Tadpole retrofit

[bigdave]

the Back in 2009 I built a sub I called the Tadpole as well, it looked like one.
It was based on a sub I had seen on another sub site across the big pond.
Built from a mayonnaise jar as the body with a tail made from brass.
I used a plastic jar for mine as there was no way I was going to run a powered sub made of glass in a swimming pool. (YMCA)
The problem with the plastic jar was it was very thin and would never seal very good.
So I have not used it very much as leaking in submarines is as we all know not a good thing.

At least that is what I have found.

Well the other day I was presented a sealable plastic cup by my best friends wife.
She was quite impressed by the fact it would seal well.
Obviously she has the rare gene that enables you to look at an object and imagine other uses than thier intended purpose.
It got me thinking it may make a good replacement for the mayo jar.
I had thought first of using the cup I was given but as it was sporting a big green (G)on the side my Bills fans buddies would never forgive me.

But as I was walking through a local Wallgreens the other day I saw it. (Q clouds parting) aaaaaa!
A cup actually bigger than the other one and equpted with the same sealing cap.
In a nice light green color. A quick price check found it to be in my price range.
So it was purchased.
Now comes the task of retrofitting it to the old Tadpole.
So stay tuned sports fans. Let the fun begin. BD

[bigdave]

The Tadpole is a modular design so I disassembled it down to the tail assembly.
The tail is a framework made from K&S brass. The rear being 12" tubing and the front is 6/32 threaded rod.
The threaded rod is soldered into the tubing about 1/2" along with a brass washer.
The washer is used with a small O ring to seal the holes in the cap that the 4 threaded rods pass through.
I marked out the holes in the cap using the old cap as a template.
Four tail assembly, two linkage, and one vent.
The center hole where I will mount the output seal was already in the cap for the plastic straw.
Looking good so far. BD.

[redboat219]

Is that a Venti or Trenti size?

[bigdave]

Buy a lot of coffee do you? Lol

[bigdave]

Starting to reassemble the sub with the new cap.
The tail gets added first, then the motor bulkhead, followed by the servo tray assembly. BD

[bigdave]

Adding the front bulkhead which holds the ESC, RX, and light SW controller. BD.

[greg w]

Hey BD,you should add some leds inside to light it up

[bigdave]

Already has them.

[bigdave]

A few more photos. Adding the output seals and linkages.

[bigdave]

Worked on re ballasting the sub today.
I used an old 3/4" end cap mold to make lead end caps.
I drilled holes through the lead so I could mount them on the lower tech rack threaded rod.
I can slide them on the rod and use fuel tubing to hold in place.
The the orange part in the front of the sub is a huge chunk of lead made from a larger old end cap mold.
It is needed to ballast the sub as all the bouncy is up front. BD
More photos to camera come.

[redboat219]

that's a lot of frappuccino.

[bigdave]

Well my retrofit was a success.
I got the sub trimmed out in the pool and took it to our last outdoor run.
She ran great. Lots of fun. BD

[scott t]

Great job Dave. I have had one of those water glasses on my desk for more than a year.
I did not know it needed to grow a tail to become a tadpole.

Scott T

[bigdave]

Sad news.
Being the clod I am sometimes I bumped the Tadpole off its shelf and watched in terror as it plummeted 4' to the cement floor.
The sudden shock was too much for the poor sub.
The rear sealing hatch (cup lid) shattered in the center. RATPUTUTTY!
But good news is besides the work involved in rebuilding, a new pressure hull is but a short drive away at my corner drug store.
And on the bright side I have a nice thermal glass now to hold my beverage of choice.
Always look on the bright side.
BD

[greg w]

Sorry about the crash dive. You don't have enough projects cooking anyway nights as well do it again��