Seaview

[crazygary]

Would appear you have all your ducks lined up pretty well!!

Hope all goes as planned for you, and... careful with the hole saws!!!
They tend to "grab" from time to time!!

Would be happy to do a little machining for you, except for the fact
that we're on opposite "coasts"!!" In-transit" time alone would warrant
doing what ya gotta do!! Otherwise, would be happy to lend a hand!

Have a good one!

BTW: What is that Radio Shack tool in one of the photos? Heat gun??
Looks like something I "need"!! Hah!!

[greenman407]

As you can see , I go back and forth between projects. Not to mention ,working on my Moms house. Got a little bit done today. I took the 3&1/2" tube that I bought and cut it down to 8" Long and then sanded tha areas that will be CAed or epoxyed. Then I took the Venerable 3" D&E Twin motor twin drive WTC of 2005 vintage and(maybe the children should leave the room)Amputated 6&1/4" of it. Not for the faint of heart. Also, I cut out the plastic sheet strips that I will use as a spacer at the joint. I started out with 1/8" material but you have to bend it using a heat gun and if its not perfect then.........well its not perfect. Then I tried .080 thick and it left too much slop. Finally I used two pieces of .060 and that did the trick.I will jig it up on a flat surface to hold it straight while glueing. The joint will be a overlap of 1&3/4" and will be glued inside and out. The plan is to restore the original dimensions to it lengthwise. Ive got the motor bulkhead ready for a trip to my former place of employment(yes they still tolerate me) to use their drill press to machine(hack) the recessed holes for the motors into it. Details on the way next time.

[greenman407]

The motors will have to be recessed into the bulkhead 5/8". Then the bearing housing bullnose of the motor is 3/16" deep and 1/2" in diameter. Thatll have to be drilled in too. Have to be carefull I dont go all the way thru. I guess If I did I could just fill it up with epoxy and try again. Also the motor mounting bolt holes and the two pushrod seal holes. Oh yeah, we will need a hole for the antenna and two holes to hook up power.

[greenman407]

Well................................why not. Here is a 3 and 1/2" twin motor bulkhead, I got from Mike Caswell and the "Garage Sale". The modifications to convert this to direct drive will be major. My plan is to recess the motors up inside the bulkhead because the motor shafts are not long enough to reach thru on there own. Ive ordered two special seals for the 1/8" shafts but they must mount to the outside. Enough of the shaft has to extend outside the bulkhead in order to attach the brass drive dogs to them. Since I dont own or have access to a lathe, we will have to do this the hard way. The motors are 1 and 13/32" in diameter.
So, First thing is to fill up the previous motor drive holes with epoxy. After it hardens we will mark out the center and using a drill press, drill a 1/4" hole. That hole is there because the hole saw bits that Im going to use, use a 1/4" drill bit as an arbor. They dont make the size I need so we will use a 1&3/8" for the maximum outside diameter. My experience with these hole saws is that they cut a little big. If not we will open her up a little bit. We will use 1&3/8" and a 1" and a 3/4" to give us some material removal. After that we can trim the rest out with a Dremel end mill.We will dress up the bottom of the holes with a 1&3/8" Forestner bit

[greenman407]

Direct? No gear reduction? I hadnt thought of that.

[He Who Shall Not Be Named]

Cut those four-bladed impellers back to two blades and you can drive them direct from the 550 motors. Hope you don't twist the blades off the hubs!

M

[greenman407]

Another good thing is that the 3&1/2" motor bulkhead that Im going to use is the older style with the gearboxes on the outside. The good thing about that is, that I believe I can make changes to the gear ratio, if needed. Dave supplied me with some new empellors to replace the four bladed ones that I cut down to two. Thatll give it more to push with. After we get it running, we can determine If there is enough motor power to go to 2&1/2 to 1 from 3 to 1. Ofcourse, it depends on what gears are available in that size and style. SDP(Stock Drive Products) had a large selection, last time I looked. We will see. Maybe the 3 to 1 will get the job done.

[greenman407]

Got her into the water today and drove up and down the lake three or four times, submerged(DUH). I found out what I needed to know. I can now order my 3&1/2" tube and start preparing my motor bulkhead and equipment tray. This things got a lot of drag. Each of those eight windows is recessed. In other words, there is a piece of clear lexan behind those window openings. Therefore as the water hits the bow it goes into those windows and is then forced back out, spilling out over the edges, therefore, unwanted drag. I could take out the flat lexan but , having it in makes it look more real. So we need more ponys to push this thing, thus the 3&1/2" motor bulkhead and its 540 motors. The 400s in the 3", just wont cut it.

[greenman407]

[greenman407]

After running the Seaview the other day, it occured to me that , with some reconfiguration of weight and foam I could probably realize some more freeboard and thus it will float higher in the water. So that has been some of my focus today. I gutted the forward section and packed her with some more foam. I had determined at the pond how much more I would need, front and rear. It should be real close. Also at the pond the port side ESC refused to work, You see Murphys Law kicks in and allows me to drive 60 miles, and then find out it doesnt want to work. It worked fine the night before. Oh well, it gave me an excuse to go by "Lovins" and get some WINGS. So I had a spare ESC that I am installing. So the goal is to get back to the pond on Monday, along with the Scamper for more tests.
Notice that the stern is packed full of foam. Thats no easy trick. Also, the Battery WTC for the LIPO. I realized a tremendous advantage by using it. I am able to do this because the three inch Subdriver has a huge ballast tank on the order of almost 12" long.

[greenman407]

Tommorow, I have an appointment with the Seaview at the pond. I want to operate it as is so that I can see the present state of affairs before the modifacations commence.

[greenman407]

I just made a deal with Mike Caswell for an older 3&1/2" , twin motor, twin drive bulkhead. I love it when a plan comes together.

[greenman407]

Thanks Andy for your suggestions. In any endeavor, making an informed choice, is always best. To do that, I need to know all my options. Thanks for your help, as always.

[greenman407]

Thanks Andy. I already have those motors in it. They are the Speed 400 long can motors that run on 12 volts. They helped. I have some models that are powered by brushless motors. I dont feel that they and there ESCs give you much control. They are made for all out power, with very little emphasis on RPM range control. Also, I have not had much success with Hobby King and the like and the Cheap items that they sell. The motors and ESCs that Hobby King offers, are cheap, too cheap in my opinion to put any long term faith in. With Daves stuff, I know what Im getting.

[Subculture]

Not really. Tugboats tend to be fitted with fairly large can, high torque and low revving motors. They have chubby hulls which can accommodate such things. Subs sometimes have the space for bigger motors, but this one sounds fairly tight to me.