1:72 Los Angeles

[ManOwaR]

Thanks Daniel! In terms of 'master' though, I indeed have to defer to Dave for that title!

Another point on priming, is that fillers, especially the one part red lacquer types, are designed to adhere to primers, not really so much to the substrate itself. Always lay down a coat of primer on that bare surface before filling. This will pay dividends down the line when your submerging your model in cold water and you have all those different materials expanding and shrinking at different rates...you'll get less cracks etc because things are bonded together better.

[spankey]

Well, there are alot of folks on this forum who at the very least get close to that title. They might not be "The Master", but either way, I appreciate all the help!

Different coefficients of thermal expansion....I thought I left that behind when I left school....NOT SO. I will mind that, since here in the Pacific Northwest, we can still drive boats in the winter, the water is just bloody cold.

When I was out there tonight, sanding the filler on the sonar dome. I noticed that the bottom hull half, while it meets the top hull half OK, the sides/corners of the bottom half seem to stick out past the sonar dome, and into what will be oncoming water flow. Might not be describing this well, but either way, I need to restrain those corners where the bottom meets the sonar dome with something... I superglued a couple of extra chunks of indexing lip up there, and that 'sort of helps', but I am considering cutting a former of 1/2" thick plastic to fiberglass up there, just aft of the joint between the top and bottom halves at the sonar dome, and have two small machine screws on the P/S sides, going into the plastic to keep those edges in the right spot.

Anyone have thoughts on this?

I should have the camera tomorrow, so I'll have more to show then.

[spankey]

So the followup thats been needing to get posted for a few days now....

Indexing tabs shown below...



Now some prop shots... I've got a 5/16" Stainless steel shaft. Yes, you'll say this is too big, but this is a big boat. Also is a piece of 3/4" thick polycarbonate (its actually bullet-proof). It has an angle that matches the internal angle in the boat's stern. I will use it as a support for the 5/16" Oilite bearings that are coming from McMaster...

[spankey]

Part 2....

I'm working on positives for the stern planes. I haven't made rudder positives yet. These have been shapes, but they havent been sealed yet.



Next thing I'll be doing is reading David's cabal reports on how to make molds with silicone!

Yeah, I've got my work cut out for me...

[He Who Shall Not Be Named]

Good, sound engineering; you're comfortable around machine tools; and you are a bit of a Model Builder too. This is going to work!

David

[spankey]

Next batch of pics. I am working on the second bearing for this tailshaft. You can see the plexiglass shaft support. Trick here is making sure that the (Large) 5/16" oilite bearings don't bind the shaft, since there will be two of them. I fiber-glassed the plexiglass shaft support into the tail of the boat. I will be inlet-ing the extreme tail of the boat to allow for an M5 nut (going to find a thin nut, or shave it down on the lathe) to be tightened onto the prop, in addition to the red loctite that I'm going to use to make sure this excellent prop doesnt wander off when I call bells for a 'crash astern'.

also a picture of the newly wet-sanded sail. I did it with 400 grit. Going to be working on getting some primer that will stick. I'll be referring back to your posts Joel. Thanks.

Getting ready for a subdriver. I'll use Plexiglass to make supports for pressure hull when the kit comes out for the dual 545 motors in the 3.5" model.

More to follow in a few days.

[spankey]

Just a few more of the planes. First set of molds was a sorry operation. The silicone mold release stuff I had that was aerosol did not allow the two halves of the mold to separate, so I had to cut them apart. In the process of cutting them, I wasnt able to get the hinge point to go into any of the castings, so I had to make do with brass, which I attached to the plane. See pics. I know, I know, its not pretty, but they are the right shape (after copious amounts of Evercoat), and they work....i.e. the stern planes work on their hinge.





Next batch of pics I have to take are of the tailshaft again. I modified it a little bit, shortening the threaded section, and getting a couple of M5 x 0.8 nuts, which I will use in addition to the red loctite to keep the nice propshopuk screw from spinning off into the dark oblivion of the depths...

Daniel-

[spankey]

Here are a few more photos of the tail feathers.

I have to point out that the quality of the prop from PropShopUK is amazing. I did not expect that the taper of the hull would so closely match the taper of the screw hub. This was an awesome surprise.

