Scale Ship Oscar 2

[kerry addington]

Re: Scale Ship Oscar 2

2 cents:
I have engineered removability as Scott describes into all such components when possible on my boats and am always thankful. This is because I am no expert.
I am resuming a build ( 80" Seaview ) after years on the shelf and the most daunting/discouraging part of the effort is the destructive removal and refit of previously bonded pieces, including the thrust bearing surfaces. The new ones will be indexed/bolted in case I ever need to move them again. I rarely get such things right the first time. My major motivator for this mindset is the scenario where I later discover a better way to skin a particular cat, but I let that cat continue to scratch me rather than go thru the more painful reconstruction solution.
-Kerry

[greenman407]

Re: Scale Ship Oscar 2

Well I am thankful that I have a few guys looking over my shoulder so to speak and who are willing to give me a nudge now and then. All suggestions are appreciated. Thanks guys.

[greenman407]

Re: Scale Ship Oscar 2

This thread has had over 6300 hits so there are a lot of people reading this. If you just want to read it thats cool! But if you want to chime in and participate you are certainly welcome. Thats what makes these forums so interesting , people willing to share in the building process. Give me your ideas, even if I dont use it I bet someone else reading it will at some point. Either way it adds to the fun. So dont be shy!

[greenman407]

Re: Scale Ship Oscar 2

I just ordered a Sombra labs reciever from Caswell for the Oscar. My is it small, its so small its scary!

[greenman407]

Re: Scale Ship Oscar 2

Ok Boys and Girls, today for show and tell I brought pictures from this weekends activities. In all fairness I could have accomplished more but I spent time rebuilding a 3.5 cc K&B marine engine for my Aeromarine Sprint Cat. The only excuse that I can offer is that submarines need targets.............. right? .............moving right along here, the Caswell/Meriman 3.5" subdriver needed a little help. The tray that you install electronics on flexed too much for my liking so I used a piece of brass rectangular tubing to provide some additional support as you can see.

Also you can see to advantage the large snort pump siliconed to the bulkhead.

Dave Meriman was kind enough to send me a couple of different styles of snort manifolds to try. I will be using the lower profile one.I was concerned about the small diameter tube that he used in the manifold construction but he says that they will work fine. He's the man!

If anyone wants the larger one , send me your address and I will send it to you.

[greenman407]

Re: Scale Ship Oscar 2

Also progress was made on the linkages. Since the 3.5" subdriver uses 1/16" pushrod seals thats what I used for the servo pushrods. I then soldered on to them 2-56 threaded stud ends to engage the spring loaded Sullivan quick disconnects.

Here is a shot of the final configuaration of the linkages.

They are also made of 1/16" brass rod. But to prevent flexing over the relatively long distance that they run I slipped over them a piece of 3/32" brass tube and soldered that on. Out of that another piece of 1/16" rod of the proper length to engage an intermediate connector was soldered in. The intermediate connector will be featured in the next show and tell. Stay tuned until after lunch.

[greenman407]

Re: Scale Ship Oscar 2

Its after lunch. Here are the intermediate linkages.

On the one end you can see the 5/32" Dubro locking collar that is used to give a means of adjustment . On the other end is a ball coupler for attachment to your quick disconnects. To demonstrate the up close and personal focusing capabilities of my camera, here is a in the face end view of the set screw penetrating the 1/8" brass tube to bite down on the 1/16" brass rods.

To give us some perspective on this project , here are a couple of shots of the hull without the stern section showing the Subdriver lurking inside wishing that I would get on with it!
In this view you can just barely make out the snort system 1/8" brass tubes exiting the endcap just above the three servo linkage outputs. The funny looking thing sticking up at a angle from the center quick disconnect is a intermediate rod sticking upward because of spring pressure from the Sullivan coupler.


Next stop: propellor shaft thrust mounting bracket etc , etc , etc.

[greenman407]

Re: Scale Ship Oscar 2

I realize that this build thus far is rather mundane and basic. It is not intended to educate you well seasoned chaps but to help those new to the hobby/sport. Please put up with me patiently.

