Aluminaut Research Submarine 1/96th Scale

[crazygary]

Mornin', Trout!!

Coming along nicely!! Am learning alot following your wiring harness posts and thank you for posting them!!

You had mentioned a Hi-tech channel selector pack (?) for your WFly, and was wondering if you could elaborate, a bit, on what exactly it does?? I'll be using a Futabe 4YF for my subs, but, still being a "newbie" to the sub community, am not sure as to wether or not it will serve me well.

Any thoughts or input from anyone would be greatly appreciated!

Haven't had much spare time to dedicate to my little 1/350 Virginia lately, so not much in the way of progress on that one. Am still in the r&d stages of 1" wtc development.

At any rate, I applaud your preseverance on the little Aluminaut!! You are still, "Tha Man"!!

[trout]

Thanks crazygary, the hi-tec unit is this

It replaces the crystal module in the WFly 8 ch radio and now makes your radio selectable to all the channels in the 75 Mhz range.

Continued to solder the harness.Then applied the liquid tape - i think I am getting to like the fumes 8-)

Wanted to add a switch. Sam donated a broken car and it had a small switch. A little adjustment was needed to make the switch fit.

Layed the switch against the rail. It looked like it would fit and still leave enough support in the rail. so marked it and cut it out.

Trimmed the sliding portion of the switch, added a texture on the cut portion, and used rtf to mount the switch to the rail.

Time to test this phase.

Ballast works, people blender works, port works, starboard does not.
I will get some rest and hunt down the problem. The motor worked when the ESCs were installed.

[trout]

There is that hesitation when you say in your mind "I do not want to do this", but the reality is you must if you are going to finish this sub. Began testing at the motor. Lightly scratched back the wire sheath to expose a spot that I could attach my battery ends to. The motor ran fine. I checked the harness out and all was good. So it was either a ESC that died or a wire broke. Peeling back the liquid tape, I found the signal wire connection broke. The stuffing the ESCs in and out of the rear compartment stressed the wire too much. Re-soldered the connection and tested again. It worked. Another coat of liquid tape and tried to create a little strain relief to hopefully reduce the potential for another failure. It is sad to see all the guts out.

In the disassemble of the innards, the vinyl connector seemed to slip off too easy from the brass tube. Must be stretching. I might want to coat the tube with RTV and then reattach the tube. Not much room to put a zip tie around it.
Now that the starboard motor works, maybe I will know if the pmix mixing will work (thank you subculture and another gentleman named Greg).

[trout]

It all fits together. I see the front pushed out that was from the antenna crammed in there. That is the next challenge. I do not know anything about antenna stowage. My thought is to build a frame and weave the antenna underneath the mounting rails. Anyone want to give me a rundown on antenna theory and what to look out for while installing the antenna. From a rough estimate I have 5 lengths of the sub in antenna.

[trout]

Made a pattern on the computer. Researching antenna theory, I have learned that the signal is stronger if the antenna is parallel with the transmitter. Do not cross antenna over on itself. Some RX get better signal with longer antenna and some with shorter and some left the way they are, but each manufacturer is different. I learned about base loading.


The notches on the end would allow me to wrap the antenna back and forth. If I ran the antenna around the front and back of card it would thicken the space needed, something I can not afford. So I am not sure if the antenna running next to each other would qualify as crossing over.

Then fit into the hull.

I was pleased how it fit in there. Sealed up the sub and did a test to see how far I could go before losing signal. At 17' it was getting intermittent signal with antenna not fully extended. Not a good distance. But then some of the motors were not co-operating after a while (run when they should have been off). Maybe I had the mix all wrong or something got messed up. The behavior of the port and starboard motors seemed possessed and very erratic. Ballast worked and people blender worked. Then it all went silent. Nothing responded. Reset TX and RX, no change. I will make sure all is charged, undo the antenna, try a different radio (eliminate that from the problem), switch to a different RX and meter the connections. If that does not help....I will need to disassemble and test part by part. Are there any steps I might be missing or other tests you would recommend?

[crazygary]

Thanks alot for the info regarding the Hitec unit! Very cool! Recently ordered a 6-channel WFly and wondering if that unit will work in it? Not "number-of-channels-specific" is it?

Also, let me reiterate that you have the patience of a saint!! That sweet little sub is either gonna show you what you're made of, or drive ya ta heavy drinkin'!! LOL

However,I'm sure your perseverance will win out in the end!! This is still one of the best build threads out there! Glad to be able to keep up with your "adventures"!!

Thanks for your overwhelming willingness to share what you do!! Much appreciated!

[trout]

crazygary, thank you for the kind words. I am glad you are getting enjoyment out of this build. Personally, I think there are far better builds out there verses my (mis)adventures. There are some crazy good builds out there like those by David, Manfred, Ken, Mark, and others. Right now I am heading down the path of drinking and chucking this out the window.......but I can't. I got to see this through.

I do not know about the 6 channel TX if it will accept the module. Maybe Mike or David can speak to that. I am using the 8 channel.

So the latest update is this, the next day I charged up the battery and checked all my connections. The port motor runs continuously. It is not the RX because I switched out the RX and the problem followed the hull. Tested the Sombra Labs to see if there was something funky going on there. It works like a charm with regular servos attached. I am going to have to tear it apart again and check the ESC out for the port motor. I emailed Sombra Labs about antenna length and info, but have not heard back.

As far as the radio antenna goes, I am going to wrap it differently, in a spiral along the long edge of the styrene. This may not fit because I am doubling the width, but we will see.

