Albacore continued

[greenman407]

OK..............ok

[Slats]

I like the bow planes but they cut em off during phase 2.

I guess Mike's not going to move the 3" SD build to its own thread????

J

[He Who Shall Not Be Named]

How about it, Mike: Yank the 3" SD discussion to its own thread, please.

David,

[greenman407]

The bow planes were added because I didnt have a sub that used them and I wanted to see there effect first hand on a submarine. On this boat, if you try to go forward at anything other than creeping speed it will try to dive on you. It cant but it trys nontheless and then all forward motion stops as the prop comes out of the water and it looks like a duck with its tail feathers in the air looking at the bottom of the lake. By engaging the bow planes you can move forward quite fast without it diving when the bow planes are in the rise position. With the X-tail this sub is so manueverable that it doesnt need them at all.

[greenman407]

Notice last nights efforts. After making the first bulkhead and doubler I had to make another smaller one to go just behind it to carry the aft end of the second shaft. Ill get out my trusty laser projector and plot the centerline and the second shaft up and down locations for the bearings.

[greenman407]

Above you will notice all those nice little bearings. The first set is thrust bearings that will go between the two props to keep them from inducing drag to each other. I have already used a Forstner bit to countersink a space for them so that they will not be visible. The two smaller bearings will carry the second shaft. The larger ones will carry the 3/16" shaft encased inside the outer tube that will spin the larger propellor. As we move on in this thread it will become quite obvious. I have been running thrust bearings in my Oscar for a year and a half now with no problems. Of course I keep them lubed after a run..

[greenman407]

Here is a thread that I started a while back on it.

http://s181686668.onlinehome.us/phpBB3/viewtopic.php?f=21&t=8746&hilit=Forstner+bits

[greenman407]

Also I had forgotten about Dave Merimans dual prop Albacore.

[He Who Shall Not Be Named]

It was a bullet. Scary fast!!

(finishing the 3"SD bulkhead masters today).

David,

[greenman407]

After this we want to add liquid polymar injection over the hull and props!...................You got anything for that Dave?

[He Who Shall Not Be Named]

After this we want to add liquid polymar injection over the hull and props!...................You got anything for that Dave?

Yeah, I got something for that:

LAY OFF THE CAFFIENE!

You nut!

David,

[greenman407]

The best laid plans of mice and men tend to come to naught.

[greenman407]

Last nights progress. Using a laser level I projected a line down thru the center and made my marks on the bulkheads. Then I moved the projector over exactly 3/4" and made the other marks. That was for lateral location. I then did the same for up and down, using the center of the cone as a reference. Today I will drill out the holes for the bearings.

[greenman407]

Next thing was to drill some precision holes for the bearings so that we wouldnt have a sloppy fit. That was accomplished with great care. Next I cut a piece of 3/16" S.S. shaft 3 and 1/2" long. Its dia. is a little snug fitting inside the bearings so Im going to polish it down for a slip fit. You can see the gathering of parts for the secondary shaft, which includes two roller bearings, the shaft, brass drive end, teflon gear, two locking collars and two teflon washers. I did some research on glueing S.S. to teflon and what they tell you to use is CA with an accelerator. Im going to rough up the inside of the gear and outside of the shaft at the proper location and CA it there. The bearing that goes in the far back is 1/2" outside dia. So I marked it and will cut it out carefully by hand as Im afraid a 1/2" drill bit will mess it up big time..

[He Who Shall Not Be Named]

Mark,

Very good work. Now ... not to **** on your parade ... some cautionary words about the tight fit you're heading to with your running gear:

Keep in mind that the polystyrene, Nylon gears, brass bushings, and stainless-steel shafts and bearings all have different coefficients of expansion/contraction with temperature change. Secure your bearings into those bulkheads with a flexible adhesive, or work up foundations that will displace laterally and longitudinally the amount needed (figure a travel no more than .030" each way) to compensate for both temperature induced structure dimension change and torsional and compressive structure displacements as a consequence of dynamic loads on the vehicles body.

Also, you want to mount those pinion and spur gears (the ones in the wet) so they mesh loosely. Remember: your spinning this stuff in an un-compressible medium (water), and the tighter the fit of the gears, the more water-hammer effect they will suffer (think, gear-pump).


Guess what clued me into the issues of structure expansion rates, structure elasticity, and fluid incompressibility issues as they relate to the ALBACORE phase-3's running gear, Mark?!....

David,