10 second runtime

Thread Starter

trout

Joined Dec 22, 2011
27
Oh Bernard, about brass and motor sinking.... Since I am not using compressed air, I can use plastic tubing for weight savings or cast the torpedo in a light urethane, but circuit first then housing. Again I can't thank you, and all the people helping out on this, enough. You guys rock!
 

Bernard

Joined Aug 7, 2008
5,520
Stretch the size as much as possible. With dia. of 7.4 mm, displacement is about 3 gm, wt of motor, at 8mm, displacement is up to about 5.7 gm.
 

Thread Starter

trout

Joined Dec 22, 2011
27
O.K. - I will play with that, like I said, it may not be to scale (again looking up for lightning)

I will post videos and pictures once this gets going.
 

Thread Starter

trout

Joined Dec 22, 2011
27
Bernard,
Yes, I thought I posted the type of motor - currently it is the small motor that is used in the tail of those toy helicopters. Great question about stern planes...Yes, but I actually intend on the torpedo to have a spin to it to keep it running true.
Peace,
Tom
 

Wendy

Joined Mar 24, 2008
22,141
Sorry I haven't been back in a while.

I noticed Nuts and Volts magazine had a section of uber small timers in their Jan issue. They were showing a unit smaller than a medical capsule.
 

thatoneguy

Joined Feb 19, 2009
6,359
Bernard,
Yes, I thought I posted the type of motor - currently it is the small motor that is used in the tail of those toy helicopters. Great question about stern planes...Yes, but I actually intend on the torpedo to have a spin to it to keep it running true.
Peace,
Tom
I'd add a little something to the torp so the motor doesn't want to spin more than the prop. 2 hinged "fins" that are opened when water encounters them rotationally, and they stick at 90 degrees. Won't add but 1/16" to diameter, and would allow a bit of torpedo spin with fins curved to wrap tight around body, they'll unfold as curves.

That's the way the new US .mil rockets are using fins, and they are pretty stable.
 

Thread Starter

trout

Joined Dec 22, 2011
27
@Bill_Marsden Are these uber small timers something that I could do? or is it just describing what is out there? Thanks for keeping an eye out!

@thatoneguy YES that is a very good idea! I see what Bernard was getting at, the torque of the propellor would spin the torpedo more than go forward. Thank you.

@Bernard - Aha! I get your point! Thank you for your patience!
 

Wendy

Joined Mar 24, 2008
22,141
I have to admit, it was fun to watch.

BTW, the ultra small timers were in the Dec issue of Nut's and Volts.

Want me to grab a copy next time?
 

Thread Starter

trout

Joined Dec 22, 2011
27
I just got the Nuts and Volts issue (thank you Bill!) and will try to build the circuit for testing. Thank you all for your help. As promised, I will post as progress occurs.
 

BSomer

Joined Dec 28, 2011
434
I just wanted to say that this is a really cool project you have going here. I wish you the best of luck in seeing it through to completion and I will be patiently waiting to see the results.
 

Thread Starter

trout

Joined Dec 22, 2011
27
With a bit of hunting around, I believe the pill timer is the answer. I have attached a picture of the torpedoes that I will be modifying.

 

Wendy

Joined Mar 24, 2008
22,141
So the magazine helped?

If you can get those to work it will be wicked cool. You may even think about posting them in the Completed Projects thread, assuming you don't try to market them. I suspect there will be people who are interested.
 
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