Scale Ship Oscar 2

[greenman407]

This computer is slow as

This computer is slow as a slug. Ok , here we have my estimations as to where the 2 WTCs will go, front to rear based on center of gravity. Wadayathink?





As I previously posted it became necesary to add internal bracing to hold the hulls shape and proper dimensions. I went to a plastic supply house and got a small sheet of 1/8" and carved them up as you can see. The next step will be epoxying them in place. Later with my trusty Dremel I will carve out the shape of the WTCs in them. Or maybe I will do that before the epoxy

[wayne frey]

She's looking great!!!

She's looking great!!!

[greenman407]

Thanks Wayne! Yeah were going

Thanks Wayne! Yeah were going to be sinking capitalist aircraft carriers here in a couple of years.(hope it wont be that long) I have everything pretty much worked out in my head as to how I am going to make everything work, I just need a break so that I can get to it.

[wayne frey]

I should be updating my

I should be updating my build thread this weekend. There are some nice Russian boats nowdays. We will have our own "Red Fleet"! Love to see that one running alongside of Kevin's Oscar. It would be a sight!
Yes, the builds take quite a lot of time, for sure. I am having fun with mine.
No excuses! Use every spare moment!

[greenman407]

Re: Scale Ship Oscar 2

OK dudes, back at this thing





After moving two times in the last four months here is my new garage/ workshop.




Earlier we talked about the Z cut. In order to keep the two hull halves together it was necessary to cut and install a piece of plastic 1-7/8" wide and epoxy it in place at the front in order to engage the other half of the hull. Here you can see it in place held together by various clamps as the epoxy dries. Then the next thing was to work on the stiffeners/supports. As I showed in past postings , they were already formed previously. I just needed to mark the centers of them and cut out where the WTC would be cradled by them. On the SEAVIEW I set the height of the wtc above the bottom of the inside of the hull at 5/8". It worked well so I saw fit to keep it the same on this boat. I took the frames to work and used the company band saw to slice into the frames at the points that were marked and removed as much material as possible. Then in my new workshop I pulled out my Rotozip, kinda like a super Dremel. and installed a Dremel cutter as the Rotozip cutters are far too aggressive. I then put it in the vice and used it to trim out the rest of the material. It worked well








More soon!

[greenman407]

Re: Scale Ship Oscar 2

Notice this picture.

You can sense my distrust of plastic as you can see the double thickness that I used for the stiffeners. They serve the double purpose of holding the WTC , 5/8" up off the floor of the sub, as well as holding the the inside dimmension of the lower and upper hulls. I wont need to put bulkheads in the upper hull half because...................

Notice the robust indexing flange on the lower hull cast in at the factory for precision engagement . In other words it goes together easily and aligns well. This is going to work well. More later!

[greenman407]

Re: Scale Ship Oscar 2

This boat has lots of vents and scuppers. As you install the inner cross frames be sure that you put them between the individual scuppers. Otherwise as you open them up you will bump right into your frames and then forever more you will be able to look into the scuppers and see your mistake. The other concern is that as you epoxy the frames in place you dont build into the hull a twist. As you can see in the pictures I put the hull on a flat work bench and weighted it with anything I could find that would have any weight to it. Then I sighted across with my eye just to double check my alignment.



I first tacked the cross braces in first with CA and then put the two hull halves together to make sure that everything was good(proper width and good engagement). After this I put a full bead of CA all the way along one side and hit it with accelerater. My purpose here was not to hold it with strength but to seal it so that the liquid epoxy would not leak thru. Then later came the epoxy while I leaned the hull at a 45 degree angle so that the epoxy would form nice neat filets. Be forewarned that it is necessary to sand the fiberglass so that you get a good bond between it and the epoxy. I have forgotten only to have it pop lose the first time you put any pressure on it. Like when you are trying to file out all the holes. Its funny that it will pop lose from the GRP but not the plastic.












Then I test fit again the WTCs and they fit perfect. You can also see here to advantage the wood stand that I made for it. Cheers

[KevinMC]

Re: Scale Ship Oscar 2

I wont need to put bulkheads in the upper hull half because... [snip] the robust indexing flange on the lower hull cast in at the factory for precision engagement . In other words it goes together easily and aligns well.