I have another thought. I wonder if I can print the antenna on a circuit board? Like this garage door opener (blue lines zig-zagging on the right).

Anyone done that? Would that work? Kevin?

[trout]

It is looking like the ESC gave out. There is a strong acrid smell....something I have smelled before when a computer component decides to end its life and die in smoke. There are no visible burn marks, so I will unsolder everything and test each one separately. Work on that part tonight. If it turns out to be a fried ESC, I will need to order another one. Although, rumor has it, you can use the circuitry from a servo as an ESC. Hmmm.

On my antenna studies, I have been reading about quarter wave antennas and It looks like you can take a fraction of the wavelength and use that in an antenna. So far this is all magic and pixie dust to me. There are 1/2, 1/4, 1/8, or even 1/100th of a wavelength antennas. 75 MHz wavelength for Ch 69 (75.570 MHz) is 3.97 meters long. If I can use 1/100th length then the ideal would be 39.7mm?
Then in this test, Sombra Labs RX was tested with a trimmed antenna. A very interesting read and quoted below: http://www.rcgroups.com/forums/showthread.php?t=912056

"Trimmed Antenna TestingThere was a reason for "Station E" in the course chart above: it did indeed have a true and clear line of sight. This spot was ideal for performing a test of trimming the receiver antenna wire. The reason for this test is simply that many people trim the antenna wire to suit a particular setup or to reduce weight, so I felt the need to see the impact of this on the range. Many people also coil the extra length inside the plane (in fact this is recommended over trimming) but the results are the same. Coiling the wire will effectively shorten the antenna to the length that is the distance across the coil (see photo below).

• the view back to base from "Station E"
• both the trimmed and the coiled antenna represent the same effective antenna length

Trimming the antenna to a different length (either rolling coils or cutting the wire), should be done in fractions: 1/2, 1/4, 1/8, etc. Reason being that the antenna length marries to the wavelength, and trimming in these fractions will help the receivers in reading the signal.Testing

Station E - distance to station: 6,875 feet (1.3 miles)

• 1/1 - 39 inches - It was no surprise that it worked at full length when I arrived at this station.
• 1/2 - 19.5 inches - Both receivers locked-in and smooth.
• 1/4 - 10 inches - Both receivers locked-in and smooth.
• 1/8 - 5 inches - Lepton6 - locked-in and smooth. SL8 - still working, but now with the odd hesitation
• 1/16 - 2.5 inches - Lepton6 - working but with hesitation. SL8 - not working

Trimming Results

I think these results almost speak for themselves: Solid reception with 1/4 length at 1.3 miles is awesome. Lepton6 improving on this to be solid with 1/8th the antenna wire and the fact that the SL8 was getting any at this point is impressive. Truly astounding is that the Lepton6 was reading signal at 1/16th the antenna length, just 2.5 inches of antenna wire!"


The testing here is a fraction of the antenna length..... Maybe it is the same concept, just two different perspectives. I will coil my antenna to 5" (1/8th) and see what happens.
TEST: at 5" length of antenna and with antenna down on TX, I got to a little over 25' away using the Polk TX (that is just short of a 50% improvement over the original antenna wrap distance of 17') . On a whim, I tried my wFly. I got a significant improvement at 41' distance with antenna down.

[Slats]

Tom

I'm impressed. Very Very impressed.

This build has really pushed the outer envelope for what is possible in miniaturisation (something I actively say I suck at!!).

Bloody impressive stuff. Well done.

J

[trout]

Thanks John, I appreciate the kind words!

[Slats]

Thanks John, I appreciate the kind words!

Tom
thank you for sharing this project.

The hobby needs these sort of inspiring projects. It shows what can be achieved. A journey project from
-Dream
-to Idea(s)
-to Proof of Concept(s)
-to Successful working prototype!

Too often forum pages are just hot air and noise.
I prefer forum pages to be the interconnected support and literature of innovation that advances and encourages people to do.

Doers represent "signal".

You're "a doer" worth taking note of.


J

[Subculture]

If the ESC has given up the ghost, it's likely to be either a MOSFET on the h-bridge, or possibly a voltage regulator. It might be repairable if you can work with SMD- very fiddly though.

Converting a servo board will not give you the same performance as a dedicated ESC, and you usually need to increase the deadband for a decent neutral position.

[trout]

Looks like I will be delayed on this build. Need to order new ESC at best two weeks. I also am recovering from surgery so what do I do with the time?

[crazygary]

Sorry to hear that, my friend!!
I just recieved mine yesterday, same as yours, but don't think I'll be using it! I'm going to go with a little bit bigger ESC with BEC, which I have on hand.
Would be happy to mail you mine! Yours for the taking, as I'm interested in seeing your Aluminaut in the water!!
Think of it as a really early(?) Happy Birthday gift!! Hah!!
Send me your snail mail addess, and I'll get it off in the mail to you asap!
All for the good of our small but lively sub community!!
My offlist e-mail add'y is: crazy_gary_573@hotmail.com

Crazygary

[Slats]

Tom
hope its nothing too serious (surgery).

Bummer about the ESC. Part failure is annoying but inevitable. RE ESC's only ones I haven't killed / seen failure in are the big Electronize ones -way too big for this project, and on the big side for all but say a 3.5" cylinder. Nonetheless a stonking rock solid unit and the mainstay of my target projects.

http://www.electronize.co.uk/

J