Engle Gato, new to me

[g2tiger]

Hello everyone,

Just made a trade and got my hands on an Engle Gato. It appears to be an early model. It will need some work to get it up to speed. Right now I am working on getting the lower hull components dialed in and set up. I have been reviewing the youtube video of Bob re-working an early Gato similar to this model, he did quite a good job getting it up and running and I hope to use that as my benchmark.

Some details on the model: this model came with an 80 mm WTC from R & R Engineering, it is a pump model WTC. The model also has a lead keel bar under the belly and a large amount of lead shot in the middle of the hull just under where the WTC sits.

Questions, in no specific order:
How much should I be looking for on the lower hull for weight without the upper deck and the WTC? I plan to use a 12-volt lead acid battery in the forward-free flood area as Bobo did so that will be part of the weight but not part of the empty weight that I am asking for here.
Also, how large should I look for on the ballast tank? size wise 3 x 6 inches?
Is the 80 mm WTC large enough to support the model's operation with the right amount of closed-cell foam? How long should the WTC be for example? It does have a section that is for the ballast tank but it most likely will be too small based on the model's large size.

Your thoughts would be appreciated.

Charlie

[RCSubGuy]

Charlie,


Congrats on the score!

Okay:

1. It's less about ballast weight. Bear with me. My usual process is to put a lot of foam in the upper hull below the waterline, then put it in the trim tank. Ballast is infinitely easier to add than foam, and having more foam than necessarily needed will only improve static stability. So... lots of foam high, then add weight low to get her to surfaced trim. Ideally, you want to put an SLA battery in the keel area. Rather than one large one, you can put a couple of smaller ones on their sides, wired in parallel for increased voltage and/or amperage.
2. The Engel Gato is a big boat, and those subs have a lot of freeboard. I'd guess you want something like a 3.5"x10" tank to get her floating at designed waterline.
3. I'm very hesitant that the 80mm R&R unit will power a boat of this size. Yes, it might move it, but the motors are small and the servos are tiny. It's more designed for something around the 50 to 55" mark with 1" props. Using the onboard pump with a larger tank (as it sounds like you want to do), means that filling and emptying will take an eternity. This cylinder is the wrong one for this application, IMO.
   
   
   Bob

[g2tiger]

Bob,

Thanks for the quick response. I am on the same track as you. I'll take a few shots of the ballast blob in the hull and the keel and post them for reference. I believe that I will need to remove the large epoxied bead ballast in the hull as well as the lead keel block under the hull. To me, this will allow me to start with a fresh blank slate.
Then the next steps will be to locate or create a 3 to 3.5-inch WTC, determine what battery system will work, locate some better weights, and foam, and begin roughing it in.

Thanks again,

Charlie

[wlambing]

Charlie,

You will need something bigger than the 3.5" cylinder you're thinking of! A couple of us here in New England have 1/48 scale boats and we have OTW 4.25" cylinders in them. 1 of these boats is the same Engle Gato that you have. Extensively overhauled from a really poor original build and converted to use the OTW unit that was designed by Bob Dimmock to fit the 1/48 Oberon hull. Anything smaller is going to cause much frustration because of all the ballasting foam you'll end up using trying to get it right. With the 4.25" cylinder, you start off with 4-5 pounds of added ballast weight and go from that starting point. Eventually, at some point ('prolly just before I croak!), I'll be using my Oberon cylinder to populate a 1/48 Scale Shipyard Gato Class hull I've had for years. The OTW compatible cylinder saddles have been installed in it for a couple of years now. I have all the needed parts. I just need to get off my butt! Damned You Tube!!!!!!

As a suggestion; we also use NIMH 4500 mah batteries. I think they're ten AA sized cells soldered together and shrink wrapped together, encased inside a modified NEMA 4 outdoor junction box (clear, o-ring sealed lid) with a mounting plate epoxied to the bottom with a mounting tab extending off one end. The tab bolts into the forward cylinder stop-block up in the bow of the boat, below the bow planes pushrods. You have to dismount and uncase them for charging, but that's very easily done. Even in the case, they're smaller than most SLA batteries, and you can get the weight for down inside the hull without having to build a tray or other retaining system. If you have an interest, PM me and I'll see if I can dig up the battery and box part info.

