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Old Aug 06, 2009, 03:26 AM
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Brushless AZIPOD

Well, as you said, this subject deserves better... I will be moving some of the stuff here.

Intro: AZIPOD-big electric motor hanging from the hull... ish

To do a proper Azipod, you will have a problem with the choice of motor, but wait! Brushless can get wet... so this makes things easier. No need for watercooling for sure. But, just because we do not run our boats in distilled demineralized water, we need to waterproof (a bit).
The pics show you the "evolution" from foam to real thing.
Copy from springer thread:
I started out by cutting two discs to close the motor ends. Material used was... a cutout HDD disk: excellent material. Light, sandable, can be soldered.
I extended the fixings with some 4mm pipe, soldered. Added a nylon tube for the wiring, nylon square for a bit of strength.
The shape was done with some putty similar to Milliput... usually used to fix leaks in pipes
It is now hardening, will take about one hour to get to a level where I can sand it.
I'll do the nose cone later, maybe integrating the 50 mm prop in the previous pics.
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Old Aug 06, 2009, 03:28 AM
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Ready, sanded and primed. I will probably give it a layer of light FG, as I do not know how stable this material is...
I will make it a bit shorter and, once I come up with a base for it, fill some more around to smooth things up.
CG is right in the middle of the top part, so it will be easy to move & fix.

Stay tuned....
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Old Aug 06, 2009, 03:46 AM
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Now, steering could be tricky, but I tweaked a servo to rotate 180...
Basically, I cut the wires to the original pot, extended them, and soldered extra pots (4.7K) in series on the outer contacts.
The original pot needs to fixed very well in its slot, otherwise it could move and you have to reopen the servo (as I did).
It took me more to download, resample pics and upload video...

Video:
Picture 010 (0 min 12 sec)


Tomorrow morning it will get a nice PCB and box.
Will look great on a springer powered by azipod...
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Old Aug 06, 2009, 03:53 AM
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New parts for the steering: 3" HDD drive!
These are the props I have available. I need an advise on which one to try...
They are: 45, 50 and 60mm.
Maybe modify the 60 (cut it to a different shape)? I am a complete newbie here...
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Old Aug 06, 2009, 05:48 AM
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This is the main idea for now... how it SHOULD look...
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Old Aug 06, 2009, 06:39 AM
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New progress: got it mounted to a high tech ... 40x10mm washer.
The main axis is a brass threaded tube (remember the ones used for the light bulb sockets?). Sprocket was filled with putty to allow for the new 10mm hole (vs the original 4mm).
Now I have to think fixing and waterproofing...
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Old Aug 06, 2009, 09:44 AM
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READY! (prototype...)

Finally got to the test prototype. I wanted to power up and check it... but I left home Tx/Rx!!!!!!! ... I got the batteries and the Seaking ESC, though...
I struggled to cut a spacer in SS tubing to allow the assembly to be tight without pressing on the acryl... again I wish I had a lathe... If this works, I'll send the drawings to a guy I know. He is used with my strange requests, like the wire drive components...
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Old Aug 06, 2009, 09:51 AM
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I really like your idea Cornel.. and it looks as if you are well ahead on the pre production prototype..

Looking at your last pic's, the pod / motor combination looks good.. but there are going to be a lot of forces on the pod with the motor hanging out where it is.. especially when at full throttle!..
Do you think it would be possible to move the motor central under the pod so its more 'in balance'?...
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Old Aug 06, 2009, 10:01 AM
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Yes, it will be moved... Just that on this prototype I struggled with the wiring channels... So i wanted to get the wires out as vertical as possible.
Anyway, center of gravity is only 5mm further back from the axis.
This will be MUCH better if I manage to get it done in resin or fiberglass (just an empty shell, easier with the wires.
The smaller motors I ordered are not on stock, so the final versions are quite far now... They should be Robbe Roxxy 2030/12. I wanted to go for 1230/20, but the torque is quite low, being a 3.2A motor... still looking (waiting for ideas)
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Old Aug 06, 2009, 10:19 AM
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This could be ok as shape and cable exit
http://www.der-schweighofer.at/artik...batt-info%2521
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Old Aug 06, 2009, 10:30 AM
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This is cool. I would be a little nervous with the motor in a plastic sleeve. I don't know squat about brushless motors, but I am assuming that your motor will turn slow with lots of torque. What would be cool is if you rebuilt the aluminum casing the motor came in so that it was like real Azipod where the motor is the casing and then you bolted the motor right to a steel arm. Gotta stop thinking about other cool stuff I could attempt to build and get working on my model.

Looking good interested to see how it works in the water.
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Old Aug 06, 2009, 11:44 AM
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Quote:
Originally Posted by CornelP
This could be ok as shape and cable exit
http://www.der-schweighofer.at/artik...batt-info%2521
I think this motor is an outrunner, so the whole back
portion of the motor casing spins with the shaft.
Better wiring position, but the casing has to be free to spin.

Seems like I have small motors running around here... No no not this...month...
Too many regatta and events...


Thanks for posting all the progress CornelP.

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Old Aug 06, 2009, 12:18 PM
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My pleasure! Already learned a lot from you guys (and ladies).
Had no idea how that works, Umi. I'll stick to the Robbes. Once you install two, this will be enough torque...
This is the version I am going to test later on... when I get home. I am reluctant to leave the office: car is parked far, it's pouring outside, have no umbrella...

Cornel
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Old Aug 06, 2009, 12:34 PM
no wings any more, just dust!
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Quote:
Originally Posted by CornelP
VERY crude, but moves very easy, so it should work...
crude=simple
simple=good

so crude is good!

after all, nasa spent millions on developing a pen to work in zero g, russia's solution, a wood shaft with a graphite core, an item known to us as the pencil, so as the old saying goes "if its stupid and it works, it isnt stupid"
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Old Aug 06, 2009, 12:50 PM
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umi,

don't want to hijack this thread, because it is incredibly cool, and i want to see it continue with as little deviation as possible.... but...

this is something i have been considering as an alternative for the graupner schottel drives on my Alvin since the day i got the schottel drives. I was thinking of using something like the fieago 12mm motors, but they are way too high in the RPMs.

i did find this drawing however.

if you look closely you can see that according to this drawing, the main propulsion motor is actually imbedded in the hub of the propellor.

I think that a brushless outrunner small enough (i have seen ones as small as 18mm, still too big), with the rotating can making up the hub of the prop would work for an azipod. simply glue/fasten the propellor blades to the can of the motor, mount the base of the motor to a hollow vertical rod big enough to contain the wires...
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