You should be able to see the prop shaft (5/16" stainless steel). I necked it down to 5mm, then threaded it with M5 x 0.8mm threads. On the end of the shaft, I turned off the threads (inside the prop hub, the threads do not continue all the way out to the end of the hub). Anyhow, there is room to have a small nut on the shaft, which I will use to lock the prop on there in addition to the red loctite. This is necessary when you are dealing with a 2.8" diameter prop that cost like $95. Crazyness!

I have a question....I soldered up a 'U harness' to operate the top and bottom rudders, BUT I'm not completely confident that its going to be stiff enough. Does anyone have any ideas about what else I could use to operate the stern planes and the rudders that might be stronger?



Daniel-

[He Who Shall Not Be Named]

Don't aganize over the strength of the rudder yoke -- you soldered it together, you can re-solder it back together if you cream the bottom. Don't sweat the small ****! Good looking work there, Daniel.

David

[spankey]

Since the sail that came with this boat was a 2 part operation, the inside is...guess what...hollow.

I wondered if it would be advisable to 'weld'..(fiberglass) into the bottom of the sail a couple of brass threaded rods that can be used to hold down the sail, so that it would be removable....basically the same way that Mr. Merriman's 1:96 Skipjack sail is held down? The goal with the sailplanes is to couple them to a leveling device so that when the boat is trimmed for periscope depth, the sailplanes are doing the depth control rather than the stern planes. Anyone have any thoughts on this? I dont even plan on having the sailplanes controllable via radio.

[He Who Shall Not Be Named]

Yeah, make the sail removable. Duh!

No. The sail planes are so closely coupled to the boats CG (for all practical purposes, the center of rotation about the pitch, yaw and roll axis) that they are useless as pitch change-control control surfaces. They are used for depth control only. You want to hook up a gizmo to them, make it a depth-keeper. Not an angle-keeper.

Stern planes are used for control of the boats pitch-angle. The sail planes/bow planes are used to effect fine depth control.





David

[spankey]

got it, thanks. I'm working on the planes linkages now, as well as the mold for the planes.

[He Who Shall Not Be Named]

Go get 'em, Tiger!

[spankey]

Just wanted to start this one out by remembering those among us who have died in the past 10 years fighting for our country. Specifically my friend, and fellow Kings Pointer, 1LT Will Donnelly, USMC, who would have been celebrating his 1 year wedding anniversary today had he not given his life for us in Afghanistan.

Greater love hath no man than this, that a man lay down his life for his friends. Lets all keep that in mind when we're out there playing, and remember what it cost to have the freedom that we do!


Now, on to the boat....

I finished the linkages for the stern planes. It took some persuading to get them to interface with the rudder linkage that was already back there. I only have like 25-30 degrees of plane operation up or down. Rudder has like 45 degrees in either direction. I think that should be ok...?

Also, I think it should be visible, but I have not yet figured out how to attach the top half of the hull to the bottom half in the stern area... I was thinking of modeling this after Mr. Merriman's joint on his 1:96 Skipjack...? Any ideas?

[He Who Shall Not Be Named]

You don't need much throw on the stern planes. And they stall out at about 35-degrees anyway. So, you have plenty of throw back there. Nice job.

Yeah, put a single retaining screw back aft and a retaining radial lip up forward and your hull attachment worries are over.

And your dead friend:

His life was taken by enemies of the United States, he did not give his life! His life was viscously TAKEN from him. I trust he would have much preferred to have taken the lives of our enemies. But, he was there, he stood tall, and fought as he was directed. We should nuke these *******s. The criminal slobs currently stinking up the halls of our Federal government (most who have never put themselves or their kids into harms way on behalf of this country) have been running these wars for show only; being way, way too concerned on how we look to the rest of the world rather than winning these engagements -- so many of our best have died in those sand covered meat-grinders when all that was required were a few well placed nukes. This thing should have been resolved over nine years ago! Where the hell do we, as a nation, get off thinking the rest of the world should -- or could ever be made to -- 'like' us!? I'll settle for abject fear the rest of the world would have of a resolute United States of America. The kind of fear that keeps ass-holes from flying planes into our buildings.

David