Rick Teskey seaview build

[greenman407]

Funny that you should mention

Funny that you should mention that. Dave Merriman mentioned that he had a problem with that when building the Deboer Seaview. I have not experienced even the slightest tendancy to nose dive. Are other builders of Moebius Seaviews having this problem? Perhaps it is the slight difference in the design of the nose of the 4 window version verses the eight window version. If you would like to email Rick Teskey you can do so by looking it up under the members list button at the top of your screen. He can give you some insight on his adventures with his Seaviews. I have heard that this problem gets worse the faster you go. My Seaview is not very fast , so that may have a bearing on it.

[Guest]

Yes speed has everything to

Yes speed has everything to do with the dive problem.but bow planes will help.

Dave

[junglelord]

How was your Debor set

How was your Debor set up Dave?
Did you have bow planes?
How much nose dive tendency did you boat have?

Do you intend to increase the speed of this boat greenman? The scale speed and performance is eye catching as it is....really good videos.

Do you think that the increased external controls on the nicelles helps to override some nose dive tendency? Which I like by the way, very cool mod.


I know I was all hung up on cutting the manta fins, but Dave Merriman has shown me the light and given me the confidence to acheive.

[greenman407]

The videos were not taken

The videos were not taken at full speed as I am still in the testing mode trying to keep motor temperatures down. I was hoping for a little more speed with these new motors but I can live with it if I cant find anymore motors. I could go with brushless motors but then I would have to buy two new speed controls as I am independantly controling both motors on there own channel so that I can steer tighter turns if I run out of room. As far as my stern plane modifacation, I believe it is absolutely necessary unless you are going to use the sail planes. I am going to do both to ramp up the manueverability. It would seem that it helped any tendancy to head down while underway.

[junglelord]

Yes, I am hoping that

Yes, I am hoping that a combination Sail Planes and Stern will give me close to the performance of a Seaview with Bow planes.

I really love your videos...keep it coming.

[greenman407]

An interesting thing happened Dec.

An interesting thing happened Dec. of 2007. It was the occasion of the maiden voyage of my Seaview at a fun run in Georgia. I had two Hitek four channel radios, one for the Albacore and the other for the Seaview. When it came time to put the Seaview in the water it suddenly dawned on me that on the radio of the Albacore I had changed the dive plane control stick by removing the spring mechanism and replaced it with a friction device to make it easier to control the subs riding easily at periscope depth. I had not done the same for the radio of the Seaview. After all, this was to be her maiden voyage. I wanted everything perfect. Ill just use the radio from the Albacore on the Seaview, all Ill have to do is change the crystal and we will be good to go! Wrong!!! I forgot about the chance that a servo might be reversed. It was!!! It started out fine. I always leave the planes in nuetral for the dive and just flood the ballast tank and that will just carry it under , then I nudge the planes to bring it to periscope depth. As soon as it went under it nosed dived into about a 45 degree angle and headed for the bottom. Since the dive planes were reversed the apc reacted when the nose dropped and adjusted in the wrong direction. When I saw it going down I hit full up on the planes(which was actually full down). By then it was out of sight so I hit full reverse but I could not observe what was going on. I then hit the blow ballast stick. I could actually see the bubbles coming to the surface but NO SEAVIEW!!! So I went swimming and retrieved it in about eight to ten feet of water. What happened??? Stay tuned.