Take care,

Bill

[g2tiger]

Bill,

Thanks for the added input. I am intrigued by the 4.5-inch WTC. It would make life easier in the long run for sure. I have taken a few pics of the inside of the lower hull. In the pics, you can see the external lead weight (I think it's lead) and the mixed ballast weights inside the hull. The internal weights and the WTC mounts are such that any size WTC larger than about 3 inches would be above the sides of the hull which is the models' waterline. I did measure the hull and a 4-inch/4.5-inch would fit. the 4.5 would be shorter in length though. This boat is going to take a bit of work to get up and running.

I'll keep everyone posted on the progress.

Charlie

[Sinksalot]

I will be installing a new OTW 4.25 inch cylinder with a 12 inch ballast tank into my Engel Gato. Please note OTW cylinders are good, but cost more then just buying a brand new Engel kit with everything included and shipping it to the US

[g2tiger]

Sinksalot, I understand. I am on board with a top-notch larger WTC as it will make life easier when it comes to balancing the model out and getting things right. I have a buddy with an OTW and it runs like a dream. I'll see about saving up for a larger WTC, (an OTW is definitely in the top spot). Bob sells some larger WTCs and I'll check his WTCs as well. I do prefer pump systems for some reason, possibly because my first sub was an albacore and it ran really well. Hobby money is tight these days. Perhaps I can sell the 3-inch WTC that came with it as seed money.

OK, here is the skinny on the Gato weight. Can you guess the weight first?

Sixteen, One-six, 16, is the lower hull weight as pictured above. Do you guys think that is a bit heavy?

Charlie

[Sinksalot]

If the Gato sub still has is Engel center weight still. That lead weight should be 7.5 pounds

[wlambing]

Another thought: place the battery in a tube, mounted lengthwise under the cylinder. The Engle I mentioned before has its battery done that way. The late, great Dave Welch gave us that idea many years ago and my buddy ran with that for his conversion. I think, though for what you are starting with the weights that are epoxied in will have to be carved out and you'll be starting from scratch. Many things to think of and many ways to become frustrated!!!

[g2tiger]

Guys,

Lots of great information here, I'll need to be mindful on this build. I think Ill start by cleaning out the weights. Looks like a 4.25-inch WTC may be in order, need to noodle how to make that happen.

Charlie

[g2tiger]

November update:

Now hear this, Now hear this,

The lead keel weight and the bilge weight have been removed from the lower hull. The inner hull is now clean. Wooden spreaders in the lower hull have been replaced with a resin-type spreader. The props and shafts have been removed, both shafts are brass, with the port side showing signs of corrosion. Propshaft bushings are a plastic material. The supplied 3-inch WTC and radio both work. Also, a proper work stand has been built and the lower hull painted a flat dark gray. The red was bugging the Admiral. Additionally, the U-boat type of bow net cutter has been removed and a bull nose of sorts has been added.

The Budget Committee is thinking about selling the R and R Engineering 3-inch WTC and FM radio to fund a larger WTC. The LEDs on the tower have been checked and they work but the red and green are reversed.

That is all,

[wlambing]

Charlie,

My sub-buddy has informed me that the battery he installed in his Engle Gato revamp is actually a tube type that lays down in the keel area, held in place by the WTC saddles. Based on a Dave Welch design. It sits in limber holes cut in the bottoms of the saddles for water to move freely when diving or pulling out of the pond. Stacked cells inside the tube just like in a flashlight. 'Prolly easier to do a stack set similar to the one Bob did in a recent video. Advantage in either case is that the weight is stationed as low as it can get in the hull. Our other OTW hulls use the battery box that I mentioned earlier.

Take care,

Bill

[g2tiger]

Bill,

Thanks for the info. Are any pictures available?

Charlie

[SubICman]

I can get some pictures of the same style setup in the bottom of an OTW Hecht. Same tubes as in Tony's Gato that Bill speaks of.

[wlambing]

Good man, Tim!