torpedo system

[He Who Shall Not Be Named]

Hey, Great Idea!
I could mount one of the magnets, I now have ordered, in wall of launch tube, and no need for switch hole in torpedo.
A simple contact-arm switch should be fairly easy to make, if I can't find sealed reed-switches that will fit, and mount inside torpedo.
I can use a tray, with magnets built in, to deactivate and hold the torpedos when on shore.
I may have to Order More Magnets! :)
Thanks,

Good move. Keep it simple.

David,

[deepseadiver]

I will be watching this thread. you have my complete attention.

Jim:)

[toppack]

I will be watching this thread. you have my complete attention.

Jim:)

Hey, Jim, start designing and building!
Maybe we can come with a Better design if we're All working on it??
I'm still searching for a rechargable battery, the correct size, but No Joy so far. :(

[He Who Shall Not Be Named]

Hey, Jim, start designing and building!
Maybe we can come with a Better design if we're All working on it??
I'm still searching for a rechargable battery, the correct size, but No Joy so far. :(

Look at the tiny Lithium-polymer batteries used in those cheap, RTF helicopter toys.

David,

[toppack]

All I've seen so far in the Micro Li-pos is a flat card shaped pack. Too Large :(

[deepseadiver]

ok i will think of ideas also. the magnet part to swtich off and on im sure is they way to go . But i will think of some other ideas also.
Jim

[toppack]

Yes, I know I have some small reed-switches (the type sealed in glass tube), if I can find them.
My stack of Goody-boxes is Very Large, after about 50 years of scrounging and collecting, and those switches are Very Small! :D LOL :D

[toppack]

Another problem is that since the very small motors (without gearing) have High RPM but not much Torque, so the motor has trouble overcoming the drag of the shaft seal along with the force needed to turn the prop. Need a shaft seal that is water-tight but allows shaft to turn freely at high RPM.
I think some kinda tubing would make best seal, maybe teflon tubing, if I can find shaft rods and tubing the correct size to make a watertight fit.

I got some more small motors, (direct from HongKong), that are only .24" diameter, but problem with them is that motor's shaft is only .030" dia. and about .1" long, which is not much for a tubing type shaft-coupling to grab onto.
They operate well at 1.2 volts and really scream at 2.4 volts. :)

I found that motors I removed from servos don't operate well at 1.2 volts.
They like at least 3. volts, which may be okay if I have to use and stack button type batteries, since I'll have enough length space to stack a bunch of them (probably 4). (Button type like used in hearing-aids)

[toppack]

Micro Motor:
Purchased from eBay.
Click Pic:

[deepseadiver]

this looks like an ideal motor for the torpedos, im looking for some tubing that i may be able to find with threaded ends i know some one that works with plastics that may be able to help out. this way the torpedo, can be un screwed into two pieces. But i like the one thats on youtube were he has made his from scratch displaying it in the bathtub, running it for the first time. I have written him for were he has gotten his supplies but no responce so far.

[toppack]

It would be best to make both ends from somthing that floats (one that prop-shaft goes thru & one nose).
Yes, a good way to attach those end pieces correctly, to center tube, is a Critical and maybe difficult part of the assembly.
I've not thought about that part of it much yet.

Want to find some tube that is thin walled, not magnetic, but easy to attach.
Since it needs to be thin-walled, I doubt it could have Threads?
Maybe just a press fit with a O-ring seal, and a locking pin if necessary (if there's a small internal spring to keep a battery stack tightly together, pushing against nose piece)?
Remember we're talking about something about the size of a fountain-pen! :)

[deepseadiver]

yes thats true a fountain pen, i will see what thin wall plastic tubbing i can find and keep you updated with a picture. Meanwhile i think you are right with using a o ring simple also. battery will have to be those hearing aid batterys. Can't think of anything else to generate enough power.

[He Who Shall Not Be Named]

yes thats true a fountain pen, i will see what thin wall plastic tubbing i can find and keep you updated with a picture. Meanwhile i think you are right with using a o ring simple also. battery will have to be those hearing aid batterys. Can't think of anything else to generate enough power.

Thin walled carbon-carbon tube is ideal. Check out sources of supply that cater to the free-flight and ultra-light/indoor r/c airplane market.

David,

[toppack]

Thin walled carbon-carbon tube is ideal. David,

And the latest Technology, Also. That'll impress the neighbors! :D LOL :D

I'm Sure I don't have any of that in my Goody-boxes, tho. ;)

[deepseadiver]

Good idea David, i know a place that makes carbon fiber tubing. I will see what they have in stock. I think they make special orders so if they do i will find out how much for the tubing. I need to have a idea what's the maximum length of tube it should be and tube diameter, that would be perfect for such a project. If this works i will mail the tubing to you that are interested so we all can build one of these torpedos for testing.
Oh' by the way what about having compressed gas coming out of a small hole at the end of the torpedo, for propulsion, that sounds real simple any idea's about this.

Jim