I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

okokok, it's not quite a real sub since it's only a dynamic diver, but it works! i took a plastic model hull (CN Models Alfa 1/200 scale), made my own fins, and my very own WTC. what's really cool is that this WTC is completely removeable. i can use it in other plastic r/c hulls if i so wished! electronics: GWS 4ch rx, 7 cell 370mah nimh battery pack, Team Orion esc (no longer made), and 2 HS-50 servos.
anyhoo, here are some pics.

p.s. i must give alot of credit and motivation to Mark (forgot his last name) and Tim Smalley's website

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

what did you build your wtc out of . do you have plans. did you use servos? Please give us details and pictures

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

the WTC is made out of 2 HDPE bottles with their ends cut out and glued together. i then used some plastic sheet wrapped around the bottled to cover the seam to make it waterproof. it was all glued with silicon glue. finally i used some "tool-dip" stuff on the inside as another seal just in case. the HS-50 servos are servo-taped into a small CF box i made which is then epoxied to the inside of the WTC. unfortunately the servos cannot be serviced or removed from the WTC w/o major work; all other electronics can. until i can borrow a reasonable digital camera, i won't post any more pics. taking pics with a webcam (even if it's a firewire webcam) doesn't produce good still images. the servo linkages are sealed but having the moving metal wire-linkages inside a plastic tube about 1.5 inches long. the seal b/w the platic tube and wire-linkages is made with vaseline...but this seal is not permanent.

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

petn7,
It looks 'scratch' enough for me! LOL Very nice idea about the bottles too,. Don't know why more people don't do it that way, it's certainly seemseasier than building/making/fabricating the typical WTC you see in the pictures. (Of course, finding the right size may take some looking.)
- 'Doc

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

no kidding. i searched all over a university campus for bottles and found none last summer. i ended up buying about 10 bottles for $35!

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

ok, i finally got some nice pics up!

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

one more

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

petn7,
Just checking to see if you had a sea test and how the sub and WTC worked for you. I am thinking of copying your idea since can't see if there are any miosure probs w/pvc WTC. Do you think using plumbers tape around the threads of the top will make it a little more water tight or just a wasted step? Also what width bottles did you use? One last question, Where did you get the motor cover case? Again the WTC and sub look great.

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

The bottles are about 45mm OD and made of HDPE. i bought them from some bottle supply company online, but i forgot their name. they bascially had any type of plastic bottle you could want; HDPE, PETE, etc. they like to sell in bulk, hence why i paid alot of money for just 10 bottles. plumbers tape will probably be over kill or have very little effect on water tight integrity for a few reasons. look here:

http://www.rcuniverse.com/forum/upfi...21/Yw68127.jpg

notice how there is basically 1 thread on the bottle neck opening? the top makes a water tight seal from the pressing of the top edge of the bottle neck on the plastic-like-foam on the inside of the cap. w/o modifying this configuration, the bottles can maintain water tight integrity to at least 9ft. i tested these bottles by making a very crude r/c diving bell with a sealed ballast tank. i could make the diving bell surface and dive on command with no water leaks.

the 2 tubes where the servo wires come out are only sealed by using a thin plastic tube filled with vaseline...that's it. after these pictures were taken, i made some modification to the 2 plastic tubes filled with vaseline. i added a small plastic stuffing box which should help seal the servo wires even more. however, i doubt even this stuffing box modification can hold a water tight seal down to 9 ft reliably. another source for a water leak is where i glued the 2 bottles together, end to end. it's a pretty good seal, but that middle joint, along with where the servo wires come out of the WTC are more likely to produce a leak than the end caps.

the motor case is its own WTC. it's filled with vaseline and sealed with silicone glue. the motor WTC came with the Alfa plastic kit. see, this plastic kit was designed to run in pools under no human control. it would surface and dive automatically.

in regard to your e-mail, there is no "tray" b/c the neck of the bottle is narrower than the inner diameter of the bottle itself, so it would be hard to get the tray to fit right. since the components are bascially stuffed into the bottle WTC i have a feeling the sub will have a slighty different center of gravity everytime she runs, but since the components and wires are light, this "wild-card-weight" shouldn't be a big deal. i have only tested the sub in the bath tub and everything works fine. when the paint job is done drying, i'll take it to a neighbor's pool and do a full test and hopefully get some underwater pics.

oh, and another modification i did was make the battery smaller. now it's 4 cells instead of 7. this will be an advantage for a few reasons. one, the motor will last longer. two, this allows me to have less "wild-card-weight" so i can add more weight to fixed points outside of the WTC rather than them being loose inside the WTC.

