovators e.g. they will copy what others have done, if shown to work effectively. This is understandable, as innovation carries a fair amount of risk, and most people just want to enjoy a hobby without having to reinvent the wheel.

Once methods of doing things become well established, there tends to be a natural reluctance to alter course and switch to alternative methods, even if they're shown to be better. However every now and then some individuals will come along and rock the boat the bit, and I think that's what keeps things fresh.

Injection moulded models will almost always be higher in displacement than vac formed or well moulded GRP hulls. A minimum thickness is required to make the parts strong enough. If you're extremely patient, you could sand out the areas above the waterline, but of course then the parts will become more fragile.

In the case of the XXIII, it has one big plus over some boats- being a figure of eight style hull design, it has a very deep keel. This enables the constructor get any ballast weight low in the hull, as a result stability shouldn't be a huge issue unless you've really got things badly wrong.

[sam reichart]

I really want to build this boat as an R/C model, and I've sort of lost track on this and the other site as to whether or not anyone has successfully gotten one to run "correctly", without (as Andy put it) "reinventing the wheel".
I had hopes of employing a ballast system that would allow enough room for working torpedoes.

[Guest]

Tom got one working well with one of Dave Merriman's SD's. Sadly the boat hit a problem and was lost a couple of years ago at a sub regatta. AFAIK it was never recovered.

A recirculating ballast system may pose a challenge if you want to use a small volume cylinder, or pack other components like torpedoes in. So the snort type sustem or some other style of ballast system that is aspirated, or particularly aspirated may be beneficial.

[salmon]

The Type XXIII is a relatively easy build (one of two subs I recommend for a beginner, Bronco Type XXIII and Revell/Mobeus Skipjack), and it is a GREAT running sub.
I did lose mine because of several reasons, but a big reason was I am a numbskull for running it when I had a problem earlier. Sigh. There is still hope for recovery as the local fire department wants to use the loss sub as a recovery excersise.
I see a couple have come up for sale, good bargains too. There are a couple of YouTube videos out there of my sub running and on another site is my build. I love this sub and will build another one.
Peace,
Tom