PVC WTC

[Rogue Sub]

So after one too many refits on my Dumas Akula WTC it has given out and requires replacing. So im taking the opputunity to make a new one that can be more readily accesable. Here a couple of pic of what i have so far. Any tips or advice or coments are welcom. Im trying to figure out how to run a control rod to operate the forward planes still.

[crazy ivan]

Here's how I did mine,

Here's how I did mine, Kevin.

[Rogue Sub]

Ah yes george i am

Ah yes george i am familiar with your set up. Unfortunately my bow planes ar attatched to the upper half of my hull. Also due to how im making a 15 dollar WTC it fits up almost flush to the inner radius of the boat. I think i may have a type of solution though.

SEE HOW CLOSE


ADDED A WINDOW!


MY SOLUTION

[crazy ivan]

I used to have my

I used to have my planes on the upper section too, when I first built it stock. I didn't control the bow planes at that time. Later I found out that the real ones are centered, so I moved them. It simplified the hookup too. Depth control is better now with them working. But I see what you mean about tight. Looks like you have a handle on the problem though. Show us how it all works out when you have it connected.

[Rogue Sub]

Yeah, Actually i got the

Yeah, Actually i got the idea from a really cool guy on RCUniverse.com Couldnt believe I never thought about just mounting the servo to the cap. Just put an extention cord in to pick up the slack from twisting the cap on. I also moved the stock push rod switch to the bottom of the sub aswell. Now i just reach under and push it in to run. Im also discovering that i have alot of extra room betwwen the servos and the engine room. It screams static diver (I need more then 4 channels it would seem) I hope this thing hold water tight. HEy any ideas on how to fasten the two hull halves together and WTC to the bottom. All i have right now is ample amounts of .....Velcro.

[crazy ivan]

I use velcro straps to

I use velcro straps to hold the WTC in place. I did away with all those little tabs along the edges of the hull halves and put in a single indexing lip along both sides of the bottom half. You can see part of it in my photo; its the black strip just visible above the red hull. To hold the hull together, I have a long tab wraped around the inside of the front of the lower half that slides inside the bow cap, then a single screw on the aft deck disguised as the stern hatch.

And I run mine on just 4 channels. Throttle, Rudder, Bow Planes, and Ballast Control. The Stern Planes run by themselves automatically off an APC-4 pitch controller.

[Rogue Sub]

I never thought about just

I never thought about just letting the APC run the stern w/o any input or correction from me. I geuss i should consider a kind of ballast system huh! Doesnt seem to be alot of room for something like yours. Maybe i need a flood tank ,Wonder how large it would need to be.

My only concern with velcro is it loosing its tackyness and seperating in the middle of the lake. Id lose the hull but, i geuss the WTC would still float up from the loss of weight!

Did a test run of the servo mounted in the cap last night. Its a tight fit using full size servos but it worked. The seal moves a bit due to the angle from the servo arm moving so, I gave it a HEALTHY amount of silicone.

Still need to buy some longer brass rod to make the controll rods for the rudder and stern planes. The new servo location is about 3 inches farther back and the seals are in a diff location now.

Still waiting on my new motor aswell. Got rid of the direct drive Musahi speed 540 and ordered a cermark speed 400 and 3:1 redux.

Being how Ive never really ever seen another sub set up in person i was wondering how everyone achieves their quick disconnects for say the shaft and control rods? I want to make this WTC easily removable for servicing and if i use the shat stuffing box and what not i have now that will not be achievable. picture would be great.

[Rogue Sub]

Oh yeah new motor showed

Oh yeah new motor showed up yesterday. I was a bit surprised by its size. Heres a pic of the new and old.


Ofcourse i couldnt wait to put the redux gear on right away and start putting the new gear in my cheap little WTC



I also used the velcro strips to hold the WTC like you suggested George.




It holds pretty darn snug in there and i dont think that its going to go anywhere on me.

Next im going to add some alignment tabs along the sides of the hull and hopefully order some styrene to do the decking and rails. Also still need to order the brass rod.

I also started working on something that Wolfpack(stephen) gave me the idea for. An auto rising periscope. Ive made and initial mock up using plastics and foam and it worked pretty good. Now to make a version of it that dosnt look so... cheap. Not that i should say anything considering what im building!

[captain nemo12]

Glad the idea worked!! http://www.subcommittee.com/forum/icon_biggrin.gif

Glad the idea worked!!

[Rogue Sub]

Speak of the devil. Thanx

Speak of the devil. Thanx Capt. Didnt even know you posted on this board.

I got the auto rising periscope to work only one so far. I will post pics later. Everything else requires me to buy more stuff so I now have to sit. Geuss its time to get the Heli up and flying straight again.

[Rogue Sub]

Time for an update I

Time for an update I geuss. Went through 3 different atempts at mounting the bow planes I finally gave in. George you were right. I moved the planes down to more center line so i no longer have to make a linkage to lift the top half off. Now i have to fill the holes. The most frustrating part is that i just moved them down like 3 months ago. I hate filling holes!!!!!!!

