Last of Kevin's OSCARIIs

[southern or]

Alright, so I have good news and bad news. Good news, I'm going to be finalizing the hull portions for mating and so on. I'll also be fitting the props and the shafts so I know where to install the motors. Then on to the fins, planes, rudders, control assembles, then install the WTC. The WTC will have 1 kilo of lead shot in it then I'll add solid lead as needed.

The good: I have 2 tubes of J-B WaterWeld so I can add wet hull solid ballast in the water.

Bad: My liquid epoxy is 1/2 hour so it won't work on the WTC, but will it be okay for mating the wet hull portions?

More Good? I have a ton of Apoxie Sculpt. Like 30oz of it. I've used it in the past on surface boats without a problem and it is 2 hour epoxy. I'm thinking that I'll use that for the WTC? I'm also planning on using some of it to reinforce the diving plane and rudder holes-as in I'll add a quarter size amount on the interior side before I drill.

I'm not adding the second dry kilo weight until I know how far off balance the boat is, and I am expecting the aft to have more weight simply by design.

Feel free to make fun, but here is my solid ballast test raft. The green 1 liter has some water in it to compensate.



Edit: I forgot to factor in the weight of that stupid stainless steel lid and all of its hardware.

[southern or]

Sorry if I'm annoying and going slow, I just want to do it right and I'm having to do everything on my own. A lot of people want to see it in action but no one wants to help get it there.

[JWLaRue]

After assessing how much volume is lost from the gear, batteries, motors, ect. I came up with 4.25 liters of positive bouncy only needing 4.27 lbs. to obtain neutral.

Need to be careful to keep in mind that the volume of the dive module (WTC) is the same no matter what is inside it. The amount of water displaced by the WTC is the same regardless. Now....the weight of what is inside the WTC will help to offset the buoyancy created by displacing the 6 liters of water.

Most of us work out the amount of weight and foam empirically, but some of use at start with a general idea of what's needed by understanding the impact of the WTC buoyancy. It looks like you have successfully used plastic bottles to figure out what you'll need. (excellent!)

-Jeff

[bwi]

Sorry if I'm annoying and going slow, I just want to do it right and I'm having to do everything on my own. A lot of people want to see it in action but no one wants to help get it there.

Just take the time to do whatever you need to do. Don't hurry, that will not help. Give yourself the time to pounder about things.
Sometimes I spent several weeks to find a solution, that what’s it’s all about.

Sometimes you have to begin allover when you made a certain choice, it’s all in the game.

You’re doing fine just go for it @ a speed that is comfortable for you.

grtz,
Bart-captain slow

[southern or]

Little update:

I'm almost done with my little Kilo. It was a hard fought war and I may have lost the last war with it, but the end is so near. The little guy (a fitting name would be Sea Tiger) has proven to be a great test bed so far for approaches and materials I want to use on the Oscar. The "RTR" driver for the Kilo wasn't in any way, shape, or form RTR. The bleeder valve on the end cap for the battery was installed backwards so the water pressure could open it, the glue sealing the bellows failed on both bellows, but wouldn't come off the tube, and the wiring had no less then three shorts.
Firstly, Apoxie Sculpt is a life saver. So far is has done everything I've asked it to. It's sealed the bellows (I had to use more then I wanted to because the old "glue" wouldn't come off), it sealed the antenna hole, and bonded the planes and rudder to their rods. If all goes well during trials, I'll probably use it on the WTC for the Oscar. I filled up the air bag, capped the tube and released the solenoid actuator. The bellows expanded and the bag wouldn't deflate much so I'll take that as a successful test. It looks a bit crowded in the ESC/Receiver end because the Futaba receiver is 8 channels with the pins on the top, but it fits-just.

[southern or]

Update: So far the Apoxie Sculpt has held up really well. The WTC passed it's first dive test (finally) and I hope to have the Kilo operational by the end of the week.

[southern or]

So if anyone is still reading this, I've hit a bit of a snag. I got a lot of 1/2 hour epoxy before I was told to get 1 hour epoxy. So what is the difference and where can I get 1 hour?

[salmon]

The difference is with usage underwater, not instantly, but with time, the faster curing glue can become softened and lose it's strength, I am told. Where to get it? I got mine at a hardware store (Ace), but a search on the web will bring up what you seek. Here was a result after a quick search.... http://t.homedepot.com/p/Loctite-0-8...5604/100371825
That is a two hour,but there is a 5 hour out there too. I used 2 hour with no problem.

[southern or]

The difference is with usage underwater, not instantly, but with time, the faster curing glue can become softened and lose it's strength, I am told. Where to get it? I got mine at a hardware store (Ace), but a search on the web will bring up what you seek. Here was a result after a quick search.... http://t.homedepot.com/p/Loctite-0-8...5604/100371825
That is a two hour,but there is a 5 hour out there too. I used 2 hour with no problem.

Thanks. I already know I'm going to be needing to use Apoxie Sculpt, but in practice I've noticed that sometimes the seal isn't 100% so I'm already planning on using epoxy over the sculpt. The problem with the sculpt is that while it takes 24 hours to set, it dries very rigid and tends to crack when under stress. It makes a terrific fill, but it needs that extra reinforcement to keep it water tight.

[Guest]

Original JB weld takes some beating.

i prefer to use modified acrylics now, especially with mixed media. Devcon Plastic Welder is readily available in the States, and is very good.

[southern or]

Original JB weld takes some beating.

i prefer to use modified acrylics now, especially with mixed media. Devcon Plastic Welder is readily available in the States, and is very good.

I have a tube of JB, I just don't have enough. I'm already aware that my WTC isn't going to be a perfect fit so I'll be needing something to fill the gaps with. The nerve issues with my right hand are getting worse so some of the cuts to the WTC are um, sad. It is coming along good even though it looks like a mess right now. I hope to have the WTC fitted by the end of this week.

[southern or]

Made more progress on the WTC so everything is covered in dust now. Carbon disks work so much better (and longer) then the diamond one I was using.

I think I might have over engineered this boat a bit. With aTAE2 dive system and 2 tanks, plus a LTR6 Pitch and Depth Controller (with screen), it makes me wonder if I went overboard a bit. So far it looks like it'll all fit, but compared to the tube designs I've been seeing, it makes me wonder. On the upside, I do have 2 failsafes and the Viper ESCs have yet to fail me. Did have 3 unremarkable ESCs in RTR boats catch fire though which makes me leery.

Which reminds me, the tech deck is going to be a bit snug and the Vipers have heatsinks on the bottom, not the top. So I'm wondering, will they be fine heat wise in the PVC deck itself, or should I place them on the lead ballast?

By the way the WTC is coming along, I'm going to loose some height and width, but it will all still fit, it'll just be snug. Plus I'm using 3 NiCad batteries instead of 1 lead motorcycle battery.

[southern or]

I took a break, but I'm hopeful to start working again. I need to get some fresh JB Weld next month.

[southern or]

This WTC will be the death of me.

[southern or]

No photos, but it's progressing. It's talking a lot longer then I thought it would, but it's surprisingly easier then they Kilo is. I'll add some photos whenever get the WTC installed. She looks so much worse then when I started, but that is just how it goes whenever I build.