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

petn7,
Thanks for the reply, I am going to try using some different bottles, maybe on for the electronics and one for the motor. Again thanks for the info, when I start building I will try and post some pics. Hope the sub and changes work for you.

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

hope it all works out

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

Hi


This is really interesting and would make an ideal first "scratch build" model sub. I did a search on CN models and came across the Dallas at 1/250 scale. I am a tad confuse but are we talking of the same scale. Is it 1/200 or 250?

How long is your sub?

Are there any other plastic kits that would make agood conversion. I would like a modern US or Russian sub. I have not seen CN models before in Penang.

I normally fly RC electric planes. I have scratch build a 1/144 RC British destroyer. I have some skills and would like to undertake building a sub.


Regards

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

CN Models uses many different scales for their subs to save money. for example, the alfa is 1/200 and the akula is 1/280. however, they use exactly the same hull peices. the alfa sub that i made is about 16 inches long.

another good kit for a conversion is the trumpeter kilo; many have been successful.

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

Hi


So I would need to get one about 1/200 scale or bigger.

The CN kits have the advantageof having a 180 motor in a WTC. I do not think the Trumpeters are motorised.

16" is a very small size to work with. You must have had a hard time craming all the things in. I see you use a GWS pico RX. Still it must have being tight.

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

i had plenty of space believe it or not, since this was a dynamic diver. oh, and the motor being in it's own WTC...well that WTC fo the motor is as useful as a screen door on a submarine...literally

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

i had an idea about making a static diving system for a RC sub - since that the slightest change in density will make it rise of fall

here: get a 10ml syringe and seal some fuel tubing to the end of it and tightly connect it on,
get a ball point pen and cut a about 1cm off the top the ink tube then take tha 1cm bit and stick it in the other side of the fuel tube then push it through a hole in the hull the ink tube will seal it, then have the hole thingy inside a airtight container

or just stick a couple of EDF's to it lol

nice sub btw good luck

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

Hi. Before anything I'd like to congratulate you on scratchbuilt sub. I'm very much impressed. anyway. I'm planning on making one myself. So far, I'm stilling the planning phase. I was wondering if you could help me. Could you please share to me the plans and details on how you built you sub. Your help will be greatly appreciated. Thanks.:)

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

thanks for the kind words. as for plans, i have none. in regard to details, i dunno what to say. i think the pictures say alot, but if you have any questions about designing/building certain parts, i can help you with that.

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

- OK. Could you show some pics of the control linkages. Any plans of installing a ballast system? You could connect a servo to the end of the syringe Sabot suggested, moving it one way would draw in water and move it the other way pushing the H2O out... ;)

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

the only thing you need to make sure you do with the syringe thing is make the hole in the front where the water is sucked in bigger. Im sure almost everyone out there has sucked something into a syringe and knows that if you try to pull fast that it requires some force to move it. The reason it is this way is because only small ammounts of liquid can move threw the narrow opening at a time. So the slower you pull the easier it is to fill the syringe. Servos usually dont move slow. So the only way to fix this is to make the hole bigger so more liquid can move in faster but this will cause you to lose very precise control over how much liquid enters and exits the syringe at a time.

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

a ballast tank is out of the question since i have neither the expertise nor the equipment to make this Alfa a static diver...but i know it's possible given enough time and money. no, i can't show pics of the rudder/stern plane linkages since i've glued the hull parts together and can't get a clear shot of it. it's pretty simple though. i basically did what these guys did:

http://www.keep-on.jp/rcsub/maga-003.htm#001

look around for some pics of how they did their Kilo sub. it's there somewhere...

only these used brass wire/tubing while i used steel (yeah yeah, it rusts, i know)

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

Thanks for the advise. I'll contact you if I run into any problems building. Again GREAT SUB!:)

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

Thats a brilliant sub!!

so is is your sub from what i can see,


about your sub: you only using a small battery
" cell 370mah nimh battery pack " those batterys are meant for planes

those kind of batterys are for quick current draw for a short duration, you should use some much much bigger batterys if possible - looking at your hull
you could easyly fit a 3000mah nimh in there

whats the situation with the batterys anyway

nice sub (again) i wish i could make one but i have nowhere to run a sub apart from my bath tub [sm=frown.gif]

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

370mah batteries give plenty of time...the current draw is not that much. and no, i could not fit a 3000mah nimh battery cell in this sub. i get at least 20 minutes of runtime...i usually stop running the sub before the battery runs out. of course, i don't always spend this time running the sub at flank speed, but if i did, i'd estimate that i could get around 20 minutes of runtime.

RE: I FINALLY BUILT MY OWN SUB FROM SCRATCH!
 

finally found the pics of what i was talking about earlier...

http://www.keep-on.jp/rcsub/sanka02.htm