Arkmodel Red Shark

**Guest** · 08-11-2017, 12:54 AM

Gyros don't work on subs, get a leveller.

If the new motor is a lot lower in power, then it suggests to me that your original motor was far too fast for a direct drive 500 size can on that diameter of prop, and explains why the original quickly expired.

Dynamic diving boats need to be trimmed to decks awash for them to be fun, otherwise you need a lot of speed to stay under.

**Sonnich** · 08-11-2017, 02:37 AM

whty is the differnece of a leveler , and a gyro with heading lock ?

I have only seen a video, and it seems to do the same ?

Yes, the KV of the original motor seems way too high..

**Guest** · 08-11-2017, 02:59 AM

Levellers reference to gravity e.g. Like a spirit level. gyros reference to last commanded position and sudden changes in position like torque induced yaw, or a gust of wind.

**Sonnich** · 08-11-2017, 03:19 PM

Ok....no gyro on it today.....I can see that it will not work that great anyway :-)

Ballasted the sub down even more, and it performs great.

Still, my buddy is not a great subdriver yet, and I was filming :-)

**Sonnich** · 08-21-2017, 11:23 AM

Next phase...... Try to mess with static diving.

Want to try the pump and bag system, as it seems simple.

Got a waterpump, solonoide valve, and a bladder bag.
No room for the lipo batts, i bought 10nimh 5000 cells instead. Good for ballast too.

Never tried rhis before, so it will be a nice learning experiance.

How much water ballast will I need do you guys estimate?

My bladder is 600ml, but I guess that 300ml or half full will be enough? When on the surface, I want to see more of the submarine, than it is now.

Attached Files

**Sonnich** · 08-22-2017, 05:06 AM

Subs are cool......future projects

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**Guest** · 08-22-2017, 05:40 AM

The way to find out how much ballast you need to trim the boat to submerged trim is best found via empirical means (you can get a rough idea by calculation, but it'll be off by a bit almost guaranteed).

In a test tank, trim your boat with lead weight until only a few grams of buoyancy, then add a bit more to make it negative. Using blocks of styrene foam below the waterline, bring the boat to you intended waterline. Add up the volume of the blocks used, and that will be the size of tank you need.