Seaview

[greenman407]

OH......................................well,...I. .....uh.....

[He Who Shall Not Be Named]

I fear you're going to bend those blades.

M

[greenman407]

Thats what Im trying to work out. The two ESCs a rated at 20 amps. I dont know,....could be close. Also He tells me that a 27 turn of his variety would equal 15,000 RPM. At 3 to 1 ratio, we are talking about 5000 RPM....no load. At that point I could put in the 4 bladed impellers that you sent me. We will see. At anyrate we will know what these 12 volt motors are going to do here soon.

[He Who Shall Not Be Named]

Yesterday, I got her back together briefly for a test. With the new (broken in) motors installed, it showed a 15% increase in thrust. Cool!
So then I opened up the impeller pods to get at the impellers themselves. As you can see from the pictures I posted yesterday, I am installing longer shafts and the thrust bearings. Ill get it closed and sealed back up in a couple of days for another test. Ive got a 540 motor builder called "Team Brood" looking into the cost and feasibility of custom building me a couple of motors for this thing. If I like them Ill get two also for the upcoming Albacore repowering project. They are High Torque low speed 27 turn handwound motors with a long un-machined shaft. Full bearings, adjustable timing and standup brushes.

I'll be watching this thread with re-newed interest, Mark.

27-turn! You nut! Don't smoke that ESC.

M

[greenman407]

Yesterday, I got her back together briefly for a test. With the new (broken in) motors installed, it showed a 15% increase in thrust. Cool!
So then I opened up the impeller pods to get at the impellers themselves. As you can see from the pictures I posted yesterday, I am installing longer shafts and the thrust bearings. Ill get it closed and sealed back up in a couple of days for another test. Ive got a 540 motor builder called "Team Brood" looking into the cost and feasibility of custom building me a couple of motors for this thing. If I like them Ill get two also for the upcoming Albacore repowering project. They are High Torque low speed 27 turn handwound motors with a long un-machined shaft. Full bearings, adjustable timing and standup brushes.

[greenman407]

ARIBA...........ARIBA............ANDALE" ANDALE' YEEHAA....YEHAAA!!!(speedy Gonzalez dialog nomenclature imitation yall)

[He Who Shall Not Be Named]

Good enough. Get to it!

M

[greenman407]

OK Dave, what kind of problem is this going to create? By adding a thrust bearing between the impeller and nozzle, it moves the impeller blades forward, partially out of the nozzle. I can cut down the hub but it will only move the impeller back 3/32", not all the way. Is this any big deal?

[greenman407]

Looks like we will be able to test this on Monday.

[greenman407]

By the way, after you break in your motors using this water method, make sure after you blow it out with compressed air, you run and lubricate it . DUH.................

[He Who Shall Not Be Named]

I once read in a short-story (Killdozer) how to apply the electricity analogy to hydraulics -- had something to do with fuel-injectors.

Good stuff, Andy -- as usual, you make the hard easier to understand.

David

[Kazzer]

You said way over your head in response to my last post. A lot of modellers get confused with electrickery, but it's really very easy to get your head around.

If the talk of volts, current, resistance drives you nuts, then think of it like plumbing. Imagine your motor is a bucket that needs to be filled with water. The bucket may vary in size, a small motor will equate to a little bucket, and a larger motor equals a big bucket............................................ .......................

Not sure if that helps or confuses you even more!

Perfect! I had that explained to me years ago, and had forgotten it.

[Subculture]

You said way over your head in response to my last post. A lot of modellers get confused with electrickery, but it's really very easy to get your head around.

If the talk of volts, current, resistance drives you nuts, then think of it like plumbing. Imagine your motor is a bucket that needs to be filled with water. The bucket may vary in size, a small motor will equate to a little bucket, and a larger motor equals a big bucket.

You use a pipe to fill the bucket and the diameter of that pipe is equal to the resistance of the motor, smaller pipe equals higher resistance and and a larger pipe equals lower resistance.

To get the water to the pipe will require a certain amount of pressure, this is our voltage, low pressure equals low voltage, high pressure high voltage.

How much water we flow through the pipe is equal to current or amperage.

Overall amount of water in the bucket equals our wattage.

Now if we wish to fill out bucket as quickly as possible, there are two ways of doing this- we can increase the flow (current) or we can increase the pressure (voltage).

Increasing the flow will work up to the limit of the pipe diameter, after that the pipe restricts the flow (resistance). We either need a bigger pipe (lower resistance) or a higher pressure (higher voltage). If we can't have a bigger pipe then we can raise the pressure (volts), but there's a limit to this, increase pressure too far and the pipe will burst (you burn out your motor).

On the flipside if we have a large bucket (big motor) and a large pipe (low resistance), but low pressure (low voltage) then the bucket will take a long time to fill (low wattage). This because the water requires a degree of pressure to overcome the resistance of the pipe

Not sure if that helps or confuses you even more!

[greenman407]

Heres a picture from inside of the motor mounting locations that I cut in with hole saw and Forestner bits. Note the spring loaded teflon shaft seal.

[greenman407]

However, if you use this style 3.5" bulkhead with internal gearing then you can use the aftermarket motors because you dont have to worry about a shaft seal on the motors.