Last of Kevin's OSCARIIs

[JWLaRue]

Re: Last of Kevin's OSCARIIs

That's a pretty difficult question to answer since we don't know exactly what type of "chlorine" and other chemicals are in the water. That said, a number of folks that I run with re-trim going from freshwater ponds to/from pools by using coins to do the re-trimming. And for boats around 1/2 the size of your Oscar we're talking a couple of quarters and/or some nickels and dimes. (obviously that's in U.S. currency terms.)

In other words, it's never been anything drastic.

-Jeff

[Ralph --- SSBN 598]

Re: Last of Kevin's OSCARIIs

Don't see why not.............

[southern or]

Re: Last of Kevin's OSCARIIs

That's a pretty difficult question to answer since we don't know exactly what type of "chlorine" and other chemicals are in the water. That said, a number of folks that I run with re-trim going from freshwater ponds to/from pools by using coins to do the re-trimming. And for boats around 1/2 the size of your Oscar we're talking a couple of quarters and/or some nickels and dimes. (obviously that's in U.S. currency terms.)

In other words, it's never been anything drastic.

-Jeff

Thanks. I'm pretty sure they're using dry chlorine because the pool and the pool house are only a few years old and no one wants to use gas anymore.

[Guest]

Re: Last of Kevin's OSCARIIs

As I said in an earleir post, water varies in density by about 1% depending on temperature and mineral content.

So if your finished boat ends up displacing about 14 pounds, then it's going to vary by about 2 1/4 ounces.

[southern or]

Re: Last of Kevin's OSCARIIs

As I said in an earleir post, water varies in density by about 1% depending on temperature and mineral content.

So if your finished boat ends up displacing about 14 pounds, then it's going to vary by about 2 1/4 ounces.

Thanks, That's what I needed to know.

[Ralph --- SSBN 598]

Re: Last of Kevin's OSCARIIs

Depending on what is needed, some boat are retrimmed using foam blocks and some are retrimmed using additional weight.

I prefer the adding weight.
Find the center of gravity when submerged and mark it.
Put a peg sticking up and then make different weigh lead pieces or steel and drill a hole in them.
Add weight until you reach your desired water line.
Even magnets will stay put if you install a small metal piece at the CG.

Adding foam blocks works but I found the foam gets lost or breaks up.
As said above, if you loose your metal weights, you can use coins to get by.

I am working on an adjustable system to change the volume of the cylinder for just this purpose.
Trying to decide if it will be mechanical or radio adjustable.
Think small piston system. Not big enough for ballast but just fine adjusting of water line while in the water.

[southern or]

Re: Last of Kevin's OSCARIIs

Depending on what is needed, some boat are retrimmed using foam blocks and some are retrimmed using additional weight.

I prefer the adding weight.
Find the center of gravity when submerged and mark it.
Put a peg sticking up and then make different weigh lead pieces or steel and drill a hole in them.
Add weight until you reach your desired water line.
Even magnets will stay put if you install a small metal piece at the CG.

Adding foam blocks works but I found the foam gets lost or breaks up.
As said above, if you loose your metal weights, you can use coins to get by.

I am working on an adjustable system to change the volume of the cylinder for just this purpose.
Trying to decide if it will be mechanical or radio adjustable.
Think small piston system. Not big enough for ballast but just fine adjusting of water line while in the water.

Are you talking about trim tanks? Engel's makes custom volume tanks. I might add a pair of 250ml tanks if the current ones aren't enough. Then I'd have main tanks and trim tanks, but I don't even have the WTD done so who knows, the two current tanks could just be enough.

[Guest]

Re: Last of Kevin's OSCARIIs

You don't need trim tanks with piston tanks.

You shouldn't need foam either, unless you've screwed up on your buoyancy calculations or have a marginal metacentric height and thus poor stability.

Your centre of gravity should be decided at the start of the build, because it should align with the hulls centre of pressure if it is to perform as it should. You should then site the tanks an equal distance either side of the C.G, and the centre of your box should also align with the C.G.

By doing that you give yourself the best chance of ensuring your boat will retain an even keel when diving. If it doesn't then you may need to add some small amount of foam to counter any tendency for the boat to drop at the bow or stern, which would indicate the centree of buoyancy is not alignment with the centre of gravity.

[Ralph --- SSBN 598]

Re: Last of Kevin's OSCARIIs

If you use piston tanks, you don't need trim tank(s).
Just allow a little extra run on the piston.
Extra surface buoyancy and a little negative buoyancy when submerged.
You can control both from the radio as needed.

[JWLaRue]

Re: Last of Kevin's OSCARIIs

That's exactly what I do with my piston tank sub. Works great...drop her in the water, get an initial trim and I'm good to go without fussing with weights/foam.

-Jeff

[southern or]

Re: Last of Kevin's OSCARIIs

I'm pretty confident my current tanks will be good enough. My CG will be a bit off because I'm limited by the length of my prop shafts and the length of the pistons. The end of the WTD is a foot from the tip of the bow.

[southern or]

Re: Last of Kevin's OSCARIIs

I was wondering, my ESCs have built in safety overrides for the batteries, but the TAE system doesn't. Is there anything I should put between the battery and the TAE besides a fuse?

[southern or]

Re: Last of Kevin's OSCARIIs

I was wondering, my ESCs have built in safety overrides for the batteries, but the TAE system doesn't. Is there anything I should put between the battery and the TAE besides a fuse?

Update on progress: I haven't made any. I am thinking of cutting the top's bow off so every portion of the top of the hull that has operation parts attached to it is permanently attached to the rest of the boat. Between the pain and the amount of tremors the injury is causing, I don't trust myself in doing anything right now. I am making progress on a test Romeo right now because I have 2 kits and I can't do nothing.

[southern or]

Re: Last of Kevin's OSCARIIs

[quote]

I was wondering, my ESCs have built in safety overrides for the batteries, but the TAE system doesn't. Is there anything I should put between the battery and the TAE besides a fuse?

Update on progress]

Serious cockup. I'm going to have to fabricate the bottom shaft housings after one of them went missing.

[southern or]

Re: Last of Kevin's OSCARIIs

I've significantly shortened my lifespan, but ALL of the electrics work like a charm. 3x batteries was a good call, but the F-14 has a terrible battery life. Body work is coming along.