[greenman407]

Re: Scale Ship Oscar 2

Drum roll please! An EPIC MOMENT HAS ARRIVED!!! I just finished filing out all the drain/vent/hole things!!! I did it a little at a time so as not to get bored. The hull ranged in thickness at those points from 1/16" to 3/16" so some holes seem to take forever while others go pretty fast. One thing is for sure, this fiberglass hull is forever, unless of course you run it over or something. Ahhh the grand feeling of accomplishment!.................. OK its over. Now whats next?

[greenman407]

Re: Scale Ship Oscar 2

In responding to you chaps suggestion that I install the prop thrust bearing plate so that it can be removed, my pea brane came up with this.


These were made from 3/16" x 1/2" alluminum flat bar bent around in a vise to match the sloping of the hull on the right and left sides for good bearing. Notice the slash marks I made on one side for better epoxy retention. I then put in the prop shafts and slipped on the bearing plate and marked its location and pulled it back out . Then came the Dremel to rough up the area. It was then reinstalled and Caed with a piece of plastic filler just on the front face. I then marked and drilled the screw holes, in this case 6-32 screws. Then taking the aformentioned alluminum angles they were placed behind the plate in position and the drill bit used again just to mark them. After they were drilled and tapped it was coated with epoxy only on the side contacting the hull and this time installed with a screw. Looks good.


The next effort will be getting the Subdriver electronics squared away and to install the stern section to the midsection. There are some marks(scribing) on the stern section that is supposed to line up with some on the midsection. Unfortuately they do not, so I guess I will have to get out the old laser level and a wrap around tape measure and accurately mark out centers.

[greenman407]

Re: Scale Ship Oscar 2

As I mentioned before the reference marks on the stern section and midsection seemed highly suspect so to play it safe I decided to make my own.

Using a flexable tape measure borrowed from my wifes sewing box and using the casting lines in the stern section which seemed reliable, I measured from them all the way around to the other side, found the center and marked it there. On the mid-section I just measured from one edge to the other and found center and made a mark for that. To prep the joint I cut grooves as you can see for better grip and generally roughed things up with the Dremel.

From there it was time to put it together. Aligning my marks I CAed it at three points. Not too much in case it had to come back apart. Before moving forward it is best to check alignment. I did it three ways. One is with a electronic level.



Stands to reason that if you put your level on the two prop shafts and compare it to the reading that you get with it resting on top of the indexing rail it should read pretty close. The second way that I used was a laser level.
I used it to cast a level horizontal line along the hull to reveal its alignment with the stern section.

In these two pictures you can actually see the red laser line.

[greenman407]

Re: Scale Ship Oscar 2

I then did the same thing from the front projecting the laser back through the hull from the front to see the relationship to the propshaft bushings.

The third way I used was to install the bow planes and then to sight back from them to the stern planes by eye and note any difference.At this point I am satisfied that it came out right the first time so I wont have to cut it off and re-do it.

[greenman407]

Re: Scale Ship Oscar 2

Now we are ready for epoxy. I have at the ready my two part high strength epoxy and my fiberglass cloth. After that I will tackle a large problem that has suddenly loomed over this project concerning alignment of the top hull with the upper portion of the stern section. They dont match very well!!

[greenman407]

Re: Scale Ship Oscar 2


If you look closely at the upper right and left corners you will notice a difference in the radius of the joint.

It becomes even more noticable when you have something to compare it to such as the mid-section. It was cast lopsided. After confering with my brethren the course of action I will take is to order from Mcmaster and Carr a 8/32 stainless threaded rod 6" long. Braze a nut and washer on one end. Then drill a hole in the upper port side of the stern section neer the joint. Running the threaded rod diagonally I will allow the rod to pass through to the outside with a nut and washer on the inside and adjust the nut outwards until the misalignment equalizes. At that point cut off the extra rod protruding from the hull and finish it over while epoxying the rod in place. What a mouthful! Im trying to stay on schedule here, I want this boat in the water in another month. Will I make it???

[ericpw8818]

Re: Scale Ship Oscar 2

I had the same issues with the hull not being 100% true. The mold lines on the tail section molding, and the line the top and bottom main hull
halves have been molded to are also not 100%. I have been having issues making alignment devices as well... its on the list.