A couple of questions

[ramius-ii]

I have forgotten and can not find the posted answer. First, let me say that memory is the second thing to go and I forget what is first! It seems to me that some time ago, adding a bow thruster to a sub (Typhoon) was best done in the stern and not in the bow (as the name "bow thruster" implies). Second, I seem to have a great deal of difficulty with creating molds for parts! What is a good casting product and mold release agent. Some items have very very fine details.

Thanks to all that answer, Ed!

[Guest]

If you add thrusters at

If you add thrusters at the bow and stern, you will have a very nimble typhoon.

For resins and rubber for casting, I recommend Smooth-on, really good products and excellent advice.

http://smooth-on.com/

Others have got good mileage out of Alumite resins, but I have no personal experience of their products.

A pressure pot is a nice luxury. I made mine from a converted pressure cooker.

Andy

[tmsmalley]

Seems to me that both

Seems to me that both Skip Asay and Art Broder reported that a bow thruster did little to help turning while the boat was moving due to hydraulic effects of passage of water across the bow - or am I remembering wrong?

[ramius-ii]

Thanks!

You jogged my memory! Thanks! The bow thuster goes in the stern. It is for all the same reasons ships are steared from from the stern, and becomes as "assist" to the primary stearing. Also, thanks for the tip about smooth-on. It also seems I had see people using a product from Micro-mark. The last time I tried to make a mold, it was from some type of hard plastic and releasing the object was next to impossible. It may be advantagious to take the one day seminar which is local. I have been playing with optical lens assemblies which have very fine threads. Dies and taps are EXPENSIVE, and not knowing the exact size and thread count (all in metric) made such a task even more difficult.

Best, Ed

[Wheelerdealer]

Hi Ed, It depends on

Hi Ed, It depends on how powerful a thruster you have and the mass/length of the boat your are installing it in. My First Typhoon had a Graupner thruster in the ster in an attempt to reduce the turning circle. I had a chance to see it in action recently and I unfortunately it had no noticeable effect when the boat was underway. Even with a stern thruster your going to need a powerfull one to ovecome the momentum of this heavy boat. A directional thruster attached to the rudder would be more effective. I guess thats why super tankers dont have stern thruster to reduce their turning radius. For my latest Typhoon, I have just gone for the Graupner unit mounted in the bow for use when stationary (Skip and Art are right, doest work too well underway) inconjunction with independent throttles, to get the boat around small ponds. Differential throttles are actually pretty effective on this boat.

Ramesh

[Guest]

Have a look at the

Have a look at the Typhoon in the seven vids on Youtube-

http://youtube.com/watch?v=9yTd4kl7J4M& ... ed&search=

This shows thrusters in use.

Some of the German guys move big and heavy boats with thrusters. They use small submersible centrifugal pumps, and of the ones I've seen, they fit one pump on each corner of the boat (centrifugal pumps are not reversible). If you just want to fit one or two then you will need to think about fitting valves.

These pumps are available quite cheaply on ebay e.g.

http://cgi.ebay.co.uk/CARAVAN-REICH-10L ... dZViewItem

Much more efficient than the Graupner thrusters, which are essentially a paddle mounted in a tube.

Andy

[Wheelerdealer]

Yep he's using a 22l/min

Yep he's using a 22l/min pump (need 2 as they only pump oneway). You can get them here http://www1.uk.conrad.com Its the best choice if you have the space. I looked into it and I wouldn't have suited my boat (took up too much space and run on 12 volts -the Typhoon runs on 6v). The Graupner pump is slow but it will get there, makes for a more scale like appearance if nothing else

[Guest]

Hmmm, 6 volts with big

Hmmm, 6 volts with big piston tanks. I would really consider switching the system to 12 volts, I think you'd only need to swap out the motors.

I'm quite surprised Engel is supplying this kit with 6 volts. Isn't your lafayette 12 volts?

My Vanguard is specced out with 24 volt Pittman motors for the piston tanks.

[Wheelerdealer]

Hmmm, 6 volts with big

Hmmm, 6 volts with big piston tanks. I would really consider switching the system to 12 volts, I think you'd only need to swap out the motors.

I'm quite surprised Engel is supplying this kit with 6 volts. Isn't your lafayette 12 volts?

My Vanguard is specced out with 24 volt Pittman motors for the piston tanks.