Hooked up the Battery and tried the planes out and they work good enough to dive (hopefully)

Fineshed work on the auto rising periscope as well and it works pretty flawlessly. Cant wait to see that work in the water.

Waiting on brass to show up in the mail to fines the rest of the control rods then ill seal it up and so a pressure test on it. It would be a shame if i went through all this just to have it fail in the end.

[Rogue Sub]

Update:

WTC is complete. Did a

Update:

WTC is complete. Did a bath tub test after siliconing the top half on and installing an apc-3 (thanks to warren). I connected a test fitting to the front for the bath tub test so that when i submerged it i could blow into it and see where air came out. I only had two leaks both from the end caps. Surprise surprise. So i siliconed the rear hatch because it will not need to be opened again. For the forward access hatch I cleaned the threads and seating surfaces and applied a liberal amount of Lithium grease. Then after drying I put it back in the tub and after connecting an aquarium pump to the fitting i submerged the WTC. The forward seal finally leaked after the seals i got from mikessubworks failed. 2 leaks from the forward cap and none from the aft. After I pulled it out of the water i dissconnected the pump and air was rushing out of the WTC. Im not sure what pressure those seals fail at but there had to have been alot of pressure in there.

In Conclusion:
PVC Tube-$10
PVC Glue- $5
PVC End caps - $6
Brass- $2
Velcro-$6
---------------
Total $29

Not bad for 30 dollars. It did take more time then just ordering one but building is half the fun. If I try again using the leftover materials I would do a few things different. I would move the servos to the back of the WTC next to the motor and leave the other elec up forward. I would also allow more spaces between the forward cap and my equipment tray so that there isnt so little clearance when twisting the cap on. The forward servo needs an adapter to take out the angle of the servo arm as it travels( not sure how to really describe this). The WTC also needs a little more space between the bow planes for easier connection and more room to remove the cap. It needs a new way of mounting the APC for easy adjustment. I didnt take any pictures of what i made because well ... i hate mine but, i have a fun sail to go to and i was in a hurry. I would also change the shape of the WTC. from a tube to an hours glass by buying two 3"to 2" adapters and some 2" pipping. That way i could add a bladder around the mid section for RCABS and get rid of some bouyancy. Its very bouyant. There is alot more air in this comp than the stock one. Im still adding weight to try and ballast it. I think im close to 6lbs of diver shot in it so far.

Well thats it. If anyone wants more pictures or have questions. (Im sure you vetereans wont) Send a PM or post!

[tmsmalley]

Those seals are meant to

Those seals are meant to seal pressure from the outside not positive interior pressure- so you should be ok.

[Rogue Sub]

Well after having successfully run

Well after having successfully run my home made wtc for over 6 months and making about 8 runs with it at the regatta in carmel its time to take it out and update. Why not shouldnt my little pet project resemble my current skill level. Ive learned a bit since I first made this WTC and its time to make the neccessary improvements!

First of all, keeping with my previous tradition, I am using none other then 3" sch 80 PVC pipe. I had plenty left over from the last build so it was a no cost issue for me. I am also turning endcaps for this WTC out of 3" deralin roundstock. This will solve my problem with the wires twistin up when i had to screw the end cap on. Also it was very messy because i was using vasoline on the threads to ensure a seal

Heres the start while the endcaps get all turned up. Ive made a mounting bracket for my motor, reduction gears, and servos to attatch to the aft endcap. It is made out of black 1/4" ABS plastic that I purchased from mc masters for 36 bux. then a picked up a flat stock of aluminum from Lowes and threw this together. I measured out the ABS then cut it with my rotosaw (really fast). Then I put both the servos together on the piece out lined them and cut the hole out using a dremel and fiberglass cutting disk. Gotta take it slow on the part unless you like toxic fumes from the melting plastic. Then i bent the aluminum around it and cut it to length. Next I predrilled holes to prevent the ABS from swelling from the size of the screws and put it all together. About an hour of work so far.

[steveuk]

Hi Nuke Power,

I'm trying to

Hi Nuke Power,

I'm trying to figure out how you seal your wtc. I see you have end caps which screw on the ends and have seals and grease, but in some shots (eg showing the drive motor in situ ) half of the wtc tube appears to be removed. How does that large open section become watertight? .. or what am I looking at?

I like the costing of this
Except over here in UK I haven't come across anything resembling an end cap that goes with the pvc pipe in the shops, just bends and t junctions .

Though I notice you are now abandoning the end cap for the reasons you mentioned, and are now going to make up some end caps to size, presumably you have found a source for 'O'rings that will fit.

I have been thinking along these same lines - I can get the pvc pipe and now that I have a model lathe I will be able to turn my own endcaps (still yet to source a suitable thick material) then all I need to do is to find a good source for 'O' rings, and I'll be laughing.