Next Build Type XXI or Similar Options

[JWLaRue]

Jeff I would love to see the type XXVI at the next meet if you don't mind bringing it. Btw, it sounds like there will be almost as many XXI s in SubComEast as 212s soon.

I'll be glad to bring it with me. I had it with me last time, but you probably didn't notice it.

-Jeff

[thor]

Mike,

Yes, all of my hulls are vacuum bagged and have structural carbon fiber in strategic places to make them the most rigid and lightest hulls available. Makes for a much smaller ballast tank(much thinner laminate).

[sam reichart]

To answer one of your questions, I'll be using an OTW cylinder (exact diameter tbd). Jeff and I are going to be doing ballast tests with the XXI and my Ohio I had at Jim's at the March fun run to determine cylinder requirements. OTW cylinders are pretty much ready to go. Just add servos and a receiver. They are smooth as silk. But you do pay for it.

And yes, a two prop boat does use a cylinder with two separate motors. They do rotate in opposing directions.

Dealing with a hull with scribed details requires a little careful planning. Using light-coat primer and paint so as not to fill in the scribe lines. If they are not very deep to begin with I usually prime and then re-scribe through the primer to keep the line as prominent as possible.

-erich

Erich/Jeff- please keep us posted on what you end up with from Bob/OTW with this model? Thanks!

[JWLaRue]

Will do!

I am assuming (hoping!) that the 90mm diameter module that I am using in the Type II will have sufficient ballast to work in the Type XXI. We should know better soon.

-Jeff

[thor]

Jeff-Please take some photos of the installation when you are working through it! I would really like to show it and one other installation in the instructions we are putting together for the Type XXI.

[JWLaRue]

I'll be glad to!

-Jeff

[sam reichart]

Will do!

I am assuming (hoping!) that the 90mm diameter module that I am using in the Type II will have sufficient ballast to work in the Type XXI. We should know better soon.

-Jeff

so, that works out to Bob's 4 inch tube, then?

[Ralph --- SSBN 598]

90 mm = 3.543 inches

Handy-Dandy measurement converter

[sam reichart]

90 mm = 3.543 inches

Handy-Dandy measurement converter

heh. I even used a calculator and got it wrong. (somehow I got 3.99) . either way, I was worried a 4 inch might be tight in the opening of the type XXI hull. 3.5 makes me feel better. thanks Ralph.

[Parallax]

Erich, what type of ballast systems does the otw cylinders use? Do most of the electronics come with it?

Jeff which cylinder system are you using in your type ii? If that does not work, do you know what your call back is?

[sam reichart]

Erich, what type of ballast systems does the otw cylinders use? Do most of the electronics come with it?

Jeff which cylinder system are you using in your type ii? If that does not work, do you know what your call back is?

here you go, Mike:

http://otwdesigns.com/products/components/dive-components/

[JWLaRue]

I trial fitted the OTW 110mm dive module (their standard size) into the Type XXI. While it will fit, it appears to me to be oversized for what is needed. Plus due to the narrowness of the bow/stern you end up with some pretty acute angles for the prop shaft connections between the dive module and the shaft tubes in the fixed stern planes. When we get together for our next SubBuild day, I will take photos of both dive module sizes in the hull so that everyone can see.

Mike - the OTW modules come with everything except the receiver and servos. The ballast system is a water pump-based system that is controlled by a custom control module provided by OTW. The control module also provides an automatic shutoff when the tank is full or empty. It will also empty the tank if the voltage falls below a certain point.

I am using the 90mm OTW dive module in the Type II. Based on the amount of freeboard that the II has vs. the XXI, I'm pretty certain that it'll handle the XXI....but we'll know better in a couple of weeks!

-Jeff

[thor]

Bob will customize a cylinder for you! Just tell him what you need. He did that for me on a custom build for a client.

[sam reichart]

Bob will customize a cylinder for you! Just tell him what you need. He did that for me on a custom build for a client.

yep. he states it right on the page I linked above.

You're getting your system ready as well, right?

[thor]

Sam,

Yes, I am. As soon as the 2.5" WTC is released I'll get back to work on the system for the Type XXI and the other larger kits.