Hi Mark,

It's great to see your OSCAR build thread moving along again. Of course your experiences may turn out different than mine, but I found that over time the upper half of my OSCAR hull tended to spring outwards not inwards so the (comparable) alignment strip in my hull is not typically in contact with the upper portion of the hull.

In addition to a couple of bulkheads which I needed to support other features, I've installed numerous keeper tabs on the upper portion of the hull which make contact with the inside lip of the lower indexing flange so that the upper portion of the hull cannot bow either in or out. The combination of tabs and bulkheads (lower and upper) keeps everything in tight alignment.

You may yet want to consider installing something in the upper portion of your hull to prevent running into similar issues. YMMV

[greenman407]

Re: Scale Ship Oscar 2

Thanks Kevin. Your input is valued highly! Now that you mention it I will need at least one stiffener toward the front to mount the bow planes servo, so while I am at it perhaps I should add two more. Since the upper hull is going to be restricted in movement outwards at the front by the nose cone and at the stern by being held fast to the stern section then everywhere else in between could bow as you said. I suppose I could put in some longitudinal stiffeners as well. Ill have to give it more thought.

[greenman407]

Re: Scale Ship Oscar 2

I noticed that on the scaleships website that he now offers a bow planes retract mechanism for 138 Euros. Looks nice but I think I will stick with my original plan to make a fixed bow plane mechanism.

[pirate]

Re: Scale Ship Oscar 2

Just a note. After the regatta two years ago, I came home and took my Seawolf apart to unhook the battery and take the WTC out and open it to dry out completely. I set the top of the hull down next to the bottom and left it. It ended up sitting there apart, in two sections, for almost a year when I finally got back to it to refresh for last year's regatta. By this time the top hull half had bowed out wider than the bottom by just sitting there with nothing to hold it in place, and gravity doing its bidding.

So whether you put in tabs, or stiffeners, or whatever, don't leave the halves sit apart for any length of time unregistered to each other, or else.

Pete

[greenman407]

Re: Scale Ship Oscar 2

Thanks Pirate, I appreciate the voices of other peoples experiences. Thats what makes Forums like this one so invaluable!

[greenman407]

Re: Scale Ship Oscar 2

Back at it! On the upper hull half there are quite a few scuppers that need to be opened up. They are well formed and are square with the center recessed. As I showed before this hull comes with a sheet of brass parts and in this case the scupper covers themselves. The way they are designed reminds me of what we called trash covers. For the Crystal River nuclear power station water cooling vents we made these frames that prevented anything large from getting through them. In the picture the covers are the ones in the lower right.

I had my choice of leaving the scupper un-opened and just ca the cover over it, in such case it would look like this

I didnt like the idea so I resolved to open them up along with most of the other vents that are on the bottom of the hull( gotta let water in)!

[greenman407]

Re: Scale Ship Oscar 2

Since I want a good looking finished product ,care must be taken. How do you make a laborious task like this quicker and easier? With power tools of course!!! Tool Time Tim would be proud! First I got out the trusty Dremel and installed a 3/32" drill bit and by eye(you can mark it if you need to) carefully started to drill the hole in the center. Just barely touch it ,then withdraw it and you can see if its in the center or not, if not then adjust it. It doesnt have to be exactly perfect but you do want it to be pretty close. This is the centering hole or starter hole. After that you come back with a larger drill with a 1/4" drill bit and drill it the rest of the way out. It sounds like we are using a chain saw when you really should use a razor saw but for me it works well. I didnt make one mistake because I took my time with it. The 1/4" bit is just a little bit smaller than the scupper area.




In this shot you can see the brass cover now over the drilled scupper and it still is not what I want as you can see the edge of the 1/4" hole through the brass cover. Now the gloves come off. Its time to break out the set of modeling files. A three (3) sided one worked the best for me all though the four sided one is shown here.(Ooops, where is the picture with the file in it? Must have got lost somewhere in cyberspace) Just file out the corners and then finish up with a small flat one to true things up.


Now that looks so much better. Next steps are doing the same to the vents on the bottom, putting braces in the upper hull and working on the rudder and dive plane installation in the back section.
Plenty to do!

[boss subfixer]

Re: Scale Ship Oscar 2

Very nice!