Seaview

[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]

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

[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]

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]

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.

[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]

Gary, thanks for the offer. Yes thats a cheap Radio Shack heat gun I was using to help bend the styrene spacers. It works well.....................so far.

[greenman407]

Sometimes things will jump up and bite us. I started to put the lexan tubes together using CA. It was going well and I was sealing up all the seams inside and out. I left it alone to cure. When I came back there were all these stress cracks thru the new tube.
Apparently the tube couldnt stand the stress. I would say that the time and effort required to try and get the new tube off of the old one to start again would be too much. What now?
Well the tube that I ordered was called High Impact Polycarbonate tubing. Now I will order the more expensive variety of tube for both the three inch and the 3&1/2". Also I will use CA to tack it together but I will use 3M brand marine sealer to finish it so that there is less stress. So, it will take longer than I thought it would because I have to start over and fabricate a new three inch to graft on to but I dont give up so easily.

[trout]

I have read somewhere it might be a reaction with the CA that caused the crazing. Not sure where these bits of information comes from, but the person working with it had a fan to circulate the air and keep the fumes from attacking the tube. Sorry, I can not find the source. Maybe someone else might be able to confirm or call me crazy, oh wait that is Gary's name.

You could wrap some waterproof tape or electrical tape to prevent any leaking.

[greenman407]

All the sealing of the seams is not done yet. Im afraid that its just going to shatter.

[greenman407]

Dave, which do you recommend using? Cast Acrylic tubing or Impact resistant Polycarbonate?

[crazygary]

Weld On makes an adhesive that should work well with lexan tubing, or, polycarbonates in general!
Take a peek at this website for the rundown:

https://www.eplastics.com

I just found it through my search engine and am passing it on to you!
Hope this is what you need!

[greenman407]

Thanks Gary. Heres what Im going to do, now that Ive had time to think about it. Instead of throwing away the three inch cylinder, Ill just cut it off and cap it. Ill take a three inch cap and a 3&1/2" cap and glue them together ,back to back, and use it to join the two cylinders. So all I need to do is order another piece of 3&1/2" tube. Ill run the ballast servo wire thru the two caps. So the two sections will be connected but not glued. Yeah....that.
I just ordered two new speed controls for it. ONWARD! ALL AHEAD FLANK is going to take on a whole new meaning.

[He Who Shall Not Be Named]

Dave, which do you recommend using? Cast Acrylic tubing or Impact resistant Polycarbonate?

Acrylic is CRAP!!!!!!! Only suitable for display cases and little else. Cast is better than extruded -- but the comparison is like differentiating between a greasy fart and a fart with lumps in it. Crap-on-a-stick!

Lexan (polycarbonate). Or, in a pinch, clear PVC.

Pay the extra bucks and you'll never go wrong.

M

[crazygary]

"Thanks for the visual", M!!

Go get 'em, Greenman!!!