[junglelord]

Oh man, I hate stories

Oh man, I hate stories like that.
I hope to learn from others mistakes and not have any crucial events...but I am eager to hear the final results

[greenman407]

Why didnt blowing the ballast

Why didnt blowing the ballast tank arrest the downward plunge? It took me over a year to figure it out. I was testing it in my swimming pool one evening. I could clearly see what happened. You see I was on the surface initiating a dive in a heavily clorinated pool that was interfering with the radio signal. It went under at an extreme angle and was heading for the bottom and not responding so I shut off the transmitter. At that point the failsafe kicked right in and blew the ballast tank. I could actually see large massive bubbles leaving the bottom of the hull but the Seaview was again not coming up!!! AH HA! I got the Seaview out of the water , pulled out the WTC and put it back in the water for a little experimantation. You see the large holes on the bottom of the ballast tank are there to admit water and in this condition provide bouancy as long as the vent valve stays closed. When you blow the ballast tank , these very same holes are used to allow a way for the water to escape. But when you are at a high angle of attack such as when your sub is headed for the bottom at a forty five degree angle, The holes are in effect no longer on the bottom but are now on the side! End result is that your ballast tank will no longer hold the gas that you blow into it! Dont believe me? Take your gas operated WTC and put it under water so that the large holes are at the bottom. At this point it is full of air and you can feel the bouyancy. Now tilt it to 30 degrees then to 45 degrees. Over half of your air just escaped! No problem if its full of water going down and you are undercontrol but if you want it to come up , blowing the ballast tank wont do it. That is until it hits the bottom and probably rights itself. Then your ballast tank can now hold the gas you pump into it. Thats what happened over a year ago.

[greenman407]

Whats that you say? Why

Whats that you say? Why didnt the Seaview after hitting the bottom not then respond to blowing the ballast tank and come up? Very simple. I had it ballasted in a not very conservative way. I was running it " in the wild". I did that because I wanted to be able to dive without any forward motion. Thats fine, but if you leave it that way without readjusting the ballast so that your upper sail sticks out of the water with your ballast tank full of water ,you run the chance of finding yourself on the bottom and not enough reserve bouancy to get it to rise. Of course if you only run in shallow water then youve got no worrys mate. Thought that I would share that with you.

[greenman407]

To illustrate this effect ,

To illustrate this effect , take a properly trimmed sub with a flooded ballast tank and the sail just sticking out of the water, grab it and push it down under the water about 18 " and let it go. It will come back to the surface but very slowly. Now push it down harder so that it goes out of reach, down to about 3 or 4 feet and see what happens. It wont come back up, in fact it will start on its way to the bottom going faster and faster on its way down as it in reality becomes heavier. Thats because the added pressure at that depth and deeper cause a constricting of the hull and thus reduced bouyancy. Is that spelled right? Its weird but its true. Took me a while to figure it out.

[greenman407]

I mentioned earlier that I

I mentioned earlier that I was going to make a alluminum motor mount. Well here it is.



A local machine shop provided me with the alluminum and counterbored the holes for the motors. I then had to shape it and carfully drill the holes , including the new holes to mount the motors with. Since there would be a conflict with the heads of the screws and the mounting surfaces I had to countersink them using a countersink






After that I moved on to changing out the damaged gears with new ones.

Here is the copper pipe that was used to make the motor heat sinks shown installed here.

Next weekend I will run it and give yall a full report

[greenman407]

Look at these brushless motors.

Look at these brushless motors. They might make good motors to swap out for the speed 400s
http://www.hobbybarn.com/proddetail.php ... 00&cat=138

[greenman407]

How about these nifty speed

How about these nifty speed controls. I would need two of them. Anybody have any experience with this brand of speed control and motors , good or bad?

http://www.hobbybarn.com/proddetail.php?prod=EFLA312B

[greenman407]

Success!! I ran it today

Success!! I ran it today for about 35 minutes without a problem. When I was finished I opened up the WTC and touched the motors and heat sinks. They were too hot to comfortably leave your hand on them but not hot enough to be worried about. As far as speed was concerned I am satisfied. Its not a speed demon but it is quite acceptable. Just as an experiment I disconnected the apc and ran it to see what would happen. To my surprise It needs an APC to keep it stable, otherwise its up and down. The next step is to run it at night with the lights on. I will try to get it on video but I dont know how well it will turn out. After that the next step will be the sail planes.

[junglelord]

I LOVE your Seaview. Congradulations

I LOVE your Seaview. Congradulations on a success conversion.