Yes the the newer boats seem to be 12v. Main drive, piston tanks, periscope, plane retract motors all 6v, just too much effort to convert them all. Draws more current but seems to work well enough, 12 AH battery last longer than I have stamina ....if it aint broke....

[ramius-ii]

Great Info!

Hi Guys!
Again it is great to be taking with people in the know! I did a complete conversion to 12 volts a couple of years ago. In basic electronics, the formula for "power" is I2R. The current squared times the resistance. The result of such a power conversion is that you use 1/4 the amp hours for the same results! All the motors were replaced with motors from Mack motors. The relays took a little more research and were easily replaced with the 12 volt equivlents. It is very much the same as the power company sending power over long distances. They raise the voltage to reduce loss. On home appliances in America, a clothes dryer runs on 220 volts and not the 110 volts used for televisions, radios, etc. Also, when you wish to have a lower voltage to operate a BEC at 5 volts, you get better regulation. 6 volts is too close to 5 volts and regulators wish about 2 volts higher to run correctly. Right now I am just about finished with with a periscope camera! I work at Fox television and we have an "undercover" group that uses covert cameras to gather video on criminal groups. With some big help with the optical engineers at Edmund Scientific, and the discovery of what is called a "snake" camera, the results have been wonderful! The periscope uses 1/8" (3 mm) lenses and only one mirror at the top. Thus the camera points straight up the "tube" and at less than 1/2 inch (12 mm) it is very small. One friend who designs transmitter antennas for military aircraft came up with an antenna system that allows video to work at 39" (1 meter) underwater! It may work deeper, the limit is the depth of my jacuzzi for testing. What is next is to mount the optics, which is a challenge! Thanks for the link for the Typhoon and the other links. When I am not working 12 hour days, it will be fun to "study" them.

Best, Ed

[Guest]

On the 24 volt systems,

On the 24 volt systems, I'm using switchmode BEC's, as 24 volt to 5 volt regulation for the RX and servo's is a bit of a drop for a linear regulator when you are drawing reasonable current.

My power electronics are good upto 27 volts.

How about an article for the report on that camera and TX, sounds awesome, I'd certainly like to play, and 1 meter is probably as deep as most would require.

What's the resolution of the unit?

Andy

[KevinMC]

Hi Ed,

I too am interested

Hi Ed,

I too am interested in the details of your camera... What frequency do you transmit the signal on? And, please, lets see some photos of your setup...

[ramius-ii]

Camera

Hi Andy and guys,
The camera I chose is a PC229XP. It is a 1/4 inch CCD with 470 lines of resolution, and .05 Lux. 1 lux is the same as the light from 1 candle. The camera head is .45 inches square and the electronics are seperate. This allows the cable from the camera head to be placed in a small tube and the electronics the be located in the "dry" section. There were some initial problems with the camera not producing a proper video signal. The sync part of the video signal was way too high. I took some pictures of the waveform and sent them to Supercircuits. When the sync is high, most video devices will attempt to reduce the overall signal plus at 1.5 volts of video, the transmitter was not happy. Frequency wise, 1.2 GHz is the best frequency for use with water. Lower is better and is not practicle if you wish for a small antenna and equipment size. 2 GHz is the resonant frequency of water (look at the operating frequency of your microwave oven), thus the water will act as a big sponge and you will have great difficulties getting a signal out. 2 GHz is nice if you wish to warm the water around you sub as this is about all you will end up doing. Secondary design considerations have to do with the antenna. The transmitter is mounted on a brass plate thus the "mounting" acts as a reflector so the signal goes mostly up and you still maintain a 360 degree hoizontal radiation pattern. At such high frequencies, silver is the best material. There is a product called "cool amp" that is a silver plating powder so the antenna is silver plated. The way you obtain more power from the transmitter is to use an antenna with "gain". In the antenna design, each time you can add 3 db of gain you have effectively doubled the transmitters power. A single whip antenna basically has no gain so your power is small. A "coaxial" design will provide gain. The other trick is to avoid using metal around or close to the antenna which will cause the signal to become "directional" in the horizontal plane.
As for BEC's, etc. I stopped using the "standard" BEC's some time ago as most will not produce much current (1 amp max). To me, it is easier to use an adjustable regulator that will give 2 amps or more.

Best, Ed