Akula 1/144 Scratch built

[bwi 971]

Bart, looks really good! Its been my experience that automatic pitch controls all seem to have one Big disadvantage, and that is they pick up mechanical vibrations from propellers, electric motors drive shafts even from a servo. By moving your APC up front youve distanced it from the source of the vibrations. However.......you may find that they come back. You may need to insulate the APC by mounting it on a bed of silicone or rubber or both. Also ive noticed that reducing the sensitivity of the APC helps tremendously. All of the submarines that I have do not need max sensitivity. In fact most of them run well on the least sensitive setting. Thats assuming that your APC is adjustable. I dont recognize that particular model of the Subtek APC. I dont know if you can adjust its sensitivity.

Mark is right, we call that harmonics, we also have to account the fact we do our testing dry on the bench.<br />
The most ideal place to pick up vibrations, i would go for a foamrubber stand to imitate the surrounding water.<br />
<br />
Manfred (european partner in crime)

After installing all components x times, shortening all servo leads, installing 15 servo connectors,…..For the moment my sensitivity is on max..........so if the SOB servo start to jitter again...........I guarantee you will see a real flying sub

Serious now, I'm a newbie on this subject so all this advice is very useful thks I will keep it in mind.

Grtz,
Bart

[bwi 971]

m
Where did you get that clear plastic wrap you use to get all that wiring spaghetti under control? I like it.

http://www.hobbyking.com/hobbyking/store/RC_PRODUCT_SEARCH.asp?strSearch=spiral+wrap+clear

Grtz,
Bart

[MFR1964]

Mark is right, we call that harmonics, we also have to account the fact we do our testing dry on the bench.<br />
The most ideal place to pick up vibrations, i would go for a foamrubber stand to imitate the surrounding water.<br />
<br />
Manfred (european partner in crime)

[greenman407]

Bart, looks really good! Its been my experience that automatic pitch controls all seem to have one Big disadvantage, and that is they pick up mechanical vibrations from propellers, electric motors drive shafts even from a servo. By moving your APC up front youve distanced it from the source of the vibrations. However.......you may find that they come back. You may need to insulate the APC by mounting it on a bed of silicone or rubber or both. Also ive noticed that reducing the sensitivity of the APC helps tremendously. All of the submarines that I have do not need max sensitivity. In fact most of them run well on the least sensitive setting. Thats assuming that your APC is adjustable. I dont recognize that particular model of the Subtek APC. I dont know if you can adjust its sensitivity.

[He Who Shall Not Be Named]

My hurt feelings aside ... what a wonderful job, Bart. You and your fellow partner in crime from the other side of the equator have taught me a thing or two over the years. Is is, very much, a two-way street we have here. You both took a good product and made it unreasonably good.

Now, that's what a WIP should look like, Bart: big pictures; call-outs within the pictures for clarity; and a classic problem identification- problem solution-fix presentation. An excellent job, sir.

Where did you get that clear plastic wrap you use to get all that wiring spaghetti under control? I like it.

[bwi 971]

Some details of the ER arrangement

Grtz,
Bart

[bwi 971]

Nice work ... ah .... hey!... WTF!!!! That conduit tube is not stock!!!!

Warranty Alert .... Warranty Alert!!!!!!

You ruined EVERYTHING!!!!!!!

I buy you people books; I send you to school; I pay for tutors, and what do you do? You eat the ****ing Teacher!

M

My intention was to post an “overall view” picture, so nobody would notice that I raped the SD.
Now that I’m busted I will tell the story behind it.

I did had to make some adaptions not because the SD wasn’t good enough but because circumstances left me with no choice.
I had already purchase some electronic parts before I ordered the SD an ESC’s for a brushless motor was such a thing lying around.

I took the SD apart to convert it to Brushless. It was a hard job to find a brushless motor with a 2.3mm shaft though, but I succeeded. Why I bothered? I did that because I wanted the reuse the max amount of the parts, and not jeopardize the design of the SD. I even managed to use the original bold holes for fasting the motor. There was no need to wide them up. I will run the motor at 50% max. as the SD was not designed to take the power of a 300W E-motor.



Also grinded out the slots of the servo carrier to take slightly longer servo’s but here again I had purchased them already.



No sweat so far, but here is the point where it got really messy.

I have a Subtech depth controller and a KM “depth cruiser” (DC). I tried to enclose both in the Fwd compartment along with the battery. I tried to squeeze all the necessary wires in the conduit tube but it didn’t work. I had to make a compromise, I would only use the DC as this is the smallest of the two devices. All the necessary wires fitted in the conduit tube this way.

Here comes the part that Manfred pointed out.

Everything was installed all tested to satisfaction until I turned on the pump, the servo witch was connected to the subtech ADF2 started to jitter. I tried everything I knew, ferrite cores,…… you name it I tried it (I HATE ELECTRICAL NOISE). I doubted the pump was the issue as it is filtered. I tried running the propulsion motor and guess what….. samesame……ADF2 servo started to jitter.
Normally brushless motors do not give any interference. So my conclusion is that the subtech ADF2 is very sensitive to noise.

I removed the ADF from the engine room pack, placed it 2inches away from the pack and the jittering stopped. You feel it coming I had to place the ADF in the fwd battery room…..feeding two additional servo cables trough the already cramped conduit tube…..that was impossible.
The only solution was to install a conduit tube with a larger diameter. So I lined up all the issues that I would come across:

• Existing seals would not fit anymore
• I have to enlarge the holes in the bulkheads and drill holes off center from the existing holes, the servo to blow the ballast tank is to close.
• I have to dismantle the SD, without breaking anything
• Make a new conduit tube with a 8mm bore, without adding to much weight
• Provide a new sealing arrangement
• A larger conduit tube meant less ballast tank capacity resulting in an above waterline structure displacement that will be less.

You understand I wasn’t so anxious to do it but I had no choice.

I made a new crossover out of aluminum, started with an outside diameter of 10mm, and drilled a 8mm hole in it. Turned it down to an outside diameter of 9,5 mm. A hole of 9.5mm was drilled in both bulkheads eccentric from the existing ones. Next the new bores were partly drilled out to 12mm so they would take the new O-ring. Everything turned out well to my relief. Everything was re-assembled The water tightness was tested without remark.






The weight of new crossover was 5gr more than the original, the loss of displacement was also 5gr…..the total deviation of the “factory SD” is 10gr that’s 0.35 ounces. (yes I’m good too).

I also added a tray to the Fwd battery compartment so everything will be kept in the same place, in addition it is also used as a platform for the ADF2 and DC.






I’m not going to blow sunshine up his holiness arse , but the process of executing all a.m. works resulted in the fact that I dismantled almost the complete SD. I know craftsmanship when I see it, and I saw the result in every part I handled. And if you are not a CB like me you will buy all the necessary parts from the subdriver site everything will fit perfectly together.

But as I’m a SOB I don’t want to end this story with those words, so I will end it with Manfred’s quote.

David, we europeans like to annoy you americans by altering a very good product into a perfect product, you teached us well.

Grtz,
Bart

[bwi 971]

Bart,<br />
<br />
If that's a SAS SD, you better hook up a hose to the inlet near your ADF inside the SD, and lead this to the lower part under the battery.<br />
Sometimes you can suck in some droplets of water stuck to the rubber of your inletvalve, not much, but enough to damage you electronics nearby, made inside my XXIII SAS SD a provision to catch up those droplets, works like a charm.<br />
<br />
Manfred.

Ok will do thks Manfred

Grtz,
Bart

[MFR1964]

Bart,<br />
<br />
If that's a SAS SD, you better hook up a hose to the inlet near your ADF inside the SD, and lead this to the lower part under the battery.<br />
Sometimes you can suck in some droplets of water stuck to the rubber of your inletvalve, not much, but enough to damage you electronics nearby, made inside my XXIII SAS SD a provision to catch up those droplets, works like a charm.<br />
<br />
Manfred.

[MFR1964]

I see Bart has followed the same route as me, removed the stock conduit tube for a bigger one, this way you've got more room for cables, if i've seen right he also has placed his ADF in the front compartment away from al those pesty electronic noises and vibrations.<br />
<br />
David, we europeans like to annoy you americans by altering a very good product into a perfect product, you teached us well.<br />
<br />
Manfred

[He Who Shall Not Be Named]

Engine room equipment installed….just waiting on a waterproof switch to finish the job.

Grtz,
Bart

[ATTACH=CONFIG]n112528[/ATTACH]

Nice work ... ah .... hey!... WTF!!!! That conduit tube is not stock!!!!

Warranty Alert .... Warranty Alert!!!!!!

You ruined EVERYTHING!!!!!!!

I buy you people books; I send you to school; I pay for tutors, and what do you do? You eat the ****ing Teacher!

M

[trout]

Looks like a really clean install. Well done!

[bwi 971]

Engine room equipment installed….just waiting on a waterproof switch to finish the job.

Grtz,
Bart

[Albion]

Yep, boxes and cats, they simply can't resist them, i know the problem myself.

Manfred.

Cats and subs on the edge of work bench, they simply cant resist them :(

[HardRock]

PITA. I like it.