The Revell German 212 Submarine model 1:144 scale

[Kazzer]

I've been going through our inventory of these smaller boats with a view to seeing which ones are the most readily convertible to R/C with the minimum of effort.

All of these models are really only suitable for conversion to dynamic diving. In other words, they are not afforded the luxury of a ballast tank as there simply isn't any room. Diving is achieved by using the rear control surfaces and speed to force the boat under water.

My first choice is this Revell German 212 model, as the actual build seems to be minimal and we already have a suitable Sub-driver, so not too many things need to be custom made. What slows up the launching of these smaller vessels is the need for His Flatulence to make Fittings Kits, as every one of these takes at least a week of his time and some expense in molds etc.

I am not really attempting to build this boat to get it in the water and be a masterpiece, so I don't want to hear any dumb comments about the lack of my building skills. Lets get this straight now - I suck at this, and have never professed to be a 'kit assembler' or a model maker. In fact, only today, I discovered my utter dislike of Solvent Welder as I left two damned great fingerprints firmly embedded in the hull of this boat. Object of the exercise is to determine what's needed, and a general procedure here. My lack of skills here should uncover most glitches in the build process.

Onward!

Firstly, I needed to figure out how to get the Sub-driver into the model. The two halves of this boat have a flat 'shelf' under the superstructure, so the only way to get the Sub-driver in was to remove this. The superstructure, when glued to the sail, makes a good one piece part, ideally suited to be locked into place using locating tabs and screws.

I determined that the model could be split along the 'superstructure', so I took a scribe and made a number of passes along the crease between the hull and the superstructure on each half of the model. I included the sail. I managed to bend the sail back and forth until it detached, and did the same with the flat areas under the superstructure. To some degree, this was a mistake because the 'cut' wasn't quite clean enough and the bending back and forth removed a little too much material from the hull. So now I have to do a little filling there. I think I would have been better off making scribe marks on the outside, rather than the easier crease on the inside.


Here is the way I've decided to split the model. We'll not dwell on the small repairs I may make on the joint line. However, it would be worth some of you developing an improved technique to part these pieces more cleanly.



This is The Skipjack Sub-driver installed. Prod Code SD125SK $59.95
So far, I think its a perfect drop-in for this boat, but His Incredibleness might determine that we need a slightly longer cylinder. That is an easy fix and we can send that part later.

I discussed with His Almighty all the paraphernalia that is supposed to be added to the superstructure like bollards, masts, railings, and we agreed that this junk should be relegated to the trash bin. It simply catches weeds, fishing line and slows up the boat. Not that I'm recommending you sail this baby in a dirty old pond. This is a pool toy!

We also determined that the sail planes could be fixed, non operational, so I've glued them into a horizontal position.

The business end of this model is of course the X Tail. For those not familiar with X Tails, the diagonally opposing fin planes are fixed to the same shaft, so operate in the same direction when operated. All they did here was take a cross configuration of upper and lower rudder and rear planes and twist them 45 degrees. They are more complicated at the servo end, which I shall attempt to cover later. These fin planes (for want of a better name) are attached to a standard yolk system as in the photo below. (This is NOT the Revell 212 tail)


I stared at this photo for a while, imagining where the push-rods connect to the yokes, an then imagined the yoke servo being physically pulled back and forth. Then the penny dropped! I could see exactly how this works for the first time! Try and figure it out!


Here you can see a setup where we have 3 servos. The one outside the box is a sliding servo and the brass bar is connected to one of the other servos in the box. As the other servo is operated, it slides the yoke servo back and forth, giving us pitch and yaw. The third servo isn't used in this application.



Mr Wiz says that we can use the existing propeller without too much trouble, however, I noticed the hole in it was about 1/8" diameter. A 1/8" shaft would work, so we'd need two 1/8" shaft seals, then the inner end of it needs to be machined down to about 1/6" in order to put a rubber tube to the motor to make the flexible joint coupler.

To be continued (by you lot - I hope)

[Outrider]

Thinking about the fittings kit, the Revell 1:144 Type 212 should be a bit less time consuming for David than some other boats "in the rotation" based on the fine work he's done with the 1:96 D&E Type 212. Changing scale isn't push-button easy, but there surely are some benefits from, for example, the screw and tail sections he's already made in 1:96.

I think there is good reason for a fittings kit for this sub, if for no other reason than the X-tail. A resin X-Tail doesn't make a white metal prop a necessity, but it surely would add value and serviceability, if not performance. A metal screw would not only be more durable, it could be more easily adapted to the drivetrain David has in mind. (And David can provide spares readily. Herr Revell wants you to buy the whole kit over again.)

One challenge for this boat is sorting out the need for an X-tail mixer. (I'm not certain whether or not the "sliding servo" functions as a mechanical mixer or whether an electronic mixer is needed. There's also an open question as to which--mechanical or electronic--would work better here.) A longer (compared to the 1:232 Skipjack) WTC may provide enough room for the X-tail mixer in addition to everything else in the electronics compartment.

Another Revell 1:144 kit is ripe for RC conversion as well--the Type 214. Here's a link to the Builder's Thread entry my son made on his Type 214, which sadly still sits much as you see it in the thread:

http://forum.sub-driver.com/showthread.php?682-1-144-Revell-Germany-Type-214

Since the 214 has a more conventional control layout, it's likely to